US2925148A - Lubricator for air-operated tool - Google Patents

Description

Feb. 16, 1960 J. R. MOSHER LUBRICATOR FOR AIR-OPERATED TOOL 2 Sheets-Sheet 1 Filed June 7. 195'? A TTOR/VEY Feb. 16,1960 J. R. MOSHER LUBRICATOR FOR AIR-OPERATED TOOL 2 SheetsSheet 2 Filed June 7, 195'? IN VENTOK.

JAMES R05 M08 ER ATTORNEY.

tad s Pfltefit' f r LUBRICATOR FOR AIR-OPERATED TOOL James Ross Mosher, Santa Clara, Calif., assignor to Bean Rubber Manufacturing Company, San Jose, Calif., 'a

corporation of California Application June 7, 1957, Serial No. 664,395

12 Claims. (Cl. 184-5'5) known has been that slugs of oil accumulated when the air compressor was shut down. The result was that when air was again supplied, the slug of oil was shot into the tool and splattered over the work and the workman, or flooded the tool mechanism. It is understandable, therefore, why many workmen and engineers did not like automatic lubrication and insisted on'manual lubrication (as by a push button or the like) of their fpneumatic tools. V

1 The trouble with manual lubrication wasthat the user Chad to remember to lubricate periodically bypushing the button or other meteringcontrol, or else the'tool would be burned out. Manyworkmen being somewhat forgetful, the result'wasfrequent damage to tools due to failure to press thebutton. Thus, one important object,

of the present invention isto provide an automatic lubricator with an automatic cutoff device which prevents the accumulation of excess oil anywhere in the line to the tool.

Another problem has been the difficulty in obtaining a regular metered feeding of the lubricant. Pneumatic hammers are noted for their jarring action, and the lubricators heretofore in use were affected by the pulsations. As a result they fed the lubricant. irregularly with the foreseeable consequences of improper lubrication. Therefore, another object of this invention is to provide a device that consistently feeds metered amounts of lubricant to the tool. This object is achieved by a structure which applies air pressure to the oil reservoir to maintain a force-feeding of the oil into the air line at a venturi. The pulsations that would affect the venturi are countered by the constant air pressure in the oil reservoir itself.

Another problem with the lubricant feeding devices of the past has been their delicate nature. Some of them have been made of glass while others have been made of light metals. Breakage and other damage has been common, which is not surprising, since the tools are used in conjunction with heavy construction equipment and since the operators have not been noted for handling this type of equipment with care.

The present invention provides an unusually rugged construction. The oil reservoir itself is made of a flexible, resilient synthetic rubber-like material of the oilresistant type, such as neoprene, and the lubricant metering mechanism is bonded and enclosed in the same package with the oil reservoir and with a portion of the air feed line, so that the entire lubricator is fully protected. While rugged, it is also simply constructed.

"Another problem with lubricators in use heretofore has 2,925,148 r Patented. Feb. 16, .1960

been that, because of their fragility, the lubricators were located remote from their associated pneumatic tool. As a result, the oil tended to coat the inside of the air hose and not to reach the pneumatic tool until the inside of the hose was fully coated. Also, pockets of oil were created where the hose followed an up-and-down path on its way to the tool. The present invention can be located immediately adjacent the pneumatic tool in the feed line leading directly to its cylinder. The lubricant is thus fed directly and immediately to the tool. Moreover, it is fed evenly in a metered fashion instead of in spurts, as was the case where the distance between the lubricator and the tool was great.

Another important advantage of the present construc tion is that the oil reservoir is united with the air-feed hose so that there is no possibility of losing it when storing the tool. Being flexible, the reservoir is more dur able and never damaged by normal conditions of use. If damaged at all, it is in conjunction with the air hose itself. Thus repairing is not delayed by ignorance of the damage.

Another advantage of the invention is the relatively light weight of the complete device, including both the oil reservoir and the metering mechanism.

Still another advantage is the fact that the flexible oil reservoir will go around corners, even though it holds a full eight-hours supply of oil.

