US3439134A - Switch with over-travel actuator - Google Patents

Description

A ril 15, 1969 A. J. CARLI 3,439,134

SWITCH WITH OVER-TRAVEL ACTUATOR Filed March 28, 1966 fi l6 GEQTU I INVENTOR.

ALVIN J. CARL) WW VII-f" United States Patent 3,439,134 SWITCH WITH OVER-TRAVEL ACTUATOR Alvin J. Carli, Sebring, Ohio, assignor to Consolidated Electronics Industries Corp., a corporation of Delaware Filed Mar. 28, 1966, Ser. No. 538,051 Int. Cl. H01h 3/16 US. Cl. 20047 3 Claims ABSTRACT OF THE DISCLOSURE A switch is disclosed which is simple and reliable and constructed of few parts. A lever is moved in a first direction and stresses a wire-like spring which in turn has another portion deflecting a leaf spring carrying a switch contact. Considerable over-travel of the lever is permitted by deflection of the wire-like spring without appreciably further stressing the leaf spring. The lever may be moved in the opposite direction without actuating the switch.

The present invention relates in general to switches and more particularly to limit switches wherein provision is made for overtravel of the actuating member.

Limit switches have been known and used for many purposes in the art and particularly in the automatic garage door art for example, wherein it is desired to electrically deactuate an electric motor when the door has arrived at either an open or closed position. Because of the inertia of the mechanism which engages and actuates the switch it is often necessary to make provision for overtravel without damage to the switch, i.e. the contacts or member(s) which engage the contacts upon actuation. Many devices of this type have been relatively complicated in construction and operation and as a result comparatively expensive to manufacture.

It is therefore an object of the present invention to provide a limit switch of the type described which is of an economical construction yet is reliable in operation.

Another object of the present invention is to provide a limit switch which provides a simple and reliable construction for overtravel between the movable member and the switch contact or contacts which are actuated.

Another object of the present invention is to provide a limit switch which includes contact means actuated through the medium of lever means fixedly carrying spring means therewith, with another portion of the spring means actuating the contact means upon movement of the lever means and the spring means permitting further movement of the lever means after the contact means have been actuated.

Other objects and a fuller understanding of this invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings in which:

FIGURE 1 is an elevational view showing the environmnet of two switches of the present invention as associated with a motor operated garage door;

FIGURE 2 is an enlarged elevational view of the limit switch of the present invention in actuated condition;

FIGURE 3 is a view taken generally along the line 3-3 of FIGURE 2; and

FIGURE 4 is a view taken generally along the line 4-4 of FIGURE 3 showing the switch in unactuated condition.

The limit switch of the present invention is susceptible of many uses, however, in order to illustrate .a preferred embodiment, it has been illustrated in its use with a motor operated garage door. In this connection there has been shown in FIGURE 1 a garage door .15 which is adapted to move on a track 16 between an up position 19 wherein it is generally parallel with the ceiling of the Patented Apr. 15, 1969 enclosure 17 which it closes, and a down position in which it is shown in the full line position of FIGURE 1. A channel 24 is secured to the ceiling of the enclosure and comprises a horizontal guideway 25 within which a carriage 27 is adapted to move back and forth. The channel 24 serves to house a worm 29 which is rotatably driven by an electric motor and appropriate gear reduction mechanism contained in housing 30. Driving connection is made between the worm 29 and the carriage 27 t by means of a partial nut 32 which meshes with the worm 29 and at an opposite portion (not shown) is connected to the carriage. The carriage 27 is pivotally connected to one end of a drive link 18 at 21 and the other end of the link is pivotally connected at 23 to the door 15. As a result of this construction the door moves between its up and down positions as the carriage 27 travels back and forth in the guideway 25.

Two of the limit switches of the present invention have been illustrated in FIGURE 1 and have been identified respectively by the reference numerals 35 and 36. As mentioned, these two limit switches are adapted to control the up and down movement of the door and in that sense control electrical circuit means which supply power to the motor contained in housing 30. The electrical circuit means will not be further described in this application, however, the function performed by switches 35 .and 36 may be the same as that performed by switches 75 and 76 respectively in United States Patent No. 2,992,378 issued July 11, 1961. In this sense switch 35 may be described as a normally open momentary contact up travel limit switch and switch 36 as a normally open momentary contact down travel limit switch.

Since the details of construction of switches 35 and 36 are identical only the specific structure of switch 36 will be described hereinafter. This switch comprises a support member 38 which is fixedly secured to the channel 24 by means of a screw 39. The switch includes a first fixed contact 41 which is electrically connected to a conductor 42 by way of a terminal 43 extending from the contact 41. A second movable contact 45 is carried on one end of a leaf spring member 47, sometimes referred to as a second spring member, with the other end of the leaf spring member being carried on the support member 38. It is shown as being a grounded switch. by being secured to the metallic support member 38 by means of a rivet 48. The movable contact 45 is therefore connected to ground by way of the leaf spring member, support member 38 and the channel 24. The leaf spring member 47 also serves to, in this embodiment, maintain the second contact 45 in a first position in which the first and second contacts are normally in spaced or open relationship with respect to each other.

