US2780950A - Hydraulic control system - Google Patents

Description

Feb. 12, 1957 J. H. PROVINCE 2,780,950

' HYDRAULIC CONTROL SYSTEM Filed sept. 17, -1954 s met-sheet 1 Feb.- 12, 195.7 J. H. PROVINCE 2,780,950

HYDRAULIC CONTROL SYSTEM Filed Sept. 17. 1954 6 Sheets-Sheet 2 9o 55 leo 56o 87o "Mo '3S F/G. 3. O 7

|63 INVENToR.

v J. H. PROVINCE |67 soa' |71 lee 9o@ By 54@ no H M0* ATTORNEYS Feb. 12, 1957 J. H. PROVINCE 2,780,950

l HYDRAULIC CONTROL SYSTEM Filed Sept. 1'7, 1954 6 Sheets-Sheet 5 INVENTOR. J.H.FROVINCE BY s# ATTORNEYS Fell 12, 1957 J. H. PROVINCE HYDRAULIC CONTRO;d SYSTEM 6' Sheets-Shea#I 4 Fi1e`d Sept. 17, 1954 o 5 nw w 7.. 2

Feb. 12, 1957 J. H. PROVINCE HYDRAULIC CONTROL SYSTEM 6 Sheets-Shea?I 5 Filed Sept. 17, 1954 INVENTOR. J H PROVINCE AT TORN EYS Feb. I2, 1957 J. H. PROVINCE HYDRAULIC CONTROL SYSTEM Filed Sept. 17, 1954 6 Sheets-Sheet 6 AT TORN [YS United States ate 2,780,950 Ice 'lhented i Feb. 12, 1957 Appuetin 'septemer 17; i954; serial No; 2455,694 2s Ciiis. (Ci. 531;'53)

This invention relates' toa 4control system for hydraulic pumps. in another aspect it relatesto a hydraulic system toaotuate a pipeto'ng In anotheraspect relates to pneumatic clutch system. In anothe'rspect it relatesfto' a rotary air coupling. Iii still another aspect it relate'sto improved pipe tong in oil well servicing operations it common practice to' obtairrthe poweu'eeded to. operate thehoist'ing winch, tubing tongs and otheruuits'ffrxn a truckrnotor. Heretofore,` power operated tubing tongs h'aVeus'ually been energized pneumatically. Such t v g's require alarge supf p ly of compressed air which necessitates the Vinstallation of a large air compressorbecause-the compress c'ujv supplied for control purposes does nothave suicient capasity. This equipment is useful only iiioperating the tubing tfnjrgs.I However, modern well servicing units often ein; ploy hydraulic purnpsfor the operation dfderrick's and' other equipment. Thus', a suitable hydraulic pump nor: rnallyis available on a servicing rig. For this r'eason I propose tooperart'e the tubing' tongs'hydra'ulically.

Tub'ing tongs are provided with pipe gripping jaws whichfengage thepipe in one direction of rotationl and disengage in the opposite direction. These jaws can bereversedin vsome instances to allow th`e pi 1 e to be d r'i'vn in yeither direction. A slot i'su'sually provided in the otatingheadof the tong to all ow the tong vto beplaced on thapipe and rmQYed fli1r0z This Slot must be Cleii: tered with a` 'correspondng slot' in thejanieof thfeiton'g in order to apply or removethe tong. tis, ofcourse, des le that this centering operation be performed automat1cally. In accordance with thepresent invention a novel centering valveajssernbly is provided/,

The hydraulic pump employed -to energia" th'etubiu'g' tongsjn'onnally is driven bythe sametruck motor whichr energizes the hoisting'winch. llfliscr` s certairi dicu1ties' because the rriotor Inustbe opera at a' cons ablyhigher speed when operating the winch than' heu coupled to the hydraulic -iiiotor. Ir order t'qp nl ihe hydraulic motor trom being driven' atari excessivespeed Whe the engine s ,drivins.,th Winch; a pueuma'ti'cially Operated Clutch System prsyiddin cordnic ,with this invention to disengage the'driveshaft ,of Ythe truck from the hydraulic motor 'when the speed of the motor shaft.

une i 2 `met beds dvneelwild features '91?. f li'sviiviition should become 4ap ent ufrom thefollowing tailed description gtaken' in conjunction with the accompallxingdrawsinwhh; Figure 1 is a scheinatic representation of the co rl thisinvenition; Pi t@ .2 is .a dta11t1v.@W-afa tirstembsdf the pneurnaticallyv perated clutch mechanism including valve employed inl conjunction they tubing to digure is a detailed View,ofharsuitabletubin tong which can be used in the control system of this inven- On; ,f -fif x5- 1f [El igureis a detailed view of a second embodiment of theaircouplingtand Figure 7 is na detailed View of a third embodiment of the aircoupling. i i Referringnowtothe .drawing in d etail vand to igure l in particular thereis shown a truck motor 1Q which is einpl'oyedto energiae `awell servicing unit. The speedfat which motor lil operates is controll ed by abutteryvalve the carburetor il. tThis v alye can be positioned by@ pneu'rnatically operated controller 1`3. Controller 13, h ich can be of the formiillustrated in Figure 1'6 of,l S Pa te n t 2,`6 43 ,'093, is erg'izfed by a sourceof air pres e supplied from s torage tank 14 Tank `'s j tunecteid to an air compressor, not s l'n'rvvn,I aline l1S. `Iflfliiie 1 6 extends between tank, 14. afldfth. il 0f ,aihftl valve i The first air inlet in controller 1 3y iscoune I d totan il'i through a lin e lshaviug" a three-way soleil id V lv 2531s C Qnolldby a 'solenoid Z4 Wllh 1 S energized f rQm vsiltagfgsjui 25,.. Qriftrlliulsf voltagesourceZS is ,.cor'inectedto ground as is, one ter; Ininal o f so1e'noid-24.' The V'seoutl terminal of voltage source ZSisCOunectedto the second terminal ofis oid 24 rbya lead 27 hay ing aswitchfZS therein, A line sffilmafles between ,velyaz and ffiwsvhefe- Infhe absence of powerbeing supplied to [solen d 24, lined? communicates through valve 23 with tank 1 4. When solenoid 24 .is c uerg'ized,` line 1`9 communicates through v1ve23with'1in e 2 z.

