US2773948A

US2773948A - Contact arrangement for control relay

Info

Publication number: US2773948A
Application number: US370994A
Authority: US
Inventors: Robert A Pelz; Ellis Delbert
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1953-07-29
Filing date: 1953-07-29
Publication date: 1956-12-11
Anticipated expiration: 1973-12-11

Description

Dec. 11, 195% R. A. PELZ ET AL 2,773,948

CONTACT ARRANGEMENT FOR CONTROL RELAY Filed July 29, 1953 5 Sheets-Sheet 1 Fig.1.

\ WETNESSES: INVENTORS 5.4 I Robert A. Pelz Wj 0nd Delberi' Ellis.

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ATTORNEY 1%., 1956 R. A. PELZ ET AL 29773994?) CONTACT ARRANGEMENT FOR CONTROL RELAY Filed July 29, 1953 3 Sheets-Sheet 2 Fig.6

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ATTORNEY 3 Sheets-Sheet 3 Filed July 29, 1953 lNJENTORS s 4 mm M DIE Aw m m D f Ow W ATTORNEY United States Patent CONTACT ARRANGEMENT FOR CONTROL RELAY Robert A. Pelz and Delbert Ellis, Beaver, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application July 29, 1953, Serial No. 378,994

11 Claims. (Cl. 200-16) This invention relates to a contact assembly for contactors and more particularly, this invention relates to a contact assembly which is reversible as a unit from make to break or break to make.

In the past, contactors of the type illustrated herein have not had contacts that were interchangeable from make to break and break to make with the same parts. Other contactors have been provided with contacts which are reversible from make to break or break to make, but these contact assemblies have been somewhat complex, have had several parts which require adjustment to reverse, and have parts for the make to break position which are unused for the break to make position or vice versa. It is a distinct disadvantage if a number of loose parts which may be lost while handling, or if a number of extra parts which must be stored, must be used to change contacts from normally open to normally closed or from normally closed to normally open.

it is an object of this invention to provide a contact assembly which is reversible as a unit from make to break or break to make with the same parts.

Another object of this invention is to provide a contact assembly structure which is of a simple and economic construction and which has parts that are so disposed as to be of relatively simple and quick assembly and dis assembly.

Yet another object of this invention is to provide a reversible contact assembly structure for a contactor which is of a simple and economic construction which has parts that are so disposed as to be of relatively simple and quick assembly and disassembly.

The objects recited are merely illustrative. Other objects and advantages will become more apparent from a study of the following specification and the accompanying drawings in which:

Figure 1 shows a front view of an assembled electromagnetic contactor containing the contact assembly;

Fig. 2 shows a sectional side View of an assembled electromagnetic contactor containing one embodiment of the contact assembly in a normally closed position;

Fig. 3 shows a detailed view of one embodiment of a contact assembly in a normally open position, and contact assembly mounting means;

Figs. 4 and 5 show another embodiment of the con tact assembly means in the normally closed and the normally open positions respectively; and

Fig. 6 shows a top view of the movable contact member used in the contact assemblies.

For the purpose of illustrating the utility of embodiments of the reversible contact assembly, it is shown and described as being used in the relay or contactor for which it was originally designed. The details of the relay are shown and described in more detail in a copending application of Vincent G. Krenke and Delbert Ellis filed March 6, 1953, entitled Electromagnetic Contactor and given Serial No. 340,862 which shows an improvement of the contactor shown and described in the two copending applications of Owen L. Taylor filed March 6, 1953, entitled Electromagnetic Contactor and given Serial Numbers 340,859 and 340,860.

By referring to the drawings, it will be noted that base plate 2 is provided with displaced

portions

3, 4 and 4. The displaced

portions

3 and 4 have holes therein for receiving bolts to fix the base plate of the relay to a panel board. A resilient flat spring member 5 is provided on the back of the base plate so that the displaced

portions

3, 4 and 4 and the resilient spring member 5 will give a snug fit with a panel board when the contactor is fixed thereto. This means of mounting permits positive mounting with only two mounting screws or bolts on surfaces which may not be perfectly fiat. The resilient spring member 5 also absorbs the shock from the closing action of the contactor which decreases the armature and magnet face wear and increases the operating life of the contactor.

