US1744886A

US1744886A - Lapping machine

Info

Publication number: US1744886A
Application number: US252588A
Authority: US
Inventors: William F Groene
Original assignee: RK Leblond Machine Tool Co
Current assignee: RK Le Blond Machine Tool Co; RK Leblond Machine Tool Co
Priority date: 1928-02-07
Filing date: 1928-02-07
Publication date: 1930-01-28
Anticipated expiration: 1947-01-28

Description

Jan. 28, 1930. w. F. GROENE 1,744,886

LAPPING MACHINE Filed Feb. 7,1928 s Sheets-Sheet 1 INVEN TOR. WM 4 A TTORNEY5 Jan. 28, 1930; I GROENE 1,744,886

LAffING MACHINE led Feb. 1928 8 Sheets-Sheet 2 I NVENTOR (MM 714 n] M ATTORNEY Jan. 28, 1930; w F; GROENE I 1,744,886

LAPPING MACHINE Filed Feb. 1928 8 Sheets-Sheet 4 INVIIENTO WA. 4 m

ATTORNEY)" 8 Sheets-Sheet 6 ATTORNEYS Jan. 28, 1930. w. F. GROENE 1,744,886

LAPPING MACHINE Filed Feb. "I, 1928 8 Sheets-Sheet 7 ATTORNEYS Patented 7 Jan. 28, 1930 UNITED STATES v PATENT OFFICE Y WILLIAM F. GROENE, OF CINCINNATI, OHIO, ASSIGNOR TO THE R. K. LE BLOND MACHINE TOOL COMPANY, OF CINCINNATI, OHIO, A CORPORATION OF DELAWARE mirrme Application filed February My invention relates tolapping machines in which the bearings and the crank pins are lapped and polished to a true bearing surface in such a way as to approach very nearly actual working conditions of the shaft.

Prior practice necessitated separate operations for lappingthe main bearings and the crank pins, while my machine laps the bearings' and the pins in one operation, thus producing concentric Working surfaces with relation to the true centers of the crank shaft Other advantages, novel structures and improvements over other mechanisms for like purposes will be pointed out as the description proceeds, in which I will set forth in de-- tail onepreferred embodiment of myinvention and the novelty inherent, wherein I will state in the appended claims.

In the drawings I Figure 1 is a front elevation of the lapping mechanism. 7

- Figure 2 is a top plan view of the machine.

Figure 3 is a perspective of the rear of the machine.

Figure 4 is a vertical section through the machine showing the levers collapsed with the lapping arms in lapping position.

- Figure 5 is a vertical section through the machine showing the levers and the lapping arms expanded.

Figure 6 is a complete lapping unit detached from the machine.-

Figure 7 is an elevation of the headstock and driving mechanism of the machine.

Figures 8 and 9 are a top plan and front elevation of the spindle timing ratchet.

Figure 10 is a section through the head stock showing the component parts of the spindle and. driving mechanism.

Figure 11 is a section through the eccentric taken on the lines l111 of Figure 7.

Figure 12 is a diagrammatic perspective of I. the air supply to the-cylinders.

Figure 13 is an alternate formof the lapping unit.

Figure 14 is a diagram of the electric time control.

MACHINE 7, 192a." Serial No. 252,588.

the main bed of the machine, while the lapping arms are confined in fixed vertical planes. This lateral motion is derived from an adjustable eccentric mounted within the head stock.

The revolving crank shafts impart reciprocating motion to the lapping arms which are guided and held from lateral movement. Each arm can be fitted with grinding stones or a solid block, whichever is preferred.

Lubrication to the lapping surfaces is provided through a series of tubes coming from a common source such as a circulating pump. The pressure for lapping is obtained by means of springs compressed a determined amount to limit the depth of lap for a given number of revolutions of the crank shaft. The springs limit the depth of lap automatically because the pressure exerted by them is.

gradually decreased to zero while the springs are returning to normal unfiexed condition.-

on a pivoted member which carries the lapping arms, their guides and lubricating hose.

away from the crank shaft when air is passed into a cylinder located within the lines of the bed of the machine.

