US1333382A

US1333382A - Compressor

Info

Publication number: US1333382A
Application number: US293561A
Authority: US
Inventors: Bruand Edouard
Original assignee: Individual
Current assignee: Individual
Priority date: 1919-04-29
Filing date: 1919-04-29
Publication date: 1920-03-09
Anticipated expiration: 1937-03-09

Description

Y v EQBRUAND. l l" l COMPRESSOR.

APRLICATION ILED APR.29| 19l9.

.7 SHEETS-SHEET 2.

' Patented Mf.9,'1920. 1 l

E. BRUAND.

COMPRESSOR.

APPLICATION FlLED APR. 2.9. |9l9.

3,333,382. Patented Mar. 9,1920.

A7 SHEETS-SHEET 4- Ill/l -l yl E. BRUAND.

' COMPHEQSOL DPLlcATloN FILED APR. 29. |919.

Patented Mar. 9, 1920.

E. BRUAND.

COMPRESSOR.

APyLlcATloN min APR, 29. ma.

PatntedMar. 9, 1920. 7 SHEETS- SHEET 6.

7 SHEETS-SHEET 7.

l l I o .30 Tag l. e6 7 9 l l w 15 5 i' 1 29p a .212

` A Ja@ Jaw@ l 3 I Y adda# l' O y am@ To all whom it may concern.'

Uivrriii STATES PATENT oFFioE..

EDOUARD BRUAND, 0F VILLENEUVE, SWITZERLAND.

COMPRESSOR; l

Specicatin of Letters Patent. Patented lVIaI. 9, 1920.

Application lcd April 29. 1919. Serial No; 293.561.

Be it known thatI, EDOUARD BRUAND, a citizen of Switzerland, residing at Villeneuve, Canton of Vaud, in the Confederation of Switzerlanth'have invented certain new and useful Improvements in and Relating to Compressors, of which theI following is a specification.

The subject matt-er of the present inven-l tion 1s a compressor.

It is distinguished from other known compressors by the fact that a double acting piston operates inside a cylinder and in the interior of which are contained a crank of a driving crank shaft and a connecting 'rod connecting the crank to the piston.

Its cylinder may be provided with a single suction valve at each end. The suction valves are for instance normally operated by a cam, but are capable of operation by other means when the pressure 1n the conn on the rollers.

The above arrangement may be operative automatically under the influence of the pressure of the compressed fluid. To this effect the member adapted to turn about the axis' of rotation of the cam acting on the rollers is operated, by way of example, in one direction by a pistonsubjected to the pressure of the compressed fluid and operated by the Y above pressure when the latter reaches the predetermined value, and in the other direction, by suitable return springs.l Furthermore this arrangement may be constructed so as to produce the opening of the suction valves during the com ression stroke of the piston, this opening taking place however in such a way that there is a slight compression at the end'of the stroke.

For instance the construction comprises,

on the one hand, a; piston serving, when-r subl jected to the action of the compressed luid,v to actuate the means for producingthe idle running of the compressor; on Athe A other comprise ranged one in the other and act independ- Grooves in a member adapted to turn4 hand, a resilient membrane subjected to the action' of the compressed fluid operates a control member, whereby either the atmospheric pressure or the pressure of the compressed luid acts on the piston. The con'- trol menibeigconsisting of a 'slide valve, is. connected to a lever on which are adapted to act, on one side of the axis about which Y said lever rotates, the resilient membrane, and on the other side a spring of adjustable tension; a piston, which is also connected to the lever, may be subjected to the action of the compressed fluid-in 'order to compensate entirely or partially for any end pull exerted by said fluid on the -slide valve.

The cylinder maybe provided with auj tomaticdelivery valves, each of which may two valve bodies which are arently of one another. n f

The cylinder may be provided with a system of lubrication under pressure and-a system for circulating cooling water around the bodyV thereof or 1n the heads thereof and around the seats of the suction and delivery valves. It may be cast in one piece with a base' of the compressor, which provides a space' for the fluid drawn in and channels.

for the compressed fluid, .as well .as for the cooling water. 2

- Y In the drawing:

Figure 1 is a side elevation of thecompresser comprising my present invention. f Fig. `2 is an end elevation of the same.

Fig. 3 is a plan ofthe compressor.

Fig. 4 is a central longitudinal vertical cross sectionof the compressor. y

Fig. 5 visa transverse cross section.

