US2919331A

US2919331A - Switching means

Info

Publication number: US2919331A
Application number: US752614A
Authority: US
Inventors: Melvin T Roudebush; Wilmer L Moyer
Original assignee: NCR Corp
Current assignee: NCR Voyix Corp; National Cash Register Co
Priority date: 1958-08-01
Filing date: 1958-08-01
Publication date: 1959-12-29
Anticipated expiration: 1976-12-29
Also published as: GB861204A; FR1232652A; DE1159543B; CH357784A

Description

Dec. 29, 1959 M. T. ROUDEBUSH ETAL 2,919,331

SWITCHING MEANS Filed Aug. 1, 1958 INVENTORS MELVIN 1'. ROUDEBUSH WILMER L. MOYER M Q wmyy Tl-LElR ATTORNEYS United States Patent SWITCHING MEANS Melvin T. Roudebush and Wilmer L. Mayer, Dayton,

Ohio, assignor's to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Application August 1, 1958, Serial No. 752,614

7 Claims. (Cl. 200-153) This invention relates to improvements in switching means and more particularly to switches operating under high-speed conditions.

Previous switches of the prior art, when operating at high rates of speed, exhibited an inability to maintain a satisfactory consistent engagement of contacts which would meet the requirements for high-speed switch operation. At this high rate of cyclic operation, the switch blade structure, on which the contacts were mounted, became subject to secondary vibrations, thereby producing a stuttering effect on the operation of the contacts. Accordingly, there is a need for a switch which will operate efficiently regardless of the speed of operation.

An object of this invention, therefore, is to provide an electric switch construction which will operate efficiently under very high-speed conditions.

Another object of this invention is to provide a highspeed switch capable of maintaining a consistent contact engagement for long periods of operation.

A further object of this invention is to provide a switch with control means to insure eificient switching operation over a wide range of speeds.

With these and incidental objects in view, the invention includes certain novel features of construction and combinations of parts, a preferred form or embodiment of which is hereinafter described with reference to the drawing which accompanies and forms a part of this specification.

In the drawing:

Fig. l is a longitudinal sectional view through the assembled switch, showing the position of the cam and the contacts at the moment of closing.

Fig. 2 is a perspective View of the embodiment of this invention, showing the contacts in an open position.

Referring now to the drawing, there is shown in Fig. l a box-like switch support comprising a base 1, a front wall 2, a rear wall 3, side walls 4, and a top wall 5. This support may be constructed of any suitable insulating material. Rotatably supported in the side walls 4 are torsion bars 6 and 7, extending longitudinally between said side walls in a spaced and parallel relationship. The function of the torsion bars is to provide resilient elements for the control. and storage of torsional energy.

'Rigidly secured to the torsion bars 6 and 7, by means of pins 8, are switch

arms

10 and 9, respectively. As shown in Fig. 2, both of these switch arms are positioned on the torsion bars in the same plane for coaction with each other.

The outer stem 11 of each of the switch arms is cut down to provide a recessed surface 12, which is parallel to the inner faces 13 of the switch arms.

Located immediately below the stems 11 and on the inner faces 13 of the

switch arms

9 and 10 are electrical contacts 14. The contacts may be constructed of any suitable material which will provide a long contact life under high-speed operating conditions.

Also rigidly secured to the torsion bars 6 and 7, by means of pins 8, are

torsion arms

15 and 16, respectively. As shown in Fig. 2, the torsion arm 15 is positioned on the torsion bar 6 so as to extend above the torsion bar, while the other torsion arm, 16, extends below the torsion bar 7. Cooperating with the free end ice of each of the

torsion arms

15 and 16 are a pair of adjusting

screws

17 and 18, respectively, each of said adjusting screws being rotatably supported in the rear wall 3, and secured in position by locknuts' 19, as shown in Fig. 1. As best seen in Fig. 1, the head of each of the adjusting screws 17 and 1 8 abuts the outer surface 20 of one of the torsion arms. It can be seen that any pressure on the surfaces 20 of the

torsion arms

15 and 16 by the heads of the adjusting

screws

17 and 18 will result in counter-clockwise rotation of the torsion bars 6 and 7, and will consequently vary the pressure exerted by the contacts 14 on each other.

incorporation of the switch into an electrical circuit is accomplished bythe use of terminals 36 secured to the adjusting

screws

17 and 18 through the use of locknuts 21. Connected to the terminals 51) are wires 22' for conducting a current to and from the electrical contacts 14- by means of the adjusting

screws

17 and 13, the

torsion arms

15 and 16, the torsion bars 6 and 7, and the

switch arms

9 and 10.

