US636459A - Compressor for ice-machines. - Google Patents

Description

Patented Nov. 7, I899.

E. L. SHARPNECK. COMPRESSOR FOB ICE MACHINES.

5 Sheets-Sheet No. 636,459. Patented Nov. 7, I899.

v E. L. SHARPNECK.

COMPRESSOR FOB ICE MACHINES.

(Application filed Oct. 1, 1897.)

(No Model.) 5 Sheets-Sheet 2,

No. 636,459. Patenfed Nov. 7, I899. E.IL. SHARPNECK.

GDIIPRESSUR FOB ICE "ZACHINESJ (Application filed Oct. 1, 1897.) (No Model.) 5 Sheets$heet 3.

@9 mnzw I m 5M 9 A W minim A if) 09%? 414 9 0 I r J 7 I N0. 636,459. Patented Nov. 7, I899.

, E. L. SHARPNECK.

COMPRESSOR FUR ICE MACHINES.

(Application filed Oct. 1, 1897.)

(No Model.) 5 Sheets-Sheet 4.

. k a, I

No. 636,459. Patented Nov. 7, I899. E. L. SHARPNECK.

COMPRESSOR FOR ICE MACHINES.

(Application filed Oct. 1, 1897.) (No Model.) 5 sheets-Sheet 5.

WA m

Zine/2%).

7158 ZZ, Qi'amzzecz;

ELIEL L. SHARPNECIQOF CHICAGO,

PATE T Orrica.

ILLINOIS, ASSIGNOR TO THE IDEAL 'REFRIGERATING AND MANUFACTURING COMPANY, OF COLORADO SPRINGS, COLORADO.

COMPRESSOR FOR ICE-MACHINES.

SPECIFICATION formingpart of Letters Patent No. 636,459, dated November 7, 1899.

Application filed October 1, 1897;

To aZZ whom it may concern: I

, Be it known that I, ELIEL L. SHARPNECK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a 'new and useful Improvementin Ice-Machines, of which the following is aspecificatiom My invention relates to an improvementin ice or refrigerating apparatus generally and of the class wherein a gas, such as anhydrous ammonia, liquefiable under mechanical compression is employed as the refrigerating agent.

While my invention is not to be confined to apparatus of any especially-limited capacity or for any specific use, lnyimprovements for the most part are designed more particularly for use in connection with the smaller types of individual refrigerating plants such, for example, as are adapted for employment in cooling butchers, grocers, or domestic store-rooms or for the manufacture of ice in the smaller towns or in private establishments. \Vhile it is naturally desirable in apparatus of this class to reduce the initial cost of construction as much as possible consistent with strength, durability, and elfectiveness, the improvement which produces the greatest economy in the end is one that reduces the operating expenses by increasing the capacity for refrigeration with relation to the power employed. Individual refrigerating plapts are coming largely into use in places where power for running the plants, either electrical or steam, is rented. The rental is governed by the horse-power required, and any reduction in the power nec-. essary for operating a plant of a given capacity is one of daily economy, always to be desired and sometimes vitallynecessary. Al-. though the use of natural ice in establishments such as bu tcher-shops is attended with more or lesstrouble, discomfort, and uncleanliness, refrigerating plants intended to compete with and supersede the use of natural ice must not in the majority of cases be materially more expensive than natural ice in the end. Refrigerating plants of the class to which my in vention relates employ, generally Serial No. 653,725. (No model.)

stated, a close refrigerating-chamber in which compressed gas is discharged by the compressing device, and a storage-receptacle.

which receives the condensed gas or liquid from the condenser and from which the liquid. flows to expand in the refrigerating-coils.

Myobject is to provide a generally-improved refrigerating apparatus of the class above defined employing a com pressing-machine which shall have 00111 paratively great capacity for compressing and discharging the return gas, while requiring comparatively little power for its operation and avoiding thedischarge of any appreciable amount of oil into the refrigerating-coils and employing other improvements in various parts of the apparatus, all tending toward economy in construction, space, and operation, as well as toward efliciency, durability, and simplicity.