The drive ShatOfengue 1 0 is Connected t'houw suitable power. tal' e'o1 29 and ajshaftSQ tooue mem; bei of a clutch The second member ofclutchi is Cerl'ncfd by ashaft 32 we hydfauliapvmp. .Clutch 31 iS saged by the, vanalist@ H911 0f pneumatic Dfllsift.; 'eeto through' a coupling Sawhich ilsfounfed @Shaft 3 2. Air pressure for energizing elu't'cli 3 1 is 'supplied `from as'econd'st'orage tanli whicli'is connected toline 15 a liner 3 6 having a pressure reducing' va'flv,e 37y yt Thepressurein vtank 3'5 i s less than the pressure vin t Tank 35 is connected to coupling 3`4 by aline hav a solenoid operatedthree-wayva1ve 3 9, anoiler a' quick feles'rw .4 1 thre- Yah? 39 b'y a sblii'd. ''.whlich has'sneitminal sounested. ground. The s`econdqtermina1n-of solenoil 4 3 ne'cted to ,th'eseco'n'd terminal oi' 'tage source 2 5 b: a lead44lwhich` has manually operated `sgwitch, 46 da pressure operated switch 47 therein u SWitch k47 `isfconffw. trol'led by the pressureinline which'isfapplied through a line 48, pressure above a predetermined value ppeniugl electrical switch 47 and below said value closing said l., l n *y rml.; uw g z Quick 'release valve'41 ina s taudard 3 way vquick t e lease valve, mere fflly u1u" "'-iapii p l of' VVthe lBendiXWes tiigho'u'se MMaintenance Marinai JSLW 1116 published in 1952 by the BendioWestinghouse Automotive Air Brake Co. This valve 41 is not necessary to the operation of the system and may be dispensed with, its main purpose being to allow air to vent to the latmosphere through opening 41a (when open) faster than it could vent through line 38b, oiler 40, line 38a, valve 39 and vent line 39a, thereby allowing clutch 31 to release quickly, without slipping, and frictional wear during such slipping. Valve 41 consists of a body having a chamber (not shown) with an air supply inlet and preliminary exhaust line 38h, `a quick air release outlet 41a disposed opposite 38b, and a line 38e connecting one side of the chamber to clutch 31. There is a valve seat around 38h and 41a in the chamber, and a valve head having a flexible annular rim is biased by a spring toward 38h. When pressure in 3817 is high, the valve head closes 41a and air from 38b passes the flexible rim into 38 to engage clutch 31. When pressure in 31 balances said high pressure in 38h, the exible rim closes 38h, while the valve head closes 41a. When pressure in 3811 falls below that in 38C, the valve head unseats, laided by the spring, opening vent 41a to clutch line 38C allowing quick release of air to the atmosphere. When high pressure returns to line 38b', the valve head closes 41a and the air passes the iiexible rim into 38C repeating the cycle.

Valve 41 is not necessary, and may be eliminated, as when either one of electrical switches 46 or 47 is open solenoid 43 moves valve 39 to connect line 38a to vent line 39, and air is released to the atmosphere through line 38h, oiler 40, line 38a, valve 39 and vent line 39a, while valve 39 closes line 38 from tank 35. When both switches 46 and 47 are closed solenoid 43 moves valve 39 to close vent line 39a and connect lines 38 and 38a, supplying air under pressure from tank 35 to valve 41 and line 38C to clutch 31 to engage said clutch.

The inlet of pump 33 is supplied with hydraulic iiuid from an oil storage tank 511 by a line 51 having a filter 52 therein. A fluid leakage line 49 returns to tank 50 from pump 33. The outlet of pump 33 is connected by a line 53 to a first port 54 of -a valve 55 which is described in detail hereinafter in conjunction with Figure 3. A second port 56 of valve 55 is connected to the first port 57 of a second valve 58 by a line 59. A second port 60 of valve 58 is connected by a line 61 to the first port 62 of a third valve 63. A second port 64 of valve 63 is con# nected by a line 66 to a uid opening 69 of a hydraulic motor 67. Motor 67 is connected to a gear box 68 which drives the tubing tong illustrated in Figure 5. The second fluid opening 70 of motor 67 is connected by a line 71 to a third port 73 in valve 63. The fourth port 74 in valve 63 is connected by `a line 76, a check valve 77 and a line 78 to the third port 80 of valve 58. The fourth port 81 of valve 5S is connected by lines 82 and 83 to oil tank 50. Ports 80 and 74 of respective valves 58 and 63 are connected by line 78, a centering valve 85 and line 76. A third port 87 in valve 55 is connected to a line 88 to supply hydraulic uid to other apparatus, not shown, which may be employed on the rig. The iiuid supplied by line 88 is returned through a line 89 which is connected to return line 83. The fourth port 90 of valve 5S is also connected to return line 83 by a line 91. Line 59, which connects ports 56 and 57 of respective valves 55 and 58, is connected to tank 50 by a line 92 having a pressure relief valve 93 therein. The connections between the ports in valves 55, 58 and 63 are described hereinafter.

Air coupling 34 and clutch 31 Iare illustrated in detail in Figure 2. The purpose of coupling 34 is to introduce air from line 38 of Figure l into a passage 100 in shaft 32. This air pressure in turn actuates clutch 31 to connect shafts 30 and 32. Coupling 34 comprises a stationary annular housing 101 having an inlet port 102 which communicates with line 38. The center portion of housing 101 is provided with an inwardly extending ange 103 against which is positioned a pair of ball bearing assemblies 105 and 106. These ball bearing assemblies engage stationary housing 101 at their outer edges and rotatable shaft 32 at their inner edges. M'ating rings 107 and 108 are fitted about shaft 32 in engagement with respective bearing assemblies and 106. Sleeves 110 and 111 enclose shaft 32 and engage respective mating rings 107 and 108 at their inner edges. A rst O-ring 114 is positioned between sleeve 110 and mating ring 107, and a second O-ring 115 is positioned between sleeve 111 and mating ring 108. Sleeves 110 and 111 are located in position on shaft 32 by respective retaining rings 112 and 113. A first sealing assembly 117 is positioned between housing 101 and mating ring 107. This `assembly is held in position by a retaining ring 118 and is sealed to housing 101 by an O-ring 119. A second sealing assembly 120 is positioned between housing 101 4anti mating ring 108. This second assembly is held in position by a retaining ring 121 and is sealed to housing 101 by an O-ring 122.

