US3708641A

US3708641A - Electrical switch for prefabricated wiring harnesses

Info

Publication number: US3708641A
Application number: US00133254A
Authority: US
Inventors: S Rubinstein
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-12
Filing date: 1971-04-12
Publication date: 1973-01-02
Anticipated expiration: 1990-01-02

Abstract

An electric switch adapted particularly for factory built housing that use harnesses for the electrical wiring. The switch fits directly into the wall of a building without requiring a box. Switch terminals are removable from the switch housing through the back of the housing and can be permanently connected with conductors of power cables before being inserted into the switch. A rearward portion of the switch housing is connected to a forward portion by detachable fastening means to hold the terminals in the housing and to clamp the cable to the housing. The preferred construction has terminals with barrels into which the conductors of a power cable extend, and the cable enters the switch housing and terminates in the barrels with only 90* bends of the conductors of the cable.

Description

Unite States Patent [1 1 Rubinstein 1 Jan. 2, 1973 [54] ELECTRICAL SWITCH FOR PREFABRICATED WIRING HARNESSES [76] lnventor: Solomon Rubinstein, 80 Shady Lane, Fanwood, NJ. 07023 [22] Filed: April 12, 1971 [21] Appl. No.: 133,254

[52] 11.8. CI. ..200/168 E, 200/166 CT [51] Int. Cl. ..H0lh 9/02 [58] Field of Search...3l7/ll9, 120; 200/166 CT,

200/168 E, 200/152 F I [56] References Cited UNITED STATES PATENTS 2,959,656 11/1960 Bentsen ..200/166 CT X 3,051,809 8/1962 Dell ..200/166 CT X 3,510,822 5/1970 Patterson ........339/l4 R 3,271,550 9/1966 Wiley ..200/172 Primary Examiner-H. 0. Jones Attorney-Nichol M. Sandoe et al.

[5 7 ABSTRACT An electric switch adapted particularly for factory built housing that use harnesses for the electrical wiring. The switch fits directly into the wall of a building without requiring a box. Switch terminals are removable from the switch housing through the back of the housing and can be permanently connected with conductors of power cables before being inserted into the switch. A rearward portion of the switch housing is connected to a forward portion by detachable fastening means to hold the terminals in the housing and to clamp the cable to the housing. The preferred construction has terminals with barrels into which the conductors of a power cable extend, and the cable enters the switch housing and terminates in the barrels with only 90 bends of the conductors of the cable.

14 Claims, 10 Drawing Figures PATENTEDJAN 21% ELECTRICAL SWITCH FOR PREFABRICATEI) WIRING I-IARNESSES RELATED PATENT APPLICATION For mounting the switch of this invention directly in a wall without a box, and for mounting it in walls of different thickness, a special construction is used which is disclosed and claimed in our copending patent application Ser. No. I23,7l5,filed Mar. 12,1971.

BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to a new type of electrical switch which is designed as an adjunct of prefabricated wiring harnesses for factory made homes. The ad vantages of these new devices also apply to the wiring of homes which are constructed by conventional onsite methods. The main features of these new switches are:

I. They are self contained and obviate the need for a box since a built-in bracket secures the cable. The bracket may have an angle fixture for mounting on wood or steel studs.

2. There are no exposed live terminals. This makes the switches safer than present conventional box-installed devices in the event the cover plate is removed.

3. The electrical connections to the cable are made to be integral with the current carrying terminals. By making these connections under factory controlled conditions, the electrical reliability of the new devices is higher than for present devices, especially when using aluminum conductor cables.

4. There are no open passages through the switch for moisture laden air to penetrate into the interior of the wall which would cause undesirable condensation and smoke transfer.

The invention will be described for a switch having a mercury switch contact terminal. The electrical connections are made by inserting the conductors of a power cable into rolled barrels and by means of crimping, welding or soldering sound mechanical and electrical connections are made. The same conductor connection method would be used for a switch having leaf spring or'other types of contact terminals.

