Патент USA US2128937код для вставки
Sept. 6, 1938. 2, 1, 28,937 W. B.’ HALE LONG STROKE HORIZONTAL TYPE AIR COMPRESSOR Filed March 17, 1936 3 Sheets-Sheet l} J5 IIVENTOR. ‘ 1 ATTORNEYS Sept. 6, 1938. w. B. HALE 2,128,937 LONG- S'I'ROKE HORIZONTAL TYPE AIR COMPRESSOR Filed March 17, 1936 3 Sheets-Sheet 2 (—|—\q BY 5% M , A'r'roRNEYs Sept. 6, 1938. w. B. HALE‘ 2,128,937 LONG STROKE HORIZONTAL TYPE AIR ‘COMPRESSOR Filied March 17, 1956 - 6 v 59 \ n\:n ‘I :1 ' m 40 , s Sheets-Sheet 5 41 1 rrk-?Tn \1’ h . V z\ _ <-— 5 20 22 - 4» L . ‘é / " ,5 94 ‘20 fa‘? PM kuxm v" I 2,128,937 Patented Sept. 6, 1938 UNITED STATES PATENT OFFICE 2,128,937 LONG STROKE HORIZONTAL TYPE AIR COMPRESSOR William B. Hale, Huntington Park, Calif., as signor to New Type Air Compressor Company, Huntington Park, Calif., a corporation of Ne vada Application March 17, 1936, Serial No. 69,312 15 Claims. (Cl. 230-185) This invention relates to gas compressors, and while the invention may be embodied in machines for compressing gases for any purpose whatever, in the present speci?cation the invention is de 5 scribed as applied to an air compressor, and par ticularly to a multiple-stage or two-stage com pressor of the reciprocating type. Most compressors of the reciprocating type operate at high piston speed, and have a rela 10 tively short stroke. As there is a limit to speed at which air will flow into the compression cylin der, due to the high speed of the piston there is insufficient time permitted for the cylinder to re ceive a full charge of air at atmospheric pressure .before the piston commences its return stroke to compress the charge. This occasions a loss in e?iciency. Furthermore, air in being com pressed becomes heated, and in a high speed compressor very little time elapses in each com :20 pression stroke, so that there is little time for the air being compressed to be cooled. In the operation of two-stage or multiple-stage com aligned cylinders, and these cylinders are pref- ' erably of di?erent diameters, the larger cylinder being employed in the ?rst-stage of the com pression, while the smaller cylinder is employed in the second stage. Between these cylinders a long-stroke chain drive is employed with means for driving the chain through the medium of a small motor such as an electric motor. One of the objects of the invention is to provide simple means for mounting the endless chain or chains of the drivingapparatus for reciprocating the cross-head to which the piston rods are attached, and to provide simple means for enabling ad justments of the standards or bearings for the sprocket wheels that support the chains, to be effected. The compressor is preferably of the horizontal type, the cross-head being provided with a ver tical slot which is driven by a wrist carried on the endless chain drive; and one of the objects of the invention is to provide an improved con struction for the driving wrist of the cross-head, and improved means for connecting it to the pressors heretofore, it has been the practice to provide inter-coolers for cooling the air between the compression stages, and this is usually ac driving chains. complished by circulating the air through metal coils such as copper coils surrounded with circu the general construction of two-stage air com pressors of a horizontal reciprocating type. lating water. One of the objects of the present invention is hereinafter. 30 to provide a gas compressor or air compressor A further object of the invention is to improve ' Further objects of the invention will appear The invention consists in the novel parts and of simple construction, having a relatively long combination of parts to be described hereinafter, stroke as compared with the diameter of the cyl inder in which the gas or air is compressed, and capable .of operating at a relatively slow piston 35 speed, allowing more time to be consumed on the intake stroke of the piston, to the end that the cylinder will be fully charged with air at substan .all of which contribute to produce an ef?cient tially atmospheric pressure before the compres sion stroke begins. _ Furthermore, compressors of the reciprocat 40 ing type that operate at a relatively high piston speed, have a relatively low e?iciency due to the relatively great number of strokes of the piston, for the reason that the effects of the fraction representing the volumetric efficiency becomes ' J multiplied. One of the objects of this invention is to produce a compressor of this type that will overcome this objection. A further object of the invention is to provide 50 simple means for cooling the compression cylin ders, and for cooling the air between the com pression stages without necessitating the use of circulating water, or fan. In its preferred ‘construction the compressor ;)5 involves the use of two oppositely disposed long stroke horizontal type air compressor. A preferred embodiment of the invention is