US1708781A - Dispensing device for lubricants and the like - Google Patents

Description

April 9, 1929.

F. s. BARKs DISPENSING DEVICE FOR LUBRICANTS AND THE LIKE .En l

Filed Dec. 7, 1925 @www Patented Apr. 9, 1.929.k

NT orricE.

FRANK S. BARKS, OF= ST. LOUIS, MISSOURI.

Drsrnlvsrive. DEVICE Fon LUBnIcANTs AND 'm11 LIKE.

Application led. December rl`his invention relates to dispensing apparatus and with regardto certain more specific features to grease guns and the like.

Among the several objects of the invention may be noted the provision ,of a pneumatically operable hand gun for eejcting predetermined quant-ities of material .such as grease, the provision of a grease gun which is positivelyoperable at high pressure in any position thereof; the provision of a grease c gun of the type described which permits ready release of its delivery line from clogged and impassible oiling passages; the provision of a grease gun which provides means for removing grit and the like fromv delivered grease, and the provision of a device of the kind described which is simple irl-construction and not subjectto ready derangement, light in. weight and economical of manufac- 0-0 ture. Other objects willdbe in part obvious and in part pointed out hereinafter. a

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

In the accompanying drawings, in which is shown one of variouspossible embodiments of the invention,

' Fig; 1 is a top plan viewl of the gun;

Fig. 2 .is ,a longitudinall vert-ical section taken on line 2-2 of Fig. 1;

Fig. 3 'a lateral ve line 3-.3 of Fig. 2;

Fig. 4, is a 'horizontal section taken on line 4.-'1of Fig. 2; and f Fig. 5 shows the` application of a grease line to a receiving head. j

Similar referencecharacters indicate corv responding parts `throughout the several views of the drawings f Referring now more particularly to Fig. 1,

there is illustrated a casing or cylinder 1 made preferably of drawn tubing or the like. The

cylinder'l has a relatively smooth bore for# Areceiving slidable pistons. It is made fast, by means of a screw connection'or otherwise, to 50, a grip or handle casting 3. The grip casting4 3 is providedwith a proper counterboreL 5 for receiving the cylinder 1.

The grip 3jis provided with a preferablyvv vertical cylindrical passage 7 which passage is adapted to slidably but snugly receivel a cylindrical plug or valve 9. Thevalve 9 is proline 25 attached rt-i'calsection taken on 7,'1925. Serial No. 73,640.

may readily be depressed by an operators thumb when the handlev 19 of the grip 3 is grasped. A hole 21 in the grip3 is' provided for insertion of the operators pointerlfinger while his three remaining ones encircle the handle 19.

Returning to the construction of the valve 9, it should be noted that when it is depressed to its lowermost position (Fig. 3-)Qthat the head 17 encounters the grip A3. In this position the groove 11 aligns withsaid passage 15 23 formed in the and another inlet passage grip3 and in the plane of passage 15. The passage 23 is adapted to have a pressure air thereto (Fig. 1). )Hence when the valve is fully depressed, air will flow into and from passage 23, through the groove 11, and through passage 15 tothe interior of the cylinder 1. y 1

A spring 27 is placed beneath the valve 9 to into the valve longitudinally from the bottom and passing from the bore 7 by way of la smaller passage 31. The head 33 of the guide 29 limits the upward valve travel when the spring 27 acts. The said limitation is such as to bring 'the 'said groove 11 into alignment with the said upper 'passage 13 and an exhaust 17is greater. in diameter than the vbore 7 It l 1s clear from the drawings vthat. the head 17 raise it when thumb or like pressure is taken f therefrom.AV The upward travel of thevalve is limited by means of a beaded guide'29 screwed 90 passage 35 formed' in the same plane there- Y with. Hence, in the upper position of the valve, the inlet passage 23 is cut out of communication with the cylinder 1, while air may pass from said cylinder to the-atmosphere by way of passage 13, 'groov'e 11, and exhaust passage 35.