The switch housing is made with a forward portion and a rearward portion that are connected together by detachable fastening means and one of these portions has a recessed edge which receives the cable and clamps against the other portion when the switch is in assembled condition. The switch also has a feature by which a lever for actuating the contacts is provided with a cover plate thru which it extends and by which it is held in its bearing supports in the housing.

The terminals after being secured to the conductors of the power cable are inserted into the forward portion of the switch housing through an open back of the housing and there are surfaces in the forward portion that hold the terminals against displacement in all directions except rearwardly. When the rearward portion of the housing is attached to the forward portion, it holds the terminals against rearward displacement but they can be removed at any time by merely disconnecting the rearward portion from the forward portion of the housing.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

BRIEF DESCRIPTION OF DRAWING In the drawing, forming a part hereof, which like reference characters indicate corresponding parts in all the views;

FIG. 1 is a sectional view through a switch made in accordance with this invention; the section being taken on the line 1-1 of FIG. 2;

FIG. 2 is a back view of the switch shown in FIG. I with portions broken out and in section to show the way in which one of the terminals is held in place by surfaces of the forward portion of the switch housing;

FIG. 3 is a top plan view of the switch shown in FIG.

FIG. 4 is a fragmentary front view of the switch shown in the other Figures;

FIG. 5 is a detailed view taken at the section line 5 5 of FIG. 1;

FIG. 6 is a side elevation, on a slightly enlarged scale, of the actuator for the switch shown in the other views, the view in FIG. 6 being taken from the same side as in FIG. 1;

FIG. 7 is a top plan view of the actuator shown in FIG. 6.

FIG. 8 is an enlarged rear elevation of the left hand terminal shown in FIG. 2;

FIG. 9 is a fragmentary side elevation of the upper part of the terminal shown in FIG. 8; and

FIG. 10 is a sectional view taken on the line l0-10 of FIG. 9.

DESCRIPTION OF PREFERRED EMBODIMENT FIG. I shows a switch 10 which includes a housing having a forward portion 12 and a rearward portion 13 connected together by a detachable fastening means comprising screws 14 that extend through openings in the rearward portion 13 and that screw into bosses 15 which are part of the forward portion of the housing 12.

There is a recess 16 which has a rough surface 18 and into which a power cable 20 fits. This recess 16 is in the front edge of the rearward portion 13 of the housing and the cable 20 is inserted into the recess before the rearward portion 13 is attached to the forward portion 12. When the screws 14 are pulled up tight to hold the rearward portion 13 firmly against the back surface of the forward portion 12 of the housing, the power cable 20 is firmly clamped against the back wall of the forward portion and held against any axial movement by the rough surface 18 of the recess 16.

The power cable 20 preferably has three

conductors

22, 24 and 26, best shown in FIG. 3. The

conductors

22 and 26 connect with

terminals

28 and 30; and the conductor 24 is preferably a grounding wire which connects with a metal plate of the switch in a manner which will be described in connection with other Figures of the drawing.

FIG. 2 shows the terminal 30 with a barrel 34 at its upper end into which the conductor 26 extends. The conductor is integrally connected with the terminal 30 by a construction that will be described in connection with FIGS. 8 and 10; but for present purposes it is sufficient to understand that the conductor 26 is connected with the terminal 30 so as to be of integral construction therewith and this connection is made before the terminal 30 is inserted into the switch housing.

The forward portion 12 of the switch housing has surfaces that are the sides of a socket 36 which prevents displacement of the terminal 30 in all directions except rearwardly. At its lower end, the terminal 30 fits into another socket 38 for holding the intermediate portion of the terminal against displacement.

Near its center portion, the terminal 30 has a boss 40, preferably formed by displacing metal of the terminal 30, and this boss fits into an axial socket 42 of a mercury switch element or switch unit 44. The terminal 28 on the other side of the switch is of the same con struction as the terminal 30 except for the difference in shape necessary to make it a right hand element in contrast to the terminal 30 which is a left hand element as viewed in FIG. 2. Thus the mercury switch unit 44 is held between the two

terminals

28 and 30 and is retained in place by the resilience of these terminals and the circuits of the mercury switch unit 44 are constructed so as to make the

terminals

28 and 30 the external parts of the circuit. Thus with the mercury switch element in one position the circuit is completed from the terminal 28 to the terminal 30 and when the mercury switch unit 44 is rocked into another position this circuit is broken. Such mercury switch elements are well known and no further description of it is necessary for complete understanding of this invention.

