US2081163A - Lubricating apparatus - Google Patents

Description

May 25, 1937. F. s. BARKS ET AL LUBRICATING APPARATUS 2 Sheets-Sheet l Filed May 22, 1956 was!!! l 0 1 1 |,!U,v/vf/V UN 2, m e f 9 v .":Mvl LN 2 G 247 Z H a, w S w 0 M w 6 6 V, A w

n m 1 71 a 6 s m s. u K

S M n JMIMMHWH B .F 3 x 3 0 d, 4. 3 4 2 m f n .4l

y 8 4 Jl Patented May 25, 1937 LUBRICATING APPARATUS Frank S. Barks and Victor G. Klein, St. Louis,

Mo., assignors to Lincoln Engineering Company, St. Louis, Mo., a' corporation of Missouri Application May 22, 1936, Serial No. 81,254 16 claims.i (c1. azi-47.3)

This invention relates to lubricating apparatus, and with regard to certain more specic features, to an improvement upon the semi-automatic, portable, hand-injector pump, disclosed in the United States patent of Lutwin C'. Rotter et al., No. 2,038,761, led April 3, 1935, dated April 2S, 1936 for lubricating apparatus.

Among the several objects of the invention ,may be noted the provision of the improvement over the construction of said patent application comprising the provision .of a separate, one-stroke power head which is very quickly and simply attachable to any of a group of tube assemblies, each containing a diiferent lubricant; ythe provision of apparatus of the class described which will permit of very convenient re-lling of each of the said lubricant tube assemblies; and the provision of apparatus of this class which is simple and compact in :construction vand quite easily operated. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features .of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is illustrated one of various possible embodiments of the invention,

Fig. 1 is a longitudinal section embodying the invention, certain valve parts having been eliminated for clarity;

Fig. 2 is an enlarged cross section taken on line 2 2 of Fig. 1 but showing said Valve parts;

Fig. 3 is a cross section taken on line 3--3 of Fig. 2;

Fig. 4 is a fragmentary cross section taken on line 4-4 of Fig. 2;

Fig. 5 is a fragmentary cross section taken on line 5--5 of Fig. 2;

Fig. 6 is a longitudinal section of a lubricant tube with power head and outlet head removed and shown in lling position;

Fig. 7 is `a .side elevation of the power head which has been removed from the structure of Fig. 6;

Fig. 8 is a side elevation, parts being broken' away, of the outlet head which has been removed from the tube of Fig. 6; and,

Fig. 9 is a view similar to Fig. 6 but showing a succeeding position of parts and said head of Fig. 8 applied preparatory to applying the power head of Fig. 7. Similar reference characters indicate correspending parts Y.throu'ghoutthe several views of the drawings. v

Referring now Vmore particularly to Fig. 1, there is shown at numeral l a cylinder to which is removably threaded an outlet head `3, sealed at washer 2D, the head ki carrying a curved, removable outlet pipe 5 at the end of which is a nozzle t6.' The pipe 5 is one of a set of similar ones that may be used. Each `has a different curvature for reaching lubricant inlets in various locations. The nozzle I6 is also arranged to be removable .to have other nozzles applied. The type of nozzle to be used .depends upon the type of lubricant in the cylinder 1, and'upon the type of receiving opening for accommodating the nozzle.

The head A3 has therein an outlet check valve 'I and is internally provided with a pump cylinder 9 adapted to slidably receive a pump plunger II. The forward end of the plunger Il is conic as indicated at numeral i3 and the rearward end of the cylinder 9 is :beveled as shown at numeral I5 to more readily effect entry of the plunger into the vcylinderon a forward stroke. The head 3 also A-carriesan inlet .connection II for theinilling vof lubricant where the operator has available a pressure iilling device.

The plunger ll is threaded into the hexagonal shoulder vI2 of a rod 2l, a suitable cross passageA 23 for a wrench or the like being provided for this purpose. A floating follower piston 25 is pro- Videdwith suitable sealing means 21 operative both in connection with the wall of the cylinder l and with said .rod 2 I.

(Fig. 1) into two compartments, namely, a forwardly located lubricant compartment (to the left of the piston) and a rearwardly located air compartment (to the right of the piston).

