US3291953A - Switch mount and protector - Google Patents

Description

Dec. 13, 1966 LUlK 3,291,953

SWITCH MOUNT AND PROTECTOR Filed May 21, 1964 2 Sheets-Sheet l I 4: BY m M/ gi fl arr/vars:

Dec. 13, 1966 F. D. LUIK 3,291,953

SWITCH MOUNT AND PROTECTOR Filed May 21, 1964 2 Sheets-Sheet 2 INVENTQR.

United States Patent Ofitice 3,291,953 Patented Dec. 13, 1966 3,291,953 SWITCH MOUNT AND PROTECTOR Frank D. Luik, Clawson, Mich., assignor to Artco Inc., Fraser, Mich., a corporation of Michigan Filed May 21, 1964, Ser. No. 369,270 8 Claims. (Cl. 200172) This invention relates to devices for actuating and protecting electrical switches.

Limit switches are used in industry in various applications and are frequently used in situations requiring repetitive actuation as by a plurality of trip arms, etc., on a conveyor line. In such applications the limit switch is continuously subject to shock, vibration, etc., and, being of a mechanical construction for essentially light duty operation, is susceptible to rapid wear, damage, loss of adjustment, etc. It is an object of this invention to provide an actuating mechanism for use with a limit switch which isolates the limit switch from direct contact with the trip arms, as on conveyor lines, and which mechanism is of a heavy duty, rugged construction to more readily withstand shock, vibration, etc., and which mechanism protects the limit switch from dam-age.

It is a general object of this invention to provide a device of a novel and improved construction for actuating and protecting limit switches.

Other objects, features, and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a pictorial view depicting a preferred form of the limit switch protecting and actuating device in assembly relationship with a conveyor line;

FIGURE 2 is a pictorial view of a body member of the device of FIGURE 1;

FIGURE 3 is a front elevational view of the limit switch protecting and actuating device of FIGURE 1 with parts shown broken away and others shown in section;

FIGURE 4 is a side elevational view of the assembly of FIGURE 3 taken substantially along the line 44;

FIGURE 5 is a front elevational view of the limit switch protecting and actuating device of FIGURES 14 shown in assembly relationship with an adapter member permitting selectable adjustment of the location of the protecting and actuating device;

FIGURE 6 is a top elevational view to reduced scale of the adapter member of FIGURE 5 shown with portions of the protecting and actuating device depicted in phantom; and

FIGURE 7 is a fragmentary front elevational view of a modified form of the limit switch protecting and actuating device of FIGURES 14 for use with a pair of limit switches.

Looking now to FIGURES 1-4, a limit switch actuating and protecting device is generally indicated by the numeral 10 and is shown in assembly relationship with an assembly line (partially shown) which includes a frame member 12 and a convey-or line 14 which is movable relatively thereto in the direction of the arrow A. The device 10 in general includes a mounting plate 16, a body member 18 and a cam lever 20, all of which are of heavy cross-sections for rugged operation. The mounting plate 16 is elongated and generally rectangularly, uniformly shaped and can be secured to the frame 12 by screws or welding and provides means for attaching the device 10 to the frame 12. The mounting plate 16 has a pair of threaded bores 22 which are located substantially centrally laterally and permit the body member 18 to be mounted to and selectively positioned on the mounting plate 16 in a manner to be presently seen. The body member 18 (FIGURE 2) has a back wall 23 with a longitudinally extending slide groove 24 in its rear surface of a width substantially equal to the width of the mounting plate 16; the groove 24 receives the front portion of the mounting plate 16 and acts as a guide in positioning the body member 18 along one axis, up or down as shown in FIGURES l-4. The back wall 23 of the body member 18 has a longitudinally extending through slot 26 which, with the body member 18 located on the plate 16, is in line with the threaded bores 22. A flat, elongated retainer plate 28 is located on the forward surface of the back wall 23 and has a pair of holes 30 spaced identically with threaded bores 22 in mounting plate 16 and is secured thereto by bolts 32 which extend through the holes 30 and through slot 26 thereby clamping the body member 18 to the mounting plate 16. It can be seen that while the retainer plate 28 is fixed to the mounting plate 16, the body member 18 can be slidab'ly positioned along the mounting plate 16 simply by loosening the bolts 32. In this regard, the width of the slide groove 24 is accurately formed relative to the width of the mounting plate 16 so that precise up-and-down adjustments can be made.