In the drawings, Figure 1 is a longitudinal vertical section through the compressor with certain details, however, in elevation; Fig. 2, a transverse section taken on line 2 of Fig. 1 and viewed in the direction of the arrow; Fig. 3, an enlarged section of the upper part of the compressor, the section being taken on line 3 of Fig. 4 in the same plane as Fig. 2; Fig. 4, a plan section taken on line 4 of Fig. 3; Fig.

5, an enlarged plan section taken on line 5 of Fig. 1; Fig. 6, a section taken on line 6 of Fig. 7, giving a top plan View of a cross-head;

Fig. 7, a section taken on the irregular line 7 7 in Fig. 6; Fig. 8, an elevation of a detail of the construction of the cross-head, showing it connected with an oil-supply pipe or piston; Figs. 9 and 10, enlarged broken sections taken, respectively, on lines 9 and 10 of Fig. 2; Fig. 11,'a diagrammatic view of an ex tended form of toggle-operating mechanism which may be employed in place of that shown in Figs. 1 and 2, and Fig. 12 a rear elevation of the toggle mechanism shown in Fig. 11.

The shell or frame of the compressor A comprises a base-section A, an intermediate section A a removable cover-section A a compressor-cylinder A and a removable cylindcr-hcad or cap A.

E is a drive-shaft journaled toward opposite ends in boxes t at the opposite inner sides of the shell or casing and provided beyond the casing with fly-wheels E E, one of which may be the driving-pulley. The shaft E is in the form of a crank-shaft, to which is secured one end of a pitman or connecting-rod F.

G is a toggle-lever having a lower arm or member G and an upper arm or member G The arm G is mounted to rock upon or with a shaft .9, journaled or mounted in bearings s in the base of the chamber or section A.

'In the shell-section A are cross-head guides 0' r. The arms or members of the toggle G are piv'otally con nccted together by means of a pin or shaft G to which the connecting-rod F is pivotally secured. The construction of the joint may be as most plainly shown in Fig. 2.

G is a cross-head provided at opposite sides with blocks or shoes q, which move in the vertical guides 1'. Extending transversely through the cross-head is a pin or bolt 1), with which the toggle-arm G is pivotallyconnectcd at its upper end, as shown.

The compressor-cylinder A comprise a chamber 1, surrounded by a water -jack it, having an inlet-pipe n and an outlet-pi; 21 At the lower side of the cylinder is a gas-induction port 172, communicating with a vortical gas-induction passage m, co; in the shell. Extending to the passage m a horizontal passage m cored in a boss 7.4 on the side of the shell and having a threaficd mouth 772 to which the return pipe or conduit of the expansion-coil leads. Extending t rough the cap or cylinder-head A is a central vertical opening I, surrounded at the top by an annular seat I and tapered at its lower end to present a seat or shoulder if. The opening is enlarged at- Z to afford an annular chamber communicating with the gas eduction passage Z cored in the head r and communieating with a vertical pas. cored in the part A, terminating in a ho zontal passage l, having a threaded mouth from which extends the gas-discharge pipe ll. Fitting the opening Z is a cylindrical valve shell. or chamber 7;, tapered at its iowcr end to fit the seat Z and afford an annular valveseat 7.1, surrounding the educiion-portot the cylinder. In the wall of the shell In at the chamber Z is an annular writs of openings L7 Fitting upon the upper end of the valre-shell 7c is a valve-stein guide having a reduced downward-extending part It. The upperend .of the opening I is closed by means of a capplate 7J0, having a central upward-extending boss and held in place with bolts k Extending through the cap-plate It is a screw it. Fitting the seat It is the gas-eduction valve 7r, having a stem 7a which passes loosely through the guide k into an air-cushioning cup In", hcid in place by the screw is. Surrounding the reduced portion 7.1 of the guide and-bearing against the valve to press the latter normally to its seat is a spring 7.4

The construction of all the parts in the opening Z is such that the valve and the valve-seatmay be quickly removed and replaced when desired and held when in place with great security. The valve k is cushioned against shock in rising by the entrance of its stem into the air-cushioning cup It. When the valve is closed, its under face is in the plane of the under t'ace ofthe cylinder-hcad A.