The rearward portion 13 of the switch housing has bosses 50 which are preferably one piece construction with the rest of the rearward portion, and these bosses extend forward into the immediate vicinity of the

terminals

28 and 30 and prevent the terminals from moving rearwardly. There are four such bosses 50, as shown by FIGS. 1 3.

The front of the switch housing is closed by a metal plate 54 which is attached to the front face of the forward portion 12 of the housing by screws 56 that thread into openings in the housing. The metal plate 54 has an opening 58 through which a portion of an actuator 60 extends, and the metal plate 54, on opposite sides of the opening 58 and at the mid-portion of the metal plate has a curved section 64. The center of curvature of the section 64 is substantially coincident with the center of rotation of the mercury switch element 44 and the actuator 64 has a curved face 66 that bears against the inside surface of the curved section 64 to hold the actuator 60 in assembled relation with the rest of the switch and in contact with the circumference of the mercury switch element 44.

There are complimentary notches and projections on the mercury switch unit 44 for making the switch element turn angularly as a unit with the actuator 60.

FIGS. 6 and 7 show the actuator 60 in more detail. It includes a handle 72 which is moved angularly to operate the switch element between open and closed positions. There is a socket 74 on the inner face of the actuator 72 for receiving a complimentary projection of the switch element. There are pads 76 above and below the handle 72 on which the legends off and on are printed, one of which is shown in FIG. 4. Thus with the handle 72 in raised position the switch is closed and with the handle 72 in its lowered-position the switch is open.

Other plates 80, preferably metal, are located at the upper and lower ends of the front portion 12 of the housing as shown in FIG. 1. These plates 80 extend above the top and bottom of the housing and also extend beyond the sides of the housing, as shown in FIGS. 2 and 4. The purpose of the plates 80 is to prevent the switch housing from passing any further into a wall opening than is intended. The plates 80 strike against the wall above and below the opening and limit the extent to which the switch housing can be pushed into the opening. Thus the switch housing is held substantially flush with the front surface of the wall in accordance with conventional practice.

The metal plate 54 which holds the actuator in the switch, and the retaining plates 80, are grounded. This is accomplished by having screws 82, which hold the plates 80 on the housing, extend into threaded openings in the housing and clamp the plates 80 against the front of the metal plate 54. The ground conductor 24 (FIG. 1) extends forward in the switch housing to a location under the upper screw 56, and then the ground conductor 24 extends upwardly into a recess 86 formed in the front surface of the forward portion 12 and extending upwardly and to one side of the screw 56 as shown in FIG. 5. The ground conductor 24 is large enough to project somewhat above the front surface of the forward portion 12 so that when the plate 54 is clamped against the front of the switch housing by the screw 56, it is clamped in firm contact with the ground conductor 24 as indicated in FIG. 4.

FIGS. 8, 9 and 10 show the construction of the terminal 30. It has its upper end curved to form a barrel 90 which fits tightly around the conductor 26 and beyond the barrel 90, the strip metal of which the terminal 30 is made has a portion 92 bent back on itself and parallel to the main part of the terminal which extends upward from the socket 40. This parallel end portion 92 is held firmly clamped against the other part of the terminal 30 by tabs 94 which originally project from both edges of the main part of the terminal 30 and which are bent around the edges of the parallel portion 92 and then inward behind the parallel portion 92 as shown in FIGS. 8 10. There are projections 96 along both edges of the downwardly bent portion 92 and these projections 96 extend through openings 98 in the tabs 94 in order to lock the barrel closed and to prevent the downwardly bent parallel portion 92 from sliding upward and increasing the diameter of the barrel with resulting lessening of the clamping pressure of the barrel on the conductor 26.

Although the construction shown in FIGS. 8 10 obtains a strong crimped connection which is sufficient to make the terminal 80 an integral part of the conductor 26,.other connecting expedients can be used such as solder and swedging.