The body member 18 is symmetrical about a longitudinal center line and has a pair of longitudinally extending, downwardly tapering side ribs 34 which extend transversely, outwardly from opposite sides of the back wall 23. The back wall 23 and side ribs 34 are connected at their upper ends by a top portion 36 which includes a pair of upwardly extending, transversely spaced lugs 38, which have transversely extending, aligned bores 40. In between the lugs 38 are located laterally, outwardly extending, downwardly inclined stop surfaces 42 which have downwardly extending bores 44; a coil spring 46 and a removable plug 47 are located in different ones of the bores 46 and serve a purpose to be presently described.

The cam lever 20 is pivotally mounted between the lugs 36 by a pin 48 which extends through the bores 44 in lugs 38 and through a bore 49 (FIGURES 3 and 4) in the lever 20. The pin 48 is secured to lugs 38 at its opposite ends by cotter pins 50; a bearing of sintered metal or other suitable construction can be located between the pin 48 and the bore 49 in the lever 20.

The cam lever 20 has an arm portion 52 which extends to one side of bore 49 and is mounted to body member 16 with the arm portion 52 extending toward the side with the spring 46; the arm portion 52 has upper and lower earn surfaces 54 and 56, respectively. A stop engaging surface 58 (FIGURE 3) is located on the arm side of the bore 49 and is in confrontation with the stop surface 42 on that side of body member 16. A projection 60 extends from the stop engaging surface 58 and extends pa;- tially within the coil spring 46 to prevent the spring 46 from sliding. The spring 46 is in precompression and normally urges the arm portion 52 upwardly or in a counterclockwise direction, as viewed in FIGURES 1-4, to a posit-ion determined by the point of engagement of a projection 62 on the cam lever 52 at the opposite side of the bore 49 with the plug 47. The travel of the cam lever 20, and hence arm portion 52, in an opposite, clockwise, direction is limited to a position at which the stop engaging surface 58 on arm portion 52 engages the stop surface 42 on that side of the body member 18.

A limit switch 64, which can be of a construction well known in the art, is mounted to an attachment plate 66 which in turn is mounted to one of the side ribs 34 via bolts 68. Each of the side ribs 34 is provided with a pair of similarly located laterally extending through bores 70 for bolts 68 whereby a switch, such as switch 64, and plate 66 can be mounted to either side. As shown in FIG- URES 1-4, the switch 64 is mounted on the right side of body member 18 and, of course, the cam lever 20 is mounted with its arm portion 52 extending to the right. If a switch, such as switch 64, and plate 66 were mounted on the left side of body member 16 then the cam lever 20 would be mounted with the arm portion 52 extending to the left; at the same time, the spring 46 and plug 47 would be interchanged in their respective bores 44.

A switch arm 72 is pivotally mounted on the switch 64 and is movable between extreme positions tor actuating or deactuating the circuit of switch 634. The switch arm 72 has a cam roller 7-4 at its outer end which is continuously, resiliently urged (by conventional means not shown) into engagement with the lower cam surface 46 on arm portion 52. Thus as the cam lever 20 is moved between the positions fixed by its stops the switch arm 72 is moved between its extreme positions.

In operation a plurality of trip arms, such as arm 76, can be fixed to the conveyor line 14 and positioned so as to engage the upper cam surface 54 as the conveyor 14 moves in the direction of the arrow A to pivot the cam lever 20 clockwise, and hence to move the switch arm 72 to one extreme position (as shown in phantom in FIGURE 3). As the trip arm 76 moves out of engagement with the arm portion 52, the spring 46 moves the cam lever 20 to its opposite extreme position, with the switch arm 72 following to its other extreme position.