A bearing bracket 7 and'electromagnet brackets 8 are also fixed to the base member 2. The electromagnet brackets 8 fit on each side of the electromagnet core 1 to hold the laminations together. A portion of each electromagnet bracket 8 extends perpendicular to the plane of the laminations and away from the core 1 so that the brackets may be fixed to the base member 2 and thus hold the core 1 in position. A coil 9 is provided on the center leg of the E-shaped electromagnet.

The bearing bracket 7 is one of four plates which form a parallelogram arrangement. The bearing bracket 7 has bearing surfaces at each end which are engaged by bearing edges of an upper rocker arm 19 and a lower rocker arm 11, respectively. The opposite bearing edge of the upper rocker arm 10 engages a bearing surface of the armature bracket 12 and the bearing edge of the opposite end of the lower rocker arm 11 engages the lower bearing surface of the armature bracket 12. The armature bracket 12 has a mounting bolt 13 projecting through two extensions on the armature bracket to secure the armature 14 of the contactor between the extensions. Extensions at the upper end of the armature bracket 12 are fixed to a contact actuating arm or support 15 by means of screws 16. The contact actuating arm has wall portions 15 which mate with wall portions 17 of the contact support means 6. The mating wall portions 15' and 17 increase the arc path between the contacts.

When the coil 9 is energized it causes the armature 1G to pick up and thus transmit motion through the parallelogram arrangement to the actuating arm 15. The contact assemblies 18 are actuated by the contact actuating arm 15 and thus the movable contacts of the contact assemblies 18 either bridge the fixed contacts 25 supported by the contact support means 6 or open the circuit between the fixed contacts. The coil 9 is held in position on the center leg of E-shaped electromagnet by means of spring members 19 fixed to the electromagnet bracket 8 on the sides of the electromagnet. The spring members 19 are fixed in such a manner that they may be rotated out of contact with the coil 9 to allow easy removal of the coil.

Figs. 2 and 3 show views of sections through the recesses in the contact support means 6. The contact assembly 18 is shown in its normally closed position in Fig. 2 and in its normally open position in Fig. 3. The

stationary contact members 25 are held in position by the screws 26. The terminals 27 are brought out above contact support means 6 so that they are readily accessible. The movable contact members 28 have four recesses along the sides which mate with the guide links 34) on the saddles 29.

In the normally open contact position shown in Fig. 3, the threaded end of the screw 31 enters a tapped saddle guide 32 and fastens the moving contact assembly 18 to the contact actuating arm 15.

greases The saddle 29 is formed at both ends. The bend at one end contains a clearance hole for mounting in the normally open position. The bend at the other end forms a large area which, when in contact with the actuating arm 15 during its travel assures little wear of the actuating arm surface and thus assures a long reliable life. A biasing spring 33 is provided between the bridging movable contact members 25 and the saddle guide 32, in order to hold the movable contacts 28 in position and assure good contact. The contacts spring pressure may be varied to produce a loading more in line with the particular magnet design. If the movable contact assembly 18 is normally open as is shown in Fig. 3, when the armature 14 is picked up, the movable contacts 23 are forced to bridge the stationary contacts 25. The normally closed contact assembly, as shown in Fig. 2, is such that movement of the contact actuating arm 15 will move the saddle member 29 upward and thus cause the movable contacts 28 to be lifted from the stationary contact members 25. The configuration of the contact actuating arm 15, the saddle guide member 32, the sad dle 29 and the contact support means 6 is such and the interrelationship of these parts is such that the saddle member 29 can be clamped only in the one position giving the right contact gap, alignment, and travel for the contacts in either the normally open or the normally closed arrangement.

To change from a normally open to a normally closed contact assembly it is merely necessary to remove the two mounting screws 16 for the contact actuating arm 15, remove the mounting screw 31 for the saddle guide member 32, invert the entire movable contact assembly 18 and place in the position shown in Fig. 2. The mounting screw 31 for the saddle guide member 32 loses its mounting function for the normally closed position of the contact assembly 18, since the contact biasing spring 33 will hold the assembly in position when the contacts are either closed or actuated by the contact actuating arm 15. The mounting screw 31 extends through a clearance hole in the fixed contact support means 6 and into a tapped hole provided in the saddle guide member or retainer 32 so that the contacts will be closed. The design is such that it is possible to assemble only in the correct position and with the minimum of wasted motion.

Figs. 4 and show another embodiment of the movable contact assembly which may be used. The components are the same as those shown for the previously described embodiments except that a special screw 40 is used instead of the screw 31.