The above mentioned member does not come into play before an outer member has been thrown back by means of another cylinder which actuates a toggle between the two members and causes them to separate. The inner member does not move until the limit of the toggle has been reached. Simultaneously, While the. limit of the toggle is reached, the lapping arms are locked from sliding by a chain pulling on a latch mounted within the bearings of the lapping arms. Mounted on the outer member there is a cam which operates two whistle valves .through which the air is excluded from the vertical cylinder and by-passed into the second horizontal cylinder below the bed of the machine. This by-passing of the air to the horizontal cylinder causes the pistons to swing the inner and outer members away from the machine as a single unit and consequently draw the lapping arms away from the crank shaft in such a manner that they will be in their proper position to come forward and receive the next crank shaft when it has been put in the machine.

The return to osition of lapping is a reverse sequence 0 operation as described for the removal of the work.

My machine stops after a predetermined number of revolutions of the crank shaft necessary to produce the proper bearing surface. This is accomplished by means of a suitable electrical time element shown diagrammatically in Figure 14. My machine can also be stopped at will by suitable mechanism described later. While the machine can be stopped during any part of a revolution, it is' essential that the crank shafts be removed and installed while in a definite position so as to provide a constant relation of the shafts to the lapping arms. I have accomplished this by means of a ratchet and slidably mounted stopping post. This stopping post cannot be operated before the power to the spindle driving the crank shaft has been disconnected. The power is applied through any suitable clutch arrangement combined with a spindle and face plate similar in construction to lathes.

I have shown the main stand or bed 1 upon which is mounted a sliding plate 2 confined to a definite reci rocating motion by the eccentric 3 rotata ly mounted in the head stock 4 and sliding block 5. Since the head stock and tail stock 5 are fixedly mounted on the base plate 2 they move back and forth with the base plate as a single unit, and thereby transmit horizontal reciprocating lateral motion to the crank shaft G'when it is placed between the centers of the head and tail stocks.

The eccentric 3 consists of a shaft 7 having keyed thereon the gear 8 which meshes and is driven by the gear 9 keyed on the main spindle 10. The shaft 7 is journaled in the head' stock at 7 7 and has an eccentric portion 11 on its left end which protrudes beyond the outside of head stock. Upon this eccentric end 11 I mount a bushing 12 with an eccentric drilled hole 12 therein. After assembling these parts I rotate the bushing 12 on the eccentric end of the shaft so as to fix the movement of the sliding plate 2 to the desired amount. I then clamp the bushing fast to the eccentric of the shaftby means of the locknut 14. The rotation of the two eccentrics as a single unit within the sliding block causes the sliding plate to move back and forth because the-sliding block is confined in the bifurcated member 15 which is fixed on the main stand of my machine. Since the sliding block 5- is confined to movement in the vertical plane and the sliding plate 2 in the horizontal plane, it is apparent that the resultant motion of the sliding plate is a horizontal reciprocating motion due to the eccentric circle described by the surface of the bushing 12 with relation to the center of the hole in the sliding block. Varying the rethe slight variations encountered in the lengths of the crank shaft-s.

Disengagement of the clutch is accomplished by clockwise motion of the lever 20 pinned to the shaft 21. The shaft 21 has mounted thereon a fork 22 which engages the slidably mounted collar 23 on the spindle 10. This collar has a through pin 24: free to slide in a slot 25 in the spindle and connects the collar 23 with the clutch release rod 26 which disengages the clutch through the adjustable bell crank 27. The face plate 28 of the spindle contains a stud 29 which engages and drives the crank shaft to be lapped, as will be described below.

In order to index the crank shaft with relation to the lapping arms I have rigidly mounted on the spindle a ratchet wheel 30 having a shrouded portion 30 with a stopping point slot 31 which is engaged by the sliding latch 32 mounted in the head stock 4. This latch is confined to horizontal movement and is moved by the lever 33 on the shaft 33 which has a pinion 34 fastened thereon and engages the rack teeth cut on the latch.

As a matter of precaution I provide an intcrlock pin 36 held slidably in a housing 36 grammatically in Figure 14.. lVhcn the lever 20 on the lathe is thrown to engage the clutch a small limit switch 37, which has contacts normally held open by a spring, will also be depressed, closing the contacts, which will energize a relay 3?". After a definite time has elapsed, as determined by the setting of the relay, a contact will be closed in the relay between the terminals 25, t, causing the contactor 37 to pick up and in turn energize the solenoid, which will trip out the clutch and throwthe lever 20 back will= then be free to revolve;

to the stop position, which will release the limit switch and cause it to open its contacts.

