US3350948A - Linear motion transmitting device - Google Patents

Description

A. S. CZUBAK Nov. 7, 1967 LINEAR MOTION TRANSMITTING DEVICE 2 Sheets-Sheet 1 Filed June 4, 1965 5 R r mK NA P O w m m2 6 T C A s M m w 6 A s S .Ln Q 9 F v NOV. 7, 1967 CZUBAK LINEAR MOTION TRANSMITTING DEVICE 2- Sheets-Sheet 2 Filed June 4, 1965 INVENTOR.

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m M B 6 3,350,948 LINEAR MOTION TRANSMITTING DEVICE Albin S. Czubak, Detroit, Micln, assignor to Micromatic Hone Corporation Filed June 4, 1965, Ser. No. 461,466 2 Claims. (Cl. 74-53) ABSTRACT OF THE DISCLOSURE A motion transmitting mechanism whereby a slide assembly is adapted for linear movement effected by a revolving eccentric-cam movement.

This invention relates to a fixture which is adapted to be connected to a machine to move a workpiece to and from a workpiece station.

An object of the invention is to provide an apparatus which provides a maximum slide movement with a minimum amount of cam movement.

Another object of this invention is to provide an antijamming apparatus which allows continued rotation of the cam even if one slide is accidentally displaced or if the slide is prevented from sliding to and from an operative position.

A further object of the invention is to provide a slide apparatus which is adapted to be readily engaged and disengaged while preventing possible injury to the operator and damage to the fixtures and/ or machine tool structure.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

FIG. 1 is a front elevation of the slide and cam assembly; 1 t FIG. 2 is a top plan view of FIG. 1; and

FIG. 3 is a view taken along line 3-3 of FIG. 2. The novel apparatus of the present invention is illustrated as applied to a machine for moving a workpiece to and from aworkpiece station and as shown in FIG. I, mounted on a base of a machine not shown. Mounted on the base 10 is a spacer slide 12 having two upstanding brackets 14 and 16 which contain recesses 18, 19, 2d and 21. Shafts 22 and 24 are mounted in' secured relationship in recesses-18, and 19,21 respectively. The slide assembly comprises slide arms 32 and 34which are mounted on slide bracket assembly 36. The slide bracket assembly consists of two depending brackets 38 and 40'. Depending brackets-38 and 40 contain recesses 41, 42, 43 and 44. Ball bushings 46, 47, 48 and 49 are mounted in recesses 41, 42, 43 and 44 respectively. A top bracket 50 is secured to the slide bracket assembly 36 by a bolt 51. The top bracket 50 extends longitudinally past the slide assembly for the purpose of moving a workpiece into and out of a workpiece station, not shown. The extent of the movement ofthe slide assembly is evident from view of FIG. 1, which showsthe slide assembly 30 mounted for longitudinal movement onshafts 22 and 24 and limited in its longitudinal travel by brackets 38 and 40 of the slide bracket assembly 36 and the brackets 14 and 16 of the spacer slide assembly.

Detachably secured by a pin 53 on the depending bracket 40 of the slide bracket assembly 36 is a shaft slide 52 which is adapted for integral movement there with. Mounted at each end of the shaft slide 52 are two switch trip devices 54 and 56 which contact arm 58 of switch 60. The purpose of switch 60 is to give an indication when the slide assembly has not made the proper travel in both directions. The switch 60 is operated at each end of the slide travel by switch trip devices 54 and 56.

United States Patent 0 3,354,948 Patented Nov. 7, 1967 For example, if the slide assembly is jammed due to a misalignment of the workpiece at a workpiece station, the switch is not energized thus indicating a malfunction and means are provided to either stop the machine or to provide a visual indication of the malfunction, such means are not shown but are well known to the people skilled in the art.

A spring bracket 62 is secured on the end of the shaft 24, or any stationary part, for the purpose of providing a mounting for one end of the spring 64, see FIG. 1. The other end of the spring 64 is mounted or detachably secured to arm B, for the purpose to be hereinafter described. A second spring 66, as best seen in FIG. 2 and FIG. 1, has one end of the spring connected to one of the slide arms of slide bracket assembly by a bolt 68, and the other end connected to cam arm B by pin 69. As best seen in FIG. 1, the springs 64 and 65 act separately and yet in unison to keep cam arm B biased in the right direction for the purposes to be herein described.