Fig. 6 is a sectional elevation of the partsfor operating the inlet valves.

- Fig. 7 is a sectional plan of the same.

Fig. 8 is a partial elevation illustrating the parts for operating the lintake valves with the same in a different position than that shown in Fig. 6. Y

Fig. 9 is a sectional'view illustrating the check valve employed inl the circulating system.'

Fig. 10'is a sectional view yillustrating the devices for controlling the flow ofthe lubricant. Y

Fig. 11 is a partial elevationillustrating Y the reservoir for the lubricant.V f v Fig. 12 is a sectional view illustrating the v. discharge passages,

Fig. 13 is a similar view illustrating the intake passages.

Fig. 11 is a side elevation illustrating the parts employed for automatically operating the intake valves. Fig. 15 is an enlarged central vertical sectionillustratng the parts for controlling the operation of the intake valves, and

f Fig. 16 is a sectional view of a modified form lof delivery valve. l

`The cylinder a (see Figs. 1 to 5) in this formof the invention is cast in one with a metal base and is provided with two removable heads al, a2 carrying the positively operated suction or inlet valves b1, 'b2 andthe automatic delivery valves c1, c2. cylinder there is a piston (Z which has two dissimilar-heads (l1, (Z2 of the same diameter :connected by a member Z3 of slightly smaller diameter and having lateral open ings d4, d5. YThrough the opening d5 passes a horizontal driving shaft e jou-rnaled in a bearing e2 which is carried by the cylinder a and is provided eXternally with a driving pulley, (not` shown A.in the drawing) and with a crank el placed inside the piston and connectedV by a connecting rod f to one of the heads Z2 thereof. A i

The air to be compressed enters the base through an inlet h1, passesinto the space h in the base (see Figs. 4, 5, 13) and passes by the ports 71, to the suction valves b1, b2. Each of these latter has a plate `b3 provided with arod' b* whichslides in a guide bf fixedl in an opening in the corresponding head al or a2.V Each rod b4 carries a washer be against which a spring 57 acts to close the valve and also against which an operating lever z'l or 1'? acts. Each lever il, i? is pivoted at to a bra-cket y' fixed to thecover a1 or a2 and is operated, notwithstanding the action of the springs 727 by a pusher 701 or k2,

(see alsoFigs. G and '7) of rectangul:ir-cross section, sliding in guides Z1 parallel with the axis of the cylinder a. .Each pusher is provided at that end opposite the levers i1 or with a roller 7c3 normally in contact with a' cam Z on the shaft e. A spring or other means (not shown) acts on the pushers to maintain contact beWeen the rollers 7a3 and the cam Z which operates the valve b1 or b2 to open the same atthe desired moment and also permits them to close again for the compression stroke.

I also employ devices so constructed as to automatically produce the opening of the suction valves 1, b2 during the compression stroke when the pressure in a reservoir into which the compressed. air is delivered attains a predetermined value. To this end a cam m (see Figs. "G, 7 and 8) is fixed on the shaft e behind the cani Zand is in contact with two rollers-yn.` diametrically opposite each other and mountedv .on spindles .nl adapted to move in radial guides o1 of a tric with the shaft e.

In thisV member 0 which rocks on-a bearing concen- The faces of the cams Z, m are designed in such a way that they1 may be included in one and the same member. W hen the member o is in the position shown in Fig. 6, the rollers vn are not in engagement with the rollers 7c3 and cannot eXert any action on them, so that these rollers 7c3 merely follow one face of the cams Z, m, but when the member 0 is moved to the positiony shown in Fig. 8 in which'the two guides o1 are horizontal, they interposc themselves at intervals between the rollers 7c3, which are wide enough to be able to be brought into contact with them, and the cam m and cause the opening of the suction valves b1, 712' during the suction and compression strokes. The face of the cam m is nevertheless so designed that a slight compression is produced at the en d of the stroke for the purpose of obviatingl blows'between the valves and the ends of the piston and to protect the joints at each change of direction of travel of the piston (I. The opening ot' the suction valves during the compression strokes causes a scavenging ofthe cylinder. The member 0 carries an arm o2 (see also Figs. 1, 3, and 7) in which is cut a slot 03 for a pin p1 secured to a piston p moving in a .cylinder 1], which by means of a pipe fr is in communication with a special apparatus for the control of the communicationY between cylinder q and the compressed air chamber and between the cylinder Vand the outside air.

