US742906A - Electric switch. - Google Patents

Description

No. 742,906. PATENTED NOV. 3, 1903.

J. T. ROBB. 4

ELECTRIC SWITCH.

APPLICATION FILED APR. 15, 1903.

N0 MODEL.

Attorneys UNITED STATES Patented November 3, 1903 v PATENT OEEIcE.

JAMES T. ROBE, OF NEW YORK, N. Y., ASSIGNOR TO'THE MITCHELL VANCE COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 742,906, dated November 3, 1903.

Application filed April 15, 1903. Serial No. 152.712. (N0 model.)

To all whom it may concern.-

Be it known that 1, JAMES T. ROBB, a subject of the King of Great Britain, residing at Flatbush, in the borough of Brooklyn, city and State of New York, have invented a certain new and useful Improvement in Electric Switches, of which the following is a specification.

The invention relates to improvements in electric switches adapted particularly for use in connection with bracket-arms of chandeliers of that design in which the employment of socket-switches is undesirable and is an improvement of the switch disclosed in my Patent No. 653,698, dated the 17th day of July, 1900. In the switch forming the subject-matter of that patent a laterally-movable shank is used, which carries contacts adapted to engage with fixed contacts mounted on the frame. The shank is moved in one direction to complete the circuit by means of a twopart cam, one of the camparts being revolved by a key. The shank is moved in the other direction by means of a spring to break the circuit. The parts are brought into engagement by the positive motion of the cam, but are separated by the action of a spring forming a single-snap action. The objection to this arrangement is that the contacts are brought into action by the manual revolution of thecam, so that if the key be improperly manipulated and the switchbe closed sufliciently to make electric contact, but not closed sufficiently to lock the parts in engagement, the parts will separate slowly enough to form a destructive are within the switch. The present invention has for itsobject the production of a double-snap switch whereby the contacts will be positively opened and closed by a spring and all arcing prevented. Another object of theinvention istoproduce a switch having a frame within which the operative parts are mounted and which is carried within a yoke secured to the fixture whereby the yoke can be adjusted and the switch afterward introduced in place.

Another object is to produce means whereby the fixed block formed of porcelain orother insulating material and used for carrying the fixed contacts may be rigidly adjusted within the frame without danger of being broken by the strain caused by the tightening of the screws. I

Broadly stated, my improved switch com.- prises a suitable supporting-yoke, which may be interposed directly in the line of the tubing, a suitable supporting-frame removably secured within the yoke, a pair of contacts carried by the frame, a pair of movable contacts so mounted within the frame as to rotate toward or away from the stationary contacts, an actuating-cam for the moving contacts, a suitable key in engagement with the cam and adapted to be rotated in opposite directions to open and close the switch, and a spring also in engagement with the cam, so arranged that the cam may be partially revolved by the key and the movement com-.

pleted by the action of the spring, which will snap the movable contacts away from or toward the stationary contacts.

The invention further comprises a twopart sectional shell inclosing the elements of the switch and held in place with respect to the frame by means of a pair of clampingcollars, each of which engages with a shellsection.

The invention further comprises an inner shell formed of insulating material, whereby greater safety is secured.

In order that my invention may be better understood, attention is directed to the accompanying drawings, forming a part of this specification, and in which- Figure 1 is a transverse section taken on the lines 1 1 of Fig. 2. Fig. 2 is a longitudinal section taken on the lines 2 2 of Fig. 1. Fig. 3 is a top view of the frame and parts secured thereby. Fig. 4 is a perspective view of the frame and operating parts mounted therein, but separated for the purpose of being more readily understood.

Like numerals represent corresponding parts in the several views.

1 is an open yoke having extremities internally screw-threaded at 2 for the reception of the ends of the sections of the fixturearm. Mounted within the yoke is a frame 3, secured thereto by suitable screws 4: 4. This frame 3 carries all the operative parts of the 14, which also serves to impart motion to the switch, the yoke 1 being capable of adjustment between the sections of the fixture and the frame afterward inserted.