de scribed in the following speci?cation, while the broad scope of the invention is pointed out in the appended claims. In the drawings: Figure l is a side elevation of an air com pressor embodying my invention, and also illus trating the air tank connected up to the com ‘pressor to be charged with air. Fig. 2 is a plan of the compressor illustrated in Fig. 1, but with the motor omitted. Fig. 3 is a vertical section through the com pressor taken about on the line 3-3 of Fig. 4. Fig. 4 is a horizontal section taken through the compressor on the line 4—4 of Fig. 3; in this view certain parts are broken away, and the inter cooler is represented also in longitudinal section. Fig. 5 is a vertical cross-section taken about on the line 5—5 of Fig. 3 but upon an enlarged scale, and particularly illustrating the mounting for the driving mechanism of the compressor. Fig. 6 is a side elevation of the assembly of parts 55 ‘2,128,937 to be connected as one piece, into the endless chain or chains of the compressor, for driving the cross head. the shafts 33 of sprocket wheels 34 that carry the sprocket chains 2|. The standard bearings 24 are preferably held in a ?xedposition while the stand ards 31 are preferably mounted for adjustment to Fig. 7 is a cross-section taken on the line T—‘| of enable the slack of the chains- 2! to be taken up as Fig. 6, and further illustrating details of the con struction of this Wrist. This view also shows the the same become stretched. All of the standard bearings are supported on a base plate 35 that ?anged roller sleeve in cross-section, which is car ried by the wrist. This roller sleeve is omitted in ' forms the bottom for the central chamber 29, and in order to hold the standard bearings securely in Fig. 6. Fig. 8 is a fragmentary vertical section taken position, their bottom faces 36 are provided with 10 grooves 31 that engage over a longitudinal key 38, about on the line 8—8 of Fig. 3, and further illus trating details of the means for mounting the which is set in the upper side of the base plate adjustable standards that support the endless (see Fig. 5). The standards 25 have flat upper faces 39 that rest against the under face of the chains. ‘ Fig. 9 is an end view of the parts shown in Fig. 6, cover plate 40 of the chamber 29, so that when 15 that is to say it shows the end of the driving wrist this cover plate is clamped down by means of bolts and short portions of the driving chain broken 4i, these standards will be held securely in posi— tion. away. The adjustable standards 3|, however, are ca Referring more particularly to the parts, and pable of sliding on the guide tongues or keys 38, 20 20 especially to Fig. 1, l indicates a tank about which and in order to enable them to be adjusted toward a rudimentary frame 2 is built, said frame sup or from the ?xed standards 24, their upper ends porting a compressor 3. are provided with bolts 42 that extend down The casing of the compressor preferably in cludes a central box-form body 4 through which .a 25 countershaft 5 extends, said countershaft being provided on one end outside of the casing with a pulley or sprocket wheel 5 driven by a belt or sprocket chain 7 which, in turn is driven by the pulley or sprocket wheel 8 on the shaft 9 of a 30 motor Ill, preferably an electric motor. The box-form body 5 of the casing preferably has vertical end walls I i and i2, which have open ings l3 in them, which operate as seats for the inner ends of the compression cylinders 14 and l5, 35 the former of which is of relatively large diam eter, and is the ?rst-stage cylinder, while the through slots 43 formed in the cover plate, so that when the cover plate is bolted down the standard 25 will be clamped between the base plate 35 and the cover. Clamping bolts 45 are provided in the base plate 35, that pass down through slots 45a in the bases 46 of the standards 3|, being received in threaded openings 46a, in the base plate 35, (see Fig. 5). The base plate 35 may be provided with four feet or legs 48 that may be secured by bolts to the upper side bars of the frame 2 (see Fig. 1). Pistons l5 and IT are preferably provided with 35 substantially gas-tight rings 59, and are prefer latter is of relatively small diameter and is the ably mounted for adjustment on the ends of the second-stage cylinder. In these cylinders pistons piston rod sections Ila and Nb. For this purpose the ends of these rods have threaded necks 5| of reduced diameter, received in threaded openings 40 in the pistons, and the pistons can be clamped rigidly in any adjusted position desired, by means 16 and if reciprocate, said cylinders being con 40 nected by a piston rod formed in sections Ila- and lib, which connect up to a cross-head l8, said cross-head being preferably constructed of two oppositely disposed yokes with ?anges i9 that are bolted together, and these yokes cooperate to form 45 a vertical guide slot 20 for