Rotatably supported in the side walls 4 and spaced in parallel relationship with the torsion bars 6 and 7 is an operating shaft 23 powered by a motor (not shown). Rigidly secured to said shaft is a circular cam plate 24, the outer peripheral surface of which is lined with a suitable insulating material 25. As may be seen in Fig. 1, the cam plate is mounted eccentrically on the shaft 23 and is positioned (Fig. 2) on said shaft so as to engage the outer surface 26 of the switch arm 9 for movement of said arm.

Located in the rear wall 3 and rotatably supported thereby is an adjusting screw 27, the head 28 of which abuts the inner recessed face 12 of the switch arm 10;

as shown in Fig. 1. Lateral movement of the adjusting screw biases the'switch arm 10 to vary the initial air gap between the

switch arms

9 and 10, and thus adjust the timing.

In the operation of the switch, the gap between the contacts 14, located, respectively, on the

switch arms

9 and 10, is adusted by rotation of the adjusting screw 27. This gap controls the length of time the contacts are together during a single revolution of the cam 24. After the air gap has been properly adjusted, the

arms

15 and 16 are rotated in a counter-clockwise direction by the adjusting

screws

17, 18. This rotation of the

arms

15 and 16 applies a counter-clockwise twisting moment to the torsion bars 6 and 7. Since the

switch arms

9 and 16 are rigidly secured to the torsion bars, this counterclockwise moment rotates both the torsion bars and the switch arms in a counter-clockwise direction. The magnitude of this initial moment applied to the torsion bars 6 and 7 varies directly with the operational speed of the switch.

Counter-clockwise rotation of the switch arm 9 biases said arm against the outer surface of the cam 24, while the same rotation biases the switch arm 11 against the head of the adjusting screw '27. In home position of the switch, the shortest radius of the cam24 is between the shaft 23 and the switch arm 9, and the contacts 14 on the

arms

9 and 10 are spaced apart in open position. During the first half-cycle of rotation of the cam 24, the switch arm 9 is displaced by the cam in a clockwise direction about the torsion bar 7. This movement results in the contact 14 on the switch arm 9 coming into contact with the contact 14 on the switch arm 10, thereby closing the contacts 14 and displacing the arm 10 about the torsion bar 6 in a clockwise direction. This rotation of the arms 9 and 10' about the longitudinal axis of their respective torsion bars produces a clockwise twisting moment on the torsion bars. Due to the already-existing moment on the torsion bars applied by the

arms

15 and 16, this clockwise moment applied by the switch arms to --2,919,3a1 fir the torsion bar will be absorbed, and any tendency for the switch arms to be subjected to secondary vibration or for the contacts to chatter will be eliminated. This will allow the switch to be operated at very high speeds and still produce a clean making and breaking of the contacts.

Of the second half-cycle of the cam revolution, the cam surface displacing the switch arm 9 in a clockwise direction will be removed sufiiciently to allow said switch arm to be rotated in a counter-clockwise direction under the influence of the moment applied to the torsion bar by the

arms

15, 16. This counter-clockwise rotation of the switch arm will open the contacts 14 as the cam 24 returns to home position, and will thus break the circuit.

While the form of the mechanism herein shown and described is admirably adapted to fulfill the objects primarily stated, it is not intended to confine the invention to the form or embodiment herein disclosed, for it is susceptible of embodiment in various forms, all coming within the scope of the appended claims.

What is claimed is:

l. A switching device comprising, in combination, stationary mounting means; a pair of resilient members supported on the mounting means; contact supporting means secured to each of the resilient members including a first contact supporting means and a second contact supporting means; contact means mounted on each of said contact supporting means; means for biasing said first contact supporting means toward the second contact supporting means for engagement of the contact means; an arm mounted on each of said resilient members; and means for adjustably limiting the movement of said arms, wherein opposing twisting moments are exerted on each of said resilient members, the opposing moments resulting from the movement of the arms and the contact supporting means in directions opposite to each other.

