US2471706A - Crankpin grinding machine - Google Patents

Description

May 31, 1949. A. v. SPONGBERG ET AL ,7

-CRANKPIN GRINDING MACHINE Filed Feb. '7, 1946 4 Sheets-Sheet l gluon-HIM HA WW 6. PASHO m 3 3 M LO. W F] 1 May 31, 1949.

' Filed Feb. 7, 1946 A. v. SPONGBERG T L 2,471,706

CRANKPIN GRINDING MACHINE 4 Sheets-Sheet 2 25 27 54 53 37 I 5 4 as E 8 T Fig. 3

gvwa/wtom ALBIN SPONGBERG HARRY G. PASHOIAN y 1, 1949. A. v. SPONGBERG ET AL 2,471,706

CRANKPIN GRINDING MACHINE Filed Feb. 7, 1946 4 Sheets-Sheet 3 55 Flg. 5 v grwe/rm ALBIN 5PONGBERG HARRY GPAsHOIAN Wm-wm WW y 1949. A. v. SPONGBERG ET AL 2,471,706

CRANKPIN GRINDING MACHINE Filed Feb. 7, 1946 4 Sheets-Sheet 4 ALBIN SPONGBERG 3% HARRY GPA5}-\0\AN Patented May 31, 1949 UNITED STATES PATENT OFFICE CRANKPIN GRINDING MACHINE Albin V. Spongberg and Harry G. Pashoian, Worcester, Mass, assignors'to Norton Company, Worcester, Mass., a corporation ofMassachusetts Application February 7, 1946, Serial No. 645,988

Claims. 1 This invention relates to grinding machines, and more particularly to a double head crank pin grinding machine.

One of the objects of this invention is to provide a readily controllable crank pin grinding machine. Another object is to provide a crank pin grinding machine with a pair of opposed aligned pot chucks for-supporting and synchronously rotating the opposite ends of a crank shaft.

Another object of the invention is to provide acontrol valve for controlling the admission to and exhaust of fluid from the hydraulically operated pot chucks. Another object of the invention is to provide a control valve which is arranged so that if the fluid pressure fails, the valve will automatically close to lock a column of fluid within the work clamping mechanism so that the clamp will not be released.

A further object of the invention is to provide a pot chuck control valve which is inter-connected with the main control valve of the machine so that when a grinding operation has been completed and the main control valve shifted to cause a rearward movement of the wheel slide, the pot chuck control valve will be shifted under the influence of fluid under pressure to allow fluid to exhaust from the clamping cylinders and thereby to release the clamping jaw to facilitate a loading operation. Other objects will be apparent from the foregoing disclosure.

This invention accordingly consists in the fee.-

tures of construction, combinations of elements,

and arrangements of parts as will be exemplified in the structure to be hereinafter described, and

the scope of the application of which will beindicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of the invention,

Fig. 1 is a front elevation of a crank pin grinding machine embodying the invention;

Fig. 2 is a vertical sectional view, on an enlarged scale, through the right hand work head showing the hydraulic work clamping mechanism;

Fig. 3 is an end elevation, partly in section. on an enlarged scale, of the right hand pot chuck;

Fig. 4 is a cross sectional view, on an enlarged scale, taken approximately on the line 4-4 of Fig. 2, through the control valve for controlling the hydraulically operated pot chucks;

Fig. 5 is a cross sectional View, taken approximately on the line 5-5 of Fig. 4; and

Fig. 6, is a hydraulic piping diagram of the hydraulic system.

A crank pin grinding machine has been illusscribed. Both of the work driving mechanisms which supports a longitudinally movable work supporting table H. The table II serves as a support for a work driving and rotating mechanism comprising a pair of alignedspaced work heads l2 and I3" which are each provided with rotatable spindles for supportinga pair of spaced pot chucks l4 and I5 respectively.

The base It! also serves as a support for a transversely movable wheel slide l6 which is slidably transversely relative to the base In on suitable ways (not shown). The wheel slide 16 serves as a support for a rotatable grinding wheel H. The grinding wheel I! may be driven in any suitable manner such'as, for example, an electric motor I8 mounted on the upper surface of the wheel slide I6. The motor I8 is provided with an armature shaft I 9' which supports a multi V'-groove pulley 20. The pulley 20' is drivingly connected by multiple V-belts 2| with a multi V'-gr0ove pulley (not shown) which is mounted on the right hand end of the wheel spindle to rotate the grinding wheel H.