'Screw-threaded permanently and sealed to the rearward end of the cylinder I 4is a diaphragm member`2 in which are air-transmitting openings 4. The diaphragm member 2 is internally threaded to removably receive by threading an adapter tube "6 which seats and seals at its -bottom upon a gasket 8 held in a groove Within the diaphragm member 2. At its other end the adapter cylinder 6 is permanently screw-threaded The purpose of the piston 25 is to divide the cylinder I into and sealed with 'a head 29 having a closing diaphragm 3l therein. It will be apparent that -the diaphragm 3| and the diaphragm 2 differ in that the former is without air-transmitting op'en ings, whereas the latter has such. l Y

Reference to Figs. E6 and '7 will show that the adapter sleeve -6 and the head 29 with attached parts form a permanent power unit which is attachable to and detachable from the diaphragm member 2. A purpose of the diaphragm member 2 is to provide a rearward slide bearing for the rod 2| and to support the air motor unit of Fig. 7 in proper concentric position.

On the left (inner) side of the diaphragm 3| is threaded a differential cylinder 33 which extends coaxially with, and` into the cylinder 6. The rear end of the rod 2|, outside of the diaphragm 2, carries a button-like piston head I9 which contacts a differential piston 35 operating in cylinder 33. The head I9 slidablylcooperates with the interior of cylinder 33, and although not packed, it forms a fair piston-like seal in the cylinder. It should be noted Vcarefully rthat the head I0 only abuts and is easily separable from the piston 35, as indicated by the separatiorof.

parts illustrated by Figs. 6 and 1. The purpose of this is to permit the rod 2| to be actuated by said piston I0 under assembled condition, but to permit of ready disassembly and to permit the operator to use the button i9 as means for effecting manual filling operations to be described under separated conditions rof the power head. The bevelled lower end of cylinder 33 further facilitates the easy assembly.k

The differential piston 35 is provided with a rigid, hollow extension 31 which passes through the diaphragm 3|, being packed therein by means of a packing 39. 'Ihe extending stem 31 carries a power piston 4| upon the right-hand side of the diaphragm 3|, said piston 4| operating in a closed cylinder cap 43 screwed permanently to said head 29.

As shown in Figs. 2 and 3, the head 29 is provided-with an air inlet tting 41 adapted to receive an air chuck of an air line under pressure. The tting 41 screws into a recess 49 in which is a valve 5|. The recess and the valve may transmit air about the Valve (see Fig. 4), due to square, relieved portions 52. Thus air may pass from the fitting 41 and around the valve 5| when the valve is removed trom its seat 53. However, the valve is normally pressed to its seat to close Off the air by means of a spring 55 and the pressure of the air itself. Y

The valve 5| has a stem 51 which passes with clearance through a passage 59 and to the stem Bl of arsecond valve 33. The body of the valve 63 snugly but slidably ts the hole in which it works, so that no passage to atmosphere is provided around the valve. However, a passage 54 to atmosphere is provided in the head 29.

A handle 55 pivoted to the head 29 cooperates With the outer end G1 of the Valve 63 so that upon pressing the handle 35, said valve 63 may be seated against its seat 45 and the valve,5| unseated from its seat 53, both against the pressure of spring 55 and the air line pressure.

Thus, when the valve 5| is unseated, air may ow in from the fitting 41 intothe passage 59. A side passage 1| (Fig. l) communicates with passage 59 and passes into communication with said differential cylinder 33.

Beyond the seat 45 there is also a passage 13 communicating from said passage 59 and to the region beneath piston 4| in the cylinder 43 (Fig. 3). Passage 19 leads from a point ahead of seat 53 to the cylinder .6.

Assuming some lubricant to; be in the cylinder I ahead of piston 25, the operation is as follows:

By means of an air chuck, an air hose is placed in connection with the air receiving `fitting 41.

`Priming air immediately flows through the cylinder 6, holes 4 in diaphragm 2, and to the cylinder to force the follower 25 against the lubricant ahead of it. The plunger will then be back and out of cylinder 9, because air under pressure in cylinder 3, in attempting to flow into the cylinder 33, forces back the button piston I0 against the diierential piston 35. The button piston I0 has a separable sealing contact with the packing 36 of the piston 35, as shown. After Contact is initiated, it is maintained, because, as will be shown, the hollow portion 39 beneath the piston I9 is in communication with the exhaust by means of a passage 49. This is because the button piston i9 has a sliding fit in the cylinder 33. Hence open cylinder 9 is primed by grease under air pressure. 'I'he air, normally pressing upon the valve 5i holds it to its seat 53 to check any flow past the same.

