US2928574A - High-pressure gun for grease and oil - Google Patents

Description

March 15, 1960 J. WAGNER 2,928,574

HIGH-PRESSURE GUN FOR GREASE AND on.

Filed sept. 24, 1957 The invention relates vto a high-pressure, gun forgrease and oil wherein the grease or oil is sucked by means of a piston pump driven by an electric motor out of a conrainer removably attached to the rgun housing and is expelled at high pressure, from `-the nozzle which is closed .bymeans of a spring-loaded non-return valve, by .means of the lpump .piston which, `in its forward movement, closes the intake.

It is the object of the invention to develop a high-pressure gun of the aforesaid type in the sense of more com-- plete adaptation to rough service anda high working States Patent pressure and to limit the height ofthe latter by means of a suitable device which is adjustable as required.

Thesolution of this problem according tothe invention consists in that the shaft of the motor, 'which isv flangeconnected in known Vmanner to the gun housing, is coupled 'through a reduction gear to an eccentric which is mounted for 'rotation on a shaft located in the gun housing, and which rests'on the outer periphery of a ball-bearing'roller, the journal of which is secured to a preferably bent rocking lever, the free end of which rests. against the end `face of the pump piston rod which `projects into the gun housing, or'against the intermediate piston, so that, yin this manner, the pump piston, which is constantly restored to its initial position by spring pressure, is reciprocated `in time'with vthe speed of rotation of the eccentric.

:In the -end of the pump cylinder which -projects out of the gun housing, there is screwed a pressure-relief valve of which the valve tappet, which is provided with -arustoconical head and with an axial bore, is urged by plate springs against the valve seating. The force Aof these plate springs is adjustable by means of a retaining -nu-t which encases the springs and which comprises, at the end remote from the gun housing, bores for discharging the excess lubricant delivered.

Further details of the invention vcan be .seen from the following description of an example of 'an embodiment explained with reference 4to the drawing. The drawing represents a longitudinal -section through the axis lof the pump piston, partly broken away, of the high-pressure gun constructed in accordance with the invention.

The housing of the grease and oil gun, which is constructed like a pistol, is -made -of die-cast light metal or synthetic material and is giventhe reference numeral 1. The housing comprises a handle 2 on the inside of .which is conveniently mounted a'rpress-button 3 by means of which the driving motor 4, whichis llange-mounted on the housing 1 and is only -partly shown in the drawing, can be switched on and olf. The grease or oil container 5 is screwed into or otherwise secured in an easily detachable manner, to the housing 1 below the nozzle or pressure-relief valve 6 of the gun.

The stub axle 7 of the motor 4, which projects into the housing l. ends in a pinion 8 which, together with the gearwheel 9 forms a reduction gear. The gearwheel 9 is rigidly coupled to the eccentric 10. The latter is mounted for rotation on the shaft 11 which is fixed on both sides in the housing 1. The eccentric rests on the icc ` .piston A.16. The pump `piston v18 is guided in'thepu'mp cylinder k20 which is located Vinthe .gun housing by` meansof the is'etscrew 21. The spiral spring 19'rests :against .the pump cylinder' Zlland'urges the vspring:retainer 17 against the Vintermediate Apiston 16; The force fo'fthe' spr-ingl9 -ensures that the roller 12, which is mountedfor rotation font-he'rocking lever .14, always :bears against theeccentric When the shaft 7 of the `driving'motor 4 rotates, Ztlre 'eccentric 10 `rocks the lever 14 in clockwise drectionin time with the yspeed of rotation ofthe motor. This leads to a displacement of Vthe pump piston 18 inside the pump vcylinder 20against the force of the spring 19'. The lastmentioned spring restores the .pump piston 181to its .initial :position Yeach time.

:In the end vof 'the pump cylinder 20 remote .from v'the rocking lever 14 there is vinstalled a :non-return valve 221, the stem 22 of which is guided in the vmem-berZ: lscrewed into the'pump cylinder 20. This member isppr'ovided Awith vaxial passages for the @grease or oil. The non-return valve 22 vis urged against its valve `seating 'by means fof the vspring .24. The spring tension can be `ladjustedfby means of the Amember 23 which canbe screwed backwards and forwards in Vthe'axial direction- Y In the pump cylinder 20 and in the housing Y1=is a 'suction bore 25 which, through a lter 26, 'provides .a

connection' between the bore in thejpump cylinder ,V20

and the grease or oil container 5. The suction bore 25 leads to a point in the bore of the pump cylinder 2i) -which, when the pump piston 18 is displaced intothe position nearest .the driving motor 4-the suction .positionis not yet covered bythe pump piston but which is covered thereby during the'delivery .stroke of the pumpjpiston .18.

yThe pump l18, 20 automatically sucks up the .grease or oil from the container 5.

Screwed into the end of thepump cylinder .20 which i projects out of the gun housing 1 is a pressure-reliefvalve 6.1, With this Ithe maximum permissible working ,pressure can be adjusted within wide limits-about v1.00 to 1000 atmospheres. This adjustment is elec-ted bymeans 'of the retaining nut 6 which shuts 0E .the-interior vof the pressure-relief valve k6 lfrom the outside. Mounted in the recess vin the nut 6 are therplatevsprings 33 which are axially .displaceable on the valve tappet `31 provided :with an axial duct or 4bore 32 and which urge the "frustoconical head 31, of the valve tappet against Kthe vlve seating 34. This pressure is variable Lby 'screwing the retaining nut 6 to a greater or lesser extent on the valveseating member.

