US3598934A

US3598934A - Multiple pole switch for producing simultaneous opposite switching operations

Info

Publication number: US3598934A
Application number: US839447A
Authority: US
Inventors: William H O'connor
Original assignee: Black and Decker Manufacturing Co
Current assignee: Black and Decker Corp
Priority date: 1969-07-07
Filing date: 1969-07-07
Publication date: 1971-08-10
Anticipated expiration: 1988-08-10

Abstract

A multiple pole electric switch of the type wherein different poles are respectively connected and disconnected by a single movement of the switch which includes a plurality of stationary contacts, a pluraLity of movable contacts preferably positioned to bridge a gap between a pair of the stationary contacts, and insulating projection means intermediate the pair of stationary contacts. Each movable contact includes a recess which engages the projection and an extending portion which engages one of the stationary contacts in the closed position. In the open position, the movable contact is moved so that the extending portion is lifted out of engagement with the stationary contact by the projection. At least one of the movable contacts is mounted for opposite movement relative to the remainder of the movable contacts so that the one contact opens when the remainder close and closes when the remainder open. Preferably, the extending portion of the movable contact is engaged by the projection and spaced from the stationary contact for a sufficient proportion of its movement so that, during switch operation in either direction, the initially closed contacts open before the initially opened contacts close.

Description

United States Patent (72] Inventor William H. O'Connor. 111

Baltimore. Md. 1

[21] Appl. No. 839,447

(22] Filed July 7,1969

[45] Patented Aug. 10,1971

173] Assignee The Black and Decker Manufacturing Company Towson, Md.

[54] MULTIPLE POLE SWITCH FOR PRODUCING SIMULTANEOUS OPPOSITE SWITCHING OPERATIONS 10 Claims, 8 Drawing Figs.

[52] U.S.Cl 200/16 R,

[51] int. Cl ..ll0lh 15/00 [50] Field of Search 200/6, 67.7,

16, 157, 166 A, 164,6R, 16R, 67 G, 164R [56] References Cited UNITED STATES PATENTS 3,030,459 4/1962 Elliott et al. 200/6 A 3,165,604 1/1965 Sorenson ZOO/67.7

3,188,697 6/1965 Schink 200/16 3,222,488 12/1965 Matthewsm, 200/157X 3,356,814 12/1967 France,.lr 200/157 3,415,966 12/1968 Matthews ABSTRACT: A multiple pole electric switch of the type wherein different poles are respectively connected and disconnected by a single movement of the switch which includes a plurality of stationary contacts, a pluraLity of movable contacts preferably positioned to bridge a gap between a pair of the stationary contacts, and insulating projection means intermediate the pair of stationary contacts. Each movable contact includes a recess which engages the projection and an extending portion which engages one of the stationary contacts in the closed position. in the open position, the movable contact is moved so that the extending portion is lifted out of engagement with the stationary contact by the projection. At least one of the movable contacts is mounted for opposite movement relative to the remainder of the movable contacts so that the one contact opens when the remainder close and closes when the remainder open. Preferably, the extending portion of the movable contact is engaged by the projection and spaced from the stationary contact for a sufficient proportion of its movement so that, during switch operation in either direction, the initially closed contacts open before the initially opened contacts close.

PATENTEU AUG 1 01971 SHEET 1 OF 2 FIG. 5

INVENTOR WILLIAM H. O'CONNOR III ATTORNEY MULTIPLE POLE SWITCH FOR PRODUCING SIMULTANEOUS OPPOSITE SWITCHING OPERATIONS This invention relates to an improved electric switch wherein different circuits are simultaneously connected and disconnected by a single movement of the switch.

It is frequently desirable in electric switching to control multiple circuits simultaneously or in an essentially simultaneous manner but with a predetermined ordering of the circuit operation. A primary example of this is in switches for rotary electric motor-driven devices. Particularly in the case of electric saws, it is of the utmost importance for safety purposes that the brake of the device begin to operate immediately after the motor has been disconnected. Actuation of the brake before the motor has been disconnected can cause serious damage to the motor while delay of the braking action for too long a period of time after the motor has been disconnected may result in cutting the work beyond the desired stopping point or, where operator carelessness may be involved, injury to the operator. It is also of primary importance in the fields of tools and, particularly, portable tools, that the manufacturing cost be minimized.