Another object of the invention is to provide a metering device which can be easily connected and discon-' nected to the air circuit.

In general, the invention comprises a flexible housing of oil-resistant synthetic rubber in which are provided an air conduit and," parallel-thereto, an oil reservoir. A- meter'ing device'with automatic cutoff and automatic feed means is provided inside the flexible housing, bonded to it, and protected by it. This metering device provides an oil-feeding venturi interpositioned in the air conduit and passages connecting the venturi to the oil reservoir. Valves thatare actuated by the passage and non-passage of air through the conduit open and close this connecting passage and also meter theoil when it does pass into the venturi. The valves close as soon as the air stops flowing, and oil flows only when air flows. The air is also routed by the valves into the oil reservoir, where it applies pressure that aids in maintaining a consistent flow of pil into the air line when air is being applied to the too Other objects and advantages of the invention will appear from the following description of a preferred embodiment.

'In the drawings:

Fig. 1 is a view in side elevation and mostly in section of a lubricant metering, feeding, and storage device embodying the principles of the present invention, shown connected to the upper portion of a pneumatic tool, the rest of the tool having been broken off. Both the air line and the oil reservoir have been broken in the middle in order to conserve space.

Fig. 2 is a view in end elevation of a portion of the device, looking in the direction of the arrow 2 in Fig. 1.

Fig. 3 is a cross-sectional view taken along the line 33 in Fig. 1. i

Fig. 4 is an enlarged view in elevation and in section, taken along the line 44 in Fig. 2, of the metering portion of the device, shown in its closed position, which it assumes when no air is being supplied to the pneumatictool. However, the rubber housing is not shown here, inorder to show the metering device before the housing is molded about it. Three conduits are shown clamped to fittings on the metering device, the ends of these conduits being broken ofi to conserve space.

- Fig. 5 is a view of a portion of Fig. 4, but showing the metering device inits open, lubricant-feeding position, which it automatically assumes when air is supplied to the pneumatic tool.

Fig.5 is a viewofaportion of Fig. 4 enlarged still further to show details of the valves therein, the valves being'in their closed position.

Fig. 7 is an enlarged cross-section View of the filler end of the presentinventionh The device 10 incorporates.

an oil-resistant synthetic-rubber housing 11 enveloping a longitudinally extending air conduit 12 and an oil. reservoir 13 parallel to the conduit 12. The air conduit 12 is connected through a metering device 20 to a short air conduit 14 encased in a lower whip end of the housing 11. The conduit 14 has a terminal fitting 15 which is connected by an extended conduit 16. to a compressor (not shown). In other words, the device 10 is adapted to be attached between the main conduit 16 and the short conduit 8 at the upper end of the pneumatic tool. Both the air conduits 12 and 14 and the oil reservoir 13 preferably comprise wire-braided, rubber-lined hose encased in the housing 11, but they may be tubular openings through the housing 11. The oil reservoir 13 has a filler cap 17, at'itsnormally upper end and its normally lower. end. is connected to fitting 18 of the metering device Ztl. The tiller cap '17, is provided with an O-ring 19 to preventany oill eakage out through thethreads. Alsog'the female f tting 87 has atapered portion89 which allows a slow air leakas the cap 17 is being re-' moved, thus reducing the pressure gradually and pre venting any fpossible' injury to workmen.

re enera n t, a a

a the opening 24 has a smoo to the passage 31 at'the shoulder36 and an outer,

th-bore cylinder threaded portion 37.

The cylinders or bores 32 and 35 are connected together by a small-diameter passage 40, while the cylinder 35 is connected to the oil reservoir fitting 18 by two small passages 41 and 42. Theouter passage 41 serves to conduct air into the oil reservoir 13 where it subjects the oil to pneumatic pressure, while the inner passage 42, which lies between the passage 41 and the venturi 26, conducts oil from the oil reservoir 13 to the cylinder 35. The diameters of the bores 32 and'35, and especially of the bore35, may be varied to suit particular applications. The larger the diameter of' the bore 35 (and of the piston valve 70 therein) the lower the operating pressure may be; so the proper diameter can be determined when the line pressures of a particular application are known.