The special apparatuslFigs. 1l and 15) comprises a base plate 20 fixed on cylinder r] by means of two forked arms 21 anda neck 2()2 screwed on to the pipe r. eck 2O2 is in constant communication with a passage 221 within a casting 22 fixed to the base plate 20 and provided with lateral ports 223` 224 leading into a cylinder 222 in the casting 22. In a cylindrical slide 23 fitted intosaid cylinder 222 there are provided passage ways 231 leading into a peripheral groove 23 whichis adapted to register with the port. holes 223. In'the lower position. of slide 23 (asrepresented in Fig. 15) the passage ways 231 are closed while when in a raised position rsaidways are open and the groove 232 registers with the port hole 223 so as to put the inside of cylinder f; into.communication with a passage 204 made in the base plate 2O and leading into a neck 20l connected by any suitable means with a compressed air chamber which is not shown in the drawing. IV-hen the slide 2?) is raised therefore the cylinder g is filled with compressed air. The portholes` 22%" are in constant communication' with a passage in the slide 23 in which there are also radial ports 23" by which an open passage is provided when in proper position into openings (not shown in the drawing) in the casting 22 and leading iso the upper position to fthe'initsideair. In the-'lower position ot the slide 2 3 the cylinderg istherefore` inf communication with tlieatmosphere.

`The slide is connected at 2-11`to one end ot' a lever24 piv'joted' in'242,tthe other end of said lever being provided with a screw 24f1" bearing by iiieansof capv 2,5xr

against. a spring 25 located within an open cup 2G which is part ofthe casting 22. [Normally the lifting a'ction ot' the'spring 25 is counterbalanced by a sliank'27 movable `in a guide V26,1 andl supported vby a`ublocl'281`:

rigidly attached to a diaphragm 28 against which the air-,pressure within passage 20 acts. Between the hinge 241 and shan'k`27 a rod 29 is hinged at 244 to the lei'fer24 saidrod being fast l to a, piston 291 .mounted in a cylinder casting 22.; .By meeting with the'heald 29?v of the cylinder 228'the piston 221 will stop the upWardinove-ment oi slide 23; Furthermore the upper face ot' 4 the piston. may be subjected Vto the pressure in the passagev 202 diie 'to the f actfthat vin ot' slide 23 the groove h232 communicates with aI port 22T 'connected by Va passage 221" 'and a port inside of eylindeij225. y' v The operation 4ot' this apparatus is as followsz.

The tension ot spring 25 is regulated by means of the screw 24E so a'stofcounteiw balance the vupward pressure of the jaiiyin. the passage 20'4 on diaphragm 28 when there 1 is a predetermined pressure in the coinaction ott-he compressed-air ivitliin' passage 20* which acts only against a smallsiirtace of said slide. Therefore :the inside of cylinder y]y `will communicate normally vwith the atmosphere through tlie`1` arts"r.202i 221,- "224, 233, 23, Spil'ingstA actingvonpinf )1 .maintain the piston p `^in the position inc 'i- (i aiidftli'erollers n are in their j that when tliecoinpressor is running normally. f "f At the moment when.hepre'ssurfof the rese'ryoir- Vand within the passage 20* reaches' thee predetermined' i'al'ue thej diap" riragrr'rA 28 iisesaiid carriestheslianlr '27 into 'Contact the' "lever by the shank-Pis substantially the same asfthatexertedjby- 228 which is also a part ofthe ofthe compressed aii" 22 with thev arev arranged f and of the arm o2( leverf 24', but the" pressure thus 'exertedv gainst ab' the spring 25 l.and consequently the lever 24 will `not'fbe moved. f

If" the pressure' exceeds the "predetermined value the pressure on the diaphragm 28 will begr-eater than that of spring 25 and thev lever 24j will `niove to compress the spring andraise the slide 23. After. the initial upward movement of the slide S23-the air'fr'onr passage 20* acts on agireatersurface. of the slide-and assists the "risingmoveme'nt As a result of-` this movement the lgroove. 23?v reaches the: poits 223 f' and 227. ,When theV port223' isz'luncvered the interior otcylinder y is put` inw communication-with thecom'- )ressed air vessel, and tlietpiston p is vmoved rom right to left'as illustrated,'and therollers n come between cani m and rollerslt-, l.

so that the compressor will stop feeding the air in to said vessel. uncovered the Acompressed air enters cylinder 22B 'acting' downward on thefpiston therein.