Accordingly, the present invention is directed to the provision of a multiple pole switch which provides the desired relationship of operations and which performs these operations in the course of a single movement.

An object of this invention is the provision of a new and improved switch which performs ordered operations on a multiplicity of circuits in a single movement of the switch.

It is another object of this invention to provide a new and improved switch which provides an ordered connection and disconnection of multiple circuits in a single switch movement.

A further object of this invention is the provision of a new and improved low cost switch for controlling multiple circuits.

Other objects and advantages of the present invention will be apparent from the accompanying drawings and description and the essential features thereof are set forth in the appended claims.

Briefly, in accord with one embodiment of this invention, I provide a multiple pole switch of the type wherein different poles are respectively connected and disconnected by a single movement of the switch. Specifically, the switch includes a plurality of stationary contacts and a plurality of movable contacts, each of the movable contacts being arranged to engage one of the stationary contacts upon appropriate movement. This is accomplished by providing the movable contacts with an extending portion and a recessed portion and by providing an insulating projection adjacent the stationary contacts so that, when the recessed portion registers with the projection, the extending portion engages the stationary contact and when the movable contact is moved, the projection cams the contacts apart by engaging the extending portion. In particular accord with this invention, the movable contacts are arranged so that at least one of the movable contacts is moved from the engaged position to the disengaged position by the same movement of the switch-operating member which moves at least one other movable contact from the disengaged position to the engaged position.

In a preferred embodiment of this invention, the extending portion of the movable contact is engaged by the projecting means and spaced from the stationary contact for a sufficient proportion of the distance moved so that the initially closed contacts are opened by engagement of the extending portion with the projection before the initially open contacts are allowed to close.

In The Drawings FIG. I is a perspective. exploded view of a switch constructed in accord with the present invention;

FIGS. 2A and 2B are simultaneous views of the positions of two different sets of contacts in one stable position of the operating lever of a switch in accord with this invention;

FIGS. 3A and 3B are simultaneous views of the contacts of FIGS. 2A and 28 at an intermediate point during the movement of the operating lever;

FIGS. 4A and 4B are simultaneous views of the contacts of FIGS. 2A and 28 after movement of the operating lever to its second position; and

FIG. 5 is a schematic illustration of a circuit incorporating a switch in accord with the present invention.

Theswitch assembly shown in FIG. 1 includes a base 10 of insulating material which carries a pair of

stationary contacts

11, 12. The reverse side of the insulating base 10 is substantially similar and it carries another pair of

stationary contacts

13, 14 shown in FIG. 2B. A housing, not shown, is usually provided which encloses the sides of the switch. Contact is made to the stationary contacts by inserting the bared end of a wire from the external circuit through the bottom of the base so that they are gripped in place against the stationary contacts ll, 12 by the

spring metal members

25, 16. Further detail as to the construction and use of this switch is contained in U.S. Pat. Nos. 3,222,488 and 3,415,966, the subject matter of which is incorporated herein by reference.

The switch also includes a pair of

movable contacts

17 and 18. These movable contacts are mounted in an actuator block 19 which is provided with

slots

20 and 21. The slots are sized so that they do not permit any substantial movement in the horizontal direction but they do permit vertical movement of the contacts. The contacts are biased downwardly against the stationary contacts by means of

springs

22, 23 which are mounted in any appropriate manner such as by means of cylindrical holes, not shown, which extend within the actuator block above the

slots

20 and 21.

