US2733687A - schmid - Google Patents

Description

P. E. SCHMlD REVERSING VALVE Feb. 7, 1956 3 Sheets-Sheet 1 Filed Oct. 27, 1954 INVENTOR. Pau/ E. Jcfim/a ATTORNEY P.- E. SCHMID REVERSING VALVE Feb. 7, 1956 3 Sheets-Sheet 2 Filed Oct. 27, 1954 INVENTOR. Pau/ Jc/zm/c/ ATTORNEY Feb. 7, 1956 Filed Oct. 27, 1954 P. E. SCHMID REVERSING VALVE.

IN VEN T0 Pau/ E. Jchm/ ATTORNEY REVERSING VALVE Paul E. Schmid, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Application October 27, 1954, Serial No. 464,927

, Claims. (Cl. 121-34) This invention relates broadly to pneumatic tools, but more particularly to an improved [reversing valve for rotary pneumatic tools such as nut setters and the like.

One object of this inventionis to provide a reversible rotary fluid actuated toolor motor with a simple and efiicient reversing valve which can be built within the rear end of the tool with an operating handle blending within the general configuration of the tool, thereby eliminating undue protuberances found'to be cumbersome for the proper and efficient use of the tool.

Anotherobject of this invention is to provide simple and eificient means for supporting and positioning the valve in two different positions.

Another object of this invention is to design such a reversing valve which will operate smoothly, with minimum amount of wear and requiring little or no attention.

Other objects. of theinvention will become apparent from the followin detailed description wherein similar characters of reference designate corresponding parts, and wherein:

, Figure l is a side elevational view, partly in section, of a reversible pneumatic tool embodying the invention.

'Figure 2 is an enlarged longitudinal sectional view of therear end of the tool shown in Figure l.

Figures 3', 4, 5 and 6 are cross-sectional views taken on lines 3-3, 4-4, 5-5 and 66 respectively in Figure 2. g

Figure 7 is a cross-sectional view taken on line 77 in Figure 2.

In the drawings, 10 designates generally a fluid actuated rotary tool of the reversible type such as a nut setter or the like, provided with an outer casing 11 having an integral handle 12. This handle. is equipped with a connection 13 adapted to receive the outlet end of a motive fluid conveying conduit, from where motive fluid is supplied to an inlet chamber 14 through a passageway 15 controlled by a throttle valve operableby a trigger 16.

The tool itself is of the usual rotary reversible type well known in this art. Briefly it comprises a stator 17 fixed within casing 11 by a'key 18 and having its rear end closed by a rotor end plate 19 also looked in place by the key 18. Stator 17 is provided with the usual eccentrically located rotor chamber 20 best shown in Figure 3,

in which is rotatably mounted a rotor 21 carrying radially movable-equally spaced vanes122. The ends of rotor 21 are reduced into shifted portion 23, one of whichis shown in Figure 2, which are journaled in adequate bearings such as 24, which in the instance of the rear end bearing is mounted within a cylindrical extension or pilot 25 extenda ing centrally backward from plate 19.

As shown in Figure 3, casing 11 is provided with two of the pin 49 but "smaller than the width of the ring 48,

opposite the line contact of the rotor with the stator, which chamber is in communication with rotor chamber through a series of longitudinally spaced ports 31.