Preferably, 'the metering device '20 has a m etal-hous-i ing 21, though it may be r'na'de'from strong pl'asticor other suitable material, and is secured permahentlydn the housing-'1ll'g preferably-jby being; encased in f and bonded thereto at the time the housing -'11" is molded Normally the meter housing 21 is almost completely:

enclosed by th'erubber housing 11,'onl y one face 22 being uncoveredso as to give access to a pair of openings '23, 24. through which'the Working parts may be adjusted. lt 'will be noted that the novel borided-in connection o'f the housing 21 in the housing 11 assures a tight fit, insures against leakage of fluid, andprotects the housing 21 from damage. It will be appreciated that all moving valve parts of the .metering device 20 can begotten at from the outside, through the openings 23 and 24, without having to remove the metering device 20 from the housing 11.

The meter housing 21 is bored longitudinally to provide a through air passage 25 that alignswith and connects the air conduits 12 and 14 and incorporates as an integral part thereof a reduced-diameter venturi 26 between an inlet fitting 27 and an outlet fitting 28. .As used herein, the term venturi is also intended to include the full extent of thep-assageway between the fittings 27 and 28 Where the hoses or conduits 12 and 14 connected to the passageway are larger than thelatter. The two openings 23,. 24 extend widthwise of the housing 21, perpendiculartothe air conduit 25 and have respective portions 39 and 31 of greatly reduced diameter which intersect the conduit 25, the passage 31 leading directly into the venturi 26, the passage 30 preferably lying therebelow. Yet while better results are normally obtained where the passage 30 is connected between-the venturi-26 and'the inlet fitting 27, theentry to the pas- The bore 32 houses a check valve 44, While the cylinder or bore 35 houses an oil-metering valve 45, the two valves being linked together pneumatically.

The check valve 44 (see Fig. 6) includes a piston-like housing 50 with an outer, threaded portion 51 that engages the threaded portion 34. The housing 50 has an axial passage 52 therethrough with a reduced-diameter inlet passage 53 and an outer threaded end 54. A radial. passage 55 leads to a relieved annular portion 56 that connects with the passage 40. A pair of O-rings 57 and 53 provide an airtight seal.

A ball 69 is normally urged by a spring 61 against a seatu62 to close oif the air inlet 53, andis forced off the seat 62 to open the inlet 53 onlywhen air coming through the passage 3% buildsup sufficient pressureto' counteract the spring 61." Thepressureof the springfil may be adjusted to balance it for proper opening and closing with respect to the air pressure being used, by a stem 64 witha head 65 which isthreadedinto the portion 54, a gasketod sealing against passage 'of air.

Normally there is no need to adjust this pressure since I it can be done at the factory, but adjustment is possible without otherwise disturbing the. assembled metering de vice 20, by means of the opening 23"which is normally closed by a screw 67.

Thus, air coming into the conduit 14 under pressure will go through the passage 25. From there a smal'l fraction of it passes via the narrow conduit 30 int'ofthe bore 32 and exerts pressure against the ball 60, forcing it away from its seat 62. Some of this air can then pass around the. ball 6% into the axial passage 52 and fro'rn' there through the radial passage 55 into the passage 40. Upon the release of pressure (by turning oi}? the air to the conduit 14) the spring 61 restores the ball to the seat 62 immediately;vso the ball 60 operates as a check to prevent any back flow.

The metering valve 45 includes a hollow spool 70 pro.- vided with four sealing O-rings 71 and two relieved portions 72, 73, both sealed off by a pair ofthe O-rings 71.

i The spool 70 is yieldably urged toward the shoulder, 3 6

by a spring 74, the tension of which may be adjusted .by'

a nut 75 that also serves to close the opening 24. A'

to set the needle 78 at. the factory, and its position is ac:

curately. adjustable to meet the field conditions, oil viscosity, and tool requirements, its tapered forward end 80 being mounted in a tapered passageway 81 with adjustable clearance.