' The reason for leading compressed air into the head ofthe cylinder 1 is to press an operating piston Pwhich is fixed toga. rodl 45,

outwardly from the head end of the cylinder. against the pressure of a. spring 37. The

spring reacts from a socket or cup 39 which by means of a flange 41, abutsa rolled in ridge 43 on the inside of the cylinder 1.

The piston P is made fast to the head end of the piston rod or plunger 45 and comprises a leather sealing cup 47, a backing washer 49 and a buEer cup 51. These pieces are clamped to said rod 45 by means of a nut and collar clamping combination abutting a vproper shoulder in the rod 45. It may be noted that ton is at the head or left end of its str oke.

the flange of cup 5l reaches out farther than the flange of the leather cup 47, thereby preventing the edge of the leather cup from striking the casting 3 when the operating pis- Itis clear that when the valve 9 is depressed (Fig. 3) that air may rush into the head end of cylinder 1, thereby driving the -operating piston P to the right and compressing the spring`37. `When the valve is released (Fig.

2) air may leave the cylinder and does so, vdue to its ownvexpansiveforce, and is entirely cleared from the cylinder as the piston P is v,returnedto the left under the expansive action of spring 37.

The rod or plunger )45 is adapted to force grease and the like from the forward portion ,of^ cylinder 1. l1n order to accomplish this end, a head H is screwed or otherwise made fast to the right or tail end of cylinder 1. This head H is formed to comprise a ball check valve 53, a hollow cylindrical portion 55 leading to the check valve and a hollow l cylindrical portion 57 leading from the valve.

The portion 57 is crossed by a pin 59 for holding in place the conventional ball and spring of the check valve. Fastened to the portions 57 is a grease or material line 61 formed either l of flexible material or stiff material such as a length of flexible or ystiff tubing. Y

Flangedl to the portions of the head H :above enumerated is the counterbored cup 63 which affords the means for fastening the head to 'thecylinder 1. Cast or otherwiseI formed* with the cup 63 is a guide bearing 65. This bearing 65 is cast on legs or eXtensions 67 which are formed with the cup 63. By means of this construction a disc-like space is left between the bearing 65 and the cylindrical portion 55. As indicated in the drawings, the bearing 65 serves to guide the right-hand end of theL plunger into the bore of the cylindrical portion 55. TvVhen the pistonP is at the left-hand end of its stroke,

the end of the plunger 45 is located at the between the bearing and portion'55.. t This fact serves a useful purpose to be made clear.

Fitted over the legs 67 is a strainingcup 69. A by-pass 7l leads from the outlet side of the check valve 53 back into the space entween the bearing and rod is such that grease y between the two is not readily pushed out by relatively high air pressures.

The purpose of the loose piston N is to push grease (heldin cylinder l) to the right, as

quantities are fed from thehead H by the stroking of the plunger 45.A As the plunger 45 moves to theright the piston N is also forced to the right by means of the compression of air behind the piston N. The compression takes place as the piston P quickly moves to the right, thereby raising the air pressure in the chambexgbetween the two pistons. A small air bleeding passage 83 in said chamber serves purposes hereinafter to be described. lts size, however, is such that at the stated sudden rise in pressure in the chamber between the pistons, not enough air can escape to immediately lower the pressure to a vsubstantial degree.v It should be noted that the movement of the piston P tothe right takes place quickly` under action of the inrushing air from the line 25. A one-way leather check valve 79 between the pistons is lforced shutrat this time.l y

In the above ldescribed manner, at each stroke of the plunger 45, the piston N is caused to pack vgrease to the right end of cylinder 1, that is, to the point of ejection of the grease. v

When air is released from the valve 9, the piston P is forced tothe left by the spring 37.