The pot chuck I4 is mounted on the right hand end of a work head spindle 22 which is rotatably journalled in bearings in the work head I2.

A work head spindle 25 is rotatably journalled in bearings 26 and 2'! which are in turn supported within the Work head l3.

A work driving mechanism is provided for synchronously rotating the work spindle 22 and 25 respectively so as to rotate the opposite ends of a crank shaft 28 to'be ground. This driving mechanism may comprise an electric motor 3!] which is preferably mounted within the base Ill of the machine. The motor 30 is connected by means of a link chain 3| with a rotatable shaft 32. The shaft 32 is operatively connected by means of a link chain" 33 to rotate the spindle 2-2. The shaft 32 is also provided with a sprocket 34" which is connected'by means of a link chain 35 with a sprocketBG which is-keyed to a rotatable shaft 31 journalled' Within a bearing 38. The bearing 38 is fixedly mounted within the housing 39'; The shaft 3Tis drivingly'connected with work spindle 25 in a manner to be hereinafter deare identical and it is therefore not believed to be necessaryto illustrate both work driving heads and mechanisms in detail.

The pot chucks l4 and [5 are identical in construction except that one chuck is right hand and the other left hand in arrangement. As illustrated in Fig. 3 pot chuck l5 has been shown in end elevation and partly broken away and shown in section. This chuck |5 comprises a half. bearing member 40 which serves as a support for an end portion 4| of the crank shaft 28. A clamping arm 42 is pivotally supported on a stud 43. The short arm of the clamping arm 42 is provided with a clamping jaw 44. The long arm of the clamping arm 42 is provided with a stud 45 which is connected to one end of a piston rod 46. The pot chuck is provided with a hydraulic cylinder 41 which contains a slidably mounted piston 48. The piston 48 is connected by means of a stud 49 with the piston rod 46. The cylinder 41 is provided with a port 50 which is arranged to admit fluid under pressure to a cylinder chamber 5|. It will be readily apparent from the foregoing disclosure that when fluid is admitted to the cylinder chamber 5|, the piston 48 will move toward the right into the position illustrated in Fig. 3. This movement rocks the clamping arm 42 in a counter-clockwise direction so that the clamping jaw 44 engages and clamps the portion 4| of the crank shaft 28 into rigid engagement with the half bearing support 40. The pot chuck I4 is identical in construction and consequently has not been illustrated in detail.

A universal driving connection 52 is provided between the shaft 31 (Fig. 2) and the work head spindle 25. This universal connection comprises a pair of diametrically opposed rollers 53 and 53a which are rotatably supported on studs which are fixed relative to the shaft 31. The opposed rollers 53 and 53a slide in elongated slots 54 and 54a which are formed in a flanged member fixed to the spindle 25.

It is desirable to provide a suitable control valve for controlling the admission to and exhaust of fluid from the clamping cylinder 41. A control valve 55 (Figs. 4 and 5) is provided with an integral flanged member 55 which is in turn fixedly mounted on the right hand end of the housing 39. This control valve is preferably a piston type valve having a slidably mounted valve member 51. The slidably mounted valve member 51 comprises integral valve pistons 58 and 59 which are arranged so that the efiective area of the piston 59 is considerably greater than the eiTective area of the piston 58. Fluid under pressure direct from a fluid pump to be hereinafter described passes through a pipe 65 and a port 6| into a valve chamber 52 formed at the right hand end of the valve piston 58. Fluid entering the valve chamber 62 forces the valve member 51 toward the left into the position illustrated in Fig. 4 so that fluid under pressure entering the chamber '62 raises the ball check valve 63 and passes into a chamber 64, through a passage 55 into a chamber 56 and then passes through a pipe 68. The pipe 68 extends through the hollow work head spindle 25 and is connected at its other end to the pot chuck 5. Fluid under pressure passing through the pipe 68 passes through a passage 69 and through the port 50 into the cylinder chamber 5| to swing the clamping arm 42 in a counter-clockwise direction to clamp the work piece within the pot chuck l5.