"Phisfpressureil will nearly fcounterbalance that against tliefbotwm tace-sidefof slide 23 When the .port 227 is i and-W il1v therefore not :interfere with the y sensitiveness ofthe apparatus. Y. f vf i "As soon'astlie pressure in the compressed air-vessel vfalls to its normal point the spring 25 .moves baekthe lever .2l and the slide 23 into ltheir former positions and the connection between the con'ipre-ssed air vessel and' the cylinder (j is cut' off and thelatteris ,put

into communication with the outside air so as' to permit the compressed air contained therein toescape ata speedwhich 1s` regulatedby a needle-valve 30; The springs s will returntlie nijei'iiber o to its .initial posi-'- tion and the` compressor then runs" norin'allyx;V

` {Regarding the air?` cylinder 22s outy along so' thaty slider 23 hasto `travel :ieertain distance iii passing from the posir-y tionl vwhere the cylinder y. communicates -witli'theoutside air to that invwliich it com-- municatcs with' `the Acoinpressed air-vessel.

without` delay'. Notwithstanding.this it is extremely sensitive for there vis bata short he base-.plate 20y and Y the cylinder 222. a; pa V:ingmay:beinterposed.

- The cams 75mandtliemember oare vcon- Itained nfaja-cket (see'Figs. 1, 3, 6, 7 )hav y Ving openings for tliepassage ofthe rollers Y.

*Each of the delivery `valves.f2-11,.c2fhas'a" sliding in `a screw-threaded pliigc5 thisevei'itually esca-pes by leakff :10b-I piston 291.v The various ports This is to' cause the apparatus :to operate plate 03 (see Fig. 4) provided ivithfa rod c* i cylindrical member.

taineiwrf1 castin one with the body of theH ends ofthe cylinder aare surrounded by,

water jackets fw; (see'Figs. l, 3,4) inlcommunication with .the water chambers w1 formed `in the heads and surrounding the valves. The inletand outlet of the cooling water take place `by `the ports'pw?l and w3. The jackets and the chamberspf the ftwo ends are connected by -tlieport w* inthe base and by the Vport on at the topl of Vthe The lubrication of the diiierentpartsl-of theV compressor isinsured by a reservoir a 20 (see Figs. 1,2, 3, 4, 5, 11) containing a lubri.- cant under pressure. This Vlatter has/,a concylinder a andata removable cover m2 held in place by winged screw plugs yengaging with screw threaded rods z screwed into the base of the reservoir. Into this latter'opens a passagel which starts from the left hand compression chamber and permits the desired pressure being obtained inV reservoir and this passageisprovided with a pointed rregulating screw :fi/and a non-returnyalve 9 (see also Fig. 2). From the reservoir run two ports each meet-ing outside afglass tube each glass tube 3 is connected to a passage l (see also Fig. 10) at each endof theic'ylindern, and serves for therlubricationthereof screws 5 permit thef-regulationof thev flow Y through these passages which is thus lconf vtrolled on'- itsfwayinthe tubes 3. Another glass tuber. permits-the level ofthe oil in lthe reservoir m to be seenat any moment. Finally there is a fourth glass tube` which .supplies the bearing c2, the-crank lpin and `the large end ot' theconnecting rod through a passage S and the medium of the pipe 9, 4connected to a passage boredin the interior of the crank shaft. v g

The oil in excessV in the cylinder a is sent back ragain intovthe reservoir *.:vby "an oil p pump 10 (see Figsfl, 3, 6), the `piston of The which is mounted on the pusher; k2.

'suction side ofl this pump is indicated at 11- land is connected by pipe 1 5 toa passage 1:6 (see alsoiFigQAyin the bottomv ofthe," "cylinder,under therbearing e2.. The' dis,`

"charge off the puinp is indicated at'lQ and is in coimmmicatioi. by a pipe 13 with an` Vinlet 'mt (see Fig. l) to the reservoir.' ,The ports-(Z4 in the pistoirwliich provide passage tothe head f of the connecting rod, prevent isX-:losingin anyl ofits positions the orifice ofthepassage 16. One ofthe screw plugs y with ajpres'sure gage 14, as shown in Figs.

may be provided 1 Bolts 17, 18 run from one end to the other sages u2, wJA and serve the purpose of tie rods.

