US1843338A - Pumping mechanism - Google Patents

Description

Feb. 2, 1932. REPLQGLE 1,843,338

PUMPING MECHANISM Filed Jan. 18, 1928 3 Sheets-Sheet l INVENTOR 7 Feb. 2, 1932. REPLQGLE 1,843,338

PUMPI NG MECHANI SM Filed Jan. 18, 1928 :5 SheetLs-Sheet 2 INVENTOR A/Vf' '5. REPLUGLE.

6 ATTORNEX Feb. 2, 1932. J. B. REPLOGLE PUMPING MECHANISM Filed Jan. 3.8, 1928 3 Shqets-Sheet 3 mm V/ mm R v 5 9 7 J BY 3 TTORNEY Patented Feb. 2, 1932 James B. REPLOGLE, or person, iircmeaitnssrenon To JAMES B. REPLOGLE LABO- naronrns INC., on BOSTON, MessAoi-rUsErrs, A coaroaa'rron or MASSACHUSETTS ruivirrnejmncnnnrsivr 7 Application filedfianuary 18, 1928. Serial No. 247,533.

This invention relates to pumping mechanism and particularly to a type thereor adapted for use as the compressor of mechanical refrigerating units, the principal object being 15 the provision of a pumping mechamsm that 1s simple in design and constructi'omsilent in operation, efhcient in use, and economical to manufacture. V

Another ob ect 1s to provlde a pumping mechanism in which all wearing surfaces are rormed of hardened steel.

Another 0b160t is to provide a pumping mechanism comprising a cylinder block which rotates about a line perpendicular to theaxes of the cylinders and in which the pistons rotate with the cylinders about a line eccentric to the axis of rotation of the cylinder block, whereby a relative reciprocation is caused between the cylinders and pistons, without actual reciprocation, which is utilized to effect a pumping action.

Another object is to provide apumping mechanism comprising a cylinder' block rotat able about a line perpendicular to the axes of the cylinders, and pistons rotatable with the block about a line eccentric to the axis of rotation thereof, a stationary head being provided for the cylinders and being provided with ports whereby the cylinders are ported in a suitable manner upon rotation of the cylinder block. 1 V

Another object is to'provide a compressor mechanism of the type described wherein the thrust on the pistons during the compression stroke is taken up by a wearingsurface independent of any sealing surface forthe fluid being pumped. V

Another object is to provide a compressor mechanism including a cylinder and piston stroke both at its head and at a point'adjacent the head of the piston when the piston is at the end of its suction stroke. v

Another object is to provide a pumping mechanism comprising a cylinder block having a plurality of radially extending cylinders formed therein, the block being rotatable about a line perpendicular to the axes of the cylinders, and a piston for each cylinder being pivotally connected to an anchor member wherein the cylinder is ported on the suction Y rotatable about a line parallel with and eccentric to the axis of rotation of the cylinder Y block, the cylinder block being driven at the same speed as the anchor member by means of members fixed to the anchor member and slidably engaging the cylinder block.

A further object is to provide a device of the type described comprising a sealed housing in which an. axle member provided with an eccentric is fixed,acylinder block being .rotatablyreceived on the eccentric and being provided with pistons, the axle memberbe- 'ing. provided with-anchor members rotatably mounted thereonon either side of the eccentric and connectedtogethe r by tie members which extend through openings in thecylinder. block and contact with the edges thereof, the pistons. being connected by suitable links to the anchor members whereby upon rotation of the cylinders and pistons the distance between-the piston face and eccentric is caused to decreaseandincrease, and the eccentric being provided with suitable port openings which are opened and closed With respect to the various cylinders and in proper sequence upon rotation of the cylinder, the ports being connected by suitable axial passages in the axlemember to suitable inlet and outlet ports.

The above being among the objects of the present invention the same consists in certain features of construction and combinations of parts to be'hereinafter described with reference to the accompanying d-r-avvings, and then claimed, having the above and other objects in view.

In the accompanying drawings which illustrate a suitable embodiment of the present invention, and in which like numerals refer to like parts throughout the several different views, w r V -Fig. 1 is a vertical sectional View taken through the center of a compressor mechanism'as'on the line 1-1 of Fig.3.

Fig. 2 isaa sectional view taken on the line 2-2 of Fig.1.

Fig. 1', the lower half of the housing being axle member.