In the chamber I of the cylinder isa piston I upon a stem l which at its lower end is adjustably secured to the cross-hcad G. At the lower end ot the chamber I is a stuffingbox K, through which the piston-stein works.

It is a fact well known in this art that any lubricating-oil finding its way into the refrigerating-coil works injury, for the reason that it tends to coat the inner surface of the coil and detract, owing to its non-conducting propcrties, from the refrigerating elliciency of the coil. For this reason manyand various more or less ingenious traps have been interposed between the com pressorand refrigerating-coil to catch particles of oil carried by the ammo nia from the compressor. It is one of my objects in the present construction to prevent any or at least any material quantity of oil from being brought into contact with the gas at the compressor, and while it is necessary that the piston-stem shall be lubricated to reduce friction at the stalling-box the construction of the striding-box shown and to be dcscribed effectively precludes any material. q' iantityof oil from entering the piston-chamlicip The stu iii rig-box K comprises a casting having the t iindcr portion tand a flange 1, at ich it secured in place between the sections A A as shown. At the top the a y ,indcr has a reduced portion 1" just large enough for the tree passage of the piston-stem. In the cylinder or tube i is an oiler-bearing hi, comprising a ring having upper and lower flanges 71, which lit the wall of the tube 1' and afford openings at the upper and lower ends of the bearing-piece just large enough forthe ready passage through them of the pistonstem. Thus, as shown most plainly in Fig. 3, inner and outer concentric chambers 71 7!?1119 formed, which communicate through an annular series of openings h". In the side of the tube i is an oil-port i to which leads an oilsupply pipe :Ifroma suitable oil-reser oir (See Fig. 1.) Above and below the oiler-bearing K are packing-rings K preferably of suitable fabric, the tube bein, closed at its lower-end by means of a gland adjizr, .ably tightened in place by means of a screw-cap K to hold the oiling and packing rings properly in place. The packing-rings permit the stem to carry off just enough oil to properly lubricate it, the tendency of any surplus oil being to Work its way downward rather than upward. The lower end of the chamber 1' of the cylinder extends slightly below the inlet-port m, and any oil out from the pistoustem by the IIO ammonia-gas will fall into the trap thus provided. As in practice but little oil'will accumulate in this trap, it is not thought necessary to provide an outlet therefor. The trap may be cleaned at any time when the machine is being overhauled and the piston removed. If desired, a hard, pulverulent, or plastic lubricant may be employed instead of oil at the oiling-bearing; but the practical operation of the present machine has demonstrated that no material or, in fact, appreciable amount of oil enters the compressor-chamber from the piston-rod lubricator. The piston 1 contains a chamberf, to which openings f lead from the under side of the piston. At the top of the chamber f is a cap-plate f fastened in place with screws, as indicated, and holding the piston-ring f in place. In the top of the cap plate f is an outlet-port surrounded by a flaring valve-seat f and below the said port is a spider f forming a guide for the stem f of an upwardly-lifting valve f ,which closes against the seat f Below the spider the stem f 6 carries a-nut 1, against which bears a confined spring f which tends to press the stern downward and hold the valve closed. The valve f when closed extends at" its upper face flush with the end face of the piston, and, as before stated, the valve 10 at its under face extends flush with the face of the cylinder-head. Thus when the piston is moved to the cylinder-head clearance is absolutely avoided. Extending vertically through the cylinderhead A is an opening m threaded at the top and tapered and reduced at its lower end m to afford a valve-seat; A reduced passage m cored or drilled'in the cylinder-shell A and cylinder-head Afi'extends from the inductionpassage on to. the passage or opening m \Vorking in the opening in is a valve m upon a stem in", passing through a stuffing-box m screwed into the upper endv of the opening. The stem m is provided with a handle m. Below the beveled seating-face of the valve m is a projection an, which fills the port at m. The stem m is threaded and passes through a threaded opening in the stuffingbox m this being a common construction, whereby when the handlemt is turned to the left the valve m is raised from its seat to open communication between the inductionpassage in and cylinder above the piston. \Vhen the handle in is turned to the right,

the valve m is seated, its lower end extending flush with the-lower face of the cylinderhead to avoid all clearance between said face and the piston.