Note that, with the device 10, the delicate limit switch 64 is not subjected to the shock loads as by direct engagement with the trip arms 76 and the initial impact loads, etc., are taken by the rugged cam lever 20. In addition, the clockwise movement of the cam lever 20 is limited by the positive stop provided by surfaces 42 and 58 on the body member 18 and cam lever 20, respectively; hence the switch arm 72 cannot be overdriven thus protecting the limit switch 64. As previously noted, the device 10 can be readily converted !for use with a limit switch on the opposite side while still utilizing the same basic elements.

With the apparatus of FIGURES 1-4 the position of the body member '18, and hence the switch 64, can be adjusted along one axis, i.e., vertically up or down. In FIGURES and 6 the use of an adapter 78 permits ad justment along a second axis to permit both vertical and horizontal positioning. In the combination shown in FIGURES 5 and 6, the mounting plate 16 is mounted with its longitudinal axis extending horizontally. The adapter 78 is generally rectangularly shaped and is elongated and is secured to the mounting plate 16 with its longitudinal axis extending horizontally. The adapter 78 has a longitudinally extending slide groove 80 in its rear surface of a width substantially equal to the width of the mounting plate 16; the groove 80 receives the front portion of the mounting plate 16 and acts as a guide in horizontally positioning the adapter 78. A longitudinally extending through slot 82 extends through the adapter 78 whereby the adapter 78 can be adjustably clamped to the mounting plate '16 via a hat retaining plate 84 (similar to retaining plate 23) and a pair of bolts 86. The adapter 78 has a pair of longitudinally extending ribs 88 on opposite sides which are connected at one extremity to a transversely, outwardly extending guide block portion 90. The guide block portion 90 is of a width to matably fit within the slide groove 24 in the body member 1 8 and has apair of threaded bores 92 which are spaced to receive the bolts 32 whereby the body member 18 can be adjustably clamped thereto via the retaining plate 23 and the vertical position of the body member can be adjusted. A substantial range of horizontal adjustments can be obtained with the combination of FIGURES 5 and 6 since the adapter 78 can be assembled to extend to the left or to the right. In the combination of FIGURES 5 and 6 the attachment plate 66 and limit switch 64 have been omitted for the sake of clairty, it being understood that these elements can be connected to the body member 18 in the manner shown in FIG- URES 1-4 and as previously described.

A further variation of the apparatus of FIGURES 1-4 is shown in FIGURE 7. In FIGURE 7 a second limit switch 64a and mounting plate 66a are secured to the left sideof the body member 18. A second spring 46a is substituted for the plug 47 in the associated bore 44 and a cam lever 20a is substituted :for the cam lever (20. The cam lever 20a is substantially symmetrically constructed about a vertical axis and has a pair of arm portions 52a extending in opposite directions from a center actuation lever portion 94. The arm portions 5 2a are engaged by the cam rollers on the switch arms of the limit switches 64, 64a whereby pivotal movement of the cam lever 20a in one direction or the other as applied to the lever portion 94 causes actuation or tie-actuation of the limit switches 64, 64a. The cam lever 20a is provided with a pair of stop engaging surfaces 58a for engaging the stop surfaces 42 on the body member -18 to provide a positive stop in either direction whereby both switches 64, 64a are protected. The springs 46 and 46a are seated in bores in the associated stop engaging surfaces 58a and are under a precompression to maintain .the cam lever 20a centered; however, the springs 46, 46a can be selected such as to normally place the cam lever 20a in one of the other extreme positions, i.e., right or left. Substantial variations in circuit arrangement of switches 64, 64a can also be obtained.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing [from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. An actuating and protecting device for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a heavy sectioned body member, means on said body member {or supporting a limit switch to said body member, a heavy sectioned lever member adapted to be enagageable with the switch arm and pivotally secured to said body member for pivotal movement about a selected axis towards and away from the limit switch, first stop means comprising a pair of engageable surfaces on said lever member and said body member for limiting the movement of said lever member in a direction away from the limit switch, and second stop means on said lever member and said body member for limiting the movement of said lever member in a direction towards the limit switch whereby damage to the limit switch is prevented from overtravel of said lever member said first and second stop means substantially symmetrically lo cated on opposite sides of said axis whereby said lever member can be utilized to actuate a limit switch located 1 on either side of said selected axis.