End plate 19 is provided With two angularly spaced sets of ports 32 and 33 constituting passages opening into corresponding sets of ports 34 and 35 respectively provided through the end wall 9, shown in Fig. 2, ofstator 17 and opening into the casing chambers 26 and 27 respectively. The back side. of end plate 19 is also provided with an arcuated exhaust passageway 36 which is incommunication with the exhaust chamber 30 through a plurality of radial ports 37 Referring now more particularly to the invention, the reversing valve 40 is preferably dome like and located for rotation Within the casing inlet chamber 14 and appropriately machined tofit closely. for rotation on the pilot 25 of end plate 19. This valve has a front end annular surface abutting against the rear face of plate 19, both being carefully finished to afford a fluid tight joint. From its front surface the valve extends rearwardly in a dome like shape over the bearing 24, to end in a cylindrical shank 41' extending through and journaled within a central bore 42 formed through the rear end of casing 11.- At the base of the shank 41, the valve is provided with an external annular spring seat engaged by the inner portion of an annular plate spring 43, which has its outer portion resting against a corresponding seat provided with casing 11. Spring 43'is shaped soas to exert axial pressure on the valve toward end plate 19 to initially maintain both abutting faces influid tight engagement. Preferably, valve shank 41 within casing bore 42 carries a packing 44 to prevent leaking of the motive fluid from chamber 14 through bore 42. Casing 11 has its extreme rear end reduced and forming with a cover plate 45, fixed thereto by countersunk screws 46, a cylindrical bearing 47 on which is closely fitted for rotation relative thereto a valve operating handle in the form of a ring 48, which is fixed to the valve shank 41 by a cross pin 49. To allow for partial rotation of the ring 48 on its bearing 47, there are provided between the casing and a cover plate 45 two diametrically opposed radial slots 50 within which cross pin 49 is free to move from one end of the slots to the other. As shown in Figure '7, the ends 'of one of the slots afford stops 51 engageable by the pin 49 for limiting the extent of rotation of the valve. The 7 width of the slots is somewhat greater than the diameter thereby causing the outer openings of the slots to be always covered by the ring. a

The front annular surface of valve 40 is provided with a relatively long, semi-circular groove 52 affording a path of communication with one or the other sets of ports or passageways 32 and 33 of e the end plate 19 with the exhaust passageway 36. Equally spaced from the ends of groove 52, there is an inlet port 53 extending through the valve and opening into the inlet chamber 14 and on the front face of the valve.

From the foregoing description,.it will be understood that the reversing valve 40 may be rotated to two different chambers 26 and 27 located one on each side of the line chamber 3!? provided within casing 11 diametrically positions determined by the engagement of the valve cross pin 49'with either stop 51. In the one position shown in the drawings, the valve inlet port 53 will register with the end plate passage 32, thereby admitting pressure fluid, supplied to the inlet chamber through the passageway 15, to the casing chamber 26 through the stator end ports 34, and therefrom into rotor chamber 20 through ports 28 to act on vanes 22 for imparting counterclockwise rotation to the rotor 21 as seen in Figure 3. After full expansion Within the rotor chamber 20, the pressure fluid will first exhaust through the exhaustports 31 and chamber 30, the latter being connected with the atmosphere through one or more exhaust ports,

, when cross pin 49 contacts the right hand stop 51 in Figure 7, the valve inlet passage 53 will register with the end plate passage 33 for admitting pressure fluid into the casing chamber 27 through stator end ports 35,

and into rotor chamber 20, through radial ports 29, to

act on the vanes 22 for imparting clockwise rotation to rotor 21 as seen in Figure 3. Concurrently, valve groove 52 is positioned to afford communication of end plate ports 32 with exhaust groove 36, thereby after primary exhaust through ports 31 enabling secondary exhaust of motive fluid through radial ports 28, chamber 26, stator end ports 34, valve groove 52, groove 36 and ports 37 which open into exhaust chamber 30.

One main advantage of thisconstruction resides in the location of the reversing valve entirely within the inlet chamber 14. As clearly shown in Figure 2, the dome like portion of the valve, or more particularly its rear face, as compared to its front face seated on the end plate 19, affords a relatively large pressure area subjected to the pressure fluid within inlet chamber 14 for holding the front face of the valve on the end plate 19 in fluid tight engagement therewith. Plate spring 43 is used primarily to maintain the front face of the valve firmly against the plate 19 when pressure fluid is not admitted into inlet chamber 14, thereby preventing pressure fluid when first supplied into chamber 14 from acting on the front end of the valve and keep it away from the plate 19. Also when the pressure fluid is off, that is, when throttle valve controlled by trigger 16 is closed, plate spring .43 exerts sufficient axial pressure on the valve to restrain the valve and its operating handle or ring 48 against free uncontrolled rotation.