connection to the driv ing means to reciprocate the pistons. The construction for reciprocating the pistons, preferably includes an endless drive chain device including two oppositely disposed endless chains 50 2!, which, toward the high pressure end of the of set screws 52. The cylinder I4 is provided at its outer end with a low pressure cylinder head 53 provided 45 with an inlet 54 for admitting the gas or air that is to be compressed. This head is formed with a transverse web 55 that divides its interior into an inlet valve chamber 56 and an outlet valve chamber 51, and these chambers are provided 50 compressor are carried on two assemblies of with an inlet valve 58 and an outlet valve 59 re sprocket wheel and shaft including sprocket wheels 22, and horizontal shafts 23, and these spectively. These valves are preferably of the poppet type with springs as illustrated. The outer end of the high pressure cylinder I5 shafts are mounted in two standards or bearings 55 24, each of these standards or bearings preferably comprising two upwardly extending posts 25. The sprocket shafts 23 are preferably mounted in ball bearings 26 Within the posts, and each sprocket shaft carries a rigid gear wheel or pinion 21 held 60 between the standards of the corresponding is provided with a suitable high pressure head 60, . and this head is divided by a central web similar to the web 55 into an inlet valve chamber BI and an outlet valve chamber 62, said chambers being provided with suitable inlet and outlet valves 63 the aforesaid countershaft 5 extends through the and 64 of the same type as: those at the low pres (it) sure end of the compressor. The gas or air compressed by the low pressure standard bearings, but only through the outer piston I6 is expelled through an outlet pipe 65, posts of the same (see Fig. 5) . This countershaft 65 5 projects at one side so as to carry a fly wheel 28, which is preferably connected to an inter-cooler 66 to cool the air between the stages of compres sion. This inter-cooler is constructed so that the standard bearing. Above the sprocket shafts 23 and within the chamber 29 that is formed in the box-form housing or body 4, a countershaft is provided with driving pinions 30 that mesh with the gears 21 to drive the sprocket wheels 22 and thereby drive the chains 2 l . Adjacent the other end of the chamber 29 and in line with the main standards 26%, a similar pair of standard bearings 3! are provided, which standards are also preferably formed with two 75 standards or posts 32, which carry bearings for air passing into the inter-cooler cools itself by expansion. And the inter-cooler is preferably constructed so that the warm compressed air from the ?rst-stage cylinder may be expanded one or more times to cool it. For this purpose the inter-cooler is preferably constructed of a plurality of sections 66a, 66b, 66c and 66d, each of these sections being composed of a plurality of laterally expanded heads forming cooling expan- 75 "2,128,937 sion‘cham'bers 61 'with a relatively largelsuper 86 at each end, and to form outside connecting ?cial area ‘exposed to the atmosphere. The ex panded cooling heads are connected by .necks 88 of reduced diameter, vand ‘through these links to be connected into the chain. These re cesses are respectively in line with the chains 2|. Beyond each recess the wrist is formed with, a ‘projecting link 81 that extends down across the 55' plane of the run of the chain, and the body of the sections 66a, 6%, etc., openings‘ '69 are formed ‘for the passage of the air or gas. These openings 89 are of substantially vthe same diameter, but the opening 666 where the air passes from the section 86a into the section 66b is of relatively small diameter; for example, three-eighths» of‘ an inch, and as the air ?ows ‘through this opening, the opening acts as an ex pansion nozzle, that is to say, the air of relatively high pressure in the section 66a expands through 15 this opening into the section 561), thereby cool ing this air by its expansion. From the section 66b the air flows through another expansion open ing. 66f of relatively small diameter but slightly larger than the opening 881;; for example, ?ve 20 eighths of an inch. And as the air expands through this opening into the section 660, it cools itself further by expansion. In the present in 25 stance no further expansion is provided for, but in practice, another expansion opening may be provided between the section 660 and section 66d. In this way the air may be cooled by successive expansions and contractions. From the last sec tion 66d the air passes out through a pipe con nection 69a that connects to the interior of a cooling jacket 18 of cylindrical form that sur rounds the high pressure cylinder l5 forming a :ooling space ‘H of relatively large volume through which the air passes, and the wall of this cylinder is provided with a plurality of outwardly project ing ?nsv or ribs 12, which greatly increase the ‘super?cial area of the cylinder. In the present instance, the air from the inter-cooler is passed ?rst to the cooling space ‘H around the high pressure cylinder, and the inter-cooler extends Hit longitudinally of the cylinders, being supported at its ends on the piping 65 and 69a. - From the cooling space ‘H the air passes by a suitable pipe connection 13 to a cooling space 14, of relatively large volume, which surrounds ' the low pressure cylinder I4, then to the cooling jacket 15, which is similar to the jacket 18 and spaced a considerable distance from the cylinder wall. This provides a relatively large space for expansion. The cylinder wall for this cylinderis also preferably provided with outwardly project ing ribs or ?ns 16 to increase its‘ super?cial area. The pipe 13 preferably connects to the cooling space 14 toward the outer end of the cylinder, and. at the inner end of the cylinder jacket 15 a pipe connection 1'! leads off to the high pressure end of the compressor where it admits the air or gas for compression, to the inlet chamber 6| of the high pressure head 60. The outlet valve chamber ‘62 is connected by a suitable pipe connection 18 ' to the tank I already referred to- in connection with Fig. 1. Each of the sprocket chains 2| preferably com prises oppositely disposed outside links 19 (see Fig. 7) ‘and inside links 88, said links being con nected together by pins-8| with rollers 82 mounted on the pins between the inside links. In order to reciprocate the cross-head I8, the chains 2| are connected by a driving wrist 83 (see Fig. 5) and this wrist is in the form of‘a iii’) cylindrical block, the body of which carries a sleeve or roller 84, the diameter of which ?ts neatly into the slot 28, and the ends of this roller or sleeve 84 are provided with flanges 85 that project over the edges of the slot 28. The ends of as 3 wrist is provided with two longitudinally disposed pins 88 that extend through the same, which are preferably of substantially the same diameter as the pins 8| of the chain. These pins 88 have a '10 driving ?t in the wrist 83, and their ends extend across the recesses 88 and into the “links” 81. Each link 81 is of substantially the same length as the outside links 19 of the chain. The chain is connected so that two inside links are placed on ‘(15 the inner side of the tongue links 81 wherethe pin is connected into the chain (see Fig. '7). The chain has the usual anti-friction rollers 82. In this way the driving wrist 83 for the cross-head is connected into the chain, so that its connection ‘20 with the chain operates substantially like. one of the links of the chain, performing the functions of the outside links, where it is connected into the chain. _ In order to support the cross-head l8 in its 525 travel to and fro between the adjacent open ends of the cylinders I4 and I5, I prefer to provide guideways 92 (see Figs. 4 and 5) that extend longitudinally in the central chamber 29, and which are secured to the base plate 35. A cross- *‘30 head engages the inner and adjacent faces of these guide rails 92, and is provided on its side faces with longitudinal grooves 93 that receive guide bars 94 that are bolted to the upper faces of the guide rails 92. If it is desired, the motor I85 I8 may be mounted so as to provide a take-up adjustment for insuring that the driving belt or chain 1 from the motor to the countershaft 5 will be sufficiently tight. For this purpose the cover plate 4|] may be provided with a slide plate “in 48a that rests on it, and which is connected to the cover plate 48 by bolts 95 running through slots 96 in the slide plate 40a, and the slide plate may be provided with upwardly projecting lugs 91, which are engaged by set screws '98 mounted in lugs 99 cast integral with the cover plate 48. Evidently by loosening the bolts 95 the slide plate 40a can be adjusted by tightening up the set screws 98, after which the bolts 95 can be tight ened up. Pads or seats 49 for the legs of the motor are carried on ‘the slide plate 48a. The general mode of operation of the compres sor will now be described. Through the driving belt or chain 1 the coun tershaft 5 is continuously rotated, thereby ena (55 bling the driving pinions 38 to rotate‘ the gear wheels 21, and these gear wheels ‘being rigid with the sprocket shafts 23, drive the sprockets 22, which in turn drive the chains 2|. The driving wrist 83 carried by the chains, of course, as it travels longitudinally along the axis of the cyl inders, will cause the cross-head 18 to reciprocate, thereby reciprocating the piston heads l6 and II. On each intake stroke of the low pressure cylinder 18, gas or air will pass in the inlet 54, pass the in- 1‘ .i let valve 58 and enter the cylinder. On each out stroke this valve will close, and the outlet valve'58 open so as to permit the compressed air to pass out through the pipe connection 65 into the .inter cooler 66. At this point the air is cooled suf?