For a normally open contact, the contact assembly 18 is positioned in the same manner as previously described and the screw 40 holds the contact assembly 18 to the contact actuating arm 15 in the same manner as did the screw 31 in the previous embodiment.

In the normally closed contact position, Fig. 5, the screw 40 also loses its mounting function, but in the embodiment shown, the screw 40 is threaded into the saddle guide 32 until the shoulder is tight against the saddle guide 32. The screw 40 is of a special construction which has a head that will be in clearance with the clearance hole in the saddle 29. Thus, the screw is retained for future use in the movable contact assembly 18 making it unnecessary to provide a threaded insert in the base or other special retaining means. It may, howeevr, be necessary to make the clearance hole in the saddle 29 larger for the embodiment of Figs. 4 and 5 than for the embodiment previously described.

It will be appreciated that the embodiment of Figs. 4 and 5 have all of the advantages described for the embodiment of Figs. 2 and 3.

It will be recognized that the objects of the invention have been achieved by providing a contact assembly which'is simple, has a minimum number of parts and which is easily reversed in a contactor as a unit from normally open to normally closed and vice versa. The

42 contact assembly has no loose parts to be lost while handling and does not require extra parts for either position which must be stored.

While in accordance with the patent statutes, one best known embodiment of the invention has been illustrated and described in detail, it is to be understood that the invention is not limited thereto or thereby, but that the inventive scope clearly includes equivalents.

We claim as our invention:

1. In an electric circuit controlling device, a contact supporting means, stationary contact members fixed to said contact supporting means, movable contact means for bridging said stationary contact members, a contact actuating arm, a saddle member formed to be U-shaped at both ends and having openings in both sides, a saddle guide adapted to slidably cradle in one U-shaped end of said saddle member, said movable contact means having portions adapted to extend into the openings in the sides of said saddle member to guide the motion of the movable contact means relative to the saddle member, a resilient biasing means, said resilient biasing means being positioned between the movable contact means and the saddle guide to bias said movable contact means and said saddle guide into position and make a unitary structure with said saddle member, said saddle guide being connected to the contact supporting means for normally closed contact operation and the end of said saddle member adjacent said saddle guide being connected to said contact actuating arm for normally open contact operation.

2. In an electric circuit controlling device, a Contact supporting means, stationary contact members fixed to said contact supporting means, movable contact means for bridging said stationary contact members, a contact actuating arm having a hole therein, a saddle member formed to be U-shaped at both ends and having openings in both sides, said saddle member also having a hole in one U-shaped end, a saddle guide adapted to slidably cradle in said one U-shaped end of said saddle member, said saddle guide having a tapped hole in alignment with said hole in the saddle member, said movable contact means having portions adapted to extend into the openings in i the sides of said saddle member to guide the motion of the movable contact means relative to the saddle member, a resilient biasing means, said resilient biasing means being positioned between the movabie contact means and the saddle guide to bias said movable contact means a "1 said saddle guide into position and make a unitary structure with said saddle member, a screw adapted to pass through said hole in said contact actuating arm, through the clearance hole in the saddle member and threaded into the tapped hole in the saddle guide member to connect the contact assembly to the contact actuating arm with said movable contact means spaced from said stationary contact members, normally closed contact operation being obtained by inverting said saddle member and mounting said saddle guide on said contact supporting means with said movable contact means bridging said stationary contact members, the remaining end of said sadthe member being disposed adjacent said contact actuating arm for engagement and operation thereby.

3. In an electric circuit controlling device, a contact supporting means having a hole therein, stationary contact members fixed to said contact supporting means, movable contact mcans for bridging said stationary contact members, a contact actuating arm, a saddle member formed to be U-shaped at both ends and having openings in both sides, a saddle guide adapted to slidably cradle in one U-shapcd end of said saddle member, said saddle guide having a tapped hole adjacent one end thereof, said movable contact means having portions adapted to extend into the openings in the sides of said saddle member to guide the motion of the movable contact means relative to the saddle member, a resilient biasing means, said resilient biasing means being positioned between the movable contact means and the saddle guide to bias said movable contact means and said saddle guide into position and make a unitary structure with said saddle member, a screw adapted to pass through said hole in said contact support means and said tapped hole in the saddle guide to connect the contact assembly to the fixed contact support means with said movable contact means engaging said stationary contact members and with the remaining end of said saddle member disposed adjacent said contact actuating arm for engagement and actuation thereby, normally open contact operation being obtained by inverting said saddle member and securing said one end of said saddle member to said contact actuating arm with said movable contact means spaced from said stationary contact members.