Sealing assembly 117 only will be described in detail, it being understood that sealing assembly 120 is of like construction. Assembly 117 comprises an annular shell 125 which surrounds sleeve 110 but is spaced therefrom to provide a clearance. Shell 125 engages an annular insert 126 at its inner end and retains this insert in slidable sealing Contact with mating ring 107. The engagement of insert 126 with mating .ring 167 provides the rotary seal. An annular cup member 127 extends between shell 125 and housing 101. Positioned within cup member 127 is an annular packer 12S which is retained against cup 127 by an expander 130 and an annular spring 131.

Housing 101 and bearings 105 and 106 define an annular chamber 133 between shaft 32 and inlet port 102 of housing 101. A passage 134 is formed in shaft 32 between passage 100 and chamber 133. Thus, the air pressure in chamber 133 is introduced into passage 160 irrespective of the relative position of shaft 32 and inlet port 102.

A spider 135 is rigidly attached to the end of shaft 32 as by a key, not shown. A fluid passage 136 is formed in one of the ribs 137 of spider 135. The inner end of passage 136 communicates with passage 100 through a radial passage 138 in shaft 32. A conduit 140 `communicates with the outer end of passage 136. A flywheel 142 is rigidly attached to the end of shaft 30 adjacent shaft 32 as by a key, not shown. The adjacent ends of shafts 30 and 32 are spaced from one another. An annu lar drum 143 is attached lto spider 135 by bolts 144 and extends outwardly to enclose flywheel 142. The annular space between flywheel 142 and drum 143 contains a pneumatically operated brake device 145. This device can be in the form of an expansion member formed of a sturdy fabric 146 having a rubber liner 147. The interior of liner 147 communicates with a port 148 in drum 143 which is connected to conduit by a conduit 149. A plurality of brake shoes 150 is attached to member 146 to enclose ywheel 142. In the absence of air pressure being applied to the interior of liner 147, brake shoes 150 are retained out of engagement with flywheel 142. However, the introduction of air pressure into liner 147 results in an expansion of member 146 so that brake shoes 150 imly engage flywheel 142. Shaft 32 then rotates with shaft 30.

Valve 55 is illustrated in detail in Figure 3. This valve comprises a body having a central passage therein. A shaft 161 is positioned in the passage of body 160 and is pivotally attached to an adjusting handle 162. The ends 163 and 164 of shaft 161 engage body 160 in a fiuid tight t by means of respective O- rings 166 and 167. The center portion 168 of shaft 161 is of the same diameter as the central passage through valve body 160. The portions and 171 of shaft 161 between portion 168 and respective ends 163and 164 are of smaller diameter than the central passage. A plurality of annular recesses 90a, 87a, 54a, 56a and 90a' is formed in body 160 surrounding the central passage. Recesses l90a and 90a are in communication with port so.. neeesses stuitte una semestri commenceront `with.rospo'ctive .ports ,54;87 and t56; not v'shown in yFigui-e 3. .Valve 55 normall'yis biased by -feans not shown, in the posit-ion illustrated.

When shaft 161 `occupies the illustrated central sposition, all vofthe recesses are in communication with one another. If handle162 is rotated clockwise about pivot point 4173i, sh'aft 161 is moved tojthe left Osuch lthat end 163 blocks recess 9021 'and portion 168 of shaft 161 is disposed between recesses 54a and 56d; At this position, recesses 54d a`nd. 87a are. in `co'rnrnnnicati'on 'as are reesses 56a and 90a'. 'Ifhandle 162is moved counterclocltwise about pivot point 173, shaft 161 is rnoved t'o the right such that end 164 blocks recess '90d' and portion 168 is disposed b'etveen recesses 544 and 87a. At this .second position;4 recesses 56d land 54a are in com'- munieation as are fecesses'87r1 and 90a'.

Valves 58 and, 63 are 'similar to valve 55 except they vare ,provided with detehts to retain shafts 163 normally at either end positions.

Centering valve 85 is shown in Figure 4. This valve comprises a hollow cylindrical bdy 180 having a cylin- -ler' 181 triountedthereon. vA cover plate 182 is fitted to the top of .cylinder 181 and the three members are held in assembled position by `screws 183. VCylinder 181. is provided with a chamber 184 adjacent plate 182. An Qfring 185 is positioned between cylindei 181 and plate 182. A longitudinal passage 186` is formed in cylinder 181 between chamber 184 and a first port 188 which receives line` 78. Port 188 also communicates with the interior of cylinder 181 through a passage 190. A second port 191 is provided in cylinder 181 opposite port 188. Port 191, whichreceives line 76; is connected to the interior, of lcylinderv 181 through a passage' 192. Passages l90an`d 192 are blockedy from-'one another .when

a piston 193 occupies theillust'tted position incylinder 1811.- Piston 193' is providedl with an' annular recess 1-94 vso that passages 190 and 192 are in communication when piston 193 occupies a second lower position. A p'air of sealingv rih'g's 196 and 179 is mounted on piston 193. The lowerend of piston 193I engagesA ay secohd pistn 200 contained within body 180. Pistoni' 200 islattached to a plunger 201' by a s`cew 202' Plungerl 201 extends downwardly, beyo`r1`df the lower' edge of body 18h and has a roller`203 attached thereto Bya pin 204; A' compression spring-,205l is-k positioned between valve body 180 and piston 201 to exert a force which te'nds to raise piston 200jwithin valve body, 180:` Roller 203' is raisedv wheny engaged-by aiy cam `2.06 which' is mounted on the tubing tong. illustrated' in .Figure 5f,