The slide assembly 30 moves in timed relationship to the rotation of cam 70. Cam 70 is secured to shaft 72 by virtue of its securement to hub 74. Hub 74 is a split hub which is secured to the shaft 72 by socket screws 75. Set screws 76 secure the cam 70 to the hub 74. A set screw or dowel 77 is inserted through the hub 74 and into shaft 72 to secure the hub 74, cam 70 and shaft '72 in a unitary relationship for the purpose of providing proper positioning of the slide assembly in relation to the other cams or other slide assemblies. Thus, the cam 70 is being constantly rotated with the shaft 72 in timed relationship to provide movement of the slide assembly 30 for the purpose of moving a workpiece into and out of a Workpiece station, The constant movement of the slide assembly in timed relationship to the cam rotation is accomplished by providing cam arms that transfer the rotational force of the cam to a directional back-and-forth motion of the slide assembly 30. This is accomplished by having one cam arm A mounted pivotally at 80 on a pivot block 82. The pivot or fulcrum point 80 is shown in FIG. 1 as being non-adjustable, however, to those skilled in the art it is considered a simple matter to replace the pivot block to provide a pivot or fulcrum. point that is either higher or lower to thus effect a change in length of slide movement.

To provide for a mechanical advantage of 2:1 or 3:1 a double cam arm arrangement has been devised that provides for maximum slide movement with a minimum amount of cam movement. In other words, the size of the cam can be made smaller and yet a larger slide movement can be obtainable. This is accomplished by the double cam arrangement which comprises a cam arm A and a cam arm B. Cam arm A is pivotally mounted on pivot block 82 and has a cam follower or roller 84- which rolls on the circumference 71 of cam 70. The roller 84 mounted on cam arm A is adapted to roll on the circumference 71 of cam 70 and thus effects movement to a position shown in FIG. 1 in dotted line configuration, 70 being the extent of the cam and A being the extent of the cam arm. Adjacent to the cam arm A is a cam arm B which is pivotally mounted to the slide at 86. The cam arm B has a roller-88, which is best shown in FIG. 2, as abutting the surface 99 of cam arm A. Referring back to FIG. 1, as cam 74 is rotated degrees cam follower 84 pivots cam arm A to a position shown in dotted line configuration A. The movement is dependent on two variables, that is, the eccentricity of the cam surface and the pivot or fulcrum point 80. As previously discussed, movement of the pivot or fulcrum point will change the longitudinal extent of slide movement, and also changing the size and shape of the cam will change the longitudinal extent of slide movement. The slide movement is dependent on rotation of the cam 70, pivotal movement of cam arm A and movement of the cam arm B. During normal operations cam arm B will effect the movement of the slide assembly 30 by virtue of the double springs 64 and 66 biasing the cam arm B toward contact with cam arm A. As shown in FIG. 1 in dotted line configuration, cam arm B is adapted to effect backward movement of the slide assembly 30 by virtue of its tangential force on its pivot pin 86 causing translational movement of the slide assembly. However, assuming that the slide assembly is misaligned or a workpiece causes the slide assembly to be jammed and thus prevented from moving, cam arm A, being fixed to the pivot or fulcrum point 80 maintains its roller contact with the surface 71 of the cam 70, and assumes a position A shown in dotted line in FIG. 1. Cam arm B, however, pivots about the pivot point 86, and thus assumes a position B" shown in dotted line in FIG. 1. Thus, it can be seen that one of the features of this invention is an anti-jam slide by virtue of the fact that even though the slide is prevented from longitudinal movement, the cam is not prevented from rotating and the cam arms A and B are not prevented from pivoting about their respective pivot points. Thus it is readily apparent that structural damage to either the cam or the slide assembly, and even the workpiece is prevented by virtue of the fact that all the interrelated parts are merely moving about their respective pivot points and the slide assembly is stationary until the operator removes the obstruction. The force applied to the slide assembly is dependent upon the two springs 64 and 66 which tend to hold the cam arm B in angular relationship to the slide assembly. It is apparent that tension of the springs 64 and 66 and/ or the cam arm angle B effects longitudinal movement of the slide assembly 30. An angle of approxi mately less than 45 degrees of the cam arm B with the slide arms maintains proper working relationship between the slide assembly and the cam arm movements. Of course, it can be readily apparent that changing the fulcrum point of cam arm A could necessitate changing the spring tensions 64 and 66 and/or change of angle relationship of cam arm B with respect to the slide arms. Moreover, it is apparent that the angle between cam arm B and the slide arms can be greater than 45 degrees, however, the spring tension must be increased to maintain a proper bias relationship between translational movement of the slide assembly and cam arm B, and a pivotal movement between cam arm B and the slide assembly. Furthermore, with the roller 88 of cam arm B rolling on surface 90 of cam arm A, and roller 84 moving on surface 71 of cam 70 this provides a mechanical advantage of 2:1 or 3:1. Note in FIG. 1 the distance that roller 88 of cam arm B moves is greater than the distance that the roller 84 of cam arm A. Thus there occurs a greater slide movement of the slide assembly with a minimal cam movement.