The preferred embodiment of the invention has been illustrated and described. Terms of orientation are, of course, relative. Features of the invention can be modified and can be used in different combinations without departing from the invention as defined in the claims.

What is claimed is:

1. An electric switch including a housing for mounting in a wall of a building, current carrying terminals in the housing with means for making integral connections between the terminals and selected conductors of a power cable, portions of said terminals comprising contacts, a switch unit in the housing in electrical contact with said contacts of the terminals, an actuator at the front of the housing for moving the switch unit for making and breaking an electric circuit of said switch unit, the housing having a forward portion with an opening toward the back thereof, a rearward portion that closes the opening, detachable fastening means securing the rearward portion to the forward portion, sockets in the forward portion of the housing confining the terminals against displacement in the housing in all except one direction, and the rearward portion of the housing having surfaces thereon that hold the terminals against displacement in said one direction the terminals being removable from the housing through said opening when the rearward portion of the housing is removed, the switch unit being held between said contacts and said contacts being bearing means that determine the location of the switch unit in the housing and that hold the switch unit against transverse displacement.

2. The electric switch described in claim 1 characterized by each of the terminals having a barrel into which the conductor is inserted and to which the conductor is permanently connected.

3. The electric switch described in claim 1 characterized by the sockets of the forward portion including the sides of separate slots into which portions of the respective terminals extend, and the rearward portion having projections thereon that project into the forward portion of the housing when the different portions of the housing are in assembled relation with one another, said surfaces of the rearward portion of the housing being on the projections and in position to hold the terminals in the slots.

4. The electric switch described in claim 1 characterized by the terminals including two terminals on different sides of a center plane of the housing, and each of the terminals having a barrel at its upper end, a recess in the upper edge of one portion of the housing where the forward and rearward portions come together, this recess forming an opening in the assembled housing through which a cable extends to the barrels of the terminals and by which the cable is clamped to the housing.

5. The electric switch described in claim 4 characterized by the barrels extending in a generally horizontal direction and a cable extending into the housing through said opening at the top of the housing, and conductors of the cable bent through substantially 90 and extending into the barrels of the terminals.

6. The electric switch described in claim 1 characterized by ametal plate closing a portion of the front of the housing and having an opening therein through which the actuator for the switch unit extends, the terminals including two terminals connected with opthe housing and holding the actuator in assembled relation with the housing, the actuator including a handle extending through an opening in the metal plate, fastening means connecting the metal plate with the plastic part of the forward portion of the housing, the housing having an opening through which a power cable enters the housing, the power cable having two power conductors and a ground wire, barrels on the terminals into which the respective power conductors extend, and an opening in the housing through which the ground wire extends to a location where it contacts with the metal plate to ground said metal plate.

8. The electric switch described in claim 7 characterized by the ground wire extending through an opening in the portion of the housing that is made of electric insulating plastic material to protect the ground wire from contact with the terminals, and the end of the ground wire being adjacent to the fastening means that connect the metal plate with the housing and being held in contact with the metal plate by pressure of said fastening means that connects the metal plate to the housing.

9. The electric switch described in claim 1 characterized by one of the confronting edge portions of the forward and rearward portions of the housing where they come together when an assembled relation being recessed to form an opening through a wall of the housing for the entrance of a power cable into the housing, the opening being substantially filled by the cross-section of the cable with which the switch unit is intended to be used, the housing having another opening in a front wall thereof for the handle of the actuator to protrude from the housing, the housingwalls being otherwise free of openings through which air from outside the housing can penetrate into the housing with resulting undesirable condensation and smoke transfer.

10. The electric switch described in claim 1 characterized by there being two terminals in the housing confined toward their opposite ends by surfaces of the housing but having mid-portions that are resilient and that confront one another over open space within the housing, the switch unit being a mercury switch unit confined between said contacts of the terminals and held between them, said mercury switch unit having its opposite sides connected electrically to the respective terminals, the actuator being in position to rock the mercury switch unit between open and closed positions.