The tubing tong 209 illustrated in Figure isa conL vention'al powe' tong which is'v adapted t' be energized lay-hydraulic' notor 6'7` in accordancewith'thisA invention. Tong209` is used to-screw and unsc'few threaded sections rofpipe," one' of which' is illustrated at 210. This' power tong comprises a base' 211 upon'- which is attached acove'r, noti shown,v by: a plurality; of. bolts 212. Posi- 't-'ionedi within base 211 is ay ring' 2-13ha'ving a 4 side'eitrance opening 214i definedl by parallel'l 'walls 21'6l and i217. Ring 213 is rotatably supportedV on base 211' by a plurality of grooved rollerst 218. y

Ring 21:3 isrotatedinl frame 21d-"by means which include a sproelet 220ffthat isA securedtojiihg 213 by screws 221i.- Sprock'et 220- is' also provided with`- an en'- .tranc'e' opening' whichxisl aiigned with opening 214 inring .213.- Sprocket-220fis`driveng byfa chain 222 whichA is woundabout idler sprockets 223' and" 224 andv a'v driv ing sprocke'tfZ-ZS'.' Sprockets 223 and224 are' n'iounted on'zr'espectiv'e" sliafts 227 and' 228: Driving/sprocket 225 `is-rnounted.ongafslilrd portion of' a'powr shaft 30` so that sprocketl225'- rotates with@ the shaft A- rstdri'ving: gear.- 231-'is11nountdY on' drive shaft 232. A3 second" driving.; gear' 233'; is? also mounted on-V v56 vided 'for shifting g'eai 236 '.eilgientent with driving gear 231 and for shifting ge' 4235 info engagement driving gear 233. This means includes' ayolr'ex240whch is carried 'on a 'pivotally mounted yok "shaft241 that 5 extends outwardly through base 211: Shaft 241 is provided with a pair of actuating levers 242 onto'pposit'e sides of thebase". Driving shaft 232 is vcnpled to l'gear box 68 of Figure 1 which is rotated by hydraulic motor 67'., f

The introduction. of hydraulic .fluid int-o motor` v67 'causes rotation of 'shaft 232. Shaft 230 can be `driven from shaft 2732 at a -low speed through 'gears 231 and v 236 or at a high speed through gears 233 and 235'. The shifting of gears is accomplished by rotating handles 2 4'2. Rotation of shaft 230 causes the..spro'cket Wheel 22S to drive chain 222 to turn i'in'g 213: v l

.Means are provided on ring 213 to. giip pipe 210. 'These means include carrier 245 on which pip' grip'- ping jaws 246 and 247 are mounted. Carrifei 245 is positioned coaXiaIly of ring 213 and i'sfree' to 'turn within the ring; Jaw `247 is fiired to carrier 245 by an at# taching pin 243 and is provided with a iSair of spaced pipe gripping dies 248 and 249. Jaw 246 carries a removable pipe gripping'die 250, A .b'rake' 251 exthds upwardly from carrier plate 245 and is 'adapted to' be contacted Vby a stationary brake band' 252 which is secured tothe cover by means not sh'own. The function of band 252 and rim 251 is to retai'd rotation of carrier 245.

After a pipe joint has been tightened- 'it is necessity to'fwitlidraw the tong from the pipe; This' requiies' that side opening 214. in ring 213 be aligned with the entrance opening in base 211. Since the thre'ad's of the pipe joint may become tightened at any random position; means must oe provided fr tui-ning r'in'g- 2'13 in a' erse di'- re'ctio'n to bring about alignment' of th openings.v is accomplished in accordance with the present invention by .centering valve 85' which cooperates with' cam 206 which is' mounted on ring 213 opposite' tle entrance' open? ing. Valve 85 is' positioned immediately above' carriY 206 as shown in' Figure 4.A

Theoper'a'tion of the hy'r'drau'lit:controlV syste'ni` of this invention can be explained' with reference to' liigu're l'., When it is4 desired to operate any of the hydraulic aci tu'ated units,l switch" '46' is' closed' to complete' a" circuit through solenoid 43. This" .opensvali 39' suchmtli'at' the air pressure in tank 35' is applied through l'in' 38, rotary coupling 34 and shaft 32'fov clutch 31. Asshown in Figure 2, the application of air pressure'to clutch 31 results i`n drinnl 143 being coupled to ilywhel 1:42 isuch that the two members rotate together. ijn thisI manner shaft 32: is rotated? with; shaft 30' to' drive pump 33'. Switch 28 can then'y be closed to' complete' a circuit throughy solenoid 24. This 'opens' valve 23' so that' the' air pressure'ifroin line 19`i's` vented throiigh line 22. *Conlh troller 1^3/is 'set-so that` with` switch' 46'cl'o'sed ahd 'switch 28 open, the motor 10`operat's'at a orni'al idlev speednd drivesy puirp 33 at1 a speedy suii'cientl to supply' power fluid for` the operationv-olf those hydraulic' units' which require comparatively' si'nallv amountof tid, such afs derrick raising mechanism, sucker rod' tongs,

operate any oftheauxiliary equipme trnot slown',"va1ve" vsure is then transmitted .to line 88 and is returned to tank through lines 89 and 83. c

n In order to energize the power tongA in a forward direction, valve is set such that ports'54 and 56 are in communication as are ports 87 and 90. Valve 58 is set such that ports' 57 and 60 are in communication as are ports and 81. Valve 63 is set such that ports 62 and -64 are in communication as are ports 73 and `'14. Under these conditions, the uid from pump 33 passes through line 53, valve 55, line 59, valve 58, line 61, valve 63 and line 66 to the opening 69 of motor 67 Fluid is returned to tank 50.from motor 67 through opening 70, line 71, valve 63, line 76, check valve 77, line 78, valve 58, line 82 and line 83. After each pipe joint has been tightened, it is necessary to remove the tong from the pipe. As previously discussed, ring 213v of the power tong may be positioned such that the outlet opening therein is not aligned with the outlet opening of base 211. Alignment is accomplished by reversing valve 58 such that ports 57 and 80 are in communication as are ports 60 and 81. The fluid under pressure then passes from line 59 through valve 58 and line 78 to the inlet port 188 of valve 85, see Figure 4.