This in turn will de-energize the relay, which.

will reset and de-energize the contactor and solenoid, leaving the equipment ready for a new start.

The shaft 33 and the shaft 21 have cams 40 and 41 thereon. Power to the machine is cutoff by rotating the shaft 21 with the lever 20 in a clockwise direction. When the shaft 21 is rotated in this direction it rotates the surface 41 of cam 41 away from the bottom endof the interlock bar 36 which falls down to the position shown and allows itslupper end to slide on the surface of the cam 40. The lever 33 can now be rotated in a clockwise direction and pull the latch 32 to the left where it will engage the slot 31 and index the spindle for removing the crank shaft that has been lapped. The interlock bar 36 isslidably mounted in the housing 36 rigidly mounted on the head stock. By referring to Fig. 7 it can be seen that lever 20 cannot be rocked to the left until the notch 32 in the latch 32 has been moved to the right, and bridge the shroud of the ratchet wheel which The lever 33 must rotate the cam 40 away from the upper end of the interlock bar 36, because the lower end of the interlock bar 36 can not ride up over the surface of the cam 41 while its upper end is against the surface of the cam 40, which prevents the interlock bar 36 from sliding upward The machine is at rest and the spindle is indexed for the next crank shaft to be lapped when the parts are in the positions shown in full lines in Fig. 7.

If the slot 31 on the ratchet wheel, which is part of the spindle, passes the latch 32 it can be brought to the point of engagement by rotating the ratchet wheel with an up and down movement of the pawl handle 42 mounted on a projecting surface 43 of the ratchet wheel and held in place by the plate 44 which is screwed to the face plate of the spindle. This plate does not interfere with the free movement of the pawl handle. The pawl 45 mounted on the pawl handle does not engage the ratchet wheel until it is lifted off the trip 45 mounted on the sliding plate 2. This trip prevents the pawl from riding the ratchet wheel while rotating during the lapping operation. The pawl 45 engages the ratchet wheel when the compression on the spring 46 is released by raising the pawl handle so that the pawl tip 45 does not'bear on the trip 45 Since each fly wheel flange of crank shafts have holes therein, I utilize these holes to drive the crank shaft by placing stud 29 in one of them While placing the crank shafts between centers. The, holes are jig drilled thereby enabling me to properly and definitely locate the crank shaft quickly because the stud 29 and the slot 31 are fixed on the spindle with, relation to each other. By placin the stud in the same hole 'on each crank s aft,

I automatically locate the crank pins and bearings with relation to the lapping arms and do not have to delay the lapping'operation by locating each lapping unit sepa'rately. This is also advantageous because I put in and remove the crank shafts when the lapping arms are expanded and away from the machine. I I

Figures 6 and 13 show two types of lapping arms which may be used on my machine. The

difference between the two is in the spring control element.

The lapping

arms

47 and 48 are arranged in pairs, using as many pairs as desired. In the one type a spring 46 is fastened in the lapping arm 47 and passes through a boss 48 on the lapping arm 48 and connects to a threaded stud 49 having on it a wing nut 50 which bears on the boss 48. By screwing down or up on the wing nut 50 I increase or decrease the tension of the spring and hence the lapping pressure. The lapping arms have

concave surfaces

47 and 48 upon which I fasten lapping stones 52 of sufficient thickness to elevate them above the concave surfaces thereby providing ample clearance for the lubricant to carry away all chips or foreign matter which would mar the surface being lapped. The lubricant is suppliedfrom a pump 53 at the rear of the machine and driven by means of a belt '54. The'lubricant passes from the pump through the flexible hose 55 to the manifold pipe 56 mounted 011 the movable frames (to be described) int-o individual flexible hoses 57 and finally through the I ed in the tubular rods 61 and pinned therein by the pin 61*. These tubular rods are then pinned to the sliding blocks 62 by the pin 62. The sliding blocks 62 are the means provided to confine the lapping arms in the vertical planes and do so because they in turn are slidably mounted and guided in the bifurcated members 63 which are adjustably mount ed on the shaft 63% This shaft is fixedly mounted on the extended arms 84 of the frame member 84.

The right hand ends of the tubular rods are the supports for the lapping arms and are slidably mountedin the pivoted

bearings

59 and 60. These bearings are of the hinge type and have a common support in theshaft 58 which is fixed in the frame 84.

