US2708816A

US2708816A - Tapered cam grinder

Info

Publication number: US2708816A
Application number: US254499A
Authority: US
Inventors: Harold E Balsiger
Original assignee: Landis Tool Co
Current assignee: Landis Tool Co
Priority date: 1951-11-02
Filing date: 1951-11-02
Publication date: 1955-05-24
Anticipated expiration: 1972-05-24

Description

May 24, 1955 Filed Nov. 2 1951 H. E- BALSIG ER TAPERED CAM GRINDER 3 Sheets-Sheet 1 INVENTOR. I-Y/HEOLD [.flALs/sEE fiTTOPNEY y 1955 H. E. BALSIGER 2,708,816

TAPERED CAM GRJENDER Filed NOV. 2 1951 3 Sheets-Sheet 2 INVENTOR.

h /MOLD [.BALS/GER BY ATTORNEY United States Patent TAPERED CAM GRINDER Harold E. Balsiger, Waynesboro, Pa assignor to Landis Tool Company, Waynesboro, Pa.

Application November 2, 1951, Serial No. 254,499

9 Claims. (Cl. 51-105) This invention relates to machines for grinding cam shafts, particularly where some of the cams are tapered in one direction and others in the opposite direction.

The present method for grinding cam shafts of this type consists of a pivotally mounted wheel support which is shifted alternately between two angular positionscorresponding to the direction of the taper to be ground on the cams of the cam shaft. The principal disadvantage of this method of providing an angular relation between the surface of the cam to be ground and the grinding Wheel lies in the fact that when the Wheel base is swivelled the surface of the grinding wheel occupies a different longitudinal position relative to the work piece in each angular position to which it is adjusted. This .disadvantage may be overcome if the pivot point is placed in such position that it is slightly in advance of the peripheral surface of the grinding wheel in the direction of the work axis. Since the front of the grinding wheel overhangs to some extent the work carriage, to place the pivot point of the wheel base in advance of the grinding wheel would mean that it would have to be somewhere directly under the work carriage. This would introduce undesirable complications in machine design.

It is therefore an object of this invention to provide a machine for grinding tapers on the cams of a cam shaft wherein the pivot point for providing the angular relation between work and grinding wheel may be located to best advantage both as to effect on the work to be ground as well as on the design of the machine.

A further object is to provide means for swivelling the work carriage about an axis in fixed longitudinal relation to the grinding wheel.

A further object is to provide a swivelling base member for the work carriage.

Fig. l is a front elevation partially cut away to show the work swivelling pivot.

Fig. 2 is an elevation with the swivelling motor in section.

Fig. 3 is a partial plan view showing relation between grinding wheel, work surface and swivel pivot.

Fig. 4 is a partial end view partly in section showing the same elements as Fig. 3.

Fig. 5 is a hydraulic and electric diagram.

The means for automatically indexing carriage from cam to cam is described in detail in co-pending application Serial No. 209,160 filed February 2, 1951, now Patent 2,654,189 granted October 6, 1953.

The means for swivelling member 17 and work car riage 10 consists of a cylinder 195 attached tosaid slide member 17 and having a piston 196 slidably mounted therein. Piston

rods

197 and 198 extend through the ends of said cylinder to engage bracket 199 on bed 9. Adjusting screws 2111 and 202 in bracket 19 9 determine the extent of movement of member 17 about swivel point 18.

Operation Assuming carriage 10 to be in the extreme left-hand position with portion 59 of plunger 53 against stop 62,

2,708,816 Patented May 24, 1955 !ever 40 is moved to the right. Valve 20 is shifted to the right also, as is valve 30. With lever in this position, projecting member 80 thereon closes headstock limit switch 81, energizes relay 83 which closes contact 84- to complete the circuit to headstock motor 82. In the right-hand position, valve 2i) directs fluid under pressure from line 121 through line 22 to the head end of cylinder 11, causing piston 12 to move carriage 10 to the right until portion 59 of plunger 53 drops into the first notch in response to the action of spring 108 transmitted through valve 104, arm 103, shaft 101, and arm 102.