. Fig. 3 is a view'takenon the line 8-3 of Y removed to better illustrate the construction.

5 is a view taken on line 5-5 of 6 is a sectional view taken on the line f Fig. 5.

7 is a sectional view taken on the line of Fig. 5.

Fig. 8 is an enlarged vertical sectional view taken centrally through the combined packing and bearing for the drive shaft at the lower end of the lower housing half.

Fig. 9 is a view of the combined packing and bearing taken on the line 99 of Fig. 8.

Fig. 10 is a view taken on the line 10-10 of Fig. 1.

The present invention deals with a pumping mechanism which is particularly adapted for use as the compressor of refrigerating mechanisms of the mechanical compression type, and provides a construction that is relatively noiseless in operation, vibrationless, compact and of extremely long life. As shown in the drawings it comprises a casing composed of an upper half 10 and lower half 11 of identical contour, each of which is provided with a peripheral flange 12, the flanges being secured together by bolts 13 and nuts 14. Each casing half is provided with a central tubular neck portion 15. Received within the neck portion 15 of the upper half 10 is a sleeve member 16 secured against movement therein by the nut 17. Extending through the sleeve member 16 and fixed against movement therein by the nut 70 is an axle member 18 which extends into the interior of the housing where it is slightly enlarged as at 19 and 20 concentric with the portion 18, and is provided with an eccentric 21 between theportions 19 and 20. Rotatably received on the eccentric 21 is a cylinderbloclr 22 having formed therein four radially disposed cylinders 23 which are closed at their inner ends by the eccentric 21. The cylinder block 22 is held against axial movement relative to the eccentric 21 by the flanged collar members 2 1 which are received on the portions 19 and 20 and secured in contact with the sides of the eccentric 21 by screws such as 25 as indicated in Fig. 4; with the flange portions thereof over-lapping the joint between the eccentric 21 and the cylin der block 22. Rotatably received on the portions 19 and 20 above and below the collar members 24 are a pair of spider or anchor members 26 and 27 each of which is provided with four equally spacedradially extending arms 28. The corresponding arms 28 of the spiders 26 and 27 are secured together in spaced relationship by means of tie rods 29 and nuts 30, the tie rods 29 extending through openings 31 in the cylinder block 22. The openings 31 are each of a diameter equal to double the eccentricity of the eccentric 21 with respect to the axis of the shaft 18 plus the diameter of the tie rods 29 so that upon rotation each tierod will be constantly in contact with the edges of its corresponding opening 31, and when driving power is applied to the spider 27, as will be described, the spider 27 through the tie rods 20 in contact with the edge of the openings 31 will cause the cylinder block 22 to be rotated in exact constant angular relation therewith, and due to the relative motion of each of the tie rods 29 with respect to the openings 31 the driving force to the cylinder block will always be through that tie rod which is in contact with that portion of the corresponding opening 31 more advanced in the direction of rotation than the others.

In each of the cylinders 23 a piston 32 is received, and projecting vertically up through each of the pistons and perpendicuar to their axes is a pin 33 which extends both above and below the cylinder block which is provided with slots 34 in the upper and lower surfaces of the wall of its cylinders to permit the necessary reciprocating movement of the pins 33 with the pistons 32. The pins 33 are anchored against movement along their axes by suitable locking means 35. A link or connecting rod 36 is pivotally secured by the bolts 37 and nuts 38 to the spiders 26 and 27 between each of the arms 28 and extend outwardly therefrom with their outer ends rotatably received on the ends of the pins These links or rods 36 thereby tie the pistons 32 at a predetermined distance from the axis of the axle 18. It will thus be apparent that upon rotation of the cylinder block 22 and cor esponding rotation of the assembly comprising the spider mem bers 26 and 27, tie rods 29, pins33 andpistons 32, and due to the fact that this assembly has an axis of rotation independentof and parallel to the axis of rotation of the cylinder block the pistons will have a relatively changing relation within the cylinders with respect to the eccentric 21 w ich terminates the cylinder opening and acts as and may be termed as a cylinder head; depending upon the particular phase of rotation that they happen to be passing through. When the device described is to be employed as a compressor, the pistons 32 are preferably so formed that their inner ends come into almost contacting relationship with respect to the surface of the eccentric 21 when in position closest to the eccentric, their faces being curved to conform to the curve of the surface of the eccentric 21 so as to cut down the clearance volume between them and the eccentric when in this position.

