US2552141A - Electrical switch - Google Patents

Description

y 1951 s. w. BRAMLEY 2,552,141

ELECTRICAL SWITCH Original Filed March 5, 1941 'INVENTOR ATTOR Y Patented May 8, 1951 UNITED STATES PATENT OFFICE ELECTRICAL SWITCH Sylvanus W. Bramley, White Plains, N. Y.

Original application March 5, 1941, Serial No.

580,951, now Patent No. 2,490,013, dated December 6, 1949. Divided and this application September 20, 1949, Serial No. 116,829

1 Claim.

This invention relates to electrical switch mechanism and application of that mechanism to various specific uses thereof and is a division of my copending application Serial No. 580,951, filed March 5, 1941, now Patent No. 2,490,013, December 6, 1949, for Electrical Switch.

In switching mechanism particularly of the spring actuated type, difiiculty has been experienced in making positive contacts free from vibration or chattering; and, particularly where the contacts are repeatedly made and broken, e. g. in ignition systems for internal combustion engines and electromagnetically operated clock mechanisms, the contacts readily become fouled and inoperative.

It is an object of the invention to provide a contact free from these and other difficulties.

It is a further object of the invention to pro vide certain specific structures embodying and applying the generic principle of the invention.

The invention will be further described and illustrated by reference to the accompanying drawings in which Fig. 1 shows a plan View of a make and break mechanism intended as part of an ignition system for an internal combustion engine;

Fig. 2 is a perspective view of the device shown in Fig. 2.

Referring to Figs. 1 and 2, a pivoted spring actuated switch pole comprising the strip or palette 28 is pivotally mounted on pin 21 by means of wings 29, 30 and bushing 35, the pin 21 passing through holes in the wings. A coil spring 31 is mounted on pin 2'! between the wings 29, 30. One end of the spring is anchored to the lever "H by passing through hole 38 herein. A portion of the strip or palette 28 is formed into a hook 39. The other end of the spring 31 passes under this hook 39 and is bent upwardly to form an arm 40. The palette may be a thin strip of magnetic steel, to the under side of which is secured a diagonally positioned bar 4! of pure silver or other highly conductive an inert metal.

Pin 21 is mounted near one end of lever H pivotally mounted to oscillate or swing about pivot 12 mounted on plate 13 which may form part of a housing '14 (shown diagrammatically in Fig. 1 with the cover removed). Lever 1| carries a slot '15 in which cam 16 mounted on shaft 11 rotates. Shaft 11 also carries cam 18. Stops 19, 80 serve to limit the movement of the pivoted switch pole.

The fixed switch pole comprises bracket 55 mounted on plate 13 (which in this case is made of insulating material) by means of rivet 51. To

2 the bracket 55, which may be made of brass, bronze or the like, there is brazed or otherwise suitably secured a bar 54 made of pure silver or other conductive and inert material.

Shaft 11 is rotated by conventional motor means and a continuation of said shaft carries a conventional rotor for distribution of current to the cylinders of an internal combustion engine. The electrical circuit includes, in series, the fixed switch pole (including bracket 55 and bar 54), the pivoted spring actuated pole (including palette 28), the lever H (which is metallic), the pivot 12 and leads 8|, 82. The circuit also includes an induction coil or transformer and a source of current such as a battery. The parts not shown in the drawing are, or may be, conventional.

With the parts as shown in Figs. 1 and 2, the free end of the pivoted palette 28 projects some distance beyond the fixed terminal or contact 54, 55 and the spring 37! has been tensioned by action of the cam 18 on arm 40. As the cam 18 rotates further in a clockwise direction, as shown in Fig. 1, the arm 40 is released and the pivoted switch pole is snapped into switch closing position, with bar 4|, in contact with bar 54. Cam 16 then swings lever H about pivot 12 and wipes the bar 4! (attached to palette 28) across the bar 54. When movement of the lever H has dragged the free end of palette 28 just beyond the fixed switch pole, cam 18 has rotated through an angle of about 360 degrees and has again engaged the arm. 40, tensioned spring 31, and caused opening of the switch by separating the fixed and pivoted switch poles. Synchronized with this movement, the lever has swung in a counterclockwise direction and has moved the parts back into the position shown in Fig. 2.

What is claimed is:

Switch mechanism for an ignition system for internal combustion engines comprising a fixed switch contact pole, a rotatably mounted shaft adapted to be driven at a predetermined speed. a lever pivoted to swing from one position of limited movement to another position. of limited movement about a first pivot spaced from said fixed switch contact pole, and toward and away from said fixed contact pole during said movement, cooperating means on said shaft and lever causing said lever to swing from said one position of limited movement to said other position of limited movement when said shaft is rotated; pivoted spring-actuated switch pole mounted on. said lever to swing about a second pivot spaced from said first pivot said pivoted spring-actuated and then release said spring-actuated contact 10 pole, whereby the spring actuated contact pole is snapped into contact with the fixed contact pole and is maintained in wiping contact therewith during a portion of the movement of said pivoted lever from one position of limited movement thereof to said other position.

SYLVANUS W. BRAMLEY.

No references cited.

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