In the illustrated embodiment, the actuator 19 is operated to move the movable contacts by means of a pivoted rocker 24 having a finger 25 which extends into a central aperture 26 in the actuator 19. The rocker 24 is pivoted, for example by means of a pin, not shown, which extends through an aperture 27 and is supported at each end by the external housing. The sides of the aperture 26 are preferably sloped to accommodate angular entry of the finger 25 while the lower portion of the aperture 26 is relatively tightly fitted to the finger so that the arcuate motion of the finger is converted to linear motion of the actuator.

The motion of the movable contact 17 in response to movement of the rocker 24 is shown in FIGS. 2A, 3A and 4A. FIG. 2A is a side elevation of the side shown in FIG. 1 with the contact 17 in the open position, which corresponds to depression of the left-hand side of the rocker 24 so that the actuator 19 and contact 17 are moved to the right in FIG. 2A. In this position, an extending portion 30 of the contact 171s engaged with the stationary contact 12 and a second extending portion 31 is spaced from the stationary contact 11 due to the camming action of an intermediate projecting portion 32 of the insulating base against surface 34. FIG. 3A illustrates an intermediate point in the switch motion and the position of contact 17 is illustrated at a moment during the depression of the right-hand side of rocker 24. As illustrated, the contact 17 has begun to move to the left in FIG. 3A and the extending portion 31 has moved relative to the projection 32. However, due to the length of the extending portion 31 relative to the distance through which contact 17 has been moved, the contact 17 has not yet engaged the stationary contact 11. In FIG. 4A, the movement of the contact 17 has been completed, corresponding to complete depression of the right-hand side of rocker 24. In this position, the extending portion 31 has moved away from the projection 32 so that the projection now registers with a recess 33 in the contact 17 and the extending portion 31 is now in engagement with the stationary contact 11. Meanwhile. the extending portion 30 has remained in sliding contact with the stationary contact 12. Good electrical con tinuity between the movable contact 17 and the stationary contacts II and I2 is insured by the action of spring 23.

In accord with the present invention, the contact 18, illustrated in FIG. 2B, is closed when contact 17 is opened and is open when contact 17 is closed. Also, in the preferred con- 1. A multiple pole electric switch of the type wherein difstruction, there is a point in the switching operation when both ferent poles are respectively connected and disconnected by a contacts are open. To demonstrate this, FIGS. 2B 3B and 48 single movement of the switch comprising:

illustrate the position of contact 18 at exactly the same moan insulator base;

ments in time as illustrated in FIGS. 2A, 3A and 4A respec- 5 a plurality of stationary electrical contacts mounted on said tively. In FIG. 2B, the contact 18 is in its right-hand position, base;

corresponding to depression of the left-hand side of rocker 24. a plurality of movable electrical contacts mounted for lon- Thus, the projection means 42 is within the recess 43 and the gitudinal movement relative to said base, each of said extending

portions

40 and 41 are respectively in contact with movable contacts having a portion arranged to be moved the.

stationary contacts

13 and 14 due to the action of the coil into engagement with one of said stationary contacts; spring 22. In FIG. 3B, the contact 18 has been moved to the said movable contacts and said base having cooperating left the same distance as contact 17 in FIG. 3A. However, due camming surfaces;

to the immediate action of the projection 42 against an initial each of said movable contacts being movable between a point of camming urface 44 at th tt m f p rti 41, th l 5 first position wherein said camming surfaces permit said connection between extending portion 41 and stationary conengaging -tio t ta t aid stationary contact and a tact 14 has been broken. Thus, as illustrated in FIGS. 3A and second position wherein said camming surfaces separate 38, there is a moment during the operation of the rocker 24 aid engaging ortion from said stationary contact; and when both

contacts

17 and 18 are disconnected from the means f ovin at lea t one of said movable contacts respective stationary contacts which complete the external 20 between id fi t d aid ond o itions during the circuit. This is the preferred embodiment of this invention; same i h operation as h movement f h remainder however, y Shaping the contacts that the distance of said contacts between said second and said first positraversed by the projection within the recess is larger than that i under the extending P the pp effect could be 2. An electric switch as claimed in claim 1 wherein said tained and a moment would exist when both circuits would be camming surfaces incjude a projection f i base, a closed Prior to opening ofthe initially closed contactsrecessed portion in said movable contact, and an extending In FIG. 4B, depression of the right-hand side of rocker 24 portion f id movable Contact;

has been completed so that the contact 18 is now moved Said engaging Portion comprises a part of said extending completely to the left. The engagement of projection means portion;