The cylinders 23 are ported in the following manner. An axial opening 39 is provided in the portion 20 of the axle 18 and leads from the lower end thereof to a point within the eccentric 21 where it meets the transverse opening 40 which emerges at the surface of the eccentric at such a posit-ion that its extreme edges are in simultaneous engagement with'the adjacent edges of .the

cylinder having its piston 1n most remote relation to the surface of the eccentric and the following cylinder respectively." Another axial opening 41 is provided in the axle .18 .and extends therethrough from its upper end to a point within the eccentric 21 spaced from the opening 39. An opening 42 connects the opening 41 with the exterior surface of the eccentric 21 at a point thereon which lies at the diametrically opposite point on the ec-.

centric 21 from the point where the opening 40 intersects it and in the same relationship with respect to the remaining two cylinders. As indicated in Fig.2 the size of the openings 40 and 42 on the surface of the eccentric 21 is slightly larger thanthe distance between the adjacent edges of adjacent cylinders 23 as measured on the surfaces of the eccentric 21, so that the openings 40 and42, both which serve as and are referred to as ports, are in communication with more than one cylinder at a particular time during rotation of the cylinder block 22 onthe eccentric Referring to Fig.2 and considering the cylinder block to be rotated in an anti-clockwise direction as indicated by the arrow shown in that figure, it will be apparent that the distance between the faces of the pistons 32 and the eccentric 21 in moving from the left hand side of the figureto the right in rotating with the cylinder blockv will increase, and in moving from the right handside of the figure to the left hand side thereof will decrease. When the mechanismis in the position indicated in Fig. 2 the inner walls of the cylinder block substantially close the ports 40 and 41. Considering the left hand piston in that figure, it will be apparent that it is at the end of the compression phase and its cylinder has just been closed to communication with the outlet port 41. Asthis piston moves downwardly during operation through a distance of 90 it will assume the position indicated by the lower piston in that figure. During this phase of rotation it will be apparent that its cylinder has been closed to communication with either port 40 and 42 so that a nearly complete vacuum has been set up in the cylinder. It will also be apparent .th at it is just being put into. communication wi+h the inlet port 40. During the next 90 of movement the piston will move to the po sition indicated by'right hand piston in Fig. 2, and during this phase of movement its distance from the eccentric 21 will increase and at the same time the cylinder will be in com munication with the inlet port-4O which will allow the fluid beingpumped to flow into the cylinder through the port 40 and opening and will be cut ofi'from communication with the inlet port 40 at the end of this phase of movement. i

It is to be noted at this poi-ntthat in order to increase the volumetric eificiency of the device at high rotational speeds, I extend the slots 34 inwardly towardsthe center of the .cylinder block a sufiicient distance so that when the pistons 32 are at the most remote phase from the eccentric their ends uncover the inner ends of the corresponding slots 34 as indicated at 60,thereby providing an additional port for the entrance of the fluid being conducted to the cylinders. While this feature is of markeda-dvantage; where the gas to be compressedis fed into the interior of a housing enclosing the mechanism as shown, it will, of course be necessary to eliminate the same where no such'housing.

of movement inasmuch as the cylinder will not be in communication with either port 40 or 42, the fluid which has been drawn into the'cylinder through the inlet port 40 will be partially compressed as the distance of its piston from the eccentric 21 decreases; During the next phase of movement the piston will move through an arc of 90 to the first mentioned position in which-its distance from the eccentric approaches zero, and during which phase of movement its cylinder is in communication with the outlet port, 42, the fluid in the cylinder thus being driven out of the same and into the port 42 where it is conducted to the opening 41 and discharged from the'mechanism. V

In practice I prefer to support the mechanism in an axially vertical position as indicated in Fig. 1, supported on a'base such as 43 by means of standards 44 above an electric motor 45 or other suitable driving means. The motor 45 is provided with a shaft 46 to the upperend of which I secure the hub '47 of a fan 48 by means of a screw 49. The blades of the fan 48 are each provided with an upwardly extending tongue 50 preferably struck out from the metal of the blades. The

motor is'connected to the mechanism in the following manner. A shaft 51 ofrelatively small diameter is provided .with tapered squared ends 52. To the upper squared end 52 issec'ure d a member 55 which is closelyv received in the interior of the spider member 27 and is provided with radially extending pins slight misalignment betweenfthe: axes of the shaft 51 and the spider 27. The lower squared end 52 is provided with a cross member 58 secured thereto by the nut 59 and has its outer ends bent downwardly to provide attaching flanges. A coil spring 60 is held under tension between each end of the member 58 and each of the tongues 50 on the fan 48 thus resiliently connecting the shaft- 51 to the fan 18 for equal rotation therewith. This connection relieves any shock that otherwise might be transmitted between the motor 15 and the pump mechanism and serve to float the shaft 51 axially above the fan 18.