The general operation of the apparatus is in the main the same as other apparatus of this character. Return gas entering the port on is compressed in the cylinder by the piston and discharged through the port It" and passages Z Z l to the pipe II. When the gas has done itswork in the expansion-coil, it is returned through the port m and passages m m to the cylinder-chamber I. In the downstroke of the piston I the gas beneath it in the chamber 1 opens the valve f and passes above the piston. In the rise of the piston the said gas is forced through the port is, opening the valve against the back pressure in the system, and thus compressing the gas.

To produce the best results and prevent waste of power, there should be absolutely no clearance between the piston and cylinderhead. The expansive force of the gas when compressed as compared with that entering from the return-pipe .may be as one hundred and twenty pounds to twenty pounds, more or less, whereby a clearance one-eighth of an inch or even less would causea piston having a traverse of five or six inches to perform no useful work. No valve which lifts from its seat and is seated by the back pressure of fluid under the suction action of a piston will close without permitting the retrogression of more or less fluid through the valve. In

other words, were the valve 70 not to close until the piston turns upon. its downstroke a certain quantity of compressed gas would be drawn or sucked back into the cylinder and by its expansion prevent the piston from doing useful work throughout more or less of its stroke. For the sake of economy, there fore, it is necessary that the piston shall remain practically quiescent at the end of its upstroke for a period sufficiently prolonged to permit thevalve It to close before the piston starts upon the downstroke. The principal object of the toggle construction which I have shown and described is to accomplish this result and absolutely preclude the retrogression of gas through the valve k in the descent of the piston. In the construction shown in Figs. 1 and 2 in the rotation of the drive-shaft the piston will ascend nearly three-quarters of the distance of its traverse in the first quarter-revolution of the shaft and rise at gradually-slowing speed to the top of the cylinder. There while the levers are at the dead-center and the crank is crossing the dead-center the piston remainspractically quiescent for a period long enough to permit the valve k to close. The piston-,stem at its lower end is screwed into a socket in the top of the cross-head G as shown in Fig. 3. The object of this construction is to render the stem ad justable to a limited extengt to adjust the piston toward or away from the cross-head, and in practice this adjustment should be such that the piston will just touchv without apparent impact against the under A face of the cylinder-head when it reaches the limit of its rise. Thus as the valves when. closed are flush with the surrounding surfaces praetically no clearance will exist and all gas will be expelled. While the piston is practically at a standstill, the eduction-valve 70, closes and in closing expcls the gas upward from between it and its seat. Thus when the piston starts on its downstroke it leaves no gas above it to expand and interfere with its-useful work. I

If it is desired to prolong the practical stoppage of the piston at the end of its upward stroke, the connecting-rod F may be shortened slightly by screwing it a little farther into the coupling F, which joins it to the toggle-lever, so that the toggle lever will be drawn slightly past its dead-center. A further great advantage of this construction involving the toggle mechanism lies in that it greatly reduces the power necessary to produce a given compression, for .the reason that the leverage increases as the resistance increases.