Fluid is transmitted through passages 190 and 186 of valve to the chamber 184 above piston 193. Piston 193 initially occupies the illustrated position due to compression 205 even though roller 203 does not rest upon cam 206. It should be observed that roller 203 rests upon cam 206 only when the opening in ring 213 is aligned with the opening in base 211. The introduction of uid into chamber 184 results in piston 193 being displaced downwardly until the annular recess 194 communicates between inlet passage 190 and outlet passage 192. The uid under pressure is thus transmitted through valve 85, line 76, valve 63 and line 71 to enter motor 67 t through opening 7 0. This causes motor 67 to move in the reverse direction until cam 206 is moved into engagement with roller 203 at which time piston 193 is moved back to the position illustrated in Figure 4. The piston then blocks the opening between passages 190 and 192 and no additional uid is pumped into motor 67. At this point, the opening of ring 213 is aligned with the opening of base 211 so that the pipe can be removed. When motor 67 is operated in the reverse direction, iluicl is returned to tank 50 through line 66, valve 63, line 6l, valve 58= line 82 and line 83.

When the power tong is employed to unscrcw pipe sections, valve 58 is positioned such that ports 57 and 60 are in communication as are ports 80 and 81. Valve 63 is positioned such that ports 62 and '73 are in communication as are ports 64 and 74. The uid under pressure is then transmitted from line S9 through valve 58, line 61, valve 63 and line 71 to port 70 of motor 67. Fluid is returned to tank 50 through line 66, valve 63, line 76, check valve 77, line 78, valve 58, line 82 and line 83. In order to center the tubing tong when operated in the reverse direction, valve 58 is reversed. Fluid is then transmitted from line 59 through valve 58, line 78, centering valve 85, line 76, valve 63 and line 66 to port 69 of motor 67. The return uid is transmitted to tank 50 through line 71, valve 63, line 61, valve 58, line 82 and line 83.

When truck motor 10 is employed to actuate the hoisting winch or other heavy cquipment, it is necessary that the motor be operated at a higher speed. This is accomplished by manipulation of throttle valve 17 which adjusts the vair pressure applied to controller 13 through line 21. Controller 13 in turn further opens the valve in carburetor 11 to supply additional fuel to motor 10. When motor 10 is operated at these higher speeds it is important to disconnect hydraulic pump 33. This is accomplished in accordance with the present invention in an automatic manner by pressure responsive switch 47. Whenever the pressure in line 21 reaches a predeterminedvalue, switch 47 is automatically opened to de energize solenoid 43. Air pressure is no longer applied 8 to clutch 31 so that pump 33 vis disengaged from rotating shaft 30. Alternatively, valve 39 can be a pressure operated valve and line 48 can supply pressure to close valve 39 when the pressure in line 48 exceeds a predetermined value.

In Figure 6 there is illustrated a second embodiment of the rotaryv air coupling and clutch assembly. The rotary air coupling comprises a sleeve 270 which is mounted on shaft 32 by retaining rings 271 and 272. A key, not shown, is provided to prevent sleeve 270 from rotating about shaft 32. A longitudinal passage 274 is formed in sleeve 270. One end of passage 274 is closed by a plug 275 and the second end is connected to a passage 136' in a spider 135 by a connecting conduit 277. A stationary annular housing 278 is positioned about sleeve 270. Housing 278 is provided with an` inlet port 279 which communicates with air line38 of Figure l. A radial passage 280 is formed in'sleeve 270 such that port 279 is in communication with the pneumatically operated clutch through passages 280 and 274, conduit 277 and passage 136'.

First and second mating rings 282 and 283 abut a central flanged portion of sleeve 270. O- rings 285 and 286 are positioned between sleeve 270 and respective rings 282 and 283. Sleeves 287 and 288 engage respective mating rings 282 and 283 as do respective inserts 290 and 291. Sealing assemblies 293 and 294 are mounted adjacent respective inserts 290 and 291.` O- rings 295 and 296 are contained inV housing 278 adjacent these two sealing assemblies. v The sealing assemblies 293 and 294 are of the same form as assemblies 117 and 120 which are illustrated in Figure 2. Sealing assemblies 293 and 294 are retained in position by respective retaining rings 297 and 298. Ball bearing assemblies 299 and 300 are posi tioned between housing 278 and sleeve 270 adjacent respective retaining rings 297 and 298. These'ball'bea'ring assemblies are held in position by respective retaining rings 302 and 303.

Lubricating ports V304 and 305 are formed in housing 278 outside respective ball bearing assemblies 299 and 300. Lubricating seals 306 and 307 are positioned behousing 278 and sleeve 270 outside'respective ports 304 and 305. These seals are held in position by respective retaining rings 309 and 310. Seal 306 comprises a rst annular housing plate 311 which is fitted against housing 278, and an O-ring 312 is positioned between these two members. Plate 311 receives an annular diaphragm 313 which is held in engagement with sleeve 270 at its inner edge by a coil spring 315. The outer edge of diaphragm 313 is engaged by a pair of plates 317 and 318 which are fitted in plate 311. Seal 307 is of the same construction as seal 306. When the rotary air coupling of Figure 6 is employed, oiler 40 of Figure l is not needed because the ball bearing assemblies are lubricated through respective ports 304 and 305. The air coupling of Figure 6 has certain advantages in that it can be readily attached to a shaft without drilling a hollow passage through'the shaft. This assembly is particularly useful when it is desired to actuate individually more than onel device mounted on a common shaft.