A lever member 50 is provided which has first and second end portions and a pivot member 52 pivotally connects the first end portion of the lever member to the support tmember 38. This lever member 50 normally hangs by the action of gravity in the position in which it is shown in FIGURES 3 and 4. A wire-like spring member 54 is provided which has first and second end portions 56 and 57, respectively, and an intermediate portion 58. The first end portion of the wire-like spring member is fixedly connected to the lever member by means of extending through a strap 60 which is formed of the material of the lever member as shown in the drawings. The intermediate portion of the spring member 54 extends or is wound around the pivot member 52 with the second end portion 57 extending to a position immediately adjacent the leaf spring member 47 in the area of the movable contact 45 when the lever member 50 is in its inactive position as shown in FIGURE 4.

The carriage 27, sometimes referred to as a movable member, carries a projection or moving member 62 in the nature of a coil spring which is adapted to engage the lower or second end portion of the lever member 50 when it reaches a given position after movement in a first direction shown by arrow 45? When the projection 62 engages the lever member the lever member is adapted to rotate in a counter-clockwise direction as seen in FIGURES 2 and 4 which in turn causes the second end portion 57 of the wire-like spring member to engage the leaf spring member 47 and overcome the force thereof to move the movable contact into engagement with the fixed contact 41 thereby performing the electrical function for which it is designed, The door 15 and moving carriage 27 have inertia and it is necessary to expend this inertia without causing damage to any of the switch parts. As a result, over-travel of the lever member 50 is permitted because the wire-like spring member 54 and particularly the intermediate portion 58 thereof simply is resiliently deformed as seen in FIGURE because the closed contacts resist further movement with a force greater than that of spring member 54, which permit the lever member to move further without causing further movement of the switch contacts. If the inertia is suificient, the projection 62 may pass to the right completely beyond engagement with the second end portion of the lever member before coming to a complete stop at which time gravity will cause the lever member to reassume the position shown in FIG- URE 4. When the carriage 27 is caused to move to the left so as to bring the door to the completely open position, when desired by an operator, movement of the lever member 50 in a clockwise direction is permitted without causing further functioning of the switch because of the position of the lever member and spring member 54 relative to the fixed movable contacts of the switch. The projection 62 engages the lever member 50 of switch 35 when the door reaches its open position and functions in the same manner to cause de-energization of the drive motor.

It will thus be seen that in accordance with the teachings of the present invention a limit switch has been provided that is of an economical construction and yet is reliable in operation. The combination of the lever and spring means provides a novel overtravel construction.

The wire-like spring member 54 may also be considered a first resilient means which is movably carried on the support member 38 for actuating the contact means 41 and 45 by movement of the moving member 62. This first resilient means 54 has an actuator arm or first end portion 56, an actuated arm or second end portion 57 and has an overtravel means or intermediate portion 58. This overtravel means is wound and is capable of being stressed as a torsion spring. During actuation of the switch 36 by the projection 62 moving in the direction of the arrow 63, the actuator arm 56 is moved counter-clockwise as viewed in the drawing and this first closes the contacts 41 and 45 by stressing and overcoming the resistance of the second resilient means or leaf spring member 47. After the contacts 41 and 45 are closed then the contact 45 is in the second position and this resists further movement of the leaf spring member 47. Accordingly for further movements of the moving member 62 in the direction of the arrow 63, the first resilient means 54 is merely stressed further to permit movement of the first end portion 56 and the lever member 50. This overtravel stresses the intermediate portion 58 as a torsion spring to readily permit such overtravel without harm to the switch mechanism 36 and without material further movement of this leaf spring member 47.

Although this invention has been described in its pre ferred form with a certain degree of particularly, it is understood that the present disclosure of the preferred form has been made only by Way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. A limit switch including in combination, a support member,

fixed contact means,

movable contact means cooperable with said fixed contact means,

a leaf spring member having first and second end portions,

means fixedly connecting said first end portion of said leaf spring member to said support member,

said movable contact means being mounted on said second end portion of said leaf spring member,

a flat lever member having first and second end portions,

pivot means pivotally connecting said first end portion of said lever member to said support member with said flat lever member having a width dimension parallel to said support member at the pivot means to be guided in pivotal movement by said support member,

a wire-like spring member having first and second end portions and an intermediate portion,

said first end portion of said wire-like spring member being fixedly connected to said lever member and said intermediate portion extending around said pivot means with said second end portion extending to a position adjacent said second end portion of said leaf spring member,

said second end portion of said lever member adapted to be engaged by a moving member moving in a first direction and when so engaged pivotally moving said lever member about said pivot means and angularly moving said second end portion of said Wire-like spring member into engagement with said leaf spring member to move said contact means relative to each other anad said wire-like spring member deflecting to permit continued overtravel movement of said lever member relative to said contact means after said contact means have been moved relative to each other.

2. A switch as claimed in claim 1, wherein said second end portion of said lever member is arranged to be moved in a second direction opposite to said first direction to move said wire-like spring member away from said leaf spring member for non-actuation of said contact means.

3. A switch as claimed in claim 1, wherein said pivot means pivotally interconnects said support member and said lever member at only one location with said lever member guided in movement by said support member.

References Cited UNITED STATES PATENTS 2,511,271 6/1950 Kaminky et al. 2,939,337 6/1960 Sweger.

ROBERT K. SCHAEFER, Primary Examiner.

D. SMITH, JR., Assistant Examiner.

US. Cl. X.R. 200153

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