When the spool 70 is in the position shown .inFigsQA- and 6, it closes off the passage 41 from the passage .49 and a ts inroniunction with th hall c ek valve 441.

instantly prevent the passage of oil from the passage 42 into the passage 31 andto the venturi 26. It will be noted that the passage 31 between the needle valve 78 and the venturi 26 is very short; so it is not possible for oil to accumulate there in any significant amount.

The spool 70 is operated by pressure from the venturi 26 through the restricted pas sagejLand oearing against the spools inneP-end'SZ When air flows in the conduits 14 and 25, the pressure that builds up in the passage 31 pushes the spool 70 from its closed position shown in Figs. 4 and 6 to its open position shown in Fig. 5. I Then the relieved portion 72 communicates with the passage 41 and the relieved portion 73 communicates with the passage 42. Since the air pressure has simultaneously pushed the ball check valve 60 off its seat 62, air entering from the conduit 14 and flowing through the passage 25 will pass through the passage 30, through the check valve 44 to the conduit 40 and from there, via the relieved portion 72 into the conduit 41 and into the oil reservoir 13 to build up the pressure therein. It takes but a moment to build up the necessary pressure, at the most a few seconds, and once it is built up, it will not drop ofi rapidly, because of the small diameter of the passages 30, 31, 40, 41, 42, and the check valve 44, etc. Consequently, it will maintain a consistent pressure in the oil reservoir 13 even though the pressure of the air passing through the air conduits 14, 25, 26, 12 may be fluctuating or pulsating rapidly. This is an important feature of the invention, since it provides a steady pressure forcing the oil down into the metering value 45 at all times, even though reliance is made upon aventuri 26 to mix the oil with the air.

The oil is driven from the reservoir 13 into the passage 42 principally by the air pressure built up in the reservoir 13. This force is augmented somewhat by gravity. As

a result of the pressure, oil flows into the second relieved portion 73 of the spool 70 and'from thence by the radial passage 76 and axialpassage 77 into the metering orifice provided between the needle80 and the tapered seat 81.

From there it .flows directly :into the, venturi26 where tity larger than that permitted by the metered orifice 80,.

81 while the head of air in the oil reservoir 13 keeps an even pressure on the oil supplied to the metered orifice and assures a steady supply thereto. It will also be noted that the metering device 20 and the venturi 26 are located within about three feet of the pneumatictooLas against upwards of twenty or thirtyfeet in many lubricators heretofore on the market. r

- Reviewing the operation of the device: when the air pressure is ed, the check valve 44 is closed and the metering valve 45 is closed.- Even if there is air pressure in the oil reservoir 13 from previous action, there will be no flow of oil because the spool 70 is out of alignment with the passage 42. Upon the application of air to the pneumatic device, air will immediately pass into the passageway 30 to the ball check valve 60, push it off its seat 62, pass into the passage 40 to and around the relieved portion 72 of the spool valve 70 to the oil reservoir 13, where pressure is built up. It can do this because meantime the air pressure has moved the spool 70 outwardly to align the relieved portion 72 with the passages 40 and 41. Oil is then supplied under pressure via the passage 42 to the second relieved portion 73 and from there intothe metering orifice between the tapered needle 80 and thejtapered seat 81 into the passage 31 and from thence into the venturi 26 and'the air line12. It is thus mixed constantly with the air and gives consistent lubrication to the pneumatic tool.

The manufacture of the device 10 is also simple. The prepared metering valve 20 is connected to the three conduits 12, 13, and 14 comprising the air line and the oil reservoir. As stated earlier, these conduits 12, 13, and 141 are preferably wire-braided tubes with rubber lining,

althoughany suitable rubber-lined hose may be used.'

CIampsSS are used to provide a tight engagement with. U.

of the liousing21 and conduits 12, 13, and 14 and outer end fittings 87, 88 is then placed in a mold and the housing 11 is molded around them, bonding itself to them and sealing against leakage.