2. An actuating and protecting device for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a heavy sectioned body member, means on said body member for supporting a limit switch .to said body member, a heavy sectioned lever member adapted to be engageable with the switch arm and pivotally secured to said body member for pivotal movement about a selected axis towards and away from the limit switch, first stop means comprising a pair of engageable surfaces on said lever member and said body member for limiting the movement of said lever member in a direction away from the limit switch, second stop means on said lever member and said body member for limiting the movement of said lever member in a direction towards the limit switch whereby damage to the limit switch is prevented from overtravel of said lever member, and spring means for resiliently unging said lever member to the limit position established by said first stop means said first and second stop means substantially sy-mmetrically located on opposite sides of said axis whereby said lever member can be utilized to actuate a limit switch located on either side of said selected axis.

3. An actuating and protecting device for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a heavy sectioned body member, means on said body member for supporting a pair of limit switches on opposite sides of said body member, a heavy sectioned lever member adapted to be engageable with the switch arms of both limit switches and pivotally secured to said body member for pivotal movement in one direction toward one and away from the other of the limit switches and in an opposite direction away from the one and toward the other of the limit switches, stop means on said lever member and said body member for limiting the movement of said lever member in said one and said opposite directions whereby damage to the limit switch is prevented, and spring means simultaneously urging said lever member in said one and said opposite direction.

4. An actuating and protecting device for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a heavy sectioned body member having a substantially symmetrical construction relative to one axis, means on said body member for supporting a limit switch to either of two sides of said body member on opposite sides of said one axis, a heavy sectioned lever member having a pivot support and having an arm portion extending away from said pivot support, and means for pivotally securing said lever member to said body member at said pivot support with said arm portion extending in a direction towards either of said two sides of said body member and with said arm portion adapted to be in close proximity with the switch arm of the limit switch and for pivotal movement towards and away from the limit switch.

5. An actuating and protecting device for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a heavy sectioned body member having a substantially symmetrical construction relative to one axis, means on said body member for supporting a limit switch to either of two sides of said body member on opposite sides of said one axis, a heavy sectioned lever member having a pivot support and having an arm portion extending away from said pivot support, means for pivotally securing said lever member to said body member at said pivot support with said arm portion extending in a direction towards either of said two sides of said body member and with said arm portion adapted to be in close proximity with the switch arm of the limit switch and for pivotal movement towards and away from the limit switch, first stop means on said lever member and said body member for limiting the movement of said lever member in a direction away from the limit switch, second stop means on said lever member and said body member for limiting the movement of said lever member in a direction towards the limit switch whereby damage to the limit switch is prevented from overtravel of said lever member, and spring means for resiliently urging said lever member to the limit position established by said first stop means.

6. An actuating and rotecting device adapted to be mounted to a support member for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a heavy sectioned body member having a substantially symmetrical construction relative to one axis, means on said body member for supporting a limit switch to either of two sides of said body member on opposite sides of said one axis, a heavy sectioned lever member having a pivot support, means for pivotal-1y securing said lever member to said body member at said pivot support with said arm portion extending in a direction towards either of said two sides of said body member and with said arm portion adapted to be in close proximity with the switch arm of the limit switch and for pivotal movement towards and away from the'limit switch, first stop means on said lever member and said body member for limiting the movement of said lever member in a direction away from the limit switch, second stop means on said lever member and said body member for limiting the movement of said lever member in a direction towards the limit switch whereby damage to the limit switch is prevented from overtravel of said lever member, spring means for resiliently urging said lever member to the limit position established by said first stop means, and means for supporting said body member on the support member and permitting selective adjustment of said body member relative to the support member along two mutually perpendicular axes.