- 170 ciently to enable it to be employed'for cooling the wall of the high pressure cylinder I5 .when this air passes through the jacket space ‘H surround ing this cylinder. From this point the‘gas or'air the wrist 83 are cutlawaysoasitoiform a recess passes ‘through the. low .pressurejacket space 34, :75 4 2,128,937 through which it flows to cool the wall of the low pressure cylinder. From this point the gas or compressed'air passes through the pipe connec tion ‘I’! to the inlet chamber 6! of the high pres sure cylinder head 60, and from this point the partially compressed air passes into the high pres sure cylinder [5 on each in-stroke of this pis ton. The motor should drive the chain at suffi cient speed to give about 95 to 170‘ strokes of the piston per minute, depending of course, largely upon the duty of the compressor. By adjusting the positions of the pistons on the rods, they can be positioned so that at the end of the out-stroke they will lie very close to the inner face of their corresponding heads. For this reason the volumetric e?iciency of the cylin cross-head; and a driving wrist driven by the chain and engaging the cross-head for recipro cating the same, and means for driving the end— less chains, said chain operating to give the pis ton rod relatively few strokes for a given volume of gas compressed, and thereby reducing the clear ance losses during compression of a given volume of gas. ' 2. In a two-stage gas compressor, the combina tion of a pair of coaxial long-stroke horizontal 10 cylinders arranged in tandem and disposed apart, one of said cylinders being of relatively large diameter, and the other of said cylinders being of a relatively small diameter, a pair of endless chains mounted to run longitudinally with the 15 cylinders between the same, said chains located respectively on opposite sides of the axis of said cylinders, piston heads in the cylinders respec tively operating to compress the gas in the cyl inder ends, said pistons having a piston rod con 20 necting the same and lying between the chains, said rod having a cross-head, and a driving wrist carried by the chain and engaging the cross-head for reciprocating the same, means for driving the ders is very high, as there is substantially no clearance space. In this connection it should be noted that the valves are, placed in the heads so 20 that the inner faces of the valves are substan tially ?ush with the inner faces of the heads, in accordance with the usual practice where such valves are placed in compressor heads. The efficiency of this compressor will be evident 25 from the following considerations: At the end of endless chains, said chain operating to give the each compression stroke of a piston a small piston rod relatively few strokes for a given vol quantity of compressed air is left in the end of the ume of gas compressed, and thereby reducing the cylinder, and hence the greater the number of clearance losses during compression of a given strokes the piston makes, the greater will be the volume of gas, an inlet valve for admitting the gas 30 loss due to the volume of air remaining in the , to be compressed at the outer end of the cylinder cylinder. The cylinders of my compressor, due of relatively large diameter, an outlet valve to the construction I employ, have very high volu located at the outer end of the same cylinder, metric e?iciency; and on account of the fact that an inter-cooler receiving the compressed air from relatively few strokes occur in compressing the the outlet valve having a relatively large radiating air, the efliciency of the compressor is very high surface for cooling the gas by expansion and con as compared with that of ordinary reciprocating traction, cooling jackets of relatively large vol compressors. ume respectively surrounding the cylinders, and The central chamber 29 is preferably ?lled with means connecting the inter-cooler with the cool lubricating oil, which covers the driving chains ing jackets for circulating the cooled air through 40 and the cross-head, thereby lubricating the driv the same, and permitting the air to expand in the ing chain of the pins and its contacts with the cooling jackets. cross-head. Furthermore, this oil passes into the 3. In a two-stage gas compressor, the combina open ends of the cylinders hi and I5, and main tion of a pair of long-stroke coaxial horizontal tains the walls of these cylinders very effectively cylinders arranged in tandem and disposed apart, 45 lubricated to reduce the friction of the pistons l6 one of said cylinders being of a relatively large and IT. . diameter, and the other of said cylinders being of When it is necessary to take up slack in the a relatively small diameter, a pair of endless driving chains 2|, this of course, is accomplished chains mounted to run longitudinally with the by loosening