The metering device 20 is rugged and simple and it is protected from damage by its encasement in. the housing 11. Being located immediately adjacent the tool, the lubricator 10 does not have the drawbacks inherent in remote lubricators. Being not only rugged but also resilient, it is not subject to damage from the normal, hard conditions of use. It can survive being run over by trucks, being dropped on the pavement, and so on. At the same time, it is automatic and practically foolproof.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit andscope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting. For example, the tool is not limited to use with lubricating oil, and where the term oil is used, it is intended to include other suitable materials which are capable of being similarly fed in to a line.

I claim:

1. A lubricator fora pneumatic tool including in combination: a casing having an air conduit and an oil reservoir,: said conduit having a venturi; pressure-supplying means for said reservoir connecting said conduit to said reservoir when \andonly when there is air pressure in said conduit; separate oilconduit means connecting said venturi to said reservoir when only when there are both pressure in said reservoir and airpassing through said venturi; and metering means in said oil conduit means for limiting the amount of oil passing into said venturi.

. 2. A lubricator for a pneumatic tool including in combination: a resilient casing having an air conduit therethrough and an oil reservoir; a rigid housing supported by said casing and providing aventuri in said air conduit, said housing also having a first passage opening into said air conduit and leading air to said reservoir, a second passage opening into said venturi and conducting oil thereto from said reservoir; an air-responsive check valve normally closing said first passage but opening it when air pressure is supplied to said conduit; metering means in said second passage for governing the amount of oil supplied to said venturi; and air-responsive valve means normally closing off said second passage but operable by air pressure in said second passage from said venturi to open said second passage, so that during operation of said pneumatic tool air opens said check valve and flows into said oil reservoir to build up pressure therein, and moves said valve means to open said second passage for sending oil from said reservoir into said venturi in pressure-impelled metered amounts.

3. A lubricator for a pneumatic tool, including in combination: an oil-resistant, synthetic rubber casing having an air conduit therethrough and an oil reservoir therein;

a rigid housing bonded into said rubber casing and havervoir, and a second passageway connecting said second passage to said oil reservoir; an air-responsive check valve normally closing 011 said first passageway from said first passage but connecting them when air pressure is supplied to said first passage; metering means between .Sfiid second passageway and said second passage for:

a overnin he am u t. f oi that can; be forced theret-hrwsh; d respon e al 'meansnorm lly cl ias r tdmeterinam s rom said sec nd. pas ageway but operable-byair pressureiinsaid second passage to connectthem, so that during operation of saidpneumatic ply oil in metered amounts to said tool via the air that 15,

operates said tool, said lubricator including in combination: an oil-resistant, synthetic rubber casing having a firstair conduit therethrough and an oil: reservoir parallel to said air conduit; a control device having a rigid housing bonded into said'rubber casing, said housing having a second air conduit in and as part of said first a-ir conduit and having a venturi, an inlet end, and an outlet end, said housing also having a first passage openin-ginto said second air conduit; on the inlet side of said venturi, a second passage opening into said venturi, a first passageway connecting said first and second passages, and second and third passageways connectingsaid second passage to said oil reservoir, said device also having a check valve closing off said first passageway from said first passage in the absence of air pressurefin said first passage and connecting them when airris supplied to said first passage under pressure, as during operation'of, said pneumatic tool, metering means between'said third pas-- sagewayand said second passage for governing the amount of oil that can be forcedgtherethrough, and valve,

means normally closingoft said-metering means from said third passageway and ;-normally closing oifv said,

second, passageway from said firstpassageway, but operable byjair pressure in said'second passage, as during 8 7 through and an oilreserv'oir parallel to said air conduit: a'rigid housing bonded into said rubber casing and en-, closed on all except one face thereo'f, said'housing' hav ing a second air conduit interposed in and as part of said first air conduit, and having a venturi, aninlet. end,'an'd an'ffoutl-et-wnd, Said, housing also. having a, first passage 7 opening from said one face into said second air conduit operation of said pneumatic tool, for-passing air from 4 said first, passageway through said second passageway into said oil reservoir: to build uppressure therein, and for connecting said third passageway. to said metering means for sending oil: into said venturi in pressureimpelled'metered amounts for conveyance to said'tool by the air passing through said first air, conduit.