When portion 59 of plunger 53 drops into the first notch 60', lever 100, moving in a counterclockwise direction in response to the action of said spring 108, acts through yoke 160 to move along adjusting screw 161 until it engages stem 162 of valve 163 and moves said valve to the right so that ball 213, pressed by spring 214, slips out of groove 211, which locates said valve in the left-hand position, and into groove 212, which locates said valve in the right hand position. counterclockwise movement of lever 160 releases valve 170, which is moved to its right-hand position by spring 171. in this position, fluid from the rod end of cylinder 11 is prevented from discharging through line 172 and through said valve to exhaust passage 173. Line .172 is connected to exhaust 173 through throttle valve 174. This cushions the stopping of the carriage after plunger 59 drops into one of the notches in spacing bar 61.

In the right hand position of valve 163, fluid under pressure from pump 12%), line 121, and line 210, is connected to line 215 leading to the front end of cylinder 195 and causing said cylinder to move forwardly (in Fig. 5) to shift member 17 and work carriage 10 in a clockwise direction to place said carriage in the position shown in Fig. 5 for grinding a tapered surface corresponding to the angular position of said carriage. When member 17 is thus swivelled, guide surfaces for said support which are on said member are also shifted so that in the new position the carriage 10 may be indexed in a direction parallel to the tapered surface to be ground on the work piece.

Carriage 10 continues to move after the plunger has entered the notch until the side of the notch engages said plunger, shifting the plunger to the right. This movement is transmitted through sliding member 52 to lever 50, moving said lever in a clockwise direction and shifting valve 20 to the left until line 121 is blocked, thus preventing further flow of fluid under pressure to cylinder 11 and stopping the movement of carriage 10.

As indicated above, the counterclockwise movement of lever is effected by spring 103, shifting valve 104'to the right in engagement with the extension 103 of lever 100. In the right-hand position of valve 104, fluid under pressure from line 121 enters said valve through line 123 and is directed by said valve through line 226 to the head end of the piston 190, initiating the rapid positioning movement of wheel support 181. At the same time, a differential pump type fluid supply, such as shown in Patent No. 2,509,368, granted May 30, 1950, serves to supply fluid under pressure at a measured rate to the head end of slow feed piston 191. Said system consists of two

pumps

230 and 231 which may be of different displacement or operated at different speeds so that pump 231 discharges a supply smaller in volume than pump 230. The discharge end of pump 23:) is connected through a line 232 to the intake end of pump 231. Another line 233 connects line 232 with the head end of piston 191 and supplies a small volume of fluid thereto at all times, which is the difference between the output of pump 230 and that of pump 231.

It should be noted here that lever St) is moved in a clockwise direction while lever 40 remains stationary in its right-hand position. This movement of lever 50 While pin 42 in lever 40 remains stationary causes spring 58 to be placed in tension against pin 56.

When valve 30 moves to the right, the connection between lines 31 and 32 is blocked so that fluid under pressure will be conducted to the head end of piston 12. At the same time the left-hand section 23 of reversing valve 20 directs fluid under pressure from line 126 through lines 128 and 129, valve 130 and line 131 to the left-hand section 33 of valve 30. With valve 30 in the right-hand position, fluid from line 131 is directed through line 132 to the left hand end of valve 110, shifting said valve to the right to connect line 145 with line 148 leading to exhaust line 150. Line 145 through valve 110 connects line 144 and the head end of cylinder 107 with said exhaust passage 150.

The head end of cylinder 107 being thus connected with exhaust line 150, the fluid under pressure always available in line 140 at the other end of said cylinder moves piston 106 to the right until stopped by adjusting screw 109. This permits the above described action by which plunger 53 engages the first notch in the spacing bar.

After carriage has been positioned for the grinding of the first cam, timer 118 may be started by any suitable means, such as movement of wheel base 181 to grinding position, to determine the duration of the grinding operation or any part thereof.

At the end of the predetermined period, said timer deenergizes solenoid 116; and valve 115 is moved to the right by spring 117. In this position of valve 115, the fluid under pressure in line 141 is directed through line 142, check valve 143, and line 144 to the right-hand end of cylinder 107, moving piston 106 to the left. This movement of piston 106 causes arm 103 and associated parts to be rotated in a clockwise direction to withdraw plunger 53 from the first notch 60 in spacing bar 61 and also to shift valve 104 to the left against spring 108.