In order to unclamp the work piece, fluid may be passed through a pipe ill through a port 1| into a chamber 12 formed at the left hand end of the valve 55, this pressure being the same as that admitted to the chamber 62. Due to the larger effective area of the piston 59 fluid under pressure admitted to the chamber 12 will cause the slidably mounted valve member 51 to move toward the right so that fluid from the cylinder chamber 5| may exhaust through the port 50, the passage 59, the pipe t5, the chamber 66, and out through a port 13 (Fig. 4) through a valve chamber 14 formed between the valve pistons 58 and 55 and may pass out through an exhaust port 75 and pipe 1'5 which returns exhausting fluid to the reservoir to be hereinafter described.

A similar control valve 55a is provided for controlling the admission to and exhaust of fluid from the pot chuck 4. The control valve 55a is provided with integral flanged member 55a which is fixedly mounted on the housing 35a. The details'oi the valve 55a have not been illustrated since this valve is identical with valve 55 above described. Fluid under pressure from the fluid pressure pump is passed through pipe 68a to actuate the clamping jaw of the pot chuck M to clamp the left hand end of the work piece 28 in position within the pot chuck l4. When it is desired to release the clamping jaw, fluid under pressure is passed through a pipe 78a to shift the control valve 55a to shift the valve to an exhaust position so that the clamping jaw of the pot chuck I4 will be unclamped.

In order to attain one of the objects of this invention it is desirable to construct the valve 550. so that in case the fluid pump fails or there is an appreciable drop in the pressure of the fluid within the system, the slidably mounted valve member 51 will be moved toward the right a suiiicient distance so that the valve piston 58 closes the port connected to the ball check valve 63 and thus looks a column of fluid within the passages, chambers and the cylinder chamber 5| to hold the clamping jaw 44 in a clamped position thus preventing release of the work piece from the pot chuck I5. This mechanism preferably comprises a slidably mounted sleeve 7'! which surrounds a stud 18 which is screw threaded into the slidably mounted valve member 57. A compression spring 19 surrounds the stud l8 and it is contained within apertures formed within the valve piston 55 and the member V1. The compression of the spring 19 is such that in case fluid pressure drops within the valve chamber 52, the compression of the spring 79 will move the slidably mounted valve member 51 toward the right until the'head of the stud 13 engages the left hand end of the member 11 in which position the valve piston 58 has closed oil the port connecting the valve chamber 82 with the ball check valve 63 thus automatically look-- ing a column of fluid within the clamping cylinder 43' and the connecting passages and chambers.

It is desirable that the passage of fluid through pipes 78 and ma be automatically controlled so that after a grinding operation has been completed and the wheel slide I5 moved to a rearward or inoperative position, fluid under pressure will be automatically conveyed through the pipes 75 and 10a to unclamp the pot chucks I4 and i5 respectively. In order to obtain this desired resuit the pipes It and Mia are preferably connected with the main control valve of the ma chine which may be arranged substantially the same as that shown in the prior U. S. Patent to H. A. Silven No. 2,151,666, dated March 21, 1939, to which reference may be had for details of disclosure not contained herein.

The hydraulic control system has been illustrated in Fig. 5 in which a hydraulic cylinder 85 is provided with a piston 86. The piston 86 is connected by a piston rod 81 with the old and under pressure through a pipe 89 into the" left hand end of the cylinder 85 the piston 86 willbe moved toward the rightto transmit a corresponding movement to the wheel slide I6 and grinding wheel I 1. During this movement, fluid-within the right hand chamber of the cylinder 85' may exhaust through a pipe 89. I

A main control valve 90 is provided for controlling the admission to and exhaust of fluid" fromthe wheel feed mechanism above described.

to the work clamp mechanism above described and also to actuate a steadyrest to be hereinafter described;

A vertically movable steadyrest 91 is provided which may be moved vertically to and from an operative position. The details of this steadyrest have not been illustrated since this rest isidentical with that shown in the prior patent to Silven above described. The steadyrest 9i is connected to the lower end of a piston rod '92. A piston 93 is fixedly mounted on the upper end of the piston rod 92 and is slidably mounted within a cylinder 94. The steadyrest as illustrated in Fig. 6 is shown in an uppermost croperative position. When it is desired to lower the steadyrest to an inoperative position after a grinding operation, fluid under pressure from the control valve 90 is passed through the pipe 08 into a chamber formed at the upper end of the cylinder 90 to cause a downward movement of the piston 93 and the steadyrest 9|.