The reversing valve actuating handle or ring 48 located at the extreme rear end of the tool, and blending generally within the configuration of the casing 11, provides an efiicient and readily accessiblevalve operating means well protected against accidental rotation. If desired, the outer peripheral wall of ring 48 may be-knurled or made of a shape shown in Figure 7 to be more readily grasped by theopera tor.

The details of structure and arrangement of parts shown and described may be variously changed and modified without departing from the spirit and scope of the invention.

I claim:

1. In a reversing valve for a pressure fluid actuated rotary tool including a rotor and a rotor 'end'plate within said casing, two angularly spaced passages. through said end plate and an exhaust passageway opening through the rear face of said plate, an inlet chamber within said casing adjacent said plate, means for admitting pressure fluid into said chamber, a dome like valve rotatable in said chamber to two positions, a front annular surface on said valve seated against the rear face of said plate face of saidplate, a shank. extending from said'valve through one end of said casing, a cover plate over one end of said shank fixed to said casing, a cylindrical bearing on said casing adjacent said shank, and a ring-like handle rotatable on said bearing fixed to said shank for rotating said valve to said positions.

2. In a reversing valve for a pressure fluid actuated rotary tool including a casing, a rotor and a rotor end plate within said casing, two angularly spaced passages through said end plate and an exhaust passageway opening through the rear face of said plate, a pressure fluid chamber within said casing adjacent said end plate, a pilot extending from said end plate rearwardly into said chamber, a valve rotatable on said pilot to two positions within said chamber, a front annular surface on said valve seated against the rear face of said plate, an inlet port through said valve leading from said chamber to said front surface for individual registry with said passages upon rotation of said valve to said two positions, a groove within the front face of said valve affording a path of communication between said exhaust passageway and the one of said passages out of registry with said inlet port in either position of said valve, a pressure surface for said valves opposed to said annular surface subjected to fluid pressure within said chamber for seating said front surface against the rear face of said plate, means restraining the rotation of said valve when pressure fluid is cut off from said chamber, and means extending from said valve to the exterior of said casing for rotating said valve to either of said two positions.

3. In a reversing valve for a pressure fluid actuated rotary tool including a casing, a rotor within said casing and a rotor end plate fixed within one end of said casing, a pair of angularly spacedpassages through said end plate and an exhaust passageway opening through the rear face of said plate, a pressure fluid chamber within said casing end, a valve rotatable within said chamber to two positions, a front annular surface on said valve seated against the rear face of said plate to normally seal said passages and passageway from each other, an inlet port through said valve leading from said chamber to said front surface capable of individual registry with said passages upon rotation of said valve to said two positions, means within said valve affording a path of communication between said exhaust passageway and the one of said passages out of registry with said inlet port in either position of said valve, spring means active on said valve to maintain its annular front face seated on the rear face of said plate, and aring like handle fixed to said valve and rotatably mounted on said one casing end for rotating said valve to said two positions.

, 4. A valve mounting including a tubular casing, a valve body rotatable within one end of said casing, a bore through said one casing end, an integral shank for said valve extending through said bore, a cover plate over the end of said shank fixed to said casing end, a cylindrical bearing on said casing concentric with said bore, a ring like handle rotatably supported on said bearing, a cross pin securing said handle to said shank, and a radial slot for said pin between said casing end and cover plate having its outer opening covered by said handle.

5. A valve mounting including a casing formed with a cylindrical 'end, a valve body rotatable within said casing, a bore centrally through said casing end, an integral shank for said valve extending through said bore, a cover plate over the endof said shank fixed to said casing end, a ring-like handle rotatably mounted on'said cylindrical end, a cross pin securing said handle to said shank, and a radial slot for said pin between said casing end and cover plate having its outer opening covered by said handle, the radial ends of said slot forming stops engageable by said pin to limit the extent of rotation of said valve.

9 References Cited in the file of this patent UNITED STATES PATENTS 2,414,638 Dobie Jan. 21, 1947

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