US3392251A - Electrical pushbutton type switches - Google Patents

Description

July 9, 1968 D. RUSHTON ELECTRICAL PUSHBUTTON TYPE SWITCHES 4 Sheets-Sheet 1 Filed Feb. 7, 1966 y 1968 D. RUSHTON 3,392,251

ELECTRICAL PUSHBUTTON TYPE SWITCHES Filed Feb. 7, 1966 4 Sheets-Sheet 2 l I A. I...

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ELECTRICAL PUSHBUTTON TYPE SWITCHES Filed Feb. 7, 1966 4 Sheets-Sheet 5 /k 1a 12 fl' j fl 10 D. RUSHTON ELECTRICAL PUSHBUTTON TYPE SWITCHES July 9, 1968 4 Sheets-Sheet 4 Filed Feb. 7, 1966 United States Patent 3,392,251 ELECTRICAL PUSHBUTTON TYPE SWITCHES Derek Rushton, Accrington, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England, a

British company Filed Feb. 7, 1966, Scr. No. 525,677 2 Claims. (Cl. 200-459) ABSTRACT OF THE DISCLOSURE An electrical switch comprising a pushbutton controlling the movem ent of an operating element, movement of the pushbutton causing travel of the operating element in a relatively transverse direction such movement being controlled by a pin and track on the pushbutton arm and operating element respectively, and the track having two positions for the pin in which it can be releasabiy retained, the operating element carrying a contact plate which is movable transversely of the direction of the movement of the pushbutton between a position to engage a contact on a printed circuit board, and a further position spaced from such contact.

This invention relates to electrical switches of the kind movable between on and oil positions in response to manual pressure upon a resiliently biased push button.

The object of the invention is to provide a convenient form of such a switch.

According to the present invention an electrical switch of the kind specified comprises a pair of members comprising an arm and an operating element which are each slidably mounted so as to be movable in mutually transverse directions, one of said members having a pin which is engageable in a track provided on the other member, the track being so arranged that movement of said arm will result in transverse movement of said operating element between two limiting positions relative to the arm, said track being shaped to provide two positions corresponding to said limiting positions of the operating element in which the pin is releasably retained by the track, said arm being connected to the push button so as to be movable in one direction by said push button and resilient means being provided for moving the arm in the opposite direction, and the pin being movable from either of said positions to the other by a sliding motion of the arm which consists in part of movement imparted by said push button and in part of movement imparted by said resilient means, the operating element being operatively connected to a contact plate adapted, in said limiting positions of the operating element, respectively electrically to connect and separate electrical contacts.

The invention will now be described by way of example with reference to the accompanying drawings in which:

FIGURE 1 is a cross-sectional side elevation view of the switch,

FIGURE 2 is a view on the line IIII in FIGURE 1,

FIGURE 3 is a similar view to FIGURE 2 but showing the parts in a switch on position, and

FIGURE 4 is a view on the line IV-IV in FIGURE 2.

In this example the switch comprises a body arranged to be secured to a panel by means of an attachment flange 11. The body is of hollow box like form and has openings in opposite end walls which serve as guides for an arm 12, one end of which extends out of the body and has an integral or a separate push button 13. One of the end walls is formed by a detachable closure member 14 secured to the remainder of the .body by two screws 15.

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The end walls of the body 10 also guide an operating element 16 in the form of a block-like member slidable in a direction transversely to the direction of movement of the arm 12.

The body 10 has, at its end remote from that from which the arm extends, an integral closed ended channel shaped extension 17. This extension of the body contains a compression spring 18 which abuts against the closed end of the channel and, at its other end, against the inner end of a recess in the arm 12, this spring urging the arm towards its outer position, shown in FIGURES 1, 2 and 3. A spigot 19 is formed on the end of the channel to locate the spring laterally.

The arm 12 has a laterally extending blind bore 20 which contains a pin 21 loaded by a compression spring 22, the pin 21 having a rounded nose normally protruding from the bore 20, but this pin 21 is capable of being retract'ed wholly within the bore 20, against the action of the spring 22. The operating element 16 has an integral peg 23 for engagement by one end of a compression spring 24 which urges the operating element 16 towards one side of the housing 10. The opposite end of the spring 24 is located on a peg 25 formed on an extension of the closure member 14. The operating element 16 has an integral bridge portion 26, which joins the operating element to a contact carrier 27. This contact carrier extends through one of the openings in the end wall of the body beside the extension 17 of the body.