Next, the nozzle valve Hi is placed in communication with the opening which it is desire-d to have receive the lubricant. When the lever 35 is pressed, the exhaust Valve 53 is seated, the inlet valve 5| is opened and air is admitted to the passage 59, but notto thepassage 13. Hence air under pressure passes through the sideward passage 1| (Fig. l) to the cylinder 33 to impress its force upon the top of differential piston 35 te produce a balanced pressure condition and hence canceling the return action of air beneath the button piston I0.

Some of the charge of air which enters the cylinder 33 passes through the hollow stem 31, via the port 11 and out into the, cylinder 43, where it impresses its force upon the top of power piston 4| to force down the rod 31 and piston 35 against. the piston I9. This forces rod 2| to push plunger into the cylinder 9 to eiiect a single discharge of lubricant therefrom. In the meantime air exhausts from beneath the piston 4| via passage 54. Fig. l illustrates the discharging position of parts. The air pressure in cylinder 33 and the air pressure in/ cylinder 3 being equal, the air pressure on opposite sides of the combined pistons I9 and 35 is equalized, thus leaving the full pressure on piston 4| without any back pressure to resist it in forcing the rod 2| through a discharging stroke.

Upon releasing the handle 65, the flow of air to the passage 59 is cut off by valve 5|, and thus flow is cut oi to the top of the power piston 4|. At the same time the valve 93 is opened so that the air in cylinder 43 above piston 4i may exhaust to cylinder 33 through stem 3'. and the air from cylinder 33 exhausts via port 1 passage 59,

the pressure in the hollow pcrtion 33 between pistons lil and 35 is exhausted through ports 49,

leakage whatsoever to the cylinder 33 from the cylinder 6. Thus another charge of lubricant is drawn or forced into said cylinder 9.

In View of the fact that pressure of air isy maintained behind the follower piston 25 and in the cylinder because of passage 19 leading from a point ahead of the valve 5I in communication with the inlet fitting 41, every time that an air line is attached to the fitting 41, priming air is immediately forced into the cylinder I behind the follower 25 and said pressure is released as soon as the air line is removed. Thus no reliance is placed upon holding an isolated charge of air in the cylinder I. Each time that a connection is made, the device is primed and made ready for a power stroke.

has been released that the pistons 4I and 35 will be always in return position (see dotted lines, Fig. '7) when the power unit isre-applied. Also, since the air hose is disconnected from fitting I1 prior to unscrewing the power unit, there will be zero pressure in the cylinders 6 and I upon their separation and after the power unit parts are in their Fig. '1 dotted-line positions.

Since the above is true, the piston I0 will be seen to have always been pushed part way out upon separation, whereby it is in a position tobe easily grasped for relling.

One of the advantages of the invention is that a lubricant service station may carry various a.,- semblies of lubricant-containing cylinders I, with lubricants of different kinds respectively therein, such as, for instance, water-pump lubricant, universal joint lubricant, chassis lubricant, and the like. For all of these, only one one-stroke air motor or power unit, such as shown in Fig. '1, needs to be carried, because said unit may be screwed into the diaphragm member 2 of any lubricant-carrying assembly. For instance, an operator may screw the power unit to a cylinder I carrying water pump lubricant and lubricate a water pump. Then, he may unscrew the power unit from said water-pump-lubricant-containing cylinder and apply it to a cylinder I containing, say universal joint lubricant, and proceed to lubricate such a joint. Thus a variety of supplies of lubricants are ready, and the user need purchase only one of the power units. In this respect, the present invention is an improvement upon the one described in said application. Furthermore, it is advantageous in comparison with other single power unit and multi-cylinder devices in that the power unit is of the single-shot variety which gives economy in dispensing and the connection is easier, simpler and more sure by reason of the mere abutment between members II! and 35 which are pneumatically held together.

Furthermore, the movement of assembling the power unit with the reservoir is all that is required to abut the pistons I0 and 35 for subsequent automatic operation.