The table I I is arranged to be traversed longitudinally by a fluid. pressure mechanism comprising a cylinder 95' having a piston 99 slida'bly mounted therein. The piston 96'is connected toa double end piston. rod which extends through the opposite ends of the cylinder 95 andis connected: to brackets. depending from the underside of the table II. It will. be readily apparent from the foregoing disclosure that when fluid under pressure is passed'through a .pipe 98 into a chamber formed at the left hand end of the cylinder 95;

the piston 96 together with the table II will be it. is desired to'traverse the table II toward'the left, fluid may be admitted through the pipe 99 and exhausted through the pipe 98.

A control valve I00 is. provided for controlling admission to and exhaust of fluid from the table cylinder 95.

A main control lever I02 is pivotally mounted on astud I03 which is in turn mounted on a bracket I04. The bracket I04 is supported by a rock shaft I05; It-will be readily apparent from the foregoing disclosure that the control lever I02 maybe rocked about the stud I03 so as to control the position of the valve 90 in a manner substantially the same-as that shown in theabove mentioned Silven patent and may be moved in a plane at right angles thereto about the axis of the stud I05 which movement serves to control the position of the valve I00.

In order to provide a self-contained fluid pressure system for the machine, a reservoir I08 is formed within the base I0 of the machine, A motor driven fluid pressure pump I06 is operatively connected to draw fluid through pipe I01 from the reservoir I08 and to pass fluid under pressure through a pipe I09: Fluidunder'pressure in thepip'e I09pa'ssest'o. the control valve 90, the control valve I00 and simultaneously through the pipes 60 andit0a to thecontrol valves 55- and 55a to actuate the clamping jaws.

After agrinding operation hasbeen completed,

the lever [02' is rocked. in a clockwise direction about the axis of the stud I03 to move the valve "toward the right so as to pass fluidunder'pressure through thepipe'88'to-m0ve the wheel slide I6 and grindingwheel IT rearward'to an inopera tive position and at the same time to. move: the steadyrest 9 If downwardly to an inoperative position in a manner above described. When. the control valve 90 reaches its extreme right hand end position; fluid under pressure will pass through the pipe 10 and 10a" into control valves 50 and 50a respectively to unclamp the clampso that fluid'under pressure will be passed through the pipes (i0 and 60a to actuate the clamping jaws andthereby clamp the crank shaft within the'pot chucks: I4- and I5. After the control valve 90 has moved further toward the left, fluid under pressure will be passedzthrough the pipe 89 to cause a forward feeding movement of the grinding wheel and after a still further movement of the: valve 90-will be passed through a pipe IIPI to raise'the steadyrest 9| into an operating position relative to the work In case thereis a drop in fluid pressure within the pipes 60 and 600,, the released compression of the spring 19 will close the-port so as to look a column of fluid within the clamping cylinders and thus lock the clamping. jawsin a clamped position. After a grinding operation has been completed the lever I02 may be moved in a clockwise direction to cause the grinding wheel to move-to-an inoperative position and-the steadyrest to be lowered to an inoperative position. With the steadyrest and grinding wheel in inoperative positions, the control lever I02- may be rocked about the'axis of the stud I05 to actuate the valve I00 and thereby traverse the table II to position the next crank pin in an operative position relativeto the grinding wheel. I1. After all of the crank pins have been ground; the control lever I02 may be rocked in a clock wise direction. to shift the main control valve 90- to its extreme right hand position to unclamp the ground crank pin shaft.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are" successfully achieved. As many possible embodimerits. may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter'hereinbefore set forth, or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

We claim-:

1. In a crankpin grinding machine having a transversely movable rotatable grinding wheel, a work support including a pair of opposed aligned work heads. a rotatable spindle in each of said heads, a pot chuck on the adjacent ends of each of said spindles, a pivoted clamping jaw on each of said chucks, a piston and cylinder on each of said chucks to actuate said clamping jaws, means including a fluid pressure pump to supply fluid under pressure to each of said cylin ders, independent control valve on each of said heads between the pump and the chuck cylinders, each of said control valves comprising a slidably mounted valve piston, a port in each of said valves to convey fluid under pressure to the pot chuck cylinders, a compression spring in each of said valves normally to maintain said port closed, direct fluid connections with an end chamber in each of said valves to shift said valve against the compression of said springs to open said port and thereby admit fluid under pressure to actuate the clamping jaws, and fluid connections to convey fluid under pressure simultaneously to an end chamber at the other end of each of said valves to shift said valves so as to unclamp said Jaws.