In the left-hand position of valve 104, fluid under pressure from line 123 is directed through line 240, line 241 to the rod end of both of the

pistons

190 and 191 to cause withdrawal of wheel support 181 from grinding position and resetting of slow feed piston 191. Fluid under pressure from line 240 also passes through line 242 to dresser valve 98. However, no dressing operation occurs until all the cams on a shaft have been ground, at which time valve 98 is shifted by solenoid 95.

The clockwise movement of lever 100 also serves to shift yoke 160 to the left. Near the end of its movement in this direction, said yoke picks up the head of adjusting screw 161 in valve stem 162 of valve 163 and shifts said valve to the left-hand position shown. In this position, fluid under pressure from line 210 is directed through line 250 to the rear end of cylinder 195, moving said cylinder backwardly and shifting said support in a counterclockwise direction. In this position, grinding wheel 180 will grind the next cam on the shaft to a surface tapered in the opposite direction to that of the first cam.

Where two or more successive cams are tapered in the same direction followed by two or more tapered in the opposite direction, the swivelling of the work carriage may be controlled by using a spacing bar in which the deep and shallow notches are arranged to conform to the grouping or arrangement of cams according to the direction of taper. For example, in the arrangement mentioned above the spacing bar would have two or more successive deep notches followed by two or more shallow notches as shown in Fig. 1.

Because of the tension in spring 58, lever 50 is rotated in a counterclockwise direction about its pivot 51 to shift valve to the right and sliding member 52 and plunger 53 to the left out of alignment with the notch from which it has just been withdrawn. The previously described indexing movement is repeated, carriage 10 moving again to the right until the plunger drops in the next notch. The next notch is not as deep as the first notch 60, and as portion 59 of plunger 53 drops into notch 60, lever 100 moves in a counterclockwise direction; but because of the fact that notch 60 is not as deep as notch 60', the movement of said lever is limited so that it does not move far enough to shift valve 163, which remains in the left-hand position. The cycle of operations which constitute the grinding of a single cam is repeated for successive cams until the last one is ground.

After grinding the last cam on a shaft, lever 40 is moved manually to the left-hand position. This movement releases headstock limit switch 81, shifts valve 30 to the left-hand position, and puts spring 57 in tension. Valve 20 remains in central position.

Opening switch 81 deenergizes relay 83 and opens the circuit to motor 82 through contact 84.

As carriage 10 moves into position to grind the last cam, dog on said carriage engages dresser limit switch 91, energizing relay 92 and

closing contacts

93 and 94. Closing contact 94 completes a circuit parallel to that through contact 84 and maintains motor 92 in operation after the contact 84 has been opened. When carriage 10 returns to its left-hand position switch 91 is released and motor 82 stops.

Contact 93 completes a circuit to dresser solenoid 95 to initiate a wheel dressing operation similar to those described in the above mentioned patents. Said solenoid shifts a valve 98 to direct fluid under pressure to actuate a dressing mechanism, (not shown).

With valve 30 in the left-hand position, the connection between lines 31 and 32 is blocked. In this position the left-hand section 33 of valve 30 blocks line 131, preventing fiow of fluid under pressure to the left end of valve and exhausts the left-hand end of valve 110 through line 132 and valve 30 so that said valve 110 moves to the left-hand position.

When timer 118 functions at the end of the grinding operation on the last cam, deenergizing valve 116, valve is returned to the right-hand position, directing fluid under pressure through line 142, check valve 143, line 144 to the head end of cylinder 107, moving piston 106 to shift valve 104 to the left and withdraw plunger 53 from spacing bar 61. The withdrawal of said plunger permits spring 57 to shift lever 50 in a clockwise direction, moving valve 20 to the left and directing fluid under pressure from line 121 through line 21 to the right-hand end of cylinder 11. Piston 12 and carriage 10 move to the left, but plunger 53 is prevented from dropping into the

notches

60 and 60 during this movement because valve 110 has remained in the left-hand position, thus maintaining pressure fluid on the head end of cylinder 107. The carriage, therefore, continues to move to the left under plunger 53 is engaged by stop 62, shifting said plunger slightly to the left and through sliding member 52, rotating lever 50 in a counterclockwise direction to return valve 20 to neutral position and thus shut off the supply of fluid to cylinder 11.