A third embodiment of the air coupling is illustrated in Figure 7. In this arrangement the air pressure from line 38 in Figure l is transmitted into the end of hollow shaft 32. A sleeve `member 330 is threaded into the end of shaft 32 such that the central passage 331 in sleeve 330 communicates with the passage in shaft 32. An O-ring 332 is positioned between shaft 32 and sleeve 330. A cup shaped housing 333 encloses sleeve 330 and is spaced therefrom. Housing 333 is provided with a pair of inlet ports 334 and 335 which communicate directly with the open end of sleeve 330. Air line 38 of Figure 1 can be connected to either of these ports, it being understood that the second port is plugged.

A mating ring 337 is abutted against the anged'en'd portion 338 of sleeve 330. An `Oring 339 is positioned between ring 337 and sleeve 330. An annular insert 9 341 engages matingring 337 and is retainedn position by a sealing assembly 342 which is identicalto sealing' assembly 117 of Figure 2. Assembly 342 is retained in position by a ball bearing assembly343 which in turn is held in position by' retaining rings 344 and 345 which are fitted into housing 333 and sleeve 330,- respectively. An O-ring 346' is positioned between sealing assembly 342 and housing 333. A second sealingnassembly 346, which is identical to assembly 306 and 307 of Figure 6, is positioned between sleeve 330 and' housing 333 in spaced relationship with ball bearingassembly 343 by means of a i'etainingring 347. A lubricating port 34S is provided in housing 333 to communicate with the annular space between sleeve 330 and V'h ousing'333 between assemblies 343 and .346. It should be apparent that the air coupling of Figure 7 functions in substantially the same manner as the couplings in Figures 2 and 6` except that the air pressureis admitted to the end of shaft 32 rather than through a -radial opening in the shaft.

From the foregoing description it should be apparent that there is provided in accordance with this invention an improved control systemfor the operation of power tongs by a hydraulic pump. While this invention has been described in conjunction with present preferred ernbodiments thereof it should be apparent that the invention is not limited thereto.

What is claimed is: i

l. A hydraulic fiuid control system comprising, in combination, a variable vspeed motor, a pneumatically oper ated controller to regulate the speed of said motor, a source of fluid pressure, first conduit means to supply fluid pressure to said controller, a throttle valve in said first conduit means, a `hydraulic fluid reservoir, a hydraulic pump connected to said reservoir to supply hydraulic fiuid under pressure, a first drive shaft connected to said pump, a second drive shaft connected to said motor, a stationary housing enclosing one of said drive shafts and spaced therefrom, an inlet port in saidhous-v ing, conduit means to supply fluid pressure to said inlet port, means to interrupt the supply of fiuid to lsaid inlet port when a predetermined pressure is applied to said controller, sealing means disposed between 'said housing and said one shaft, a fluid passage extending longitudinally of said shaft, one end of said passage being in communication with said inlet port, a ywheel attached to the end of said second'shaft adjacent said first shaft, a' first annular member attached to the end of said firstV shaft adjacent said flywheel, said first annular member enclosing said flywheel, an inflatablemember secured to said first annular member adjacent said "flywheel, the second end of said passage being in'communication with said infiatable member Vwhereby the application of fluid pressure to said inlet port results in' said infiatable member expanding to engage said ywheel so that said annular member and said flywheel rotate together and said pump is energized, a tong base having a first openingv therein, an annular member mounted on said base, pipe gripping jaws attached to said annular member, said member having a second opening therein whereby a pipe can be introduced into said member'tobeengaged by said jaws when said first and second openings are aligned, a hydraulic motor coupled to said annular member to rotate said member on said base, avcam attachedv vto said annular member, first valved conduit ymeans extending between Asaid hydraulic pump andsaid vhydraulicmotor to rotate said hydraulic motor in a first direction, a valve body defining a piston chamber, a first port in said valve body communicating lwith said piston chamber intermediate the ends thereof, a second' 'port at said valve body communicating with said piston chamber intermediate the ends thereof, a piston ldisposed in said piston chamber, said piston having a recess therein whereby said `first and lsecond vports are incommunication when said piston occupies a first position in saidpiston. chamber, means urging said piston towardone 'endfof said pi'stonchamber whereby said first and second portsI are separated by said piston, second conduit means extending between said first port and said one e'nd of said piston chamber whereby fluid pressure appliedv to said port tends to overcome said urging means to move said piston to said first position, means extending fromv said piston externally of said valve body whereby a force applied thereto results in said piston being moved toward said first end of said piston chamber, said valve body being positioned whereby said cam engages said last-mentioned means when said first and secondV openings are aligned, third valved conduit means extending between said pump and said first port, and fourth conduit means extending between said second port and said motor Vfor rotating said hydraulic motor in a second direction.

2. A hydraulic fluid actuated power tong system com-` prising, in combination, a tong base having a first opening therein, an annular member mounted on said base, pipe gripping jaws attached to said annular member, said member having a second opening therein whereby a pipe can be introduced into said member Vto be en- Vgaged by said jaws when said first and second openings are aligned, a hydraulic motor coupled to said annular member to rotate said member on said base, a cam attached to said annular member, a hydraulic fiuid reser- Voir, a hydraulic pump connected to said reservoir to supply hydraulic iiuid under pressure, first valved conduit means extending between said hydraulic pump and said hydraulic motor to rotate said hydraulic'motor in a first direction, a valve body defining a piston chamber, a first port in said valve body communicating with said piston chamber intermediate the ends thereof, a second port at said valve body communicating with said piston chamber intermediate theends thereof, a piston disposed in said piston chamber, said piston having a recess therein whereby said first and second'p'orts are in communi cation when said piston occupies a first position in said piston chamber, means urging said piston toward one end of said piston chamber whereby said first and second ports are separated by said piston, second conduit means extending between said first port and said one end of said piston chamber whereby fluid pressure applied to said first port tends to overcome said urging means to move said piston to said first position, means extending from said piston externally of said valve body whereby a force applied thereto results in said piston being moved toward said first end of said piston chamber, said valve body being positioned whereby said cam engages said last-mentioned means when vsaid first and second openings are aligned, third valved conduit means extending between said pump and said first port, and fourth conduit means extending between said second port and said motor for rotating said hydraulic motor in a second direction.

