US3777092A

US3777092A - Trigger operated actuating mechanism for an electric switch with integrally molded fulcrum and snap-on connecting means associated with the trigger

Info

Publication number: US3777092A
Application number: US00273302A
Authority: US
Inventors: L Yeske
Original assignee: Arrow Hart Inc
Current assignee: Cooper Industries LLC; Arrow Hart Inc
Priority date: 1972-07-19
Filing date: 1972-07-19
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04
Also published as: GB1415064A; AU5791473A; CA976590A; FR2193237B1; NL7308949A; DE2335879A1; FR2193237A1

Abstract

A trigger operated electric switch with a movable actuator which engages an over-center compression spring of an electric switch mechanism. The actuator is positioned between the switch casing and an actuator cover and is constrained to move rectilinearly therebetween, biased in one direction by a longitudinal spring. The trigger member has a fulcrum-type bearing molded integrally therewith and seated in a recess in the cover member. Skirt portions depend from the trigger member and provide a snap-on connection with the actuator when the bearing of the triggermember is seated in the recess.

Description

United States Patent 1 Yeske [54] TRIGGER OPERATED ACTUA'IING MECHANISM FOR AN ELECTRIC SWITCH WITH INTEGRALLY MOLDED FULCRIJM AND SNAP-0N CONNECTING MEANS ASSOCIATED WITH THE TRIGGER [75] Inventor: Louis A. Yeslke, Hartford, Conn.

[73 Assignee: Arrow-Hart, Inc, Hartford, Conn.

[22] Filed: July 19, 1972 [21] Appl. No.: 273,302

[52] US. Cl. 200/172 R, 200/157 [51] Int. CI. H0111] 3/02, 1-I01h 9/06 [58] Field of Search 200/157, 74, 172 R,

[56] References Cited UNITED STATES PATENTS 3,348,010 10/1967 Johnson 200/157 3,711,666 1/ 1973 Sahrbacker 200/157 3,329,789 7/1967 Sahrbacker.. 200/157 2,810,051 10/1957 Johnson 200/74 X FOREIGN PATENTS OR APPLICATIONS 1,147,777 4/1969 Great Britain 200/157 Primary ExaminerRobert K. Schaefer Assistant Examiner-R0bert A. Vanderhye Att0rneyWi1liam F. Sonnekalb, Jr. et a1.

[ 5 7 ABSTRACT A trigger operated electric switch with a movable actuator which engages an over-center compression spring of an electric switch mechanism. The actuator is positioned between the switch casing and an actuator cover and is constrained to move rectilinearly therebetween, biased in one direction by a longitudinal spring. The trigger member has a fulcrum-type bearing molded integrally therewith and seated in a recess in the cover member. Skirt portions depend from the trigger member and provide a snap-on connection with the actuator when the bearing of the tn'gger-member is seated in the recess.

4 Claims, 5 Drawing Figures TRIGGER OPERATED ACTUATING MECHANISM FOR AN ELECTRIC SWITCH WITH INTEGRALLY MOLDED FULCRUM AND SNAP-ON CONNECTING MEANS ASSOCIATED WITH THE TRIGGER The present invention relates to electric switches and more particularly to a trigger operated actuating mechanism for over-center electric switches.

Trigger operated switches have been known for many years and have been marketed in many forms and constructions. (One metal trigger switch is disclosed in U. S. Pat. No. 2,789,170 issued to D.W. Johnson.) Developments in the plastic art have made available moldable insulation materials enabling novel improvements in the structure of electric switches and lowering of the cost of manufacturing and assembling of the switch components.

It is an object of this invention to provide an improved construction of the actuating mechanism of trigger operated switches which will enable assembly of the parts by snapping them together without the need of tools or special machinery.

Another object is to provide a construction as aforementioned in which all the parts may be molded economically from insulating material.

A particular object is to provide an improved structure for a trigger operated switch, for mounting a trigger-locking pin on the trigger support by a snap-on connection, avoiding the needfor special tools.