When carriage 10 begins to move to the left, limit switch 91 is released, opening

contacts

93 and 94. Opening contact 94 breaks the circuit to motor 82. However, contact 94 is by-passed through contact 96, which is actuated by a cam 97 on the headstock spindle. This cam engages the contact only when the cradle has been dropped to inoperative position, as described in Patent 2,243,410 granted May 27, 1941.

While the apparatus described above is specifically for grinding successive cams having oppositely tapered surfaces, it is to be understood that it may be adapted to the grinding of cam shafts on which oppositely tapered cams are irregularly distributed without departing from the spirit of the invention.

I claim:

1. In a machine of the kind described, a bed, a work support, a grinding wheel support, a grinding wheel rotatably mounted thereon, means for effecting longitudinal movement of one of said supports relative to the other, means to effect said movement intermittently to successively position said grinding wheel and spaced portions of the work piece in operative relation including a spacing bar having notches spaced in accordance with the spacing of said portions to be ground and a plunger for engaging the notches in said spacing bar, means for effecting a swivelling movement of said work support in order to grind tapered surfaces in different directions on some of said portions including a member mounted on said bed for angular adjustment about a longitudinally fixed vertical axis in the plane of said grinding wheel, said work support being slidably mounted on said angularly adjustable member so that each,of said portions is presented to the grinding wheel in the same transverse and longitudinal position in relation to said axis, and means for initiating the swivelling of said angularly adjustable member in timed relation with the intermittent movement of said carriage to place each of said spaced portions in predetermined angular relation to said grinding wheel.

2. In a machine of the kind described, a bed, a work support, a grinding wheel support, a grinding wheel rotatably mounted thereon, means for effecting a longitudinal movement of one of said supports relative to the other, means to efiect said movement intermittently to successively position said grinding wheel and spaced portions of a work piece in operative relation including a spacing bar having notches spaced in accordance with the spacing of said portions to be ground and a plunger for engaging the notches in said spacing bar, means for effecting a swivelling movement of said work support in order to grind tapered surfaces in different directions on some of said portions including a member mounted on said bed for angular adjustment about a longitudinally fixed vertical axis which is tangent to the face of the grinding wheel when said grinding wheel is in work engaging position, said work support being slidably mounted on said angularly adjustable member so that regardless of the longitudinal position of said carriage relative to the grinding wheel the portion to be ground will always be in the same position transversely thereof, means operable in response to movement of said plunger for swivelling said angularly adjustable member to place each of said spaced portions in predetermined angular relation to said grinding wheel.

3. In a machine of the kind described comprising a bed, a grinding wheel support slidably mounted thereon, a grinding wheel rotatably mounted on said support, a work support comprising a swivelling table mounted on said bed for adjustment about an axis passing through the point of contact between said grinding wheel and the surface of a work piece, a work carriage slidably mounted on said table, a headstock and footstock on said carriage for rotatably supporting a work piece thereon, means for effecting relative transverse and longitudinal movement between said carriage and said grinding wheel, means to effect said longitudinal movement intermittently to locate spaced portions of a work piece successively in operative relation to the grinding wheel and said swivel axis and means actuated by the means for effecting said intermittent movement for controlling the operation of said swivelling means to adjust said work support in opposite directions whereby the surfaces of said spaced portions are ground to a taper in opposite directions.

4. In a machine of the kind described, a bed, a grinding wheel support slidably mounted thereon, a grinding wheel rotatably mounted on said support, a work support comprising a swivelling table mounted on said bed for adjustment about an axis passing through the point of contact between said grinding wheel and the surface of a work piece, a carriage slidably mounted on said table, a headstock and footstock on said carriage for rotatably supporting the work piece thereon, means for effecting relative transverse and longitudinal movement between said carriage and grinding wheel, means to effect said longitudinal movement intermittently to locate spaced portions of a work piece successively in operative rela tion to the grinding wheel comprising a spacing bar on said carriage having notches spaced in accordance with the spacing of said portions to be ground and a plunger on said bed for engaging the notches in said spacing bar, said notches being wide enough to permit the entrance of said plunger in any position of angular adjustment of said carriage.