One mode of filling the device is to connect a lubricant filler line to the inlet I1 and vforce lubricant therethrough against piston 25 which is thus automatically forced back. At this time there is no air line connected to the fitting 41 so that the air pressure behind the follower piston 25 is atmospheric and as the follower proceeds inwardly, the air is exhausted through port 19 and open fitting 41. The diaphragm 2 functions as a stop to automatically limit the travel of a follower piston 25 and consequently the charge of the lubricant.

Sometimes the user is not equipped with lling apparatus of the class above referred to. In this event he unscrews the power component shown in Fig. 7. The member 2 remains on the cylinder or barrel I. He also unscrews the outlet head 3 from said cylinder I. He then grasps the exposed button piston I!! and withback the latter.

It will be seen that since the power unit is uncoupled only after the lever f draws the rod 2I, thereby causing the shoulder I2 on said rod to contact the piston 25 to pull Then if the lower end of` the Y.

cylinder I is in a lubricant supply .I4 such as.v

shown in Fig. 6, the suction will draw in a charger of lubricant. A filler plate or apaddle mayalso be used as known.r After the charge is complete the head 3 is applied as sho-wn in Fig. 9. The

rod 2| may then be pushed back into its position Y within the cylinder I and the piston .25 will re-r tain its position at the upper end of the cylinder I. This is because the lubricant in' the cylinder blocks movement of the piston 25 with the head 3 in position. `Thereafter the assembly of cylinder I, outlet head 3 and diaphragm 2 is ready for use by applying a power unit. A group of these each having a different lubricant therein, may be kept in readiness, say in a rack.

The threaded connection between the cylinders 6, 33, I3and the member 29 is a permanentp'ne;

whereas the connection between said cylinder 5 and the diaphragm member 2 is a quick-detachable connection. The threads between the cylinder 6 and the diaphragm memberY 2 are relatively coarse and of a nature `to be easily started.. The

pattern on the member 29 is such that slippageH of the hand is prevented in rotating the motor unit, and the diaphragm member 2 is externally knurled. Usually the operator grips the knurled diaphragm member 2 with his left lhand and screws in the motor unit with the right hand.

In view of the above, it will be seen that the several objects of the invention are achieved and 1 l. In apparatus of the class described,v a-fluid y reservoir, a reciprocating pump at one end` of said reservoir adapted to withdraw lubricant;

from the reservoir and eject it, supporting means on the other end of the reservoir, an operating means passing from said pump through the reservoir and slidably through said supporting means, a follower dividing said reservoir into a lubricant compartment and an air compartment and surrounding said operating means, a control member on said operating means outside of said supporting means, an air power unit, quick-detachable means between said power unit and said supporting means, a movable part on said power unit adapted upon one stroke merely to abut said control member to move the operating means to eject lubricant, and means whereby said power unit applies air to the control member to effect reversal of movement of said control member to prime the pump and return the power unit to starting position.

2. In apparatus of the class described, a fluid reservoir, a reciprocating pump adapted to withdraw lubricant from the reservoir and eject it, an operating member passing from said pump and from the reservoir, a control member on said operating member located exteriorly of the reservoir, and a quick-detachable air power unit adapted to be fastened to said reservoir and having a part adapted merely to abut said control member to operate the pump to eject, and to apply air to said control member to operate the force back the abutting part on the power unit.

3. In apparatus of the class described, a fluid reservoir, a reciprocating pump adapted to Withdraw lubricant from the reservoir and eject it, an operating member passing from said pump and from the reservoir, a control member on said operating member located exteriorly of the reservoir, a follower in the reservoir movable by said operating member to draw in fluid, said control member being manually operable kfrom the outside of the reservoir, a power unit, a quick-de,- tachable connection between` the power unit and the reservoir, a pressure member in the power unit, said pressure member in the power unit being adapted to force said operating member on one stroke of the power unit, and said power unit having means to cause said operating member to force the driving means to starting position on the next stroke.

4. In apparatus of the class described, a uid reservoir, a reciprocating pump adapted to withdraw lubricant from the reservoir and eject it, an operating means passing from said pump through the reservoir and to a point outside thereof, a control member on said operating means outside of the reservoir and a quick-detachable power unit for the reservoir, means in the power unit adapted when attached to abut said control member to actuate the pump upon one power stro-ke, and means in the power unit adapted to empower the control member to force the parts in the power unit back to starting position.