Another object is to provide in a trigger operated switch an improved structure and cooperation of the trigger, its supporting member, and the contact actuator for assembling them by one snap-on connection without the need for special tools.

Other objects, aspects and advantages of the present invention will become apparent as the invention is described in connection with the drawing.

Briefly, the present invention includes a trigger operated'actuating mechanism for use with an over-center electric switch of the kind described in my copending application entitled, LEVER OPERATED SWITCH," Ser. No. 230,374, filed Feb. 29, 1972. The actuating mechanism has a reciprocatable actuator with a depending lug which engages an over-center compression spring in the electric switch casing. The actuator is positioned between the electric switch casing and an actuator cover and is constrained to move rectilinearly therebetween, being biased toward its unactuated position by a spring. A trigger member is operatively connected to the actuator and the actuator cover to impart rectilinear movement to the actuator when the trigger member is pressed.

In the drawing:

FIG. I is a perspective view showing the trigger operated actuating mechanism of the present invention mounted on an over-center electric switch;

FIG. 2 is a partial exploded view of the trigger operated actuating mechanism;

FIG. 3 is a longitudinal sectional view of the trigger operated actuating mechanism with the trigger member upstanding (switch off);

FIG. 4 is a longitudinal sectional view of the trigger operated actuating mechanism with the trigger member depressed (switch on); and

FIG. 5 is an end view showing the locking pin in its locked position holding the trigger member in its depressed position.

Referring to FIG. I, the trigger operated actuating mechanism, indicated generally by the numeral 10, is mounted on a molded insulated electric switch casing, indicated generally by the numeral 12. The details of the construction of the casing 12 and the position and operation of the fixed and movable contacts included therein are as described and illustrated in my copending application entitled, LEVER OPERATED SWITCH, Ser. No. 230,374, filed Feb. 29, 1972, whose disclosure is incorporated herein by reference.

As in my copending application the switch casing 12 has an open top,

sidewalls

14 and 16 and bottom wall a 18 with two pairs of fixed contacts positioned inside the casing 12 adjacent the sidewalls I4 and 16. The contact surfaces of each pair of contacts are parallel and spaced laterally to be bridged by movable contacts. The terminals may be of the spade type or any other type as desired and are conventionally mounted in vertical slots in the corners of the casing 12.

A movable contact is carried on each of two separate parallel insulating plates, which are mounted on the side arms of a swingable yoke having trunnions seated in bearing recesses located centrally in the top edges of the

sidewalls

14 and 16 of the casing 12. Snap action is imparted to the yoke by a pressure means or overcenter compression spring 20 (see FIGS. 3 and 4), one end of which seats on a transverse portion of the yoke, while the opposite end presses against a lug 22 on a slidable molded insulation member, generally indicated by numeral 24, hereinafter more fully described. The over-center spring-swingable-yoke mechanism for controlling the movable contact members is conventional.

Referring to the FIGS, the over-center spring 20 of the conventional switch contact operating mechanism is moved from switch off position of FIG. 3 to switch on position of FIG. 4 by the reciprocative movement of the rectilinearly slidable member 24. Member 24 is molded from insulating material as a straight member with a bar portion 26 at one end (the right end in FIGS. 3 and 4) and a channel portion 28 at the other end. Member 24 is slidable over the open top of the switch casing 12 and is held in position and guided in its movement by a cover member, designated generally by the numeral 30.

The cover member 30 has a cover portion 32 at one end overlying the casing 12 and a trigger support portion 34 at its other end extending beyond the end of the casing 12. The cover portion 32 of the cover member 30 is generally U-shaped and hollow, forming a channel for receiving the slidable member 24. The channel is closed at the end 36 opposite the trigger support portion 34 and has

laterallyextending flanges

38 and 40 overlying the top of the casing 12.