The frame 84 is employed to retract and advance the lapping arms and another frame 68 is used to open the arms. The two frames outer frame 68 to swing back on the shaft 71 which also serves as a pivotal mounting for the vertical cylinder 64. \Vhile the frame 68 is moving away from the machineit pulls on the chains or cables 7 2 through the links 73 which are fixedly mounted on the shaft- 74 in the frame 68. Latches 76 are pivoted in the pivoted

slide bearings

59 and 60, on pins 77 and held out of engagement with the tubular rods 61 by the springs 77 The chains pull on the levers 75 of the latches 76 rotating them to right and left respectively. The rotation of the latches about their pins causes the lower surfaces of the latches to clamp down on the tubular rods (31 preventing them from sliding and holding them in place while they are moved away from the work. These latches are operated and set by a very slight movement of the frame 68 and during the time-the frame is moving the rest of the way the chains pulling on the levers 75 of the latches cause the lapping arms to separate by the rotation of their supporting bearings 59 and about the shaft 58.

During the time that the latching and spreading of the arms is taking place, I bypass the air to a horizontal cylinder 81 by means of the cam 78 which is rigidly mounted on the frame member 68. Before the frame 68 has completed its outward movement the lower surface of cam 78 engages a whistle valve 80 located in the air line, so as to admit air through a pipe 80 which is connected to the said horizontal cylinder 81. This cylinder is rigidly mounted on the under side of the main bed of the machne. The valve is so arranged that the by-passing of the air into the cylinder 81 does not exclude the air from the cylinder 64 because it is necessary to maintain pressure within the cylinder 64. \Vithin the cylinder 81 is'a piston 81 whose )lStOIl rod 82 is'connected to the frame 84' y means of a link 83 having pivot pins 85.

and 86, one to the frame 84.

The frame 84 is normally held in locked position by means of the gravity actuated latch 87, which is mounted pivotally by means piston rod and one to the .of a pin 88 to theframe 1, and has a notched -end 89 which engages the lug plate 90 fast on the frame 84. As can be seen, I have slotted the hole 91 in the link 83 which receives the pin 86 on theframe. This slot is provided to allow for the movement required to 'release the latch 87.1 The link 83 has its inner end formed to engage the end 87 a of the latch and thus release it from position of latching 'way control valve 81 I admit air through the pipe 92* into the right hand end of the hori .zontal cylinder 81 (Figures 4 and 5) whose piston pulls the frame 84 towards the machine until the latch 87 drops over the latch bar 90 and locks the frame 84 in place. This action also pulls the frame 68 inwardly because of the toggle. When the frames are in this position the upper whistle valve 92 will have been operated by the upper surface of the cam 78 and is so connected as to by-pass air through the pipe 92* into the top of the vertical cylinder 64. This results in pulling down the rod causing the toggle joint 67 to collapse and pull the frame 68 into place. \Vhile the frame 68 is moving into place the lapping arms are closed over the surface to be lapped by the springs 46, and as the frame 68 comes to rest it releases the pull on the chain which in turn releases the latch 76 and leaves the machine in condition to apply power and begin lapping. Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a lapping machine, the combination of means for rotating a crank shaft, lapping V and move with the surfaces of the crank shaft,

to be lapped, under power applied thereto by said shaft, and power operated means for apl 'n and removin the lappin members frfi m the said surfac les to be lapffed after a predetermined number of rotations of the crank shaft, said rotating means comprising members for giving a predetermined position of the crank shaft with relation to said lapping members.

3. In a lapping machine, the combination of means for rotating a crank shaft, lapping members arranged in pairs to engage over and move with the surfaces of the crank shaft to be lapped, under power applied thereto by said shaft, and power operated means for applying and removing the lapping members from the said surfaces tobe lapped after a predetermined number of rotations of the crank shaft, said rotating means comprising members for giving a predetermined position of the crank shaft withrelation to said lapping members, and means for inhibiting actuation of said rotating means until said predetermined position is attained.

4. In a lapping machine, the combination of means for rotating a crank shaft, lapping members arranged in pairs to engage over and move with the surfaces of the crank shaft to be lapped, under power applied thereto by said shaft, and power operated means for ap- "plying and-removing the lapping members from the said surfaces to be lapped after a predetermined number of rotations of the crank shaft, said rotating means comprising members for giving a predetermined position of the crank shaftwvitli relation to said lapping members, and means for preventing application of the lapping members until said predetermined position has been attained.