' In consequence 'of the arrangement of the crank shaft e and the connecting rod 'k inside the piston (Z 4the compressor is double acting, but has neverthelessno stufiing box, and is relatively light becauseit has no piston rod, no cross-head, no slide bars, and no extension ofanykind (bayonet or spoon art) for it and the bearings for theV crank shaft.

The frame contains the'delivery passa-ges,

those for the passage of the cooling water and alsothe space providing passage for the air drawn in. p

v In order to avoid vibration arrangement may also be made for the axis of the cylinder to he comparatively low.

It the locality where the compressor is situated contains air which is sufficiently `pureand veryfresh, the'suction valves may open directly outward instead of being connected to passages such as lz; these latter are removable for this purpose.

In order to reduce as: much as possible the Waste space resulting from the thickness of the seat of the delivery lvalves,`the body of these latter may have at its'i center a hollowe'd out enlargement intended to partially till up this space but without howeverhindering the passage oftlie'compressed fluid.

If the compressor is of small power it Ymay be atl-vantagcolvls to divide the cylinder intopt'wo separated parts'on a through-running division-line perpendicularly to the axis of the cylinder and provided ywith grooves and tongues, flanges, nutfbolts and set-pins.' `Tlierelatively small weight of the `'single pieces will make transporting the same on mans back even on high mountains milch easier than a whole cylinder may be transported. l'

In the case of compressors with small output and therefore of small size the cylinder Vmight be left in one piece, but have a larger stroke than inthe case represented, lforthe same length of cylinder. lTo obtain this hollow parts forming parts ofthe cylinderkmight be provided vabove and below ythe axis of the cylinderin the path of the connecting-rod head, said hollows presenting Curved passages 1n the walls of the cylinder for letting pass the head of the connecting rod.

.In other cases the cylinder might present two. bores of different diameter, in the larger 1 membersl 32.33,instead. oiy one c3 as shown in Fig. Il.l VThe exterior member 32 may be fitted by means ofatlange 321 and a pack. ing b2 ony a seatl 32?..providedfwithinthe valve, cam

' shock .bv a cushioning effect.

end a? of the cylinder a. Said member is attached to a hollow rod 324 sliding Within a plug c and is subjected to the action of a spring c lodged in the rod1324 around arod 327 and bearing at one end on an open disk 325 located also Within 324 and at the'other end on a Washer 32s fixed to the plug of?.

The rod 327 is fitted with a piston. '3212 mov-V,

ing iii a cylinder 3211iy This member. 32fis provided with'a" seat 321 on which thesec.- ond "member, 33', is pressed byV aspring 36.

The member 33 is inone piece With a stem 331 slidably fitted into a bore 3211fyofnrxthe rod 324.

At the time of delivery of compressed air the piston l the member 32 is lifted from. its seat 323 against the actionfof the sprmg vce and that of the'. air inclosed in the upperY chamber of the cylinder`3213 and compressed by piston 3212, so that the 'stopping of said member occurs noiselessly and Without As the delivery of the latter member will not suflice, the member 33 will also be lifted from its seat 3210. and lifting movement is stopped noise-v lessly and without shock by the compression v4of the air inclosed within the bo're 321.1 of stem 331. The springs 0G, and 36 may be ing the; piston, an inlet*valve,

a discharge the inlet valve, :'andlmeans by -Which underl i predetermined Vconditions the. Vsaid vinlet cylinder,-

'valve is opened by the, Said Clm'leViCP/ dur'f lingl he compressionustroke ofthe piston.v

In a Vcompressor land incomb'ination, a

la' pistontherein, means for *operate-y the piston,` an inlet v valve, la discharge.

va v

e, carni vdevices for normally operating the inlet valveduring the suctionV stroke V of .the Piston; .determined-.conditionsthe said inlet valve f is opened by the said 'calin devices during the compression strokelrof the piston..

and means-.by which underpre- Ina compressor and'n-'combinatiom a cylinder, a piston'therem, means for operati. ing the pisto1 1, an inlet valve, a discharge v valve, can-1fdevices-"f'orv operating the inlet valve during the suction stroke of the pis-r ton, 4and cam devices controlled` by the pres- .V sure vdeveloped-by the compressor by which A Vthe 'said inlet valve'k is opened during 'the Y compression stroke ofthe piston When -the i 6s-,pressure has reached a predetermlned point.y

4, VIn a compressor and in combinationa v and in combinatioma cylindenr'a piston thereim'means for operat-l devices for normally operating cylinder and a double acting piston therein,l l

within which piston are contained a crank of a driving shaft and a connecting rod connecting the crank to the piston, suction valves normally operatedby a cam, means for. operating :the valves when the pressure lin a compressed fluid reservoirreaches a predetermined value, said vmeans?comprising' rollers rollingov'cra second cam andadapt- .ed to be moved aroundtheI latter cani', yet

continuing toy remain incontact' therewitli l Iso that-they may assume a position inxvhich ythe rollers act on, the valves.