.At this stage the built up pressure between the pistons may have dropped to that .of the atmosphere, due to air leakage from the bleeder port 83. Hence, as the piston Precedes'to the left air at atmospheric pressure is drawn in between the pistons by way of the leather check valve 79. By this means a new charge of air is drawn in to be compressed at the next pumping stroke and an evacuating action is prevented from taking place between the pistons'. Y Hence the piston N has substan-` tially no tendency tobe drawn rearwardly. Of cour-se the piston N is also moreor less prevented Vfrom-rearward movement by frietion between it and the cylinder l, and the fact that no air can enter the grease chamber to the right thereof. i

As stated, the fit between the bearing 7 5 and plu'nger45 is such that air cannot readily find its way through the bearing, though the air pressure to the rear of piston'N may be relatively high at periods. pockets of aiir' are prevented from 'being 'blown' in the grease of cylinder- 1.- These pockets, if permitted to form would gradually build up along the plunger 45, to finally By this means reach the chambers 55 and 57,

It is clear that the piston N, asy the-gun empties itself of grease, will gradually ap- Vproach the right-hand end of the cylinder l.

. In order to prevent throwing of the piston N5 from the cylinder 1 by operation of the gun I 'when the head H is removed, an integralridge 85 blocks further movement of the piston N. `A modified form of ridge may be employed. It may be rolled outwardlypand an spring ring'held therein. By this means the device is more readily disassembled for repairs and like operations. f

- Under the assumption that 'the loose piston N is in its ldotted line position B, shown in -F ig. 2, and that the head H is removed, the

, operation f the gun will be described. Un-

, R loose piston N travels toward the cup gradually forcing air out through the'small fio der the stated conditions, the air valve 9 may or may not be depressed, although it is preferable that it be notv depressed, whereby the piston P is at the left endl of its stroke. Y

To fill the open gun, grease is'merely forced into the right end of cylinder l, whereat thg bleeder openings4 -It moves with respect to the rod and cylinder 1. After the said operation, the head H with lits strainer cup 69 is appliedto the cylinder 1 the bearing 65' cooperating with the rod 45. The by-pass'valve 73is closed.- Upon depressing the thumbvalve 9, the rod 45 is moved tothe right as described. Air and grease or pure grease (depending upon how much grease was forcedinto the c ylindrical portion is forced from the check valve 53 into the cylinder 5,7 and line 61 to bedelivered to a bea-ring or holder.

The loose piston N, durinof this said operation, has beenv forced to theright, as dei scribed, to force grease through the strainer cup 61 and down around the rod 45 at the portion between the bearing 65 and portion 5 5.

Next, the valve-9 is manually released,

Vwhereupon the rod 45 returns to the left,

under action of spring 37 and due to the exhausting of air from the valve `9. The ball-I check' valve 53 closes automatically,.and as the right-hand end of the rod 45 reaches its left-hand position A, grease rushes into the hollow cylinder 55 'from all sides of .the end thereof, that is, from its previously annular position or sha-pe`around rod 45 and into the cylinder 55. By means of the construction described it is evident that little friction is encountered by the. grease -in entering the exhausted cylinder 55. It pours in from all angles and not through `a relatively restricted passage.

On( its return stroke to the left the rod 45 doesy not move the loose piston N with it. This is beca-use (a) air pressure between the pistons is at that of the atmosphere or over (b) no air can get cylinder 1 to the right of the piston N', and (c) piston N has frictional contact with the cylinder 1.