In a face of the operating element 16 presented to the arm 12, there is provided a track 23 in the form of a channel cross-section groove in which the pin 21 is located. The track is a generally triangular closed loop. A first side 28a of the track is inclined at approximately to the direction of movement of the arm 12 and a second side 28b has a U-shaped portion intermediate its ends, the U extending towards the middle of the triangle.

The third side 28c is inclined to the direction of movement of the arm 12 at an angle of only approximately 5, the base of the third side including means for preventing movement from the first to the third side in the form of a ramp seen in FIGURE 1 occupying those parts of the side between the junctions with the other two sides, that is excluding the portions of the groove common to the first and third and second and third sides respectively. The maximum height of the ramp is approximately equal to the depth of the track 28 and the portion maximum height is adjacent to the junction between the first and third sides.

The contact carrier 27 is in the form of a rectangular block having a blind bore 29 in its end remote from the bridge portion 26 to house a spring 30 which bears against a metal contact plate 31 of generally U cross-section which is held for limited relative sliding movement against the sides of the contact carrier 27, towards and away from the operating element, by engagement of integral projections 32 on the contact carrier in openings formed in the walls of the contact plate 31. The contact plate 31 has two, or possibly more, integral contact projections which are engageable with side-by-side conducting strips on a printed circuit board B adjacent to which the switch is supported. It will be become apparent from the following description of the operation of the switch that the contact carrier 27 is slidable across the face of the board B between positions in which the strips are alternatively in electrical contact through the contact plate 31, or are separated from one another. Conveniently all the parts, with the exception of the springs and pin 21 and Contact piece 31 are formed from synthetic resinous materials.

In describing the mode of operation of the switch, the parts must be considered to be in an initial position (shown in FIGURES 1, 2 and 4) in which the push" button 13 and arm 12 are held by the spring 18 in an outermost position and the pin 21 carried by the arm 12 is held in the track 28 at the junction of the first side 28a and the third side 28c. The operating element 16 is held in a position equivalent to that in which the contact plate 31 on the contact carrier 27 would be out of contact with the strips on the member.

When the push button 13 is actuated to move the switch to the on position, the arm 12, carrying the pin 21, moves along the first inclined side 28a of the track 28, this movement of the pin 21 causing the operating element to move against the action of its spring 24 transversely to the direction of movement of the arm 12. When the push button 13 is released, the spring 18 tends to return the push button to the outermost position but the spring 24 of the operating element causes transverse movement of that element such movement being limited by the portion of the wall of the track constituting the inside of the U of the second side 28b, this portion of course being normal to the direction of movement of the operating element under the action of the Spring 24. The pin 21 is thus held, by the action of both springs in the U-shaped part of the second side 28b of the track. It will be apparent that the push button 13 only returns part of the way back to the initial position. When the operating element is held in this position, the contact plate 31 is held in a position equivalent to an electrically connecting position of the strips on the member. This position of the parts is shown in FIGURE 3.

To switch oil, the push button 13 is again depressed and the pin '21 moves out of the U of the second side 28b on the side adjacent to the third side 280 until it reaches the third side under the influence of the spring 24 this movement ceasing when the pin lies in the junction between the third and second sides of the track.

When the push button 13 is released, the pin 21 travels along the third side of the track, over the ramp and into the junction of the first and third sides of the track, that is, the initial position.

The ramp eflectively prevents the pin from moving along the third side instead of the first side when the push button is again actuated. As the slidable member completes its movement, the contact plate 31 is again, of course moved to the initial position.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. An electrical switch comprising a manually operable pushbutton, biasing means urging the pushbutton in one direction, a pair of members comprising an arm connected to the pushbutton and an operating element, a body in which the members are mounted for sliding movement in mutually transverse directions, one of the members having a pin which is engageable in a track provided in the other member, the track being so arranged that movement of the arm will result in relatively transverse movement of said operating element, between two limiting positions, said track being shaped to provide two retaining positions for the pin corresponding to the limiting positions of the operating element, movement of the pin from one of its positions to the other being controlledin part by movement imparted by the pushbutton, and in part by movement imparted by the resilient means and by further resilient means urging the operating element in one direction, the operating-element carrying an electrical contact plate which is moved transversely of the direction of travel of the pushbutton between one position in which it can engage an electrical contact on an electrical printed circuit board, and a further position offset across the face of the board out of contact with the electrical contacts thereon.

2. An electrical switch according to claim 1 in which the operating element is formed with a track which is of generally triangular form, having first and third sides which are joined to a second side which includes a portion in which the pin can be releasably retained in a position in which the contact plate can engage a contact on a printed circuit board. 1

References Cited FOREIGN PATENTS 6/1913 Netherlands. 5/ 1964 Great Britain.

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