- 5. In a compressorand in combination a cylinder and a` double actingl 'piston therein,l

Wit-hin which piston are contained acr'ank lof a driving shaft and a connecting rodv connectingthe crankto the piston, suction valves normally operated by a cam, rollers f rolling over a second cam and adapted to be moved around the lattercam, yet continuing to remain in contact therewitlnand 'spindles connectedy tothe rollers` and yv'vorking .in a` member ada ted to turn about theaXis' of rotation of t e latter cam. f Y i 6. In a compressor and in combination, a cylinder, a double acting piston therein` means for driving the piston, cylinder heads, intake valves n each of the cylinder heads,

,discharge valves in each of the cylinderV heads, cam devices for operating the intake 1valves during the suction stroke of the piston, and cam devices by which the intake valves are automatically opened during the compression stroke of the piston when the pressure developed by the compressor reaches a predetermined point..

7. In a compressor and'in combination a cylinder and 4a double acting piston therein,v vWithin which. piston'arejcontained a crank of a-driving shaft and a connectingl rod concontact therevvith,`y anda mem er connected tothe rollers, adaptedto turn about the axis nectingfthe crank to fthe piston, suction valves1 ,A

normally operated' cam,` rollers rolling y over 4afsecond cam-,Yandadapted to be moved v'around-the camfyetcontinuinV to remain 1n y1,10 i

of the cam and operated-in one direction by a piston subjectedto the pressure of `the, compressedrlluid, in theothergby one 'or-more re- Aturn' springs.`

8. Ina compressor and in combination a cylinder and 'a double acting piston therein,` :withinlwhich piston are contained a crank g'iof'a driving shaft and a connecting rod con- 'Fnecting the crank to the piston, suctionvalves A'normallyoperatedby ay cam, rollers rolling over a second'cam and adapted to be moved around the cam et continuing to remain in contact therewitli, a member connected lto axis of the cam, a piston operating the rollsure ofthe compressed fluid, and a resilient l1i`1emb' 'rane also subjected vto the pressure ofltherollers and adapted to turnl about the v ers when said piston is subjectedto the presbrane, on the other side a spring of adjust' the compressed fluid and actuating a control member by means of which either the atmos pheric pressure or the pressure of the compressed fluid acts on the piston.V

9. In a compressor and in combination a cylinderand adouble acting piston; therein, Within which piston are containedy a crank of a driving sha-ft anda connecting rod con'- necting the crank tothe piston, suction valves normally operated by a cam, rollers rolling over a second cani and adapted to be moved Y around the cam yet continuing to remain 1nA contactV therewith, a member connected to the rollers and adapted to turn about the axis of the calm, a piston operating the rollers when saidpiston is subjected to the pressure of a lcompressed fluid, and a resilientmembranealsosub'jected tothe pressure of the compressed fluid, a control slide valve operated by the resilient membrane and connected to a lever, on which act, on the one side of its axis of rotation, the resilient mem-f able tension, and a piston, also connected to the lever and adapted to subjected to the pressure of the compressed Huid. o

10. Ina, compressor and inrcombination a cylinder and a double acting 'piston therein. Within which are 'contained a1crank oit' a ldriving shafttand 'a connecting rod connectingthe crank to the piston, suction valves normally operated by a cam, and means `for also opera-ting said valveswhen the pressure in a compressed `fluid reservoir reaches a predetermined value, said means being' so arranged `that they produce the opening` of the suction valves during the delivery. stroke of the piston, this opening taking place howeyer in such a way that there is a small compression at the end of the stroke. -In testimonywhereof I have aiixed my signature in presence of two Witnesses.

Witnesses:

. RUSSEM LA CONVERSION,

JUs'r CANI).

EDOUARD BRU AND. y