Taking into consideration the resistance of the spring it, which it is desired to employ, and the quickness with which it will close the Valve b the compressor shown in Fig. 1 may be run at, say, two hundred revolutions per minute and allow just sufficient time while the piston is at the end of its upstroke for the valve to become firmly seated before the piston starts to descend. \Vhen a materiallygreater speed is desired, I prefer to provide a construction according to the diagram shown in Fig. 11. In this construction the connection between the toggle-lever G and the counecting-rod F is through an intermediate toggle N, the arms of which are somewhat longer than the distance from the joint of the toggle G to the points of connection of the arms of the toggle N with the arms of the toggle G. In the rotation of the drive-shaft the pistonwill move only about one-fifth of the distance of its traverse in one-quarter revolution and the rest of the distance in the next quarter-revolution. Thus the time during which the piston remains apparently at rest at the top of its stroke may be greatly prolonged and give as protracted a time for the valves to close when the drive-shaft is running at three hundred revolutions per minute, as is the case in the other construction running at two hundred revolutions per minute. A further advantage gained by the construction illustrated in Figsull and 12 is that a much shorter crank may be employed upon the drive-shaft to produce the same traverse of the piston, which by thus greatly incr'easin g the leverage of the crank-shaft decreases to a very material extent the power necessary for driving the machine.

It is very desirable to dispense with oil-cups at the joints of the mechanism, for the reason that they must be filled at intervals, and thus require more or less constant attention. In

the place of oil-cups I provide the following automatic lubricating means for the shaft, connecting-rod, and toggle-bearings.

The base portion A of the compressor-casing forms an oil-receptacle,which may be filled with a lubricating-oil to, say, the plane 00. This causes the crank to dip into the oil with each revolution and lubricate the bearing thereon for the connecting-rod. Fastened in one side ofthe base portion is a stem 0, carrying on the inner side of the base a head or clamp c.

P is a pump having a cylinderb in the form of a tube open at its upper end and closed at its lower end and provided nearits lower end with inlet-openings I). \Vorking in the cylinder I) is a piston in the form of a hollow tube Z1 contracted at its lowerend, as shown in Fig. 5), and having'there an inlet-opening I). In the lower end of the tube b and normallyclosing the opening Uis a movable ballvalve b. The pin or bolt 1), which forms the connection between the toggle-arm G and the cross-head, is provided internally with a longitndinally-extending passage 1), (see Fig. 5,) opening at one end into a threaded socketp in the under side of thepin. Extending from the passage 12 are radial outlet-openings 19 leading to the surface of the pin at the crosshead and toggle-arm. The hollow piston 12 is screwed at its upper end into the soeketp The cylinder 1) of the pump may be raised and lowered in the supporting-head c to increase or diminish the working stroke of the piston Z1 It will be understood that the farther the piston b passes below the openings 11 the more oil will be drawn into the cylinder with each operation and discharged. The piston if rises and falls with the cross-head G The oil discharged into the passage 1) passes for the most part through openings 1) into chambers p in the shoes q, and thence through openings q to the surfaces of the guides r. At the lower ends of the guides r I provide troughs r r respectively, which are open at the top and closed at opposite ends and receive the oil which trickles down the guides r. Extending from the center of the trough r, as shown in Fig. 1, is a pipe or duct T The rear end of. the connecting-rod coupling or bearing-head F is provided with a flaring opening a, leading to the pin G (see Fig. 10,) and the pipe 2' terminates above the path of the opening a, where the connecting-rod nears the limit of its movement in the backward direction. Thus each time the connecting-rod moves in the backward direction the opening or receptacle a passes beneath the pipe 1' and receives part of the oil discharged from the latter. From the receptacle a the oil passes into the bearing through a'duct a to lubricate the toggle-joint. Pipes or ducts r extend from opposite end portions of the trough r to the bearings 25 of the shaft E,

whereby oil trickling into the trough T will be conducted to the said bearings 13 to lubricate them.

In each side of the section A are openings w for ready access to the interior of the shell. These openings I provide with tightly-fittin but readily-removable doors w for the exclii sion of dust and to prevent oil from splashing out of the casing.

