US2281808A

US2281808A - Switch

Info

Publication number: US2281808A
Application number: US377301A
Authority: US
Inventors: Smiley Gilbert
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-02-04
Filing date: 1941-02-04
Publication date: 1942-05-05
Anticipated expiration: 1959-05-05

Description

May 5, 1942. SMILEY 2,281,808

SWITCH Filed Feb. 4, 1941 Fig.2

214 1; avert-o1 WWLQZ Patented May 5, 1942 UNITED STATES PATENT OFFICE SWITCH Gilbert Smiley, Hingham, Mass.

Application February 4, 1941, Serial No. 377,301

3 Claims.

The present invention relates to an electric switch and more particularly to a switch that may be operated by the elbow, knee, foot, or by bodily contact or the like. The invention more particularly is preferably applied to the operation of electric switches in which the motion of the contact elements are extremely small, of the order of several thousandths of an inch and 'in which the mechanism operated by the foot, elbow or the like is also comparatively small.

The advantage of the present invention resides in the constructional features of the article whereby small switches which are often called microswitches may be operated simply, positively and by means which if directlyapplied to the switch unit itself may be of such a nature that these units would not stand up.

The present invention will be more fully understood from the description in the specification below when taken in connection with the drawing, in which:

Figure 1 shows a sectional elevation of the clevice, and,

Figure 2 shows a plan view of a detail shown in Figure 1.

In Figure 1, i represents a casing which may be of metal or durable fiber material of rugged construction and comparatively substantial weight. 2 is an inlet for the electric cables, and 3 represents a friction plate so that the casing may remain fixed even though it is not screwed down to the base member. 4 is a top plate which may be held down to the sides of the casing I by means of one or more screws 5 which pass through the sides of the easing into a dependent fiange 6 from the top cover 4. A bracket or wall support I also projects downward from the cover t and this support I holds the microswitch 8 by means of the studs and bolts 9 and M respectively. The operating pin ll of the microswitch projects through a shell or tube I! from the unit 8 which shell or tube extends upward slightly beyond the top surface of the cover 4. A spring i3 shown in plan in Figure 2 is symmetrically centered about the shell l2 which projects through a hole I4 in the center of the spring which is a fiat leaf spring with three projecting leaves l5, l6 and [1. These projecting leaves are bent upwards and come in contact with the bottom of the operating plate l8, which plate the spring l8 freely supports. The plate I8 is held in position so that it cannot be removed from the cover 4 by means of the studs H which have large heads 20 abutting the inside of the cover placed with respect to the center tube l2. These studs l9 work up and down in holes 2| which are sufficiently larger than the studs ill to permit free motion of the studs, at the same time maintaining the motion of the plate up and down, but not parallel particularly to the cover 4. The plate I8 may have a cover surface 22 of rubber or other suitable material to provide easy contact and insure against friction in the operation of the switch.

The drawing shown in Figure 1 may be considered approximately full size, the spacing between the operating plate l8 and the cover plate 4 being approximately one eighth of an inch.

The switch as above described may be operated by pressure at any point on the top of the operating plate on the member 22. The motion of the cover plate under these conditions is such that even when the plate is forced down at the edge, the center of the plate over the pin 'II will force the pin downward the necessary distance for operation.

It will be noticed in the construction, the shell l2 projects beyond the surface of the cover 4 of the casing approximately no more than the thickness of the spring l3, and that the pin H within the shell projects a short distance beyond the shell so that the distance between the top of the pin and the operating cover or plate is considerably less than the distance between the cover plate 4 and the plate i8.

Further it should be noted that the pin H can be driven down flush with the top of the shell or spring because of an overtravel mechanism contained within these microswitches so that the pressure or weight on the plate 10 will be borne by the shell it.

As indicated in Figure 1 these distances are in the ratio of approximately 2 to i. The pin ii is operated by a very slight motion and this motion is obtainable by pressing the top cover at any point on its surface in the same amount.

Having now described my invention, I claim:

1. In combination a comparatively heavy casing, a switch having an operating pin operative by a longitudinal travel in the direction of the pin of the order of a small fraction of an inch, means suspending said switch within said casing in a position with the operating pin projecting from the top of the casing, a protective collar surrounding the operating pin, a leaf spring having more than two branches extending from the center hub, said center hub having a perforation through which said projecting collar extends, said 4. The studs l9 are preferably symmetrically spring t t hub resting against said casing, a

plate positioned in parallel relationship over the top of the casing in juxtaposition with said operating pin and supported by the free ends of said spring and means directing travel of said plate within limits to and from the direction of the top of the casing.

2. In combination a comparatively heavy casing, a switch having an operating pin operative by a longitudinal travel in the direction of the pin oi the order ofa small fraction of an inch, means suspending said switch within said casing in a position with the operating pin projecting from the top of the casing, a protective collar surrounding the operating pin, a leaf spring having more than two branches extending from the center hub, said center hub having a perforation through which said projecting collar extends, said spring at its hub resting against said casing, a plate positioned in parallel relationship.

over the top of the casing in juxtaposition with said operating pin and supported by the free ends of said spring and a plurality of studs extending from the plate through perforations in the top of the casing, said perforations being larger than said studs to permit comparatively iree motion of the studs through said perforations, said studs having enlarged heads at the insideoi said cas- 111g, I

3. In combination a comparatively heavy casing, a switch having an operating pin operative by a longitudinal travel" in the direction of the pin of the order of a small fraction oi! an inch, means suspending said switch within said casing in a position with the operating pin projecting through the top of the casing, a leaf spring having more than two branches and having a central hub with a perforation located therein, means centering said spring with the perforation located over said pin, said spring at its hub resting against said casing, a plate positioned in parallel relationship over the top of the casing in juxtaposition with said operating pin and supported by the free ends of the spring and means directing the travel of said plate within limits to and from the direction of the top of the casing.

GILBERT SMILEY.