US2989600A

US2989600A - Momentary contact switch

Info

Publication number: US2989600A
Application number: US811447A
Authority: US
Inventors: Fyfe Clayton
Original assignee: Badger Meter Inc
Current assignee: Badger Meter Inc
Priority date: 1959-05-06
Filing date: 1959-05-06
Publication date: 1961-06-20
Anticipated expiration: 1978-06-20

Description

June 20, 1961 c, FYFE MOMENTARY CONTACT SWITCH 2 Sheets-Sheet 1 Filed May 6, 1959 .E F EF 0 V T m 3 m 0 r C .7 8- H 3 June 20, 1961 FYFE 2,989,600

MOMENTARY CONTACT SWITCH Filed May 6, 1959 2 h s h 2 INVENTOR. CLAYTON FYFE.

ATTORNEY United States Patent 2,989,600 MOMENTARY CONTACT SWITCH Clayton Fyfe, Milwaukee, Wis., assignor to Badger Meter Manufacturing Company, Milwaukee, Wis., a corporation of Wisconsin Filed May 6, 1959, Ser. No. 811,447 Claims. (Cl. '200-30) This invention relates to switches and particularly to switch mechanism wherein the switch contacts are closed only momentarily fora constant period of time independent of the rate at which the switch is actuated.

It is the object of this invention to provide a switch of this type which is of simple construction, reliable and accurate.

This is accomplished by a switch comprising a stationary contact and a resilient switch arm carrying a movable contact mounted on a base with the switch arm adapted for swinging movement between an unstressed and a stressed position to close and open the contacts, respectively. A weight is mounted on the switch arm outwardly from the movable contact and actuating means are provided for imparting uniform increments of acceleration to the weight to cause the contacts to close and remain closed momentarily for uniform periods of time.

The actuating means employed may take many forms with the preferred embodiment comprising a resilient actuating arm mounted on the base for swinging movement between an unstressed and a stressed position. A shoulder formed on the actuating arm is adapted for engagement with the weight as the actuating arm is moved into a stressed position and then released to im part the required acceleration to the weight.

A cam means is provided to disengage the shoulder from the weight as the actuating arm snaps back to its unstressed position permitting the switch arm to swing freely to close the contacts by the momentum of the weight.

Other objects and advantages will be pointed out in, or be apparent from the specification and claims, as will obvious modifications of the single embodiment shown in the drawings, in which:

FIG. 1 is a plan view of a switch and actuating mechanism embodying my invention;

FIG. 2 is a vertical sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view taken along line 3-3 of FIG. 2; and

FIGS. 4 and 5 are simplified plan views similar to FIG. 1 showing the switch and actuating mechanism in different operating positions.

Referring now to the drawings, the illustrated embodiment of the switch of my invention includes a stationary contact mounted on a base 12 by a bracket 14 with a conductor 16 electrically connected thereto. A movable contact 18 is mounted on a resilient switch arm 20 which has a conductor 24- connected thereto. Switch arm 20 is fixedly secured at one end to base 12 by a bracket 22 with

contacts

10 and 18 normally spaced from each other as shown in FIG. 1. Thus, it is seen that by moving arm 20 to close the contacts a circuit is completed between

conductors

16 and 24.

To provide momentary closing of

switch contacts

10 and 18 for constant, predetermined periods of time in response to the variable operation of a water meter for example, -I mount a weight 26 on the free end of arm 20 outwardly from contact 18 and impart increments of uniform acceleration to the system at a frequency directly proportional to the metering rate. The means for imparting such increments of uniform acceleration may take many forms. One such actuating arrangement which 2,989,600 Patented June 20, 1961 Flce operates very well is shown in the drawings. It includes a toothed ratchet wheel 28 mounted on a shaft 30 extending through base 12 which is driven in a counterclockwise direction (as indicated by the arrow in FIG. 1) by the drive spindle of a water meter for example.

Rotation of wheel 28 will cause intermittent actuation of a resilient actuating arm 32 fixedly mounted at one end on base 12 by a bracket 34. Arm 32 has an elongated opening 66 therein through which ratchet wheel 28 extends. When wheel 28 is rotated, one tooth thereof will engage edge portion 38 of opening 36 (FIG. 2) and move arm 32 from the unstressed position shown in FIG. 1 to stressed position shown in FIG. 4. As arm 32 is thus moved a hooked finger 40 extending at right angles at the end of the arm 32 is moved into engagement with weight 26 at the end of switch arm 20. A hooked end portion or shoulder 42 formed on finger 40 slides along the edge 44 of cam member 46 mounted on base 12 until it is forced over a lip 48 on weight 26 which is held stationary in its unstressed position against a stop 50 on member 46.