42 with extending portion 41 is, of course, continued since the Said movable Contact being positioned so that said recessed movement of Contact 18 from F 38 G 48 Simply portion registers with said projection in said first position; causes the surface 44 to slide along the pro ection 42. Thus, and

the contact 18 is spaced from the stationary contact 14 so that the circuit remains broken. Depression of the left-hand side of rocker 24 will cause a sequence which is simply the reverse of that described so that contact 17 is disengaged from contact 11 and thereafter contact 18 is reengaged with contact 14. If desired, the

recesses

33 and 43 and projection means 32 and 42 may be designed so that the respective sets of contacts open and close at the same time.

FIG. 5 illustrates a circuit wherein the illustrated embodiment of this invention is of particular use. Specifically, the circuit shown is that of a permanent magnet motor 45 which is driven by AC current received from line plug 46 through the full wave rectifying bridge 47. A switch 48, corresponding to that described in connection with FIGS. l4 is shown in the ON position wherein one of the contacts, for example 18, is in a position to complete the circuit to the rectifier bridge while the other contact 17 is in the disconnected position. Thus, this 50 An elefmc swlich as i i m clam 1 wherem the position would correspond to that Shown in FIGS 1, 2A and length of said extending portion IS greater than the length of 2B the movement of said projection means in said recessed portion and wherein, during switch movement in either direction, said projection means engages the extending portion of the initially closed contacts prior to disengaging the extending porstationary contact in said second position.

3. An electric switch as claimed in claim 1 and including means biasing said movable contacts toward said stationary contacts. I

4. An electric switchas claimed in claim 1 wherein said extending portion of said one movable contact is located on the opposite side of said projection means from said extending portion of the remainder of said movable contacts whereby movement of said movable contacts in one direction causes opposite switching effects. 5. An electric switch as claimed in claim 4 wherein the stationary contacts engaged by said one and said remainder of said movable contacts are respectively located on opposite sides of said projection means.

In such motors, it is desirable that braking action be provided to stop rotation of the rotor very quickly after the power to the motor has been disconnected. This may best be 5 achieved by providing a short circuit between the brushes 51 tion of the initially open contacts whereby said initially closed so that current in a reverse direction is provided by residual contacts are Opened before sald y p Contacts are energy within the rotor and this interacts with the magnetic closedfield of the permanent magnets 52 to stop rotation very An electric switch as claimed in claim I wherein each of quickly. However, connection of the short circuit via contact 6 movable comacis P" a bridge between a P of 17 before the power is disconnected via contact 18 would also stahohal'y cohtacisi said extending P respectively provide a short circuit across the power line. To avoid this, it is gages and disengage-5 one Contact of said P and h r necessary that the contact 18 be opened before the contact 17 Portion Ofsaid movable Contact remains in Sliding engagement is closed. As previously described, this is accomplished by with the other Contact Ofsaid P means f the illustrated embodiment and operation f the 8. An electric switch as claimed in claim 7 wherein said exrocker or other operator-controlled means causes the contact tending Portion of Said one movable Contact is located n th 18 to open followed by closure of the contact 17, as illustrated pp si Side Of Said P j i n m ns from said extending by the OFF position shown in dashed lines in FIG. 5. portion of the remainder of said movable contacts whereby The foregoing description is of an illustrative embodiment movement of said movable contacts in one direction causes of the subject invention and it is clear that many changes and opposite switching efiects. modifications may be made by those skilled in the art. It is ac- 9. An electric switch as claimed in claim 8 wherein said cordingly intended that the appended claims cover all such means for moving said movable contacts comprises a pivot, changes and modifications as may be within the true spirit and rocker means mounted at said pivot, and means for converting scope of this invention. rotary motion of said rocker means about said pivot into linear I claim: motion of said contacts between said positions.