I provide a novel means for sealing the 4 lower end of the casing half 11 from leakage about the shaft 51. This means, as best shown in Figs. 1, 8 and 9, comprises a cup shaped member 61 which is closelyreceivef in the neck portion 15 and is provided with an enlarged opening 62 in its otherwise closed end. The open end of the cup is provided with an outwardl extending radial flange 63 adapted to seat on the end surface of the lower neck portion 15. The shaft 51 projects through the cup the ends of which are closed by the split washers 6 1 and 65. Immediately surrounding the shaft 51 between the washers 64: and 65 is a mass of cellulose material 66 preferably impregnated with deflocculated graphite, and compressed between this cellulose material and the sides of the cup is a mass of rubber 67 vulcanized in place. This provides a sealing means for the shaft 51 which is extremely long in life and substantially frictionless. The assembly comprising the cup 61, washers 64: and 65 and the material within the cup is secured in place-by the nut 68, a suitable gasket such as 69 being provided for preventing leakage between he outside of the cup and the neck portion 15. Should the bearing surfaces between the material 66 and the shaft 51 wear to such an extent that leakage occurs, it is only necessary to remove the nut 51 and unhook the springs 60 whereupon the cup and the parts carried thereby with the shaft 51 may be re moved and a new assembly of the same be inserted in its place.

In making the above described packing for the shaft 51 I prefer to follow the fol lowing process. I tightly wind the shaft 51 for the proper distance with a suitable cellulose material such as long fibre cotton. I then impregnate the cellulose material with deflocculated graphite as by dipping it in an aqueous mixture of the graphite. The washer 64 is then placed about the shaft 51 and inserted in the cup 61 in contact with the inwardly turned ends thereof. A predetermined mass of rubber followed by the washer 65 is then forced into the cup between the sides thereof and the cellulose material 66 and the assembly is then subjected to a suitable vulcanizing heat which vulcanizes the rubber to the cup and fills all possible interstices in the cellulose material with rubber. If the cup is formed of brass the sulphur in the rubber will form a sulphite of the same which will firmly bind the rubber to the walls of the cup and prevent any possible leakage at that point. Oil under pressure is then forced into the rubber with the result that the gradually growing action of the rubber because of the action of the oil upon the same tends to constantly compress the cellulose material about the shaft 51 and thereby take up any possible wear that may occur at this point.

The fluid to be pumped may be introduced into the interior of the housing through the screw collar 53'which projects through the upper housing half 10 and is held in place by means of the nut 54. Then employed as a refrigerant compressor the gasified refrigerant entering the housing through the collar 53 is directed against the moving mechanism, and the oil carried by the refrigerant is thereby discharged upon the moving parts and serves to lubricate the same. I prefer to secure a small deflector such as 70 in the path of the refrigerant flowing into the casin through the collar 53 so as to deflect some OI the refrigerant and oil carried thereby against the upper end of the central bearing for the upper spider member 26 so that the oil will be deposited upon the same so as to lubricate it and will then be carried out wardly and lubricate other bearing surfaces. The gasified refrigerant and the oil thrown from the moving parts collects in the bottom of the lower housing half 11 where it is drawn into the member 27 and then upwardly through the opening 39 and port 4L0 to the cylinders where it is compressed and discharged as previously described. By positioning the mechanism vertically as shown, the oil in the casing is collected in the bottom of the same and is thereby prevented from coming in further contact with and being thrown about by the rotating parts, which would thus offer resistance to the rotation of such parts. In fact, inasmuch as the intake passage 39 is positioned near the bottom of the casing, no great amount of oil may collect in the casing, but only sufficient to afford ample lubrication for the bearing for the shaft 51 and serve to aid in sealing the same against leakage.