Continued rotation of wheel 28 from the position shown in FIG. 4 will cause the ratchet tooth to slide off edge 38 and thereby release actuating spring arm 32. When this occurs the stored energy in spring arm 32 will be imparted to weight 26 causing it to be accelerated in the contact closing direction from the position shown in FIG. 4 to that shown in FIG. 5. When the parts reach the FIG. 5 position, hook 42 will be cammed out of engagement with lip 48 by edge 44 and arm 20 will continue to swing freely under the momentum of weight 26 until the contacts are closed. The momentum of weight 26 will, however, continue to flex arm 20 after initial contact and the contacts will remain closed until the direction of movement is reversed causing the contacts to break as weight 26 is accelerated back towards stop 50 by the internal resiliency of switch arm 20.

From the foregoing it is seen that the acceleration imparted to weight 26 by actuating arm '32 (being independent of the rate at which wheel 28 is rotated) will remain constant. Thus, the contact duration for any given increment of acceleration imparted to weight 26 will also be constant making it possible to design a switch suitable for the requirements of a particular application. Furthermore, it is noted that under no conditions are the switch contacts in more than momentary contact, it being impossible for contact to be steadily maintained regardless of rate or stopping position of ratchet wheel 28.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A switch comprising, a base, a stationary contact mounted on said base, a resilient switch arm mounted on said base and adapted for swinging movement between an unstressed and a stressed position, a movable contact mounted on said switch arm, a weight mounted on said switch arm outwardly from said movable contact toward the free end of said switch arm, a resilient actuating arm mounted on said base and adapted for swinging movement between an unstressed and a stressed position, trip means for moving said actuating arm to its stressed position and then releasing it for snap movement back to its unstressed position, a shoulder on said actuating arm adapted for engagement with said switch arm, and cam means mounted on said base adapted to cam said shoulder into and out of engagement with said switch arm as said actuating arm is first stressed and then released by said trip means, said trip means including a toothed ratchet wheel rotatably mounted on said base, said actuating arm having an elongated opening therein through which a portion of said ratchet wheel extends.

2. A switch comprising, a base, a stationary contact mounted on said base, a resilient switch arm fixedly mounted on said base, a movable contact mounted on said switch arm and spaced from said stationary contact, a weight mounted on said switch arm outwardly from said movable contact toward the free end of said switch arm, and actuating means for uniformly accelerating said weight to cause said movable contact to be moved into contact with said stationary contact and remain in contact therewith for a constant period of time, said actuating means including a resilient actuating arm fixedly mounted on said base and adapted for swinging movement between an unstressed and a stressed position, trip means for moving said actuating arm to its stressed position and then releasing it for snap movement back to its unstressed position, and engagement means adapted to first establish engagement between said actuating arm and said switch arm when said actuating arm is in stressed position and before it is released by said trip means, said engagement means further adapted to then release said arms from each other as said actuating arm snaps back to its unstressed position.

3. A switch according to claim 2 in which said engagement means includes a shoulder on the end of said actuating arm and a cam mounted on said base cooperating with said shoulder to earn said shoulder into and out of engagement with said switch arm, as said actuating arm is first stressed and then released by said trip means.

4. A switch according to claim 2 in which said strip means includes a toother ratchet wheel rotatably mounted on said base, said actuating arm having an elongated opening therein through which a portion of said ratchet Wheel extends.

5. A switch comprising, a base, a stationary contact mounted on said base, a resilient switch arm mounted on said base and adapted for swinging movement between an unstressed and a stressed position, a movable contact mounted on said switch arm, a weight mounted on said switch arm outwardly from said movable contact toward the free end of said switch arm, a resilient actuating arm mounted on said base and adapted for swinging movement between an unstressed and a stressed position, trip means for moving said actuating arm to its stressed position, and then releasing it for snap movement back to its unstressed position, a shoulder on said actuating arm adapted for engagement with said switch arm, and cam means mounted on said base adapted to cam said shoulder into and out of engagement with said switch arm as said actuating arm is first stressed and then released by said trip means.

Hall Dec. 15, 1914 Rhoades July 4, 1916