5. Ina lapping machine, the combination of means for rotating a crank shaft, lapping members arranged in pairs to engage over and move with the surfaces of the crank shaft to be lapped, under power applied thereto by said shaft, and power operated means for applying and removing the lapping members from the said surfaces to be lapped after a predetermined number of rotations of the crank shaft, said rotating means comprising members for giving a predetermined position of the crank shaft with relation to said lapping members, and means for inhibiting actuation thereof until said predetermined position is applied, and means for preventing application of the lapping members until said predetermined position has been attained.

6. In a lapping machine, the combination of means for rotating acrank shaft, lapping members arranged in pairs to engage over and move with the surfaces of the crank shaft to be lapped, under power applied thereto by said shaft, and power operated means for applying and removing the lap I ping members from the said surfaces to be lapped after a predetermined number of rotations of the crank shaft, said rotating means comprising members for giving a predetermined position of the crank shaft with relation to the lapping members at the start and finish of every lapping operation.

7. In a lapping machine, the combination of means for rotating a crank shaft, lapping members arranged in pairs to engage over and move with the surfaces of the crank shaft to be lapped, under power applied thereto by said shaft, and power operated means for applying-and removing the lapping members from the said surfaces to be lappedafter a predetermined number of rotations of the crank shaft, said means comprising a movable frame on which said lapping members are mounted, and a member movable fwith relation to said frame and connected to the".

lapping members'so as to open the same thereby releasing them from the crank shaft lapped, and means for applying and removing the lapping members from the said surfaces to be lapped, said means comprising a movable frame on which said lapping members are mounted, and a member movable with relation to said frame and connected to the lapping members so as to open the same thereby releasing them from the crank shaft surfaces, said lapping members having means to lock them in their open position.

9. In a lapping machine, the combination of means for rotating a crank shaft, lapping members arranged to engage over and move with the surfaces of the crank shaft to be lapped, and means for applying and removing the lapping members from the said surfaces to be lapped, said means comprising a movable frame on which said lapping members are mounted, and a member movable with relation to said frame and connected to the lapping members so as to open the same thereby releasing. them from the crank shaft surfaces, and power means for actuating said frame and saidvr novable member in a predetermined sequence.

10. In a lapping machine, the combination of means for rotating a crank shaft, lapping members arranged to engage over and move with thesurfaces of the crank shaft to be, lapped, and means for applying and removfaces, and power means for actuating said frame and said movable member in a predetermined sequence, said sequence being as follows ':a movement of the'movable member to open and lock the lapping members, a movement of both the movable frame and movable member to withdraw the lapping members, a movement of both the'frame and the movable member to advance the lapping members, and a movement of the movable members to unlock and permit the closure of the lapping members over the surfaces to be lapped.

11. In a lapping machine, the combination of means for rotating a crank shaft, lapping members arranged to engage over and move with the surfaces of the crank shaft to be lapped, and means for applying and removing the lapping members from said surfaces to be lapped, said means comprising a movable frame on which said lapping members are mounted, and a member movable with relation to said frame and connected to the lapping members so as to open the same thereby releasing them from the crank shaft, and

means for inhibiting the movement of the movable frames during the lapping operation.

12'. In a lapping machine. the combination of means for rotating a crank shaft, lapping members arranged to engage over and move with the surfaces of the crank shaft to be lapped, and means for applying and removing the lapping members from said surfaces to be lapped, said means comprising a movable frame on which said lapping members are mounted, and a member movable with relation to said frame and connected to the lapping members so as to open the same thereby releasing them from the crank shaft, and means for inhibiting the movement of the movable frames during the lapping operation, and a means provided on the power actuated means to release said inhibiting means after said movable frame for opening the lapping means has moved sufficiently to open and lock the lapping means in place.

13. In a lapping machine, a lapping member comprising upper and lower lapping arms slidably mounted in a means for pivotally supporting saidlapping means, and means for locking said lapping arms in a predetermined position when out of lapping position.

14. In a lapping machine, a lapping member comprising upper and lower lapping arms slidably mounted in a means for pivotally supporting said lapping means, means for locking said lapping'arms in a predetermined position when out of lapping position, and 1 means for releasing the locking means when the arms are advanced to lapping position.

WILLIAM F. GROENE.