As in my copending application above-mentioned, the cover 30 may be attached to the switch casing 12 by snap action of plate-

like skirts

42 and 44 which depend from the edges of the

flanges

38 and 40, respectively, and are spaced for positioning alongside of and parallel to the

sidewalls

14 and 16 of the casing 12. Openings 46 are provided in each

skirt

42 and 44 to receive one or more nubs 48, which extend outwardly from the sidewalls I4 and 116 of the casing 12, as the channel portion 28 of the slidable member 24 and engages the upper end of the over-center spring 20. In order to bias the slidable member 24 into switch off position, a coiled compression spring 52 is received within the channel portion 28 of the slidable member 24. One end 54 of the spring 52 engages an end 56 of the channel portion 28 (the left end in FIGS. 3 and 4), while the other end 58 of the spring 52 engages a wall 60 that depends from the inner surface of cover portion 32 of the U-shaped channel cover member 30. When the channel portion 28 is positioned within the cover portion 32 of the U-shaped channel cover member 30, the wall 60 is received within the channel portion 28 and abuts against the other end 61 of the channel portion to limit the rectilinear movement of the slidable member 24 in one direction.

For moving the slidable member 24, a trigger member, designated generally by the numeral 62, is pivotally mounted upon the trigger support portion 34 of the cover member 30. The trigger member 62 is generally U-shaped having a top wall 64 shaped to the contour ofa finger, and spaced sidewalls or

skirts

66 and 68 depending from the top wall 64. Extending downwardly from the finger receiving top wall 64 is a pivot member or lug 70 dimensioned to be received in a bearing or seat 72 formed in the upper end 74 of the trigger support portion 34. The trigger member 62 is pivotally mounted on the trigger support portion 34 by seating pivot 70 in bearing 72.

The

skirts

66 and 68 of the trigger member 62 include aligned

pin retaining grooves

76 and 78 arranged at the bottom thereof. The

pin retaining grooves

76 and 78 have converging entering slots 80 which lead to a pin receiving orifice 82, see FIG. 2, and are dimensioned to receive a pivot pin 82 molded integrally with bar portion 26 of the slidable member 24.

The pivot pin 82 has annular

peripheral recesses

84 and 86 formed thereon at each end for providing a snap-on connection with the

pin retaining grooves

76 and 78 of the trigger member. Further, the pivot pin 82 is received in

recesses

81 and 83 formed at the bottom of the trigger support portion 34 of cover member 30.

The

skirts

66 and 68 of the trigger member 62 also include locking

pin receiving apertures

85 and 87, respectively. Aperture 87 is an arcuate slot having a nonaxial portion thereof aligned with aperture 85.

The trigger support portion 34 has spaced depending sidewalls 88 and 90 with axially aligned locking

pin receiving orifices

92 and 94, respectively. Orifice 92 includes radial slots 96 which make the periphery of the orifice distortable enough to permit insertion of a radial flange 98 of a spring biased locking pin 100 therethrough. The locking pin 100 is in the shape of a stepped cylinder with an enlarged radially extending end flange 98.

To assemble the trigger on the cover member 30 and connect it with the slidable member 24, the trigger 62 is placed over the trigger support portion 34, with pivot member 70 seated in bearing 72 and pivot pin 82 is snapped into position within

pin retaining grooves

76 and 78. The flanged end of the spring biased locking pin 100 is then inserted through arcuate slot 87 and through aligned

orifices

92 and 94. The locking pin 100 is maintained in that position by the radial flange 98 which is retained against the outer surface of the sidewall 88 circumjacent the aperture 92 and a biasing spring 102 which is concentrically mounted about the pin 100 and held between enlarged cylinder I04 and sidewall 90.

Referring particularly to FIGS. 3, 4 and 5, the switch is switched on (movable contacts engaging the pairs of spaced fixed contacts) by exerting force, e.g., by a finger, on the top wall 64 of the trigger member 62. Exertion of sufficient force on the top wall 64 causes the pivot member to pivot in bearing 72 resulting in pivotal movement of the trigger member 62, causing rectilinear movement of the slidable member 24 which is pivotally connected to the trigger member 62. The movement of the trigger member 62 toward the on" position causes the slidable member 24 to move against the biasing force of the spring 52, so that the slidable member 24 and lug 22 move to the right, as shown in FIG. 4. When the lug 22 is fully moved to the right, the connection between the lug 22 and the over-center spring 20 in the switch casing 12 causes the movable contacts to snap into engagement with the pairs of fixed contacts (switch on"). The degree of depression of the trigger member 62 is limited by engagement of the front wall or stop 106 of the trigger member 62 with the trigger support portion 34, see FIG. 4.