up the nuts 44 that attach to the cylinders between the same, located respectively 50 upper ends of the adjustable standards 31, and on opposite sides of the axis of the cylinders pis also loosening up the set screws 45, whereupon ton heads in the cylinders respectively operating these standards can be moved toward the right, as to compress the gas in the cylinder ends, said pis viewed in Fig. 3, to take up the slack of the chains. tons having a piston rod connecting the same As the jacket spaces ‘H and ‘M are of relatively lying between the chains, said rod having a cross 55 large volume, the air expands as it is forced into head, and a driving wrist carried by the chain and them, thereby cooling the air in the jacket spaces engaging the cross-head for reciprocating the by its own expansion, and cooling the cylinder same, means for driving the endless chains, said walls. chain operating to give the piston rod relatively It is understood that the embodiment of the few strokes for a given volume of gas compressed, 60 invention described herein is only one of the many and thereby reducing the clearance losses during embodiments this invention may take, and I do compression of a given volume of gas, a cylinder not wish to be limited in the practice of the in head with an inlet valve for admitting the gas vention, nor in the claims, to the particular em to be compressed at the outer end of the cylinder bodiment set forth. of relatively large diameter, an outlet valve lo 65 What I claim is: cated in the said head and receiving air through 1. In a gas compressor, tne combination of a the inner face of the head, an inter-cooler re pair of coaxial long-stroke horizontal cylinders ceiving the compressed air from the outlet valve arranged in tandem and disposed apart, a pair having a relatively large radiating surface for of endless chains mounted to run longitudinally cooling the gas by the atmosphere, and by ex 70 with the cylinders, located between the same, and pansion and contraction, cooling jackets respec on opposite sides of the axis of the cylinders, pis tively, surrounding the cylinders, means connect ton heads in the cylinders respectively, operating ing the inter-cooler with the cooling jackets for to compress the gas in the cylinders ends, said circulating the cooled air through the same, and pistons having a piston rod connecting the same means for controlling flow of cooled gas there 75 and lying between the chains, said rod having a after into the cylinder of relatively small diam . 530 45 65 70 5 2,128,937 eter, including inlet and outlet valves for enabl pressure second stage compression cylinder, and ing the gas to be compressed in thesame. an inter-cooler for receiving the compressed gas from the low pressure cylinder, with means con 4. In a two-stage gas compressor, the combi nation of a pair of long-stroke, horizontal cyl~ inders arranged in tandem and disposed apart, including a low pressure cylinder and a‘ high pressure cylinder, a cylinder head corresponding to each cylinder on the outer ends thereof, an endless chain mounted to run longitudinally of the cylinders between the same, piston heads in the cylinders, respectively, with a piston rod connecting the piston heads; said rod having a cross-head, a driving wrist driven by the chain engaging the cross-head for reciprocating the same, means for driving the endless chain, each of said‘ cylinder heads having an inlet valve and an outlet valve for the gas, an intercooler extend ing longitudinally with the cylinders and con nected with the low pressure cylinder head to 20 receive gas from the same for cooling the gas, a cooling jacket surrounding the high pressure cylinder and receiving the cooled gas from the inter-cooler, a cooling jacket surrounding the low pressure cylinder with means for passing the gas from the cooling jacket of the high pres sure cylinder, through the cooling jacket of the low pressure cylinder, and means for delivering the gas from the cooling jacket of the low pres sure cylinder to- the cylinder head of the high 30 pressure cylinder for compressing the gas in the high pressure cylinder. 5. In a gascompressor, the combination of a casing having a central chamber with oppositely disposed substantially vertical end walls having aligning openings therein forming cylinder seats, coaxial cylinders mounted in said cylinder seats and open at their inner ends, piston heads for compressing the gas in the cylinders mounted to reciprocate in the cylinders, a piston rod connect 40 ing the same, with a cross-head located in the said central chamber, a pair of endless chains mounted to run longitudinally with the cylinders in the said chamber, located respectively on op posite sides of the axis of the cylinders, a driv 45 ing wrist carried by the chain and engaging the cross-head for reciprocating the same, means for driving the endless chains, and cylinder heads on the outer ends of the cylinders with inlet and outlet ports and valves therein respectively for 50 the cylinders, said ports passing through the inner face of the cylinder heads. 