[If Vthedelivery pressure vproduced by the pump piston 18 exceeds the maximum :pressure set yby means of Vthe :pressure-relief valve 6, then the head 31 o'f -the valve tappet is lifted from its valve seating 34 against the con- -tact pressure exerted by the plate springs 33. The grease or oil delivered is then partially forced pas-t the plate springs 33 and escapes through a by-pass conduit formed by the axial bores 35 provided on the end face of the retaining nut 6', to the outside. In this manner, the pressure of the lubricant reaching the lubricant point through the bore 3'2 in the valve tappet 31 and the highpressure tube 37 secured by means of the sleeve 37 t0 the tappet 31, is lowered.

In the'drawing, the lubricantcontainer 5 is constructed,

in the form of a grease container. Mounted for Vsliding in the latter is a piston 27 which can be moved up and ,down by turning the threaded rod 28 providedfwith a handle 30. ',A spiral spring 29 restng'onthe bottom of the container urges ythepiston 27 against the column of `grease lying above the latter. The lling of the grease container Sis preferably eected asfollows:

.'lheempty container 5 is pushed, withthe piston Z7 advanced, into the bucket containing .the supply` of grease, and -the handle 30 isturned back to the left. mannere acoherent column of grease, without any air, is

sucked into the V,container 5. The container 5 should..

then be screwed into the gun housing 1 in such amanner that V no air space is formed betweenthe suction head of the gun and the container. The handle `30. of the threaded rod 28,V which was previously turned to the left until it abutted against a stop is now turned to the right until it abuts against'alstop and thus the piston 27.is pressedy against the column of grease under the pressure of the spiral spring 29. reliably pushed towards the suction head of the gun, and during the suction stroke of the pump piston 18 it is lInthisV In -this manner, the .grease is the valve seating by plate springs the spring tension of which is adjustable by means of a retaining nut which encases the springs and which comprises, on the endface remote from the gun housing, axial bores for discharging the excess lubricant delivered. Y

7. A high-pressure gun having a gun housing, for use in discharging material such as grease and oil from a container'at high pressure throughgand outofanozzle,

said gun having a housing, said container being removably connected to said housing,` the combination of an electric revolving motor built into said housing, a reciproeating piston pump connected to said housing and adapted to be disposed externally of said container and having an inlet opening `communicating with said container, the

piston of said pump being oscillatable and spring biased towards a retracted suction position, transmission means between said electric motor and said piston operable for propelling said piston periodicallyforwardly into a prest sure position comprising a revoluble eccentric cam driven from said motor, a bell crank lever having one arm journalled in said housing, a cam follower connected to said lever and driven by said eccentric camV and including an anti-friction bearingvdisposed substantially at right sucked through the bore into the pump cylinder 20 and from thence, during the delivery stroke of the piston 1 8, it is forced through the adjustable pressure-relief valve 6 to the lubricating point. t

The high-pressure gun for grease described above may also be used for oil. The'grease container is unscrewed and replaced by an oil container equipped withv an oil-suction-pipe. i

-Iclaimz .j

1. A highpressure gun for grease and oil comprising in combination a gun housing, a container for grease or oil detachably secured to said housing, an electric motor ange-connected to said housing, an ejection nozzle, a spring-loaded non-return valve for `closing said nozzle,

a piston pump for sucking oil or grease out of the container and for ejecting it under high pressure through said nozzle, awreduction gear insaid housing, an'eccentnic coupled through said reduction gear with the motor shaft, a ball-bearing rollerA against the outer periphery of which the eccentric bears, and a rocking lever secured to the journal of the said roller, the free end of said lever actuating Ithe pump piston reciprocating it in time with the speed of rotation of 'the eccentric. Y

2. A high-pressure gun as claimed in claim l, wherein the rocking lever is a bent lever.

, 3. A high-pressure gun as claimed in claim 1, wherein the free end ofthe rocking lever bears againstfthe end face of' the pump piston rod projecting into the gun housing.,

4. A highfpressure gun as claimed in claim l, wherein t the free end of the rocking lever bears against the end face of an intermediate piston,l on the pump piston rod projecting into the gun housing.

5. A high-pressure gun as claimedin claim 1, wherein the pump piston when reciprocating is restoredateach stroke to its initial position byspringpressure. p 6. A high-pressure` gun as claimed in'claiiii l, characterised in that screwed into the end of the pump cylinder projecting out of the gun housing is a pressure-relief `valve of which the valve tappet, which is provided with a frusta-conical headV and an axial bore. is urged against t angle to the axis of said eccentric cam, the other arm of said lever` being in driving connection with said piston, `said piston beingactuatable to close said opening during Itheforward stroke, andy a 'rigid conduit structure connected'to said housing and supporting said nozzle dein-` ing a conduit extending between said nozzle and said pump and including a pressure relief valve for said nozzle,

whereby said eccentric cam will impart periodic impulses Y `to said cam follower land said lever will transmit these impulses to said piston impelling the piston periodically forwardly and the piston will be retracted by. said ,spring bias during the intervening time intervals, to .pump material out of said container into said conduit and through said nozzle.

8. In a high-pressure gun, as claimed inclaim 7, said pressure relief valve comprising a valve seat formed in said conduit, a tapered valve head movable to and from la valve closingV position onlsaid valve seat and having an internal bore, resilient means urging said valve head towards said valveseat, whereby normally said valve head will engage said valve'seat andthe bore will conduct the lmaterial and, respectively, upon? the occurrence of excesspressure said valve head will be lifted by the material oi the seat, said'conduit structure including means establishing a by-pass Vductfor the excess material when saidvalve head is lifted off the seat, and means operable for adjusting the force of said resilient means.

References Cited in the tile of this patent UNITEDzsTATEs PATENTS

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