US3342969A

US3342969A - Electric switches

Info

Publication number: US3342969A
Application number: US578418A
Authority: US
Inventors: Edward B Angold
Original assignee: Plessey Co Ltd
Current assignee: Plessey Co Ltd
Priority date: 1965-01-27
Filing date: 1966-01-24
Publication date: 1967-09-19
Anticipated expiration: 1984-09-19
Also published as: GB1138603A

Description

Sept. 19, 1967 ANGOLD 3,134.2;969

ELECTRI C SWITCHES Filed Jan. 24, 1966 United. States Patent .0

3,342,969 ELECTRIC SWITCHES Edward B. Angold, Emsworth, England, assignor to The Plessey Company Limited, Ilford, England, a British company Filed Jan. 24, 1966, Ser. No. 578,418 Claims priority, application Great Britain, Jan. 27, 1965,

3,616/ 65 Claims. (Cl. 200-466) ABSTRACT OF THE DISCLOSURE An electric switch having a pair of juxtaposed arms each having on one end V-shaped parts which lie side by side and are mutually embraced by one end of a coil spring and carry on their other opposing ends respectively moving contacts, the switch being actuable by means of a plunger operable for compressing the coil spring so that the pair of arms are moved in the direction of movement of the plunger thereby to urge the moving contacts into co-operation with a complementary set of fixed contacts.

This invention relates to electric switches.

According to the present invention an electric switch comprises at least two sets of contacts, the moving contacts of which are carried by separate pivoted arms which are acted on by a spring common to both arms at the common pivoting point of said arms.

Electric switches constructed according to the invention may readily be arranged so that one of the sets of contacts is operated before the other.

The moving contact-carrying arms may comprise V- shaped portions at or near the ends thereof remote from the moving contacts, which portions may be embraced by one end of a coil spring which provides in effect a displaceable pivot for the moving arms since in response to the operation of the switch by compression of the coil spring the pivot point of the two arms is moved in the direction of movement of an actuating plunger of the switch.

The moving contacts may comprise bridging contacts arranged to bridge respective pairs of fixed contacts and taking the form of rods which extend transversely to the direction of movement of the contacts through holes provided in the arms so that the moving contacts are a loose fit in these holes and can therefore swivel through a limited angle in order to afford equalisation of contact pressure between the moving and co-operating fixed contacts consequent upon the operation of the switch.

By way of example, the present invention will now be described with reference to the accompanying drawing in which:

FIGURE 1 is a somewhat diagrammatic sectional view taken through an electric switch constructed in accordance with the invention;

FIGURE 2 is a diagrammatic view of the switch mechanism taken in the direction A in FIGURE 1; and

FIGURE 3 is a view of the switch actuating plunger and loading spring of the switch of FIGURE 1.

Referring to the drawing, the switch comprises two sets of electric contacts, each set consisting of pairs of spaced apart fixed contacts 1, 2 and 3, 4 and co-operating moving

bridging contacts

5 and 6. The

bridging contacts

5 and 6 are carried respectively by arms 7 and 8 of insulating material the contacts taking the form of rods which extend loosely through holes in the arms so that the rod contacts are free to swivel through a restricted angle and thereby providing equal contact pressures when bridging the fixed contacts 1, 2 or 3, 4 in response to operation of the switch. The moving contact carrying arms 7 and 8 are located in slots extending through a body moulding of the switch. These arms 7 and 8 have V-

shaped portions

9 and 10 at the ends thereof remote from the

moving contacts

5 and 6. These V-shaped portions are embraced by the top end of a coil spring 11 which is accommodated within a cylindrical opening in the body moulding and which in effect provides a movable pivot for the arms 7 and 8. The coil spring 11 exerts upward pressure on the arms 7 and 8 maintaining the arms in the position indicated in FIGURE 1 in the unoperated condition of the switch. It will be noticed that the depth of the arm 8 is greater than that of the arm 7 and consequently the pressure exerted by the spring on the respective arms can be adjusted by adjustment of the respective widths of the two arms and by such adjustment it can be arranged that the

moving contacts

5 and 6 bridge their co-operating fixed contacts sequentially.

For the actuation of the moving contacts 5 and 6 a plunger 12, as can be seen in FIGURE 3, is provided. This plunger which is located in a slot provided in the body moulding has a generally U-shaped part 13 which straddles the coil spring 11 and which bears against the V-

shaped portions

9 and 10 of the arms 7 and 8. By depression of the plunger 12 the pivot point of the arms 7 and 8 is eifectively lowered causing the arms 7 and 8 to be moved downwardly and upon the moving contact engaging with the co-operating fixed contacts the arms pivot towards one another about the top-end of the coil spring.

Switches according to the present invention are of simple and relatively inexpensive construction and sequential operation of the switch contacts can be readily provided. Moreover, a single coil spring only is required in respect of a plurality of sets of bridging contacts.

Although the switch described has general application it is eminently suitable for use in record players as the mains switch arranged to be operated at appropriate intervals by the player mechanism.

What I claim is:

1. An electrical switch comprising at least two sets of co-operating contacts, at least two fixed contacts incorporated in each set, at least two moving contacts incorporated in each set, a pivoted arm incorporated in each set, to one end of which the moving contacts are secured, a shaped portion on the other end of each pivoted arm remote the moving contacts, a coil spring one end of which is arranged to embrace the shaped portions of each pivoted arm to provide in effect a displaceable pivot point for each of said arms, and an actuating plunger co-operating with the said shaped portions of said arms for compressing the coil spring and to actuate the switch.

2. An electric switch as claimed in claim 1 wherein the moving contacts of at least one of said sets are electrically interconnected.

3. An electric switch as claimed in claim 2 wherein the electrically interconnected moving contacts comprise a rod, a hole being provided in the pivoted arm through 3 4- which the rod extends so as to project from each end coil spring and to co-operate with the said V-shaped porthereof transversely to the direction of movement of the tions, to form a knife edge fulcrum.

moving contacts and in which hole said rod is loosely References Cited fitted.

4. An electric switch as claimed in claim 3 comprising 5 UNITED STATES PATENTS pivoted arms having differing depths in the axial direction 3,200,225 8/1965 Lernke 200-466 of the coil spring. 3,272,949 9/ 1966 Lawrence 200-166 5. An electric switch as claimed in claim 4 wherein the shaped portions of the pivoted arms are V-shaped, and ROBERT SCHAEFER Pnmary Exammer' wherein the actuating plunger is arranged to straddle the 10 H. O. JONES, Assistant Examiner.

Claims

1. AN ELECTRICAL SWITCH COMPRISING AT LEAST TWO SETS OF CO-OPERATING CONTACTS, AT LEAST TWO FIXED CONTACTS INCORPORATED IN EACH SET, AT LEAST TWO MOVING CONTACTS INCORPORATED IN EACH SET, A PIVOTED ARM INCORPORATED IN EACH SET, TO ONE END OF WHICH THE MOVING CONTACTS ARE SECURED, A SHAPED PORTION ON THE OTHER END OF EACH PIVOTED ARM REMOTE THE MOVING CONTACTS, A COIL SPRING ONE END OF WHICH IS ARRANGED TO EMBRACE THE SHAPED PORTIONS OF EACH PIVOTED ARM TO SHAPED PORTIONS OF SAID ARMS FOR COMPRESSING THE COIL PROVIDE IN EFFECT A DISPLACEABLE PIVOT POINT FOR EACH OF SAID ARMS, AND AN ACTUATING PLUNGER CO-OPERATING WITH THE SAID SPRING AND TO ACTUATE THE SWITCH.