11. The electric switch described in claim 1 characterized by a plate forming a part of the front wall of the housing and having a curved bearing surface that holds the actuator in the housing, said plate being a part of the forward portion of the housing and being connected to the rest of said forward portion by fastening means, and said plate having mounting openings for a cover plate for the switch and for flanges that bear against the front of the wall in which the housing is located.

12. The electric switch described in claim 1 characterized by the housing being located in a wall of a building and being connected directly to the wall, and a power cable leading from a power source and extending directly to the housing with its conductors connected integrally with the terminals of the switch unit.

14. The electric switch described in claim 13 characl terized by there being tabs that are of one piece construction with one of the parallel extending parts of the terminal and that are bent around opposite edges of the other parallel extending part of the terminal, slots in said tabs, and other tabs on the opposite edges of said other parallel part of the terminal extending through the slots for interlocking the different tabs on corresponding edges of the terminals.

UNITED STATES PATENT OFFICE. CERTIFICATE OF CORRECTION Patent No. 3,708,641 Dated IJanuary 2, 1973 Inventor) Solomon Rubinstein et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet, insert [73] Assignee: General' Cable Corporation, New York, N. Y., a corpozgation of New Jersey. same cover sheet "[76] Inventor: Solomon Rubinstein, 80 Shady Lane, Fanwood, N. J. 07023" should read [76] Inventor: Daniel E. Robinson, Metuchen and Solomon Rubinstein, Fanwood, N. J.

This certificate supersedes Certificate of'Correction issued August 7, 1973. 1

Signed and sealed this 9th dayof July 1974.

(SEAL) Attest:

C. MARSHALL DANN MCCOY QN, Y- Commissioner of Patents Attestlng Officer FORM (0459) I USCOMM-DC 60376-P69 I t ".5, GOVERNMENT PRINTING OFFICE 2 I569 0'-356-334'

Claims

5. The electric switch described in claim 4 characterized by the barrels extending in a generally horizontal direction and a cable extending into the housing through said opening at the top of the housing, and conductors of the cable bent through substantially 90* and extending into the barrels of the terminals.

6. The electric switch described in claim 1 characterized by a metal plate closing a portion of the front of the housing and having an opening therein through which the actuator for the switch unit extends, the terminals including two terminals connected with opposite sides of a power line and located on opposite sides of a center plane of the switch unit, and a ground wire extending between the terminals and having electric contact with the metal plate.

7. The electric switch described in claim 1 characterized by the forward and rearward portions of the housing being made of electrical insulating plastic material, the actuator being removable from the housing through an opening in the front of the housing, a metal plate closing most of said opening in the front of the housing and holding the actuator in assembled relation with the housing, the actuator including a handle extending through an opening in the metal plate, fastening means connecting the metal plate with the plastic part of the forward portion of the housing, the housing having an opening through which a power cable enters the housing, the power cable having two power conductors and a ground wire, barrels on the terminals into which the respective power conductors extend, and an opening in the housing through which the ground wire extends to a location where it contacts with the metal plate to ground said metal plate.

9. The electric switch described in claim 1 characterized by one of the confronting edge portions of the forward and rearward portions of the housing where they come together when an assembled relation being recessed to form an opening through a wall of the housing for the entrance of a power cable into the housing, the opening being substantially filled by the cross-section of the cable with which the switch unit is intended to be used, the housing having another opening in a front wall thereof for the handle of the actuator to protrude from the housing, the housing walls being otherwise free of openings through which air from outside the housing can penetrate into the housing with resulting undesirable condensation and smoke transfer.

13. The electric switch described in claim 1 characterized by each of the terminals being made of a strip material having its end bent over to form a barrel for receiving a conductor of a power cable, the material of the strip beyond the barrel extending back along itself and in contact with itself, tabs on the terminal and around the parallel extending parts of the terminal and in positions to prevent the barrel from opening.

14. The electric switch described in claim 13 characterized by there being tabs that are of one piece construction with one of the parallel extending parts of the terminal and that are bent around opposite edges of the other parallel extending part of the terminal, slots in said tabs, and other tabs on the opposite edges of said other parallel part of the terminal extending through the slots for interlocking the different tabs on corresponding edges of the terminals.