5. In apparatus of the class described, a iiuid reservoir, a reciprocating pump adapted to withdraw lubricant from the reservoir and eject it, an operating member passing from said pump and from the reservoir, a control member on said operating means exteriorly of the reservoir, and a quick-detachable single-stroking pneumatic power unit adapted to be fastened to said reservoir and by its movement of attachment to abut with said control member, means whereby the pump is operated through said abutment by operation of the power unit, and means in said power unit energizing the control member to set the power unit to starting position.

6. In apparatus of the class described, a fluid reservoir, a reciprocating pump at one end of said reservoir adapted to withdraw lubricant from the reservoir and eject it, air-transmitting supporting means on the other end of the reservoir, an operating member passing from said pump through the reservoir and slidably through said supporting means, a follower dividing said reservoir into a lubricant compartment and an air compartment and surrounding said operating means, a control member on said operating means outside of said supporting means, an air motor, quick-detachable means between said air motor and said supporting means, the quick-detachable connection comprising an air-tight cylinder, an inside cylinder therein, a piston in said inside cylinder adapted to receive pressure to force said piston against said control member, said control member slidably itting said inside cylinder, whereby air in said air-tight cylinder will force the control member to cause said pump to eiect a suction stroke and force said motor to a starting position, said air also passing through said air transmitting support to said air compartment.

'7. In apparatus of the class described, a iiuid reservoir, a reciprocating pump at one end of said reservoir adapted to withdraw lubricant from the reservoir and eject it, air-transmitting sup-` porting means on the other end of the reservoir, an operating member passing from said pump through the reservoir and slidably through said supporting means, and a follower dividing said reservoir into a lubricant compartment and an air compartment and surrounding said operating means, a control member on said operating means outside of said reservoir, an air motor, quick-detachable means between said air motor and said supporting means, a cylinderon the motor, a piston in said cylinder adapted to'receive pressure to force said piston against said control member, said control member slidabiy fitting said cylinder, and means for actuating the air engine to move the control member in one direction and to apply air to the control member to move the engine in a reverse direction, said control member being separable from the air motor upon removal ofthe latter.

8. In apparatus of the class described, a fluid reservoir, a reciprocating pump adapted to withdraw lubricant from the reservoir and eject it upon suction and compression strokes respectively, an air motor having a quick-detachable connection with the reservoir for applying superatmospheric priming pressure inside of the reservoir and to the lubricant,'a power means in said air motor, a differential cylinder therein, a control piston in said diiierential cylinder reciprocating with the pump, a dilerential piston in said differential cylinder and reciprocating with the power means, said control piston cooperating with said differential piston means for introducing air pressure on the power means in a direction to drive the pump to an ejecting stroke and at the same time to the differential piston to balance pressure thereon from said control piston.

9. In apparatus of the class described, a'

fluid reservoir, a reciprocating pump adapted to withdraw lubricant from the reservoir and eject it upon suction and compression strokes respectively, and air motor having a quick-detachable connection with the reservoir for applying superatmospheric priming pressure inside of the reservoir and to the lubricant, a power means in said air motor, a differential cylinder therein, a control piston in said diierential cylinder reciprocating with the pump, a differential piston in said differential cylinder and reciprocating with Ythe power means, said control piston cooperating with said differential piston means` for introducing air pressure on the power means in a direction to drive the pump to an ejecting stroke and at the same time to the differential piston to balance pressure thereon from said con-v trol piston, and subsequently to exhaust the said introduced air and to introduce air to prime the reservoir and to press the control piston toward said differential piston to return the motor.

10. In apparatus of the class described, a pump, a lubricant supply chamber, a follower in said chamber, a separate air motor for operating said pump, a quick-detachable connection between said air motor and said supply chamber, a differential cylinder associated with said air motor, control means extending from the pump and adapted to t into said differential cylinder when the air motor is applied to the chamber, a differential piston carried by the air motor and in said differential cylinder and abutting said control means, and valved means on the motor adapted in one position of parts to direct air behind said follower and against said control means while effecting exhaust from the diierential piston, and in another position to direct air against the said differential piston and to the air motor to energize the abutting control means to operate the pump.