2. In a crankpin grinding machine having a transversely movable rotatable grinding wheel, a pair of opposed aligned crank heads, a rotatable spindle in each of said heads, a pot chuck on the adjacent ends of each of said spindles, a clamping jaw pivotally mounted on each of said chucks, a piston and cylinder on each of said chucks to actuate said clamping jaws, means including a fluid pump for supplying fluid under pressure to said cylinders, a fluid actuated control valve on each of said heads, direct fluid connections between one end of said valve and the fluid pump normally to pass fluid under pressure direct from the pump to said cylinder, a manually operable main control valve for controlling the various mechanisms of the machine, and operative connections between said main control valve and the other end of said fluid actuated valve, said connections being arranged so that when the main control valve is shifted to a work unclamp position, fluid under pressure is passed to shift said fluid pressure actuated control valve to out off the flow of fluid under pressure to said cylinder and to open an exhaust port to allow fluid to exhaust from said chuck cylinder and thereby to unclamp said jaw.

3. In a crankpin grinding machine having a transversely movable rotatable grinding wheel, a work support comprising a pair of aligned opposed work heads, a rotatable spindle in each of said heads, a pot chuck on each of said spindles including a pivotally mounted clamping jaw and a piston and cylinder to actuate said jaw, a fluid pump, means including a control valve to control the admission to and exhaust of fluid from said chuck cylinder to clamp and release said clamping jaw, a spring normally to maintain said valve in a closed position, direct connections between the fluid pump and said valve to open said valve and clamp said jaw to hold a crankshaft in said chuck, and fluid connections to close said valve after a grinding operation has been completed so as to exhaust fluid from the chuck cylinder and thereby unclamp said jaw to release the finished crankshaft.

4. In a crankpin grinding machine having a transversely movable rotatable grinding wheel, a work support comprising a pair of aligned opposed work heads, a rotatable spindle in each of said heads, a pot chuck on each of said spindles including a pivotally mounted claimping jaw and a piston and cylinder to actuate said jaw, a piston type control valve including a slidably mounted valve member having a pair of spaced pistons each having differential efiective piston areas, a valve chamber in the opposite ends of said valve, a port in the end chamber adjacent to the smaller piston area which is connected to convey fluid under pressure to said chuck cylinder, a compression spring normally to maintain said port closed, direct fluid connections between said pump and said chamber to supply fluid under pressure to open said port against the compression of said spring so as to actuate said; clamping jaw, an exhaust port in said valve toi exhaust fluid from said chuck cylinder which is closed while pressure is supplied to hold the clamping jaw in a clamped position, and connections between a main control valve and the valve chamber adjacent to the larger piston area to shift said valve piston so as to close said port and open said exhaust port after a grinding operation has been completed to release said clamping jaw.

5. In a crankpin grinding machine having a transversely movable rotatable grinding wheel, a work support comprising a pair of aligned opposed work heads, a rotatable spindle in each of said heads, a pot chuck on each of said spindles including a pivotally mounted jaw and a piston and cylinder to actuate said jaw, a fluid pump, a piston type control valve including a slidably mounted valve member having a pair of spaced pistons each having differential efiective piston areas, a valve chamber in opposite ends of said valve, a port in the end chamber adjacent to the smaller piston area which is connected to convey fluid under pressure to said chuck cylinder, a compression spring normally to maintain :said port closed, direct fluid connections between said pump and said chamber to supply fluid under pressure to open said port against the compression of said spring so as to actuate said clamping jaw, an exhaust port in said valve to exhaust fluid from said chuck cylinder which is closed when pressure is supplied to hold the clamping jaw in a clamped position, and connections between a main control valve and the valve chamber adjacent to the larger piston area to shift said valve piston so as to close said port and open said exhaust port after a grinding operation has been completed to release said clamping jaw, said spring being arranged to close said pressure port and thereby prevent release of the clamping jaw in case of failure of fluid pressure.

ALBIN V. SPONGBERG. HARRY G. PASHOIAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 509,992 Wood Dec. 5, 1893 993,967 Debauche May 30, 1911 1,755,937 Steiner Apr. 22, 1930 FOREIGN PATENTS Number Country Date 687,096 Germany Jan. 22, 1940

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