6. In a gas compressor, the combination of a 55 nected therewith for delivering the gas from the inter-cooler to the high pressure cylinder for compression therein. 7. A two-stage gas compressor constructed as described in claim 4, in which the inter-cooler is formed with expansion chambers in which the compressed gas from the ?rst stage is expanded, if) thereby developing a cooling effect. '8. In a gas compressor, the combination of a casing having a central chamber with oppositely disposed end walls having aligning‘ openings therein forming cylinder seats, cylinders mount ed in said cylinder seats and open at their inner ends, piston heads mounted to reciprocate in the cylinders, a piston rod connecting the same with a cross-head located in the said central chamber, a pair of oppositely disposed endless chains ex 20 tending longitudinally with the axes of the cyl inders and located in the said chamber, a pair of pillow blocks mounted in said chamber adja cent one end of the same, sprocket wheels ro tatably mounted in said pillow blocks with spook et wheels carrying the endless chains respec tively, a second pair of pillow blocks mounted in the said chamber adjacent the other end there of, means for supporting the same for adjust- ' ment toward or from the ?rst named pillow 30' blocks, a cover plate seating on the upper side of the casing and covering the said chamber, means on the outer side of the cover for clamp ing the second-named pillow blocks and enabling the last-named pillow blocks to be adjusted to 35 ward or from the ?rst-named pillow blocks and secured in a ?xed position with respect to the same, sprocket wheels rotatably mounted in the second-named pillowblocks with sprocket wheels for carrying the said chains, a wrist connecting 40 the said chains and engaging the cross-head for reciprocating the piston rod. 9. A gas compressor constructed as described in claim -8, in which the said clamping means for the second-named pillow blocks includes slots 4:5 formed in the cover plate, and clamping bolts passing through the slots and mounted in the upper ends of the second-named pillow blocks for securing the same. ' 10. In a gas compressor, the combination of 50 a casing having a central chamber with oppo sitely disposed end walls‘ having, aligning open casing having a central chamber with oppositely ings therein forming cylinder seats‘, cylinders disposed substantially vertical end walls having aligning openings therein forming cylinder seats, mounted in said cylinder seats and open at their inner ends, piston heads mountedto reciprocate in the cylinders, a piston rod connecting the coaxial cylinders mounted in said cylinder seats and open at their inner ends, piston heads mount ed to reciprocate in the cylinders for compressing the gas in the cylinders, a piston rod connecting same with a cross-head located in the said cen tral chamber, a pair of oppositely disposed end less chains extending longitudinally in the said chamber, a‘base plate forming the bottom for the same, with a cross-head located in the said the said chamber, a pair of oppositely disposed central chamber, a pair of endless chains mount ed to run longitudinally with the cylinders in the pillow blocks supported on the base plate adja said chamber, located respectively on opposite cent one end of the said chamber, each of said sides of the piston rod, a driving wrist carried pillow blocks comprising two upwardly extend ing standards, a sprocket wheel corresponding to 65 65 by the chains and engaging the cross-head for each pillow block carrying one of said endless reciprocating the same, means for driving the chains and having a stub shaft rotatably mount endless chains, cylinder heads on the outer ends of the cylinders with inlet and outlet valves ed in the standards of its corresponding pillow therein respectively for the cylinders, the ports block, a gear wheel carried rigidly by each stub 70 70 for said valves passing through the inner faces of shaft between the standards of its corresponding‘ said cylinder heads, one of the cylinders being pillow block, a transverse countershaft located of relatively large diameter and constituting the above the gear Wheels and having driving gear low pressure ?rst-stage compression cylinder,’ wheels meshing with the ?rst named gear Wheels for driving the chains, a second pair of pillow and the other of said cylinders being of rela 75 tively small diameter and constituting a high blocks supported on the base plate adjacent the 75 6 2,128,937 tatably supported in the second-named pillow at their inner ends, piston heads mounted to reciprocate in the cylinders, a piston rod con blocks and carrying the said chains, means for necting the same with a cross-head located