7. An actuating and protecting device for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a longitudinally extending, generally rectangularly shaped support plate, a longitudinally extending body member having a longitudinally extending slide groove of a contour for matably receiving the forward surface of said support plate, said body member having a longitudinally extending through slot in communication with said slide groove, means operatively connected with said slot for clamping said body member to said support plate and for permitting selective relative movement of said body member with said support plate along said slot, a lever member adapted to be engageable with the switch arm and pivotally secured to said body member for pivotal movement about a selected axis towards and away from the limit switch, a first stop surface on said body member, a first stop engaging surface on said lever member in confrontation with said first stop surface and adapted to be engageable with said first stop surface for limiting the movement of said lever member in a direction towards the limit switch whereby damage to the limit switch is prevented from overtravel of said lever member, a second stop surface on said body member, a second stop engaging surface on said lever member in a confrontation with said stop surface and adapted to be engageable with said stop surface for limiting the movement of said lever member in a direction away from the limit switch, and spring means located between said first stop surface and said first stop engaging surface for urging said second stop engaging surface into engagement with said second stop surface said first and second stop means substantially symmetrically located on opposite sides of said axis whereby said lever member can be utilized to actuate a limit switch located on either side of said selected axis.

8. An actuating and protecting device for protecting and actuating a limit switch having a switch arm movable for actuating and deactuating the limit switch, said device comprising: a heavy sectioned body member, means for attaching a pair of limit switches to opposite sides of said body member, a heavy sectioned lever member having a pair of oppositely extending arm portions each adapted to be engageable with one of the limit switches and being pivotally secured to said body member for pivotal movement alternatively towards one or the other limit switch, a first stop surface on said body member, a first stop engaging surface on one of said arm portions in confrontation with said first stop surface and engageable with said first stop surface for limiting the movement of said one of said arm portions towards its associated limit switch, a second stop surface on said body member, a second stop engaging surface on the other of said arm portions in confrontation with said second stop surface and engageable with said second stop surface for limiting the movement of said other of said arm portions towards its associated limit switch, first spring means located between said first stop surface and said first stop engaging surface for urging said other of said arm portions towards its associated limit switch, and second spring means located between said second 7 8 stop surface and said second stop engaging surface for 3,156,805 11/1964 Baker et a1. 200--168 X urging said one of said arm portions towards its as- 3,198,925 8/1965 Starrantino 200172 sociated limit switch.

ROBERT K. SCHAEFER, Primary Examiner. References Cited by the Examiner 5 KATHLEEN H CLAFFY, Examiner.

UNITED STATES PATENTS H. 0. JONES, Assistant Examiner.

2,338,365 1/1944 Thorp et a1. 200-172

Claims (1)

1. AN ACTUATING AND PROTECTING DEVICE FOR PROTECTING AND ACTUATING A LIMIT SWITCH HAVING A SWITCH ARM MOVABLE FOR ACTUATING AND DEACTUATING THE LIMIT SWITCH, SAID DEVICE COMPRISING: A HEAVY SECTIONED BODY MEMBER, MEANS ON SAID BODY MEMBER FOR SUPPORTING A LIMIT SWITCH TO SAID BODY MEMBER, A HEAVY SECTIONED LEVER MEMBER ADAPTED TO BE ENGAGEABLE WITH THE SWITCH ARM AND PIVOTALLY SECURED TO SAID BODY MEMBER FOR PIVOTAL MOVEMENT ABOUT A SELECTED AXIS TOWARDS AND AWAY FROM THE LIMIT SWITCH, FIRST STOP MEANS COMPRISING A PAIR OF ENGAGEABLE SURFACES ON SAID LEVER MEMBER AND SAID BODY MEMBER FOR LIMITING THE MOVEMENT OF SAID LEVER MEMBER IN A DIRECTION AWAY FROM THE LIMIT SWITCH, AND SECOND STOP MEANS ON SAID LEVER MEMBER AND SAID BODY MEMBER FOR LIMITING THE MOVEMENT OF SAID LEVER MEMBER IN A DIRECTION TOWARDS THE LIMIT SWITCH WHEREBY DAMAGE TO THE LIMIT SWITCH IS PREVENTED FROM OVERTRAVEL OF SAID LEVER MEMBER SAID FIRST AND SECOND STOP MEANS SUBSTANTIALLY SYMMETRICALLY LOCATED ON OPPOSITE SIDES OF SAID AXIS WHEREBY SAID LEVER MEMBER CAN BE UTILIZED TO ACTUATE A LIMIT SWITCH LOCATED ON EITHER SIDE OF SAID SELECTED AXIS.

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