As before stated, one of the principal objeets of my present invention is to reduce the running expenses of a plant of the class to which this invention relates to the minimum. In order that there shall be no waste of power in the compressor, it is necessary to have no clearance between the piston and cylinderhead, so that all the gas will be expelled in the upstroke of the piston. It is also necessary that the eduction-valve shall close before the piston starts on its downst-roke to prevent any retrogression of compressed gas through the eduction-valve. The construction described accomplishes these objects by causing the piston to have a practically intermitting movement instead of a regular reciprocation,the interruption or stoppage of movement taking place when the piston is at the point nearest the eduction-valve. In practice the change in angle of the various lever mechanisms and natural looseness of joints will tend very materially to prolong the actual stoppage of the piston in the final extending and flexing movement of the toggle when both the driving-crank and toggle-lever are at or crossing their dead-centers. It ma be stated that in watching the operation of the con-" struction shown in Figs. 1 and 2 while the shaft turns at one hundred and twenty-five revolutions per minute the eye can detect an appreciable prolonged stoppage of the piston at the end of the upstroke, while none can be detected at the end of the downstroke. Whether driven directly from the crank or through the toggle mechanism, as described,

the piston must reciprocate once with every revolution ofthe drive-shaft; but by the apportionment of time or change in the speed of the piston by making the latter move quickly where quickness is economy, and more slowly, even to stoppage, where economy requires it, I produce results which, so far as I am aware, cannot be effected in any other way. In the construction shown in Figs. 11 and 12 there is a still greater saving in power, as well as prolongation of the time between the ascent and descent of the piston.

\Vhen the compressor is initially started, there is a back pressure in the system against which the piston has to work when it commences the compressing operation. In a compressor which requires, say,a one-horse-power motor to keep it in operation after it has been started a motor of nearly two-horse capacity would be required to start the compressor were it to operate in its initial movements to compress the gas. To overcome this difficulty, I provide the valved starting-passage m? m described. In operation before starting the compressor the valve m is raised by turning the handle m to open communication between opposite sides of the piston. Therefore when the compressor is started the gas above the piston is forced through the port m i and around to the under side of the piston,and

as the piston descends gas flows from beneath the piston around through the starting-passage to the upper end of the compressor-chamber. In this way the piston meets with practically no resistance, the valve being left open until the fly-wheels are at full speed. When the valve m is closed after the fly-wheels have reached full speed, the compression of the gas is performed with the least expense of power. This feature of my invention is very important in those places where, as before stated, the power is rented, because a one-horse-power compressor may be run with a one-horse-power motor and the rental would be of a one-horse-power motor instead of a motor having the capacity of two-horse power.

I have designed all parts of the mechanism shown with a view to economy both in construction and operation, and it requires no especially-skilled attendant either for running it or for the adjustment or replacement of parts at any time. oiled by the machine automatically, as described, and the shell is rendered practically dust-proof. Thus the apparatus requires practically no attention except for starting and stopping it.

VVhile I prefer to construct my improvements throughout as shown and described, they may be modified in various ways, both in the matter of their arrangement and de-. tails of construction,without departingfrom the spirit of my invention as defined by the claims. I

What I claim as new, and desire to secure by Letters Patent, is

1. In a refrigerating-machine,the combination of the compressor-cylinder having in its discharge end an 'eduction-port communicat ing with the discharge-conduit, an inwardlyclosing valve at said port, a piston in the 0yinder, and toggle mechanism for driving the piston to avoid clearance at the end of its discharge-stroke and for interrupting the movement of the piston ,for a period sufficiently prolonged to allow the vaTve to become seated before the piston advances upon its suctionstroke.

2; In a refrigerating-machine,the combination with the compressor-cylinder and the gas return and discharge conduits, of an eduction-port in the cylinder-head communi-. eating with the discharge-conduit, an inwardly-closing valve at said port, a piston in the cylinder, and means for operating the piston to move the same to the cylinder-head approximately without clearance, comprising a toggle-lever mounted to rock at one of its arms on a fulcrum and operative] y connected at its other arm with the piston, and togglelever-driving means geared to the toggle-1ever to flex the same to one side, to produce the suction-stroke of the piston, and to extend the same to a dead-center, to produce the discharge-stroke of the piston, and at the end of the discharge-stroke to interrupt movement of the piston for a period sufficiently prolonged to permit seating of the eductionvalve before the piston advances upon its suction-stroke, substantially as and for the purpose'set forth.