2. A switching device comprising, in combination, stationary mounting means; a pair of resilient members supported on the mounting means; elongated supporting means having one end of each means secured to one of said resilient members and comprising a first support means and a second support means; contact means mounted on the free end of each of said support means; means for biasing said first support means towards the second support means for engagement of the contact means; an arm mounted on each of said resilient members; and means for adjustably limiting the movement of said arms, wherein opposing twisting moments are exerted on each of said resilient members, the opposing moments resulting from the movement of the arms and the contact supporting means in directions opposite to each other.

3. A switching device comprising, in combination, stationary mounting means; a pair of torsion bars supported on said mounting means in a spaced and parallel relationship; elongated support means having one end of each means secured to one of said torsion bars and comprising a first support means and a second support means; contact means mounted on the free end of each of said support means; means for biasing said first support means towards said second support means for engagement of the contact means; an arm mounted on each of said torsion bars; and means for adjustably limiting the movement of said arms, wherein opposing twisting moments are exerted on each of said torsion bars, the opposing moments resulting from the movement of the arms and the contact supporting means in directions opposite to each other.

4. A switch comprising, in combination, stationary mounting means; a pair of to'rsion bars rotatably supported on the mounting means in a-spaced and parallel relationship; means comprising a first elongated switch arm and a second elongated switch arm, each arm having one end rigidly mounted to one of said torsion bars; contact means mounted on the free ends of said switch 4 7 arms; means for biasing the first switch arm towards the second switch arm for engagement of the contacts on said arms; an arm mounted on each of said torsion bars; and means for adjustably limiting the movement of said arms, wherein opposing twisting mo'ments are exerted on each of said torsion bars, the opposing moments resulting from the movement of the arms and the contact supporting means in directions opposite to each other.

5. A switch comprising, in combination, insulated mounting means; a pair of torsion bars rotatably sup ported on the mounting means in a spaced and parallel relationship; a pair of switch arms, each having an end rigidly mounted to one of said torsion bars; a pair of contacts, due of which is mounted on the free end of each of said switch arms; means including an insulated cam, rotatably supported on said mounting means, for biasing one of said switch arms towards the other of said switch arm for engagement of the contacts on said arm; an arm mounted on each of said torsion bars; and means for adjustably limiting the movement of said arms, where in opposing twisting moments are exerted on each of said torsion bars, the opposing moments resulting from the movement of the arms and the contact supporting means in directions opposite to each other.

6. A switching device comprising stationary mounting means; a pair of resilient members supported on the mounting means; means including a first switch arm rigidly secured to one of said resilient means and a second switch arm rigidly secured to the other of said resilient means; contact means mounted on each of said switch arms; means for biasing said first switch arm towards the second switch arm for engagement of the contact means on said arms; a first arm rigidly mounted on one of said resilient members and a second arm rigidly mounted on the other of said resilient members and a pair of adjusting screws threadedly supported on the mounting means, said adjusting screw abutting said first and second arms for adjustably limiting the movement of said arms, wherein opposing twisting moments are exerted on each of said resilient members, the opposing moments resulting from the movement of the arms and the switch arms in directions opposite to each other.

7. A switching device comprising insulated, mounting means; a pair of torsion bars rotatably supported on said mounting means in a spaced and parallel relationship; a first switch arm having one end rigidly secured at right angles to one of said torsion bars; a second switch arm having one end rigidly secured at right angles to the other of said torsion bars; means rotatably supported on said mounting means and located in abutting relationship with said second switch arm, thereby preventing relative movement of said arm in one direction; a pair of electrical contacts, each one of which is supported on the free end of said switch arms; an actuating means comprising a rotatable shaft carrying an insulated rotary cam and supported on said mounting means, said cam being in operative relation with said first switch arm such that upon rotation of said cam the first switch arm is displaced towards said second switch arm for engage: ment therewith; a third arm having one end rigidly secured at right angles to one of said torsion bars; a fourth arm having one end rigidly secured at right angles to the other of said torsion bars; and a pair of adjusting screws threadedly supported on said mounting means and abutting said third and fourth arms for adjustably limiting the movement of said arms, wherein opposing twisting moments are exerted on each of said torsion bars, the opposing moments resulting from the movement of the third and fourth arms in a direction Opposite to that of the movement of the first and second switch arms.

References Cited in the file of this patent UNITED STATES PATENTS 2,284,437 Lake May 26, 1942