To support the shaft for rotation, a pillow block 90 is mounted on the base 10. The pillow block is interspaced along the length of the shaft depending on the number of slide assemblies necessary in a machine complex.

While in the foregoing description the invention was explained in connection with one possible form or embodiment thereof wherefore certain specific terms and language have been used herein, it is to be understood that the present disclosure is illustrative rather than restrictive and that changes and modifications may be resorted to without departing from the spirit of the invention as defined by the claims which follow.

What is claimed is:

1. A motion transmitting mechanism for moving a slide assembly comprising: a base; a shaft; a first means mounted on said base for supporting said shaft; a second means supported on said shaft for longitudinal movement thereon; a cam mounted on said base adapted for rotation; a cam follower arm means for coacting with said cam to effect movement of said second means; said cam follower arm means includes a pair of cam follower arms, one of said pair of cam follower arms adapted for pivotal movement and having a fulcrum point connected to said base, the other of said pair of cam follower arms having its pivot point connected to said second means, whereby movement of said second means in a longitudinal direction is effected by pivotal movement of said one of said pair of cam arms against said other of said pair of cam arms.

2. A motion transmitting mechanism for moving a workpiece in and out of a workpiece station comprising: a base; a spacer member having two upstanding bracket arms; shaft means mounted on said spacer member; a slide bracket having two depending bracket arms mounted on said shaft means and adapted for longitudinal slidable movement thereon; a slide means secured to said slide bracket adapted for longitudinal movement therewith; a cam supported on said base and adapted to rotate in a specific timed relationship, a first cam follower arm pivotally supported on said base having a cam follower connected thereon for rolling contact on the periphery of said cam, a second cam follower arm pivotally connected to said slide means and having a cam follower connected thereon for rolling contact with said first cam follower; a bracket secured to one end of said shaft means; a first spring mounted on said second cam follower arm and on said slide means; a second spring mounted on said second follower cam arm and on said bracket; whereby said second cam follower arm is biased against the movement of said first cam follower arm, and rotation of said cam causes angular movement of said first cam follower arm with resulting translational movement of said second cam follower arm effecting longitudinal movement of said slide means, or effecting pivotal movement of said second cam arm without longitudinal movement of said slide means.

References Cited UNITED STATES PATENTS 1,893,217 1/1933 Babitch 7453 X 2,285,240 6/ 1942 Tuchscherer 7453 X 2,386,706 10/ 1945 Moessinger 7447 2,404,210 7/1946 Bechler 74569 3,001,418 9/1961 Nectoux 7453 X 3,186,244 6/1965 Baker et al. 74*107 X FOREIGN PATENTS 668,263 3/1952 Great Britain.

MILTON KAUFMAN, Primary Examiner.

FRED C. MATTERN, HALL C. COE, Examiners.

D, H. THIEL, Assistant Examiner,

Claims (1)

1. A MOTION TRANSMITTING MECHANISM FOR MOVING A SLIDE ASSEMBLY COMPRISING: A BASE; A SHAFT; A FIRST MEANS MOUNTED ON SAID BASE FOR SUPPORTING SAID SHAFT; A SECOND MEANS SUPPORTED ON SAID SHAFT FOR LONGITUDINAL MOVEMENT THEREON; A CAM MOUNTED ON SAID BASE ADAPTED FOR ROTATION; A CAM FOLLOWER ARM MEANS FOR COACTING WITH SAID CAM TO EFFECT MOVEMENT OF SAID SECOND MEANS; SAID CAM FOLLOWER ARM MEANS INCLUDES A PAIR OF CAM FOLLOWER ARMS, ONE OF SAID PAIR OF CAM FOLLOWER ARMS ADAPTED FOR

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