3. In arefrigerating-machine, the combination with the compressor-cylinder and the gas return and discharge conduits, of an eduction-port in the cylinder-head communi- ICC eating with the disehargcconduit, an inwardly-closing valve at said port, a piston in the cylinder, and means for operating the piston to move the same to the cylinder-head approximately without clearance, comprising a toggle-lever mounted to rock at one of its arms on a fulcrum and operatively connected at its other arm with the piston, and togglelever-driving means comprising a crank-shaft geared to the toggle-lever, to flex the same to one side and produce the suction-stroke of the piston, in the movement of the crank to one dead-center, and to extend the toggle-lever to a dead-center, and produce the dischargestroke of the piston, in the movement of the crank to its other dead-center, and interrupt movement of the piston at the end of its discharge-stroke for a prolonged period,whereby the seating of the eduction-valve is effected during suchinterruption,substantiallyas and for the purpose set forth.

4. In a refrigerating-maehine,'the combination with the compressor-cylinder and the gas return and discharge conduits, of an eductionport in the cylinder-head communicating with the discharge-conduit, an inwardly-closing valve at said port, an induction-port toward the opposite end of the cylinder communicating with the return-conduit, a passage extending from the cylinder-head to the opposite end portion of the cylinder, a valve for opening and closing said passage, a piston in the cylinder, and means-for operating the piston to move the same to the cylinder-head approximately without clearance, comprising a toggle-lever mounted to rock at one of its arms on a fulcrum and operatively connected at its other arm with the piston, and toggle-leverdriving means geared to the toggle-lever to flex the same to one side, to produce the suction-stroke of the piston, and to extend the same to a dead-center, to produce the dischargestroke of the piston, and at the end of the discharge-stroke to interrupt movement of the piston for a period sufliciently prolonged to permit seating of the eduetion-valve before the piston advances upon its suctionstroke, substantially as and for the purpose set forth.

5. Inarefrigeratirig-machine, thecombination with the compressoncylinder, and the gas return and discharge conduits, of an eductionport in the cylinder-head communicating with the discharge-conduit, an inwardly-closing valve at said port extending when seated flush with the inner face of the cylinder-head, an induction-port toward the opposite end of the cylinder communicating with the returnconduit, a passage through the piston, an induction-valve on the piston for opening and closing said passage and extending when seated flush with the end of the piston, and means for operating the piston to move the .same to the cylinder-head approximately without clearance, comprising a toggle-lever mounted to rock at one of its arms on a fulcrum and operatively connected at its other arm with the piston, and toggle-lever-driving means geared to the toggle-lever to flex the .for a period sulticiently prolonged to permit seating of the eduction-valve before the piston advances upon its suction-stroke,substantially as and for the purpose set forth.

6. In a compressor, the combination with the compressor-cylinder, piston in the cylinder, and drive-shaft, of a toggle-lever-mounted to rock at one of its arms on a fixed fulcrum, and operatively connected at its other arm with the piston, a pitman connected in eccentric operative relation to the shaft, and intermediate toggle mechanism forming a connection between the said pitman and toggle,- lever, substantially as and for the purpose set forth.

7. In a compressor, the combination with the shell having a base portion forming an oilreservoir and supporting the cylinder, driveshaft, piston, piston-stem and piston-stemdriving cross-head, of bearings for the driveshaft on the inner sides of the said base provided with oiling-openings, a chamber in the cross-head having outlets to the cross-head guides, an oil-pump in the said base portion actuated from the compressor-driving mechanism and discharging into the said chamber, and oil-conveying ducts extending from below said cross-head guide to the said oilingopenings at the drive-shaft, substantially as and forthe purpose set forth.

ELIEL L. SIIARPNECK.

In presence of- M.-J. Fnos'r, J. H. LEE.

Images