in guiding the second-named pillow blocks longi the said central chamber, a pair of endless chains mounted to run longitudinally with the other end of said chamber, sprocket wheels ro tudinally of the chains, means for securing the second-named pillow blocks in a ?xed position, and a wrist carried by the said chains and en gaging the said cross—head for reciprocating the 10 piston rod. cross-head having a substantially vertical slot 11. In a gas compressor, the combination of a casing having a central chamber with oppo for receiving the said wrist to reciprocate the pis sitely disposed end walls having aligning open ings therein forming cylinder seats, cylinders mounted in said cylinder seats and open at their 15 inner ends, piston heads mounted to reciprocate in the cylinders, a piston rod connecting the same with a cross-head located in the said cen tral chamber, a pair of oppositely disposed end~ less chains mounted to run longitudinally with 20 the cylinders in the said chamber, a driving wrist connecting the said endless chains, said driving wrist consisting of a cylindrical block having recesses out in the ends thereof in line with the said chains respectively and secured to the said chains, said cross-head having a substantially vertical slot receiving the body of said wrist between said chains for, reciprocating the cross— head. 12. In a gas compressor, the combination of a ton rods, said wrist consisting of a cylindrical block with recesses cut in the ends thereof in line with the chains, a pair of pins extending longitudinally through the said wrist between the said recesses extending into the recessesand se,-' cured at their outer ends to a link of the chain adjacent each recess, and a flanged roller sleeve ?tting over the body of the wrist and engaging the edges of the said slot. 14. A two-stage gas compressor constructed as described in claim 4, in which the inter-cooler consists of a plurality of connected sections, each section having a plurality of laterally expanded chambers therein with reduced necks connecting the same, said inter-cooler being provided with an expansion opening of reduced area whereby the compressed gas in passing through the inter cooler expands intoithe expanded chambers and thereby reduces its own temperature. casing having a central chamber with oppositely disposed substantially vertical end walls having nation of a pair of long-stroke horizontal cylin aligning openings therein forming cylinder seats, ders arranged in tandem and disposed apart, in cylinders mounted in said cylinder seats and open at their inner ends, piston heads mounted cluding a low pressure cylinder and a high pres sure cylinder, a cylinder head corresponding to each cylinder on the outer ends thereof, an end~ 35 less chain mounted to run longitudinally of the 35 to reciprocate in the cylinders, a piston rod con necting the same with a cross-head located in the said central chamber, a pair of endless chains mounted to run longitudinally with the cylinders in the said chamber, sprocket wheels supported 40 in the chamber for supporting the chains, a wrist connecting the said chains, said cross-head having a substantially vertical slot for receiving the said wrist to reciprocate the piston rods, said wrist consisting of a cylindrical block with re 45 cesses out in the ends thereof in line with the chains, a pair of pins extending longitudinally through the said wrist between the said recesses, the links of the chain adjacent said pins having bushings through which the ends of the said pins 50 cylinders in the said chamber, sprocket wheels, supported in the chamber for supporting the chains, a wrist connecting the said chains, said pass so that the ends of the said wrist operate as links in the said endless chains. ' 13. In a gas compressor, the combination of a casing having a central chamber with oppositely disposed substantially vertical end walls having aligning openings therein forming cylinder seats, cylinders mounted in said cylinder seats and open 15. In a two-stage gas compressor, the combi 3O cylinders between the same, piston heads in the cylinders respectively with a piston rod connect ing the piston heads, said rod having a cross head, a driving wrist driven by the chain engag ing' the cross head for reciprocating the same, means for :driving the endless chain, each of said cylinder heads having an inlet valve and an out let valve for' the gas, an inter-cooler for receiving the gas compressed in the low‘pressure cylinder, said inter-cooler having an expansion chamber for the gas with an expansion opening through which the gas?ows in passing into the expansion chamber whereby the gas reduces its own tem perature by its expansion in the expansion cham- r ber, and means for admitting the gas from the expansion chamber thereafter into the high pres sure cylinder to compress the same through the second stage._ , WILLIAM B. HALE.