3. A controlsystem to prevent a driven member from being operated at excessive speeds compri-sing, in combination, a variable speed driving member, a driven member, a first drive shaft connected to said driving member, a second drive shaft connected to said driven member, a pneumatically operated clutch to connect said first and second shafts when energized, conduit means to supply fluid pressure to said clutch, a valve in said conduit means, and means responsive to the speed of operation of said driving means to aotuate said valve when the speed of operation of said driving means exceeds a predetermined value, said clutch thereby being deenergized.

4. The combination inaccordance with claim 3 wherein said clutch comprises expansible means positioned between said first and second shafts, said expansible means being secured to one of said shafts and `adapted to engage the other of said shafts when duid pressu-re is applied thereto, and means forming a part of said conduit means to -apply fluid pressure to said expansible means.

i 5. The combination -in accordance with claim 4 wherein said means 'forming a part of said conduitmeans com prises a stationary housing enclosing said one shaft, said assenso housing having an inlet port communicating with said conduit means, means defining a passage extending at least in part longitudinally of said shaft, and rotary sealing means extending between said housing and said one shaft to form a chamber between said one shaft and said housing, said chamber being in communication with said port and one end of said passage, the second end of said passage being in communication with said expansible means.

6. The combination 1in accordance with claim 5 wherein said passage extending longitudinally of said one shaft is formed within said one shaft, 'and wherein a second passage is formed in said one shaft between said chamber and said first mentioned passage.

7. The combination in accordance with claim wherein said passage extending longitudinally of said one shaft is external of said one shaft.

8. The combination in accordance with claim 3 wherein said clutch comprises a flywheel attached to the end of one of said shafts adjacent the other of said shafts, an annular member attached to the end of the other of said shafts adjacent said one shaft, said annular member enclosing said ywheel, an inflatable member secured to said annular member adjacent said flywheel, and means communicating with said inflatable member to supply fluid pressure thereto whereby said inflatable member expands to engage said flywheel so that said annular member and said flywheel rotate together.

9. A pump speed control system comprising, in combination, a variable speed motor, a pneumatically operated controller to regulate the speed of said motor, first conduit means to supply fluid pressure -to said controller, a throttle exceeds a predetermined value, said clutch thereby being 4 deenergized.

l0, The combination in accordance with claim 9 wherein said -second valve is electrically operated and wherein said last-mentioned means comprises a pressure ope-rated electrical switch in communication with said first conduit means, said switch being connected in circuit with said second valve.

l1. A rotary air coupling to transmit fluid pressure from a stationary fluid line to a device mounted on a rotatable shaft comprising, in combination, a shaft, a stationary housing enclosing said shaft and spaced therefrom, an inlet port in said housing, sealing means disposed between said housing and said shaft, and means defining a fluid passage extending longitudinally of said shaft, one end of said passage being in communication with the 4interior of said housing adjacent said inlet port.

l2. A rotary coupling 4to transmit fluid pressure from a. stationary fluid line to a device mounted on a rotatable shaft comprising, in combination, a shaft, a stationary housing enclosing said shaft and :spaced therefrom, an inlet port in said housing, first sealing means disposed between said housing and said shaft on one side of said por-t, second sealing means disposed between said housing and said shaft on the other side of said port, and means defining a fiuid passage extending longitudinally of said shaft, one end of said passage being in communication with the region between said two sealing means which is in communication with said port.

13. A rotary coupling to transmit fluid pressure from a stationary fluid line to a device mounted on a rotatable shaft comprising, in combination, a shaft, a stationary annular housing enclosing said shaft and spaced therefrom, an inlet port in said housing, a pair of spaced bearing assemblies positioned between said housing and said 'shaft to permit rotation of said shaft within said housing, first sealing means disposed between said housing and said shaft on one side of said port, second sealing means disposed between said housing `and said shaft on the other side of said port, and means defining a uid passage extending longitudinally of said shaft, one end of said passage being in communication with the region between said two sealing means which is in communication with said port.

14. The combination in accordance with claim i3 wherein each of 4said sealing means comprises a mating r-ing in fluid tight engagement with said shaft, an annular casing in fiuid tight engagement with said housing, a U- shaped annular packer in -said casing, an expansion ring engaging said packer to force saidV packer into engagement with said casing when fluid pressure is introduced into said housing through said inlet port, and an annular insert disposed between said mating ring and said casing, said insert being in fluid tight engagement with said casing and making slidable fluid tight contact with said mating ring.

l5. A rotary coupling to transmit fluid pressure from a stationary fluid line to a device mounted on a rotatable shaft comprising, in combination, a shaft having a passage therein extending longitudinally thereof, a stationary annular housing enclosing said shaft and spaced therefrom, an inlet port in said housing, a pair of spaced bearing assemblies positioned between said housing and said shaft to permit rotation of said shaft within said housing, first sealing means disposed between said housing and said shaft on one side of said port, second sealing means disposed between said housing and said shaft on the other side of said port, and means defining a passage between the passage in said shaft and the region between said two sealing means which is in communication with said port.

16. A rotary coupling to transmit fluid pressure from a stationary fluid line to a device mounted on a rotatable shaft comprising, in combination, a shaft, Va sleeve attached to and enclosing said shaft, said sleeve having a passa-ge formed therein extending longitudinally of said shaft, a stationary housing enclosing said sleeve and spaced therefrom, an inlet port in said housing, first sealing means disposed between said housing and said shaft on one side of said port, second sealing means disposed between said housing and said shaft on the other side of said port, and means vdefining a passage between the passage in sa-id sleeve and the region between said two sealing means which is in communication with said port.