In supporting the device with its axis extended vertically as shown, it will be apparent that a thrust is set up due to the weight of the assembly comprising the spiders 26 and 27, tie rods 29 and other connected parts. This thrust is taken up at the point of contact between the upper collar 24 and the upper spider 26, and the contacting surfaces at this point are beveled as indicated to provide more perfect and longer wearing surfaces.

In the preferred embodiment of this pump mechanism I form all of those parts whose surfaces may be subject to wear of steel, and

harden and grind such surfacesso that all wearing surfaces'are hardened steel against hardened steel. This insures substantially no wearing of the parts in operation which would otherwise tend to permit leakage of the gas being compressed during the compression phase of operation and thereby render the operation of the device less efiicient, and provides a construction in which substantially no service is required. The loss of efliciency usually present due to friction of piston rings and similar devices is mized in this device by the use of hardened ground and lapped steel or other hard surfaces, as close fits can be produced without prohibitive commercial expense sufficiently close. to reduce leakage to permissible amounts. Such fits areimpractical with softer materials and render piston rings imperative. Z I

It will be further apparent that by the con-- struction shown the possible wear due to the load exerted on the pistons during the compression stroke will in no way tend to produce a leakage of gas from the cylinders due to such wear: This is due to the fact that the act of compression-exerts no force on the cylinders radially of the eccentric, the actual force being directly between the eccentric and the face of the pistons, the reaction being transmitted through the pistons to the pins 33 and through the links 36 to the spiders 26 and 27 and where it is taken up between the same at the point where they bear on the portions 19' and 20 of the eccentric axle. Any wear from this cause thereby takes place between the spiders26 and27 and theportions 19' and 20 respectively, which wear has no effect whatever on the seal between the cylinder block 22 and the eccentric 21. All of the parts are, of course, amply lubricated when the device is being employed in a refrigerat ing system by the lubricating oil carried by the refrigerant, because such oil will be directed into exterior contact with these parts and deflected to .the center bearing upon entering the housing and will be carried through the interior. of the mechanism while the refrigerant is being drawn into and com pressed within. the same. i f

Although a device of this construction may be made with only one cylinder, it is preferable that at least two and preferablymore cylinders are provided. Where two ormore cylinders are provided the device may be perfectly balanced dynamically inasmuch as the cylinder block has only rotary motion and the assembly comprising the spiders-26 and 27, rods 29, pistons 32, pins 33, and links 36 have an only rotary motion withoutreciprocation. With the exception of the very slight swinging movement of the links 36 on the bolts 37. no'actual reciprocation, except the relative reciprocationof the pistons in the cylinders, takes place, which results in the.

elimination of reciprocatory forces andthis permits the mechanism to be rotated athigh speeds without setting up any secondary or higher vibrational forces during ope'ration such as are'bound to be present in the usual piston type of pump construction. I Further,

when a plurality of pistons are employedin' a device of this type, the resistance which is built up by the compression of the fluid to the driving of the mechanism, and which is commonly referred. to as. the stall torque, is cut down and merged by them whereby a more even torque is produced which permits I the mechanism to be driven by motor having less torque than would otherwise be necessary. In view of the fact that all the motion is substantially rotary which thereby permits the mechanism to be driven in a relatively higher speed than in the conventional constructions, a relatively greater amount of fluid may be pumped with the device shown than in a mechanism of conventional constructions, a relatively greater amount of fluid may be pumped with the device shown.

than in a mechanism of. conventional construction and of the same size. This permits a relative reduction in the size of thedevice which results in less weight and permits it.

merous modifications which may be nece ssary ordesirable to adapt it for use for one purpose or another, such as, for instance, the increasing of the size of the ports in theeccentrio to adapt the construction for use in pumping liquids, which modifications will be readily apparent to those skilled in the art, and formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

1. In combination, a fixed stationary mem her, a cylinder rotatable about said member and closed at one end thereby, a piston in I said cylinder rotatable about a line eccentric to the axis of, rotation of said cylinder,'a.

port in said member communicating with said cylinder upon rotation thereof, and a port in saidcylinder controlled by the reciprocation of said piston therein. 2. In combination, animperforate casing,

a centrally disposed stationary member fixedat one end in said casing, an eccentricformed" on said member, a cylinder block rotatably mounted on said eccentric and provided with cylinders closed at their inner ends by said eccentric, pistons in said cylinders, means connecting said pistons to said member in a constant radial relation therewith, an inlet port in said eccentric, an outlet port in said eccentric, a passage connecting said inlet port with a point within and adjacent the bottom of said casing, a passage connecting said outlet port with a point exterior to said casing, and an inlet passage for said casing entering said casing at a point above said cylinder block.