Upon next depressing the valve 9 the operation is repeated except that upon all strokes after' the firstone, the'operator is sure of receiving but little ai1 with the grease ejection from the gun, that is if it were filled without excessive air There are various obvious ways of so filling a gun. s

If the gun is loaded with grease carelessly relatively large air pockets (more or less connected) vrwill probably "be formed. These pockets may readily be eliminated by completely opening thevalve 7 3 and operating the gun one or more times. The piston N .then acts compressively on the grease whereby the pocketed air is driven or pumped out by way of either or both branches of the passage 71. Theaction is ysimilar to that which is had when the gun loses its prime except that the air is exhaus ed. 'When grease appears at the out-let ofA passage 71, the valve 73 maybe 'eplaced and the ,device isready for opera- The gun, asdescribed, may be successfully filledand/or operated'inany and all positions thereof. It should be noted that the volume of the cylindrical portion 55-is of a predetermined amount so that a predetermined weight of material is ejected at each stroke. By this means an operator may gage the amount fof material being used by the number of strokes required for filling a de-` vice. i

. It is also evidentthat the ratios of the areas of the operatingpiston P and the end of the plunger orrod 45 are such that unit pressures are multiplied. Several thousand pounds pressure per square inch is attainable in the line 61 with only a nominalair pressure on the piston P, and this with a practicable proportional construction of parts such as indicated in the drawings.

The line 6l is usually provided with a bayonet slottedtip 87 for cooperation with the pin 89 'of a grease receiving head 91. The

head 91 is provided lwith a ball check valve also. The head 91 is of tvhe type used in several ycommercial systems for greasing machinery.

pockets being in the grease.

llO

l At times the lines-connected with the head 91 become clogged, so that if the tip 87 is applied and the above described gun operated,l

It is to be understood that grease may be ejected directly from the passage 57 'of the gun or from the line G1 without the use of tips such as indicated at numeral 87.

In view of the above, it is believed that the various features of this invention Will -be clear Without further elaboration, and it will be seenv that with the apparatus herein described, the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above construction without departing from the scope of the invention, it is intended that vallmatter contained in the labove description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

,I claim: j p

1. A grease gun Comprising a cylinder vadapted to carry grease, a plunger therein adaptedv to be reciprocated, a head for said cylinder comprising a cylindrical portion into and out of which the plunger is adapted to travel,`a check valve associated with said portion, an outlet passage from the valve and a manually operable valved by-pass leading from said'outlet passage tothe first-named to the atmosphere from said manually operable means.

"2. A grease gun comprising a 'cylinder adapted to carry grease, a plunger therein adapted to be reeiprocated, means for reciprocating the'plunger comprisingan air operated pistonthereon in said cylinder, a valve for admitting air against the` piston andreleasing air therefrom3 and a spring adapted to return the piston when air is releasedha head for said cylinder comprising a cylindrical portion into and out of' which the .plunger is adapted to travel, a chec-lr valve" associated with said portion, an outlet passagefrom the valve and a valved by-pass leading from said outlet passagev tothe firstnamed cylinder, and means'for open-ing the by-pass tothe atmosphere.

3. A grease guncomprising a cylinder adapted to carry grease, a plunger therein adapted to be reciprocated to force grease from thel gun, a grip on the .cylinder Where by the gun may be grasped, means for reciprocating the plunger comprising an air operated pistonthereon in said cylinder, a valve in the grip adapted to be operated by the hand'on the Vgrip for admitting and releasing air against and from the piston, and a spring adapted to return the piston When the air is released at the valve, a head for said cylinder comprising a cylindrical portion into and out of which the plunger is adapted to travel, a check valve associated with sai'd. portion, an outlet passage from the valve and a valved by-pass leading from 4said outlet passa-ge to therst-namedcylinder,andmeans for opening the by-pass to the atmosphere.

4. A grease gun'comprising a cylinder'for. grease and the like, a reciprocating Jplunger for ejecting grease from the cylinder extending longitudinally through'the cylinder',-

an operating piston on the plunger adapted to reciprocate the plunger, means for reciprocating said piston, a loose piston on the plunger for packing grease toward the point ofv ejection under 'the compressive action of 'said operating piston on air between the pistons, means for trapping air between the pistons When the operating piston moves to eject,

anair inlet check valve adapted to feed airv -cylinder, and means for opening the -by-pass-` between the pistons to vprevent an evacuatingl FRANK s. BARKS.'

Vaction when the operating piston moves to ai

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