US 3413430 A
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Description (OCR text may contain errors)
Nov. 26, 1968 Filed Feb. 2, 1967 United States Patent ABSTRACT OF THE DISCLOSURE A rocker switch having contacts operated in response to movement of the operating member of the switch, through a cam member detachably supported in the body of the switch.
This invention relates to electric switches.
An electric switch according to the invention comprises in combination a body carrying contacts, a detachable cam member engaged with the body for operating the contacts, an operating member, and resilient means extending between the operating member and cam memher, the operating member acting through the resilient means to contact the cam member.
A three-position electric switch constructed in accordance with one example of the invention is illustrated in the accompanying drawings wherein FIGURE 1 is a part sectional side view of the switch, FIGURE 2 is a sectional view on the line 2-2 in FIGURE 1, FIGURE 3 is a view of an inside wall of the body of the switch, FIGURE 4 is an enlarged side view of a cam member forming part of the switch and FIGURE 5 is a sectional view of the cam member shown in FIGURE 4.
Referring first to FIGURES 1 and 2 there is provided a switch having a body 11 and an operating member 12 pivotally engaged therewith, both the body and the operating member being moulded in a synthetic resin material. V
The body '11 is of open box like construction including side walls'13, end walls 14a, 14b, of unequal length, a base 15, and mounting lugs a, 10b, integral with the walls 14a, 14b, respectively. The base 15 comprises three integral portions, a first portion 15a, which extends at right angles to the two walls 14a, a second portion 15b, parallel with but spaced from the portion 15a, and a sloping portion 150, joining the portions 15a, 15b.
Extending within the body 11 parallel to the walls 13 are a pair of spring contacts 16, 17 secured at one end to the base portion 15a, by rivets which also serve to secure external terminal blades 19, 21 to the body 11, the rivets connecting the blades to the contacts electrically. The contacts 16, 17 are movable into engagement with a pair of contact pieces 24, 25 on the base portion 15b. The contact pieces 24, 25 are connected by way of conductive rivets to external terminal blades 27, 28 respectively.
The walls 13 are moulded with upwardly extending portions 29 formed with holes 31 for pivotally supporting the operating member 12. Formed on the inner surface of each of the walls 13 is a vertically extending channel 32 which narrows towards its lower end and terminates in a pair of a spaced semicircular depressions 32a.
A cam member 33 (FIGURES 4 and 5) is supported in the channels 32 by means of integral lugs 34 (FIG- URES 2 and 4). The lugs 34 are of width substantially equal to that of the lower ends of channels 32 and are each formed with a pair of downwardly extending semicircular projections 35, 36 which are arranged to engage with the corresponding semicircular depressions at the 3,413,430 Patented Nov. 26, 1968 ice lower end of the channels 32. The cam member 33 can pivot about either the projections 35 or the projections 36.
The lower face of the member 33 is shaped to form a pair of cam profiles 38, 39 which can engage the contacts 16, 17 respectively to cause them to engage contact pieces 24, 25 respectively.
In the upper face of the member 33 is a groove the ends of which are defined by a lower pair of sloping walls 44 meeting in a line which lies in a plane bisecting the lugs 34, an intermediate pair of walls 43 which slope less steeply than the walls 44, and an upper pair of vertical walls 42.
The operating member 12 (FIGURES l and 2) is formed integrally with short posts 54 which are received in the holes 31 in the body .portions 29 thus supporting the member 12 for pivotal' movement on the body 11. A tubular finger 52 extends integrally from the member 12 into the groove 41 in the cam member 33, and within the bore in the finger 52 is a compression spring 55 which urges a ball 56 into contact with the walls of the groove 41.
The switch is used to control two circuits one of which includes the contact 16 and its associated terminal blades 19, 27 and the other of which includes the contact 17 and its associated terminal blades 21, 28. Each circuit is opened or closed by movement of its respective spring contact in response to movements of the cam member 33, the cam profiles 38, 39 being so arranged that when the switch is in its off position both the circuits are open, when the switch is in its first operative position shown in FIGURES l and 2 the circuit through contact 16 is closed and the circuit through contact 17 is open and when the switch is in its second operative position both circuits are closed. I
In the first operative position shown the projections 35, 36 are engaged in their corresponding depressions at the lower ends of the channels 32, and the ball 56 is engaged with both surfaces 44 to maintain the switch in position.
To move the switch to its off position the operating member 12 is pivoted in afcounter clockwise direction about the posts 54, until its lower left hand edge engages with the lug 10b. This movement causes the ball 56 to ride up one of the surfaces 44 and on to the adjacent surface 43 of the groove 41. Due to the action of the spring 55 on the ball 56 as it engages the surface 43, the cam member 33 is caused to pivot in a clockwise direction about the projections 36, thus lifting the cam profile 38 clear of the contact 16, which allows the contact 16 to open its circuit. The ball 56 slides along the surface 43 until it comes into contact with the adjacent surface 42. The ball is now urged against surface 43 and surface 42 and in this position there is no tendency for the cam member 33 to pivot. Thus the switch is maintained in its off position with both circuits open.
The operation when the switch is moved from the first to the second operative position is similar to that described above, except that pivoting takes place about the projections 35, and the cam profiles 38, 39 close both circuits.
The cam profiles 38, 39 and the configuration of the groove 41 can be altered to provide any desired sequence of operation of the switch, so that a wide range of switches can be manufactured using similar mouldings.
Having thus described my invention what I claim as new and desire to secure by Letters Patent is:
1. An electric rocker switch comprising in combination a body having at least two movable contacts attached thereto, a detachable cam member engageable with the contacts for selective operation thereof, an operating member, resilient means extending between said operating member and said cam member so that said operating member coacts with said resilient means and cam member to make and break at least one circuit.
2. An electric switch as claimed in claim 1 wherein said body, said detachable cam member and said operating member are each molded of synthetic resin.
3. An electric switch as claimed in claim 1 wherein said body carries contacts associated with two electrical circuits, said cam member being so shaped as to be able to make both circuits in a predetermined sequence so they are both energized.
4. An electric switch as claimed in claim 1 wherein said resilient means comprises a hollow finger integral with said operating member, and housing a ball, said ball being spring urged into engagement with said cam member.
4 5. An electric switch as claimed in claim 1 wherein said cam member has two operative cam profiles successively engageable With said two contacts.
References Cited ROBERT K. SCHAEFER, Primary Examiner.
H. BURKS, Assistant Examiner.