said projection separates said extending portion from said said projection means engages the extending portion of the initially closed contacts prior to disengaging the extending portion of the initially open contacts whereby said initially closed contacts are opened before said contacts are closed.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. a 934 Dated AUGUST 10, 1971 O Inventods) WILLIAM H. 0 Cormon, I I

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

COLUMN 2, LINE 6, BETWEEN "SECOND" AND osnnon", msEr-rr STABLE LINE 18, "25" SHOULD BE 15 COLUMN 6, LINE 4, BETWEEN "smo" AND "CONTACTS", INSERT INITIALLY OPEN Signed and sealed this 30th day of May 1972.

(SEAL) Amer; t1:

EDWARD I LFIEECJEILER ,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents M po'wso (m'sg) uscoMM-Dc suave-Poe a I-LS GOVERNMENT PRINYING OFFICE I '9" 0-5..1!

Claims

1. A multiple pole electric switch of the type wherein different poles are respectively connected and disconnected by a single movement of the switch comprising: an insulator base; a plurality of stationary electrical contacts mounted on said base; a plurality of movable electrical contacts mounted for longitudinal movement relative to said base, each of said movable contacts having a portion arranged to be moved into engagement with one of said stationary contacts; said movable contacts and said base having cooperating camming surfaces; each of said movable contacts being movable between a first position wherein said camming surfaces permit said engaging portion to contact said stationary contact and a second position wherein said camming surfaces separate said engaging portion from said stationary contact; and means for moving at least one of said movable contacts between said first and said second positions during the same switch operation as the movement of the remainder of said contacts between said second and said first positions.

2. An electric switch as claimed in claim 1 wherein said camming surfaces include a projection from said base, a recessed portion in said movable contact, and an extending portion of said movable contact; said engaging portion comprises a part of said extending portion; said movable contact being positioned so that said recessed portion registers with said projection in said first position; and said projection separates said extending portIon from said stationary contact in said second position.

3. An electric switch as claimed in claim 1 and including means biasing said movable contacts toward said stationary contacts.

4. An electric switch as claimed in claim 1 wherein said extending portion of said one movable contact is located on the opposite side of said projection means from said extending portion of the remainder of said movable contacts whereby movement of said movable contacts in one direction causes opposite switching effects.

5. An electric switch as claimed in claim 4 wherein the stationary contacts engaged by said one and said remainder of said movable contacts are respectively located on opposite sides of said projection means.

6. An electric switch as claimed in claim 1 wherein the length of said extending portion is greater than the length of the movement of said projection means in said recessed portion and wherein, during switch movement in either direction, said projection means engages the extending portion of the initially closed contacts prior to disengaging the extending portion of the initially open contacts whereby said initially closed contacts are opened before said initially open contacts are closed.

7. An electric switch as claimed in claim 1 wherein each of said movable contacts comprises a bridge between a pair of stationary contacts, said extending portion respectively engages and disengages one contact of said pair, and another portion of said movable contact remains in sliding engagement with the other contact of said pair.

8. An electric switch as claimed in claim 7 wherein said extending portion of said one movable contact is located on the opposite side of said projection means from said extending portion of the remainder of said movable contacts whereby movement of said movable contacts in one direction causes opposite switching effects.

9. An electric switch as claimed in claim 8 wherein said means for moving said movable contacts comprises a pivot, rocker means mounted at said pivot, and means for converting rotary motion of said rocker means about said pivot into linear motion of said contacts between said positions.

10. An electric switch as claimed in claim 8 wherein the length of said extending portion is greater than the length of the movement of said projection means in said recessed portion and wherein, during switch movement in either direction, said projection means engages the extending portion of the initially closed contacts prior to disengaging the extending portion of the initially open contacts whereby said initially closed contacts are opened before said initially open contacts are closed.