4. In an electric circuit controlling device, a contact supporting means, stationary contact members fixed to said contact supporting means, movable contact means for bridging said stationary contact members, a contact actuating arm, a saddle member formed to be U-shaped at both ends and having openings in both sides, a saddle guide adapted to slidably cradle in one U-shaped end of said saddle member, said movable contact means having portions adapted to extend into the openings in the sides of said saddle member to guide the motion of said movable contact means relative to the saddle member, a resilient biasing means, said resilient biasing means being positioned between the movable contact means and the saddle guide to bias said movable contact means and said saddle guide into position and make a unitary structure with said saddle member, said saddle guide being mounted on said contact supporting means and positioning said saddle member so that the movable contact means bridges said stationary contact members and said resilient biasing means biases said saddle guide into engagement with said stationary contact supporting means to hold the contact assembly in position, the end of said saddle member opposite said one end thereof being disposed adjacent said contact actuating arm to be engaged and actuated thereby.

5. In an electric switch, a stationary support, a movable support movable along a path toward and away from said stationary support, a pair of spaced stationary contcts insulatedly supported on said stationary support, a movable contact bridge, a saddle member slidably mounting said movable contact bridge, means for limiting sliding movement of said contact bridge toward one end of said saddle member, a saddle guide slidably engaging said saddle member, means for limiting sliding movement of said saddle guide toward the other end of said saddle member, resilient biasing means disposed between said movable contact bridge and said saddle guide and bias ing said movable contact bridge and said saddle guide to their respective limits of movement on said saddle member, said movablecontact bridge being spaced from said stationary contacts along the path of movement of said movable member for normally open contact operation in a first position of said saddle member in which said other end of said saddle member is secured to said movable member, and being disposed for normally closed contact operation with said movable contact bridge bridging said stationary contacts with said saddle member inverted from said first position and said saddle guide being supported on said stationary support, in said inverted position of said saddle member said one end thereof being disposed in the path of movement of said movable member to be engaged and actuated thereby.

6. An electric switch having an invertible movable contact assembly providing selective normally open and normally closed contact operation comprising, a stationary support, a movable support movable along a path toward and away from said stationary support, spaced stationary contacts insulatedly mounted on said stationary support, a saddle member, a contact bridge slidably engaging said saddle member, a saddle guide slidably engaging said saddle member, spaced stop means on said saddle member, resilient biasing means disposed between said contact bridge and said saddle guide and biasing said contact bridge and saddle guide toward opposite ends of said saddle member against said respective spaced stop means, means providing mounting of said saddle member in a first position with the end of said saddle member adjacent said saddle bracket secured to said movable member and with said contact bridge spaced from said stationary contacts to provide normally open contact operation, and means providing mountingof said saddle guide on said stationary support with said saddle member inverted from said first named position and said contact bridge engaging said stationary contacts, the end of said saddle member opposite said saddle guide being disposed in the path of movement of said movable support for actuation thereby.

7. An electric switch having an invertible moving contact assembly providing selective normally open and normally closed contact operation comprising, a stationary support, a movable support movable along a path toward and away from said stationary support, a stationary contact mounted on said stationary support, a movable contact mount, a movable contact slidably mounted on said mount, a guide slidably engaging said mount, resilient means disposed between said movable contact and said guide and resiliently biasing said movable contact and guide to given spaced positions on said mount, said mount providing normally open contact operation in a first position with the end thereof adjacent said guide secured to said movable support and providing normally closed con tact operation in a position inverted with respect to said first position in which said guide is secured to said stationary support with said moving contact engaging said stationary contact and with the end of said mount adjacent said moving contact confronting said movable support to be actuated thereby.

8. An electric switch having an invertible movable contact assembly providing selective normally open and normally closed contact operation comprising, an elongated movable contact mount, having axially spaced confronting stops thereon, a movable contact slidably disposed on said mount between said stops, a guide slidably disposed on said mount between said stops, resilient means compressed between said guide and said movable contact and biasing said guide and movable contact against said respective stops, a stationary support having a guide seat thereon, a stationary contact mounted on said stationary support and spaced from said guide seat, a movable support movable between inoperative and operative positions along a path directed toward said stationary contact, the distance between said movable support in said inoperative position and said stationary contact being greater than the distance between the end of said mount adjacent said guide and said movable contact and the distance between said guide seat on said stationary support and said stationary contact being less than the distance between said guide and said movable contact, said movable contact assembly providing normally open contact operation in a first position with the end of said mount adjacent said guide secured to said movable support, and providing normally closed contact operation in a position inverted with respect to said first position in which said guide is secured in said guide seat with said moving contact engaging said stationary contact and with the remaining end of said mount confronting said movable support to be actuated thereby.