5. A shock-resistant and flexible lubricator ,adaptedto supply a pneumatic tool with metered amounts of lubricant via the air that operates said tool, said lubricator, including in combination: an elongated oil-resistant, syn:- thetic rubber casing having a first air conduit therethrough, an oil reservoir generally parallel to said air conduit, and a; recess adjacent one end of said reservoir; a rigid housing in said recess and bonded to said casing, said housing having a second air conduit interposed in and as part of said first air conduit and having a venturi, first passage means leading from said second air conduit to said reservoir and second passage means leading from said reservoir into said venturi; check valve means closing said first passage means in the absence of air pressure in said second air conduit and opening said passage means when air is supplied to said second air conduit under pressure, as during operation of said pneumatic tool; metering 'means in said second passage means for governing the amount of oil that passes therethrough; and valvetrneans normally closing oil said metering means from said reservoir and operated by air pressure coming through said second passage means from said venturi to open said second passage and send oil into said venturi in pressureimpelled metered amounts.

6. A lubricator for use between a source of pneumatic pressure and atpneurnatic tool to supply the tool with metered amounts of oil, said lubricator includingin combination: an elongated, unitary, oil-resistant, flexible, syntheticvrubber casing havinga first air conduit thereon the inlet, side of said venturi, aseco'nd passageirom said one face opening into said venturi,'a first passageway connecting said first and second passages, and second and third passageways connecting said second pas-. sage to said oil reservoir, said third passageway'lying inter-L mediate said second passageway and said venturi; means closing said first and second passages at said one face; a; ball check valve; a spring urging said'ball check'valve to close o'r'f said first passageway from said first passage, said spring being yieldable when there is pneumatic pressure in said first passage so: that said valve will then be forced open; a spool valve in said second passage hav ing two annular relieved portions adapted respectively so that in an open position one joins said first and second passageways and the other aligns with said third passage! way, said spo'ol valve also having an axial passage and: a radial passage connecting said other relieved portion to said axial passage; spring means normally forcing said spool valve to a closed position, but yieldable to air pressure against said spool valve from said second passage, as during operation of said pneumatic tool, for moving said spool valve to. saidopen position; and a needle valve in said axial passage for governing the fiow of oil" from said reservoir to said venturi'when said spool valve is in its open position.

i 7; A lubricator foruse between a source of pneumatic pressure and pneumatic 'tool to supply'the' toolfwith metered 'amounts'of oil, said lubricator including" in combination: a unitary, oil-resistant, flexible, synthetic rubber casing having a first air conduit therethro'ugh' and an oil' reservoir therein; a rigid housing bonded into: said rubber casing, said housing having a second air conduit interposedin and aspart of said first air conduit and pro viding aventuri, saidhousing also having a first passage opening at onetend into said second an conduit and closed at the other end, a second passage opening at one end into said venturi and closed at the other end, a first passageway connecting said first and second passages, and" second and third passageways connecting said second passage to said oil reservoir, said third passageway lying intermediate said second passageway and said venturij a" check valve in said first passage adjacent a seat therein; a spring urging said check valve to close against said seat to prevent air and oil from passing to said first passageway from said first passage, said spring being yieldable when pneumatic pressure is exerted against said check valve through said first passage so that said valve will then be forced open; a spool valve in said second passage having two annular relieved portions adapted respectively so that in an open position one joins said first and second passageways and the other aligns with said third passage way,'said spool valve also having an axial passage and aradial passage connecting said otherrelieved portion to said axial passage; spring means normally forcing saidspool valve to a closed position, but'yieldable'to airpressure against said spool valve from said secondpas sage, as during operation of said pneumatic tool, for

reservoir when and only when there are both pressure in said reservoir and air passing through said venturi; and metering means in said oil conduit means for limiting the amount of oil passing into said venturi.