3. In a device of the type described, a stationary member provided with an eccentric, a cylinder block rotatably mounted on said eccentric, radially disposed cylinders formed in said block closed at their ends by said eccentric, pistons in said cylinders, said block being provided with a plurality of axially parallel openings, a spider member rotatably mounted. on said member on either side of the said eccentric, rods extending between and secured to said spider members passing through said openings and slidably engaging the edges thereof, a pin secured in each of said pistons perpendicular to the axes thereof, connecting rods pivotally connecting said pins and said spiders, and inlet and outlet ports in said eccentric.

4. In a fluid pump, in combination, an imperforate casing, a vertically disposed support in said casing, a cylinder block rotatable on said support, a member rotatable on said support above said cylinder block and eccentrically with respect to said cylinder block, a cylinder in said cylinder block, a piston in said cylinder, means connecting said member and said piston whereby said piston is caused to rotate about the same center as said member, said support being provided with an inlet port connecting said cylinder with the interior of said casing adjacent the bottom thereof, said'casing being provided with an inlet opening adjacent the top thereof, and a deflector for deflecting fluid entering said opening against said member adjacent its point of bearing on said support.

5. In a compressor structure through which gas and oil travel in cycle, a sealed casing having an inlet through which gas and oil are drawn by suction, a compressor means in the casing having an exposed bearing, a deflector directing at least some of the incoming gas and oil upon the bearing, and means through which gas compressed by the compressor passes from the casing.

(3. In combination, a sealed casing, a fixed stationary member in the casing, a cylinder rotatable about said member and closed by one end thereof, a piston in the cylinder, a pair of duct means establishing communication of the cylinder with the exterior of the casing through the stationary member,

and another duct means controlling communication between the cylinder and the casing for supplying an additional quantity of fluid thereto, said duct means being controlled by the piston.

7. In a compressor, a fixed cylinder head provided with an eccentric portion, a cylinder block rotatably mounted on the eccentric portion of the head, radially disposed cylinders formed in the block and closed at their inner ends by the eccentric portion of the head, pistons in the head, said block being provided with a plurality of axially extending parallel circular openings, a spider member rotatably mounted on the cylinder head on either side of the eccentric portion, rods extending between and secured to said spiders and passing through the openings and engaging the edges thereof, the openings having a diameter equal to double the eccentricity of the eccentric portion of the head plus the diameter of the rod passing therethrough, driving means connected with one of the spiders, and link connections between the pistons and the spiders maintaining the pistons concentric relative to the axis of the cylinder head.

8. In a compressor, a fixed cylinder head provided with an eccentric portion, a cylinder block rotatably mounted on the eccentric portion of the head, said block having openings therein parallel with the axis, pistons in the cylinder block, spiders on either side of the eccentric portion of thecylinder head, pins connecting the spiders and extending through the openings in the cylinder block, means for rotating the spiders, the engagement of the pins with the edges of the cylinder block openings causing rotation of the block around the eccentric portion of the cylinder head, and means maintaining the pistons in a concentric relation with the cylinder head axis.

9. In a compressor, a fixed cylinder head provided with an eccentric portion, a cylinder block rotatably mounted on the eccentric portion of the head, said block having slotted cylinders open to the cylinder head, means for rotating the cvlinder block including connected s iders. pistons in the cylinders, pins ex tending through the pistons and cylinder slots, and links pivotally associated intermediate the spiders and pin ends maintaining the pistons concentric with the cylinder head.

10. In a compressor, a fixed cylinder head having an eccentric portion, an apertured cylinder block rotatably mounted on the eccentric portion of the head, said cylinder block having slotted cylinders closed at one end by the head, a pair of spiders arranged one on either side ot the eccentric and concentric with the head, pins extending through the apertures in the block and securing the spiders rigidly together, said pins engaging the edges of the block forming the apertures to rotate the block, means for rotating one of JAMES B; REPLOGLE.

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