9. An electric switch having an invertible movable contact assembly providing selective normally open and normally closed contact operation comprising, a movable contact assembly including an elongated movable contact mount, a movable contact slidably mounted on said elongated mount, a stop on said elongated mount, and a spring on said mount having an end adjacent one end of said mount and the other end engaging said movable contact and spring loading said movable contact against said stop; a stationary support, a movable support movable from a normal position to an operated position along a path shrines toward said stationary support, a stationary contact disposed between said stationary support and said movable support and having opposite contact f-aces respectively confronting said movable support and said stationary support, means providing mounting said movable contact assembly in a first position with said one end of said elongated mount secured .to said movable support and with said movable contact spaced from one face of said stationary contact for normally open contact operation, and guide means secured to said stationary support and slidably mounting said one end of said elongated mount on said stationary support in a position inverted with respect to said first position, said guide means operably engaging said spring to spring load said movable contact against the opposite face of said stationary contact, the other end of said elongated mount being disposed adjacent to and in confronting relation with said movable support to be actuated thereby by movement of said movable support from said normal position toward operated position.

10. An electric switch having an invertible movable contact assembly providing selective normally open and normally closed contact operation comprising, a stationary support, a movable support having a surface confronting said stationary support, means for moving said movable support from a normal position to an operated position along a path toward said stationary support, a stationary contact disposed between said stationary and movable supports and being closer to said stationary support than said movable support when said movable sup port is in said normal position, a movable contact, an elongated mount slidably mounting said movable contact, a pair of axially spaced stops on said elongated mount, a guide slidably engaging said elongated mount, a compression spring disposed between said guide and said movable contact and spring loading said guide and said movable contact against said respective stops, means providing mounting of said elongated mount in a first position in which the end of said elongated mount adjacent said guide is disposed on said surface of said movable support, said movable contact in said first position of said elongated mount being spaced from said stationary contact and being engageable therewith by movement of said movable support from said normal position toward operated position, and means providing mounting of said guide on said stationary support with said elongated mount inverted with respect to, said first position and with said movable contact engaging said stationary contact, in said inverted position of said elongated mount the end thereof remote from said guide being disposed in confronting relation with respect to said surface of said movable support for engagement by said surface upon movement of said movable support from said normal position toward operated position.

11. An electric switch having an invertible movable contact assembly providing selective normally open and normally closed contact operation comprising, a stationary support, a movable support having a surface confronting said stationary support, means for moving said movable support from a normal position to an operated position along a path toward said stationary support, a stationary contact disposed between said stationary and movablesupports and being closer to said stationary support than said movable support when said movable support is in said normal position, the opposite faces of said stationary contact respectively confronting said stationary support and said movable support, a movable contact assembly including an elongated movable contact mount, a movable contact slidably mounted on said elongated mount, a stop on said elongated mount, and a spring on said elongated mount having one end adjacent one end of said elongated mount and the other end engaging said movable contact and spring loading said movable contact against said stop; means providing mounting of said movable contact assembly in a first position with said one end of said elongated mount secured to said surface of said movable support and with said movable contact spaced from one face of said stationary contact for normally open contact operation; and guide means slidably mounting said one end of said elongated mount on said stationary support in a position inverted with respect to said first position, said guide means operably engaging said spring to spring load said movable contact against the opposite face of said stationary contact, the other end of said elongated mount confronting said surface of said movable support to be actuated thereby by movement of said movable support from said normal position toward operated position.

References Cited in the file of this patent UNITED STATES PATENTS 2,208,387 Pierce July 16, 1940 2,276,698 Pierce Mar. 17, 1942 2,304,972 Van Valkcnburg et al Dec. 15, 1942 2,310,056 Bendz Feb. 2, 1943 2,419,072 Hall Apr. 15, 1947 2,589,167 Van Valkenburg et al. Mar. 11, 1952 FOREIGN PATENTS 470,532 Great Britain Aug. 17, 1937