When the trigger member 62 is in its fully depressed position, see FIG. 4, the aperture is axially aligned with the locking pin 100. By exerting sufficient axial force on the locking pin 100, the radial flange 98 is moved through the aperture 85 and held against the skirt 66 of the trigger member 62 by the return force of the biasing spring 52. The locking pin thus holds the slidable member 24 in the position shown in FIG. 4 and prevents return of the lug 22, so that the switch remains on."

The locking pin 100 is released by exerting a temporary downward force on the trigger member 62 to move it downward slightly, allowing the spring bias of the locking pin 100 to retract it within the aperture 85. Retraction of the locking pin 100 allows the trigger member 62 to return to its upstanding position, see FIG. 3, under the influence of the return force of the biasing spring 52.

Advantageously, sidewall 88 of the trigger support member 34 may be extended to form a flange 107 having holes 108 for mounting the assembled trigger operated actuaing mechanism 10 and switch casing 12 to the workpiece, as desired.

It should be apparent to those skilled in the art that various modifications may be made in the present invention. The specification is by way of illustration and should be construed to embrace modifications which do not depart from the spirit and scope of the invention as described in the specification and defined in the appended claims.

What is claimed is:

1. An electric switch having a casing, relatively movable contacts within said casing, a slidable contactactuating member made of molded insulation, a cover member secured on said casing and maintaining said actuating member slidably between said casing and cover member, said cover member having an open cradle-type bearing recess, a trigger member made of molded insulation and having a fulcrum-type bearing molded integrally therewith and seated in said recess, said trigger member having parallel skirt portions, and snap-on connecting means between said trigger and said actuating member engageable when the bearing of said trigger bearing is seated in said bearing recess, said connection holding said trigger and said actuating member is assembled condition on said cover.

2. An electric switch as claimed in claim 1 in which the snap-on connecting means comprises aligned recesses in said trigger member, and a pivot pin molded integrally with said actuating member and formed to become seated in said recesses by distortion of said trigger member.

3. An electric switch as claimed in claim I in which the snap-on connecting means comprises a pivot pin molded integrally with said actuating member, and aligned recesses in the skirts of said trigger member having portions retaining said pin and divergent and narrowed portions leading to said retaining portions,

said enlargement through said one aperture.

Claims

1. An electric switch having a casing, relatively movable contacts within said casing, a slidable contact-actuating member made of molded insulation, a cover member secured on said casing and maintaining said actuating member slidably between said casing and cover member, said cover member having an open cradletype bearing recess, a trigger member made of molded insulation and having a fulcrum-type bearing molded integrally therewith and seated in said recess, said trigger member having parallel skirt portions, and snap-on connecting means between said trigger and said actuating member engageable when the bearing of said trigger bearing is seated in said bearing recess, said connection holding said trigger and said actuating member is assembled condition on said cover.

3. An electric switch as claimed in claim 1 in which the snap-on connecting means comprises a pivot pin molded integrally with said actuating member, and aligned recesses in the skirts of said trigger member having portions retaining said pin and divergent and narrowed portions leading to said retaining portions, said divergent portions facilitating entrance of the pin into said retaining portions.

4. An electric switch as claimed in claim 1 having a locking pin and a biasing spring mounted on said cover member and adapted to hold said trigger in a predetermined position, said cover member having parallel wall portions with aligned apertures receiving said locking pin, and means for snap-in mounting of said pin in said apertures comprising an enlargement at one end of said pin, and means formed in the periphery of one of said apertures to permit distortion thereof and insertion of said enlargement through said one aperture.