17. A rotary coupling to transmit uid pressure from a stationary fluid line to a device mounted on a rotatable shaft comprising, in combination, a shaft, a sleeve attached to and enclosing said shaft, said sleeve having a passage formed therein extending longitudinally of said shaft, a stationary housing enclosing said sleeve and spaced therefrom, an inlet port in said housing, first sealing means disposed between said sleeve and said housing on one side of said port, a first bearing assembly disposed between said sleeve and said housing on said one side of said port farther from said port than is said first sealing means, second sealing means disposed between said sleeve and said housing on said one side of said port farther from said port than is said first bearing assembly, a second port in said housing between said first bearing assembly and said second sealing means, third sealing means disposed between said sleeve and said housing on the second side of said first-mentioned port, a second bearing 'assembly disposed between said sleeve and said housing on said second side of said first-mentioned port farther from said first-mentioned port than is said third' sealing means, fourth sealing means disposed between said sleeve and said housing on said second side of said first-mentioned port farther from said first-mentioned port than is said second bearing assembly, a third port in said housing between said second bearing assembly 13 and said fourth sealing means, and means defining a passage between the passage in said sleeve and the region between said first and third sealing means which is in communication with said first-mentioned port.

18. A rotary air coupling to transmit uid pressure from a stationary fluid line to a device mounted on a rotatable shaft comprising, in combination, a hollow shaft,`

a cup-shaped stationary housing enclosing one end of said shaft in spaced relation therewith, first sealing means dis- 'l posed between said housing and said siaft, an inlet port in said housing between said first sealing means and said one-end of said shaft, a bearing assembly between said housing and said shaft further from said one end of said shaft than is said first sealing means, second sealing means disposed between said housing and said shaft in spaced relation with said bearing assembly yand further from said one end of said shaft than is said bearing assembly, andk a second port in said housing between said bearing assembly and said second sealing means.

19. The combination in accordance with claim 18 wherein said first sealing means comprises a mating ring in fiuid tight engagement with said shaft, an annular casing in fiuid tight engagement with said housing, `a U- shaped annular packer in said casing, an expansion ring v engaging said packer to force said packer into engagement with said casing when fiuid pressure is introduced into said housing through said inlet port, and an annular insert disposed between said mating ring and said casing, said nular member, a cam attached to said annular member, a source of hydraulic fluid under pressure, first valved conduit means extending between said source of fiuid and said motor for rotating said motor in a first direction, a valve body defining a piston chamber, a first port in said valve body communicating with said piston chamber intermediate the ends thereof, a second port in said valve body communicating with said piston chamber intermediate the ends thereof, a piston disposed in said piston chamber, said piston having a recess therein whereby said first and second ports are in communication when said piston occupies a first position in'said piston chamber, means urging said piston toward one end of said piston chamber whereby said first and second ports are sepinsert being in fluid tight engagement with said casing and making slidable fiuid tight Vcontact with said mating ring.

20. A valve comprising, in combination, a valve body defining a piston chamber, a first port in said valve body communicating with said piston chamber intermediate the ends thereof, a second port in said valve body communicating with ysaid piston chamber intermediate the ends thereof, a piston disposed in said piston chamber, said piston having a recess therein whereby said first and second ports are in communication when said piston occupies a first position in said piston chamber, means urging said piston toward one end of said piston chamber whereby said first and second ports 'are separated by said piston, conduit means extending between said first port and said one end of said piston chamber whereby fluid pressure applied to said first port tends to overcome said urging means to move said piston to said first position, and means extending from said piston externally of said housing whereby the application of fonce thereto results in said piston being moved toward said first end of said piston chamber.

2 1. A valve comprising, in combination, a base having a central passage therethrough, a piston chamber secured to said base, said piston chamber having first and second ports therein intermediate the ends thereof, a piston disposed in said piston chamber, said pistonV having a recess therein whereby said first and second ports arein communication when said piston occupies a first position in said piston chamber, a member positioned in the passage of said base for movement therein, said member extending v to a region exterior of said base, a spring urging said member into engagement with said piston to move said piston toward one end of said piston chamber whereby said first and second ports are separated by said piston, said piston chamber having a passage formed therein between said first port and saidfone end of .said chambenand a plate secured'to saidfpiston chamber to cover said one end thereof.

22. A hydraulic uid actuated power tong system. comprising, in combinatiomfa base having a firstlopening l therein, an annular member mounted on said base, pipe gripping jaws attached tosaid annular member',V said member having a second opening therein whereby a pipe can be'inserted to be engaged'by said jaws when said first andfsecond openings are ,a1igned a hydraulicI motor coupledto said annular member for4 rotating said an-Y arated by said piston, second conduit means extending between said first port and said one end of said piston chamber whereby fluid pressure applied to said first port tends'to overcome said urging means to move said piston to said first position, means extending from said piston externally of said valve body whereby the application of force thereto results in said piston being moved toward said first end of said piston chamber, said valve body being positioned whereby said cam engages said last-mentioned means when said first and second openings are aligned, third valved conduit means extending between said source of fiuid and said first port, and fourth conduit means extending between said second port and said motor for rotating said motor in a second direction.

23. The combination in accordance with claim 22 wherein said first and third valve conduit means comprise a first conduit connected at one end to said source of fluid under pressure; a first valve having first, second, third and fourth openings therein, said first and fourth openings being in communication and said second and third openingsV being in communication when said first valve is in a rst position, said first and second openings being in communication and said third and fourth openings being in communication when said first valve is in a second position; a second valve having fifth, sixth, seventh and eighth openings therein, said fifth and eighth openings being in communication and said sixth and seventh openings being in communication when said second valve is in a first position, said fifth and sixth openings being in communication and said seventh and eighth openings being in communication when said second valve is in a second position; the second end of said first conduit being connected to said second opening; a second conduit extending between said third and sixth openings; a third conduit extending between said seventh opening and a terminalof said motor; a fourth conduit extending between said fifth opening and the second terminal of between said first opening and said first port.

References Cited in the file of this patent UNITED STATESIPATENTS 1,126,124 Strite et al. Jan. 26, 1,846,578 Bates -Feb. 23, 1932 2,398,087 Dodge Y Apr. 9,'1946 2,450,934 Calhoun p Oct. 12, 1948 2,544,639. Calhoun Mar. 13, 1951 2,550,045 a De Hetregca 'Apr. 24, 1951 2,556,536 Harris L June. 12, `1951 2,578,686V Fish y. Q-Dec. 18, 1951 k 2,615,681 True Oct. 28,l 1952 2,639,894 Smith n n "May 26,1953

Gardner Mar. 1,

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