11. In apparatus of the class described, a pump, a lubricant supply chamber, a follower in said chamber, an extension from said pump passing through said follower, a piston head on said extension adapted to be reached to effect indrawing of the follower by pulling out the extension, an air motor, a quick-detachable connection between said air motor and said chamber, a differential cylinder associated with said air motor and slidably accommodating said piston head, a differential piston in said differential cylinder abutting said piston head, and valve means adapted in one position to direct air behind said follower and against said piston head to effect a suction stroke of the pumping means and priming thereof, and in another position thereof to direct air to effect a pumping stroke of the pump and at the same time to direct air above said differential piston to balance the pressure from the abutting piston head.

12. In apparatus of the class described, a lubricant supply compartment, a reciprocating pump adapted to withdraw and eject lubricant from said compartment, a follower in said compartment forming a lubricant chamber on the side nearest the pump and providing an air chamber on the other side, an extension movable with said pump, a control member carried by said extension, the arrangement between the follower and said control member being such that as the pump is driven by the control member through said extension to draw in a char-ge, said follower is driven to force the charge to the pump, an air engine, a quickdetachable connection between said air engine and said compartment, a differential cylinder on said engine, a surrounding air-tight cylinder for delivering air under pressure to said air chamber, a power piston, a differential piston in said diierential cylinder, and means joining said power piston and differential piston, said control member and differential piston merely abutting when the engine is assembled to the chamber, and valve means for introducing air to said differential piston and for introducing air to such side of the power piston as will force the pump to execute an ejecting stroke.

13. In apparatus of the class described, a lubricant supply compartment, a reciprocating pump adapted to withdraw and eject lubricant from said compartment, a follower in said compartment forming a lubricant chamber on the side nearest the pump and providing an air chamber on the other side, an extension movable with said pump, a control member carried by said extension, the arrangement between the follower and said control member being such that as the pump is driven by the control member through said extension to draw in a charge, said follower is driven to force the charge to the pump, an air engine, a quick-detachable connection between said air engine and said compartment, a differential cylinder on said engine, a surrounding airtight cylinder for delivering air under pressure to said air chamber, a power piston, a differential piston in said differential cylinder, and means joining said power piston and differential piston, said control member and differential piston merely abutting when the engine is assembled to the chamber, and Valve means'for introducing air to said differential piston and for introducing air to such side of the power piston as will force the pump to execute an ejecting stroke and alternatively for introducing air against the control member to effect a pump suction stroke and also against the follower.

i4. In apparatus of the class described,'a reservoir, a pump, operating means for said pump extending from said reservoir, a priming means for the pump cooperating with said operating means for iniilling of fluid, manual control means on the operating means exteriorly of the reservoir adapted to be manipuated to cause the oper-v ating means to move the priming means to effect an iniilling of the reservoir, and a power unit having a quick-detachable connection with said reservoir and adapted upon a manipulation to mo-ve said manual control means to effect a single ejection of lubricant and by another manipulation to power said control means to force the power unit and the pump to starting position.

15. In apparatus of the class described, a fluid reservoir, a reciprocating pump adapted tol withdraw lubricant from the reservoir and eject it, an operating member passing from said pump and from the reservoir, a control member on said operating member located exteriorly of the reservoir, and a quick-detachable air power unit adapted to be fastened tosaid reservoir, a part of the power unit abutting said control member whereby the control member may be forced to opera-te the pump to eject, and means in the power unit to apply air to said control member to operate the pump to return from ejection position and tc force back the abutting part on the power unit, said control member and said abutting part on the power unit having a pneumatic seaing connection at the abutment therebetween.

16. In apparatus of the class described, lubricant pumping means adapted to be primed with lubricant under pressure obtained from air under superatmospheric pressure, a member extending from the pumping means adapted to be controlled to effect pumping, a quick-detachable air motor for said lubricant pumping means, a driving piston in said motor, a driven piston, a cylinder surrounding said driven piston and slidably accommodating said controlled member, said controlled member and driven piston having a sealing abutment in the cylinder, and means for balancing super-atmospheric pressure on opposite sides of the sealed driven piston and controlled member while said pressure is applied to the lubricant pumping means for priming purposes and to the power piston for driving purposes, and means for exhausting pressure from the power piston and from one side of the organization of sealed driven piston and controlled member, whereby said priming air effects a return action cn the air motor by driving said sealed differential piston and controlled member.

FRANK Sl. BARKS.

VICTOR G. KLEIN.

Images