5. In a machine of the kind described, a bed, a work support, a grinding wheel support, a grinding wheel rotatably mounted thereon, means for effecting a longitudinal movement of one of said supports relative to the other, means to effect said movement intermittently to. successively position said grinding wheel and spaced portions of a work piece in operative relation including a spacing bar having notches spaced in accordance with the spacing of said portions to be ground and a plunger for engaging the notches in said spacing bar, means for effecting a swivelling movement of said work support in order to grind tapered surfaces in different directions on some of said portions including a member mounted on said bed for angular adjustment about a vertical axis which is tangent to the face of the grinding wheel when said grinding wheel is in work engaging position, said work support being slidably mounted on said angularly adjustable member, means for swivelling said angularly adjustable member to place each of said spaced portions in predetermined angular relation to said grinding wheel, including a motor attached to said member and actuated in response to movement of said plunger.

6. In a machine of the kind described comprising a bed, a grinding wheel support slidably mounted thereon, a grinding wheel rotatably mounted on said support, a work support comprising a swivelling table mounted on said bed for adjustment about an axis passing through the point of contact between said grinding wheel and the surface of a work piece, a carriage slidably mounted on said table, a headstock and footstock on said carriage for rotatably supporting the work piece thereon, means for effecting relative transverse and longitudinal movement between said carriage and said grinding Wheel, means to effect said longitudinal movement intermittently to locate spaced portions of a work piece successively in operative relation to the grinding wheel and said swivel axis and means actuated by the means controlling said intermittent movement for swivelling said work support in opposite directions whereby the surfaces of said spaced portions are ground to a taper in opposite directions.

7. In a machine of the kind described comprising a bed, a grinding wheel support slidably mounted thereon, a grinding wheel rotatably mounted on said support, a work support comprising a swivelling table mounted on said bed for adjustment about an axis in the plane of the grinding wheel, a carriage slidably mounted for longitudinal movement on said table, a headstock and footstock on said carriage for rotatably supporting a work piece thereon, means for effecting relative transverse and longitudinal movement between said carriage and said grinding wheel, means to effect said longitudinal movement intermittently to locate spaced portions of a work piece successively in operative relation to the grinding wheel and said swivel axis and means including a motor actuated by the means for effecting said intermittent movement, for swivelling said work support in opposite directions whereby the surfaces of said spaced portions are ground to a taper in opposite directions.

8. In a machine of the kind described, a bed, a work support, a grinding wheel support, a grinding wheel rotatably mounted thereon, means for effecting longitudinal movement of said work support, means to effect said movement intermittently to successively position said grinding wheel and spaced portions of a work piece in operative relation, means for effecting a swivelling movement of said work support in order to grind tapered surfaces in different directions on some of said portions including a member mounted on said bed for angular adjustment, a fixed pivotal mounting for said member having a vertical axis substantially tangent to the peripheral surface of the grinding wheel when said wheel is in contact with a work piece, said work support being slidably mounted on said angularly adjustable member for movement thereon in a direction determined by said angular adjustment so that each of said portions is presented to the grinding wheel in the same longitudinal and transverse position relative to said axis.

9. In a machine of the kind described, a bed, a grinding wheel support, a grinding wheel rotatably mounted thereon, a member mounted on said bed for angular adjustment a pivotal mounting therefor in said bed having a vertical axis passing substantially through the point of contact between work and wheel, a work support slidably mounted for movement on said angularly adjustable member in a direction determined by said angular adjustment,

means to efifect said longitudinal movement intermittently to successively position said grinding wheel and spaced portions of a Work piece in operative relation for grinding, means for swivelling said pivotally mounted member in opposite directions for grinding tapered surfaces on said portions in opposite directions, so that each of said portions of the Work piece is presented to the grinding wheel in the same longitudinal and transverse position relative to said vertical axis.

References Cited in the file of this patent UNITED STATES PATENTS 1,338,320 Muller Apr. 27, 1920 1,547,566 Durkee July 28, 1925 1,845,172 Morey et al Feb. 16, 1932 1,970,000 Dunbar et al Aug. 14, 1934 2,040,820 3elden et a1. May 19, 1936 2,041.244 Green May 19, 1936 2,243,410 Balsiger et al. May 27, 1941 2,581,759 Green Jan. 8, 1952