9. A lubricator control valve for a pneumatic tool for use in combination with an air conduit and an oil reservoir, comprising a housing providing a venturi in said air conduit, said housing also having a first passage adapted for connection between said conduit and said reservoir for conducting air from said conduit to said reservoir, a second passage opening into said venturi and adapted for connection to said reservoir for conducting oil to said venturi from said reservoir; an air-responsive check valve normally closing said first passage but opening it when air pressure is supplied from said conduit; metering means in said second passage for governing the amount of oil supplied to said venturi; and air-responsive valve means normally closing ofif said second passage but operable by air pressure in said second passage from said venturi to open said second passage, so that during operation of said pneumatic tool air o'pens said check valve and flows into said oil reservoir to build up pressure therein, and moves said valve means to open said second passage for sending oil from reservoir into said venturi in pressure-impelled metered amounts.

10. A control device for a pneumatic-tool lubricator adapted to be inserted in an air conduit between a source of pneumatic pressure and a pneumatic tool and adjacent an oil reservon, said device including in combination: a rigid housing having a venturi passage adapted to be interposed inand be part of said air conduit, said housing also having a first passage adapted to open at one end into said air conduit and to open at its other end into said reservoir, 9. second passage adapted to open at one end into said reservoir and opening at its other end into said venturi; a check valve closing said first passage in the absence of air pressure from said air conduit end and opening it when air is supplied to said first passage under pressure, as during operation of said pneumatic tool; metering means in said second passage for governing the amount of oil that can be forced therethrough; and valve means normally closing ofi said second passage between said metering means and said reservoir but opening by air pressure in said second passage from said venturi, as during operation of saidv pneumatic tool, for sending oil into said venturi in pressure-impelled metered amounts.

11. A control device for a pneumatic-tool lubricator adapted to be inserted in an air conduit between a source of pneumatic pressure and a pneumatic tool and adjacent an oil reservoir, said device including in combination: a rigid housing having a venturi passage adapted to be interposed in and be part of said air conduit, said housing also having a first passage adapted to open into said air conduit, a second passage opening into said venturi, a first passageway connecting said first and second 10 passages, and second and third passageways adapted to connect said second passage to said oil reservoir; a check valve closing off said first passageway from said first passage in the absence of air pressure in said first passage and connecting them when air is suppliedto said first passage under pressure, as during operation of said pneumatic tool; metering means between said third passageway and second passage for governing the amount of oil that can be forced therethrough; and valve means nor mally closing off said metering means from said third passageway and normally closing off said second passageway from said first passageway, but operable by air pressure in said second passage, as during operation of said pneumatic tool, for passing air from said first passageway through said second passageway into said oil reservoir to build up oil pressure therein, and for connecting said third passageway to said metering means for sending oil into said venturi in pressure-impelled metered amounts.

12. A lubricator control device for a pneumatic tool where there is an air conduit and an oil reservoir, including in combination: a housing having a venturi adapted to be interposed in said air conduit, said housing also having a first passage closed at one end and adapted to open at its other end into said air conduit, a second passage closed at one end and opening into said venturi, a first passageway connecting said first and second passages, and second and third passageways adapted to connect said second passage to said oil reservoir, said third passageway lying intermediate said second passageway and said venturi; a ball check valve; a spring urging said ball check valve to close off said first passageway from said first passage, said spring being yieldable when there is pneumatic pressure in said first passage so that said valve will then be forced open; a spool valve in said second passage having two annular relieved portions adapted respectively so that in an open position one joins said first and second passageways and the other aligns with said third passageway, said spool valve also having an axial passage and a radial passage connecting said other relieved portion to said axial passage; spring means normally forcing said spool valve to a closed position, but yieldable to air pressure against said spool valve from said second passage, as during operation of said pneumatic tool, for moving said spool valve to said open positron; and a needle valve in said axial passage for governing the flow of oil from said reservoir to said venturi when said spool valve is in its open position.

References Cited in the file of this patent UNITED STATES PATENTS 1,757,084 Hansen May 6, 1930 2,501,372 Benson Mar. 21, 1950 2,571,098 Arnold Oct. 16, 1951 2,640,561 McGushin June 2, 1953 2,687,187 Lake Aug. 24, 1954

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