Mounted within the frame 3 is a fixed block 5, of porcelain or other suitable insulating material, curved at the top, as shown, so as to closely fit the inside of the frame. This fixed. block 5 is secured in position within the frame by means of the bushing 6, which has a ta pered shank and a flange 7, which engages against a shoulder cut in the center opening in the cap. The bushing 6 engages within the opening 8, formed within the top of the frame 3 and is securely locked in place by means of a screw 9. The opening 8 is not circular, but has flattened side walls, so as to make it something in the nature of a slot. The upper extremity of the bushing 6 is cut: away at 10, so as to form ashoulder or tenon which will engage within the opening 8. This shoulder or tenon engages with the lower side of the upper portion of the frame 3, and by this means the bushing and the frame may be tightly drawn together by means of the screw 9 without danger of breaking'the block 5.

The moving parts of the switch are carried upon a shaft 11, which bears within an opening formed within the bushing 6 and also within an opening 12, formed within the frame 3, and carries at its lower extremity a suitable turning-key 13. The shaft is secured in position by means of a pin or similar device cam 15. Mounted above the cam is a rotatable contact carry ing block 16, free to turn 3 upon the shaft 11. This block may be formed of porcelain or other suitable insulating material and carries the two contacts 17 17 arranged, preferably, at diametrically-opposite 1 points upon the block. Each contact embraces an enlarged head of the general shape? shown in broken lines in Fig. 1 within a de-: pression formed in the upper face of the block and is secured in place by a depending stem 18, which after passing through an open- 1 ing in a ring 19,- molded in the block, is riv-: eted, so as to lock the parts firmly in position. i The contacts and ring are preferably made of copper; but any other suitable material maybe used and serve through the shanks l8 and i the ring to permit current to flow from one contact to the other when they are brought into engagement with the two fixedcontacts 20, carried by the block 5. The two latter contacts 20 are secured to the block 5 by means of screws 21 and connecting-pieces 22. to the binding-screws 23 and are so arranged as to simultaneously engage with the movable contacts 17.

Screws 23 connect with the contacts20 and permit one'of the mains 24 to be properly connected with the break between the contacts, the other main 25 being continuous. It is preferred to so arrange the unbroken main 25 that it may pass around outside of the frame 3, a depression or bend 26 being provided for this purpose. This construction has the advantage of permitting the frame to be removed from the yoke without deranging the main 25 Y and also keeps the main clear from the moving parts of the switch.

The block 16 is actuated by means of the cam 15, which engages with a depending pin 27, formed or attached to the bushing 28, molded in the block 16. This pin engages within a recess 29, out within the upper surface of the cam 15, a recess 30 of similar form engaging with the pin 14, already referred to. A suitable spring 31, supported by the frame 3, engages with one face of the cam. A suitable limiting-stop 32, carried by the bushing 28, engages within a notch 33, out within the fixed bushing 6 and prevents the block 16 from being rotated to too great an extent, but will limit the movement thereof to cause accurate engagement between the fixed contacts 20'and the movable contacts 17. T o assist in the alinement of these parts, the upper surface of each movablecontact 17 may be formed with a depression 34:, as

3 shown in broken lines in Fig. 1, with which the curvedextremity of a .fixed contact may engage.

The entire device is inclosedby a sectional casing 35, having a lapped joint 36 formed at the top and bottom and engaging behind the screw-threaded collars 37, applied to the outside of the extensions 2 2. Suitable insulation 38 in the form of two hemispherical sheets of the same general configuration as the casing is inserted and retainedin position by engagement with the frame 3.

The operation of the switch isas follows: In installing it the yoke 1 is firstproperly adjusted between thesections of the. fixturearm. .'lhe switch-body may then be inserted and covered by the sectional casing 35, the insulation 38 being previously inserted. In actuating the switch the key upon being turned in one direction will partially rotate the cam 15 through the engagement of the pin 14 with the slot 30. During the partial revolution of the camthe spring 31 will be retracted .until thecam passes the dead-point, when the elasticity of the spring will cause the cam to complete a partial revolution. Movement will be transmitted from the cam to the block through the agency of the slot 29 engaging with the pin 27, and the block will be given a rapid partial revolution, causing the contacts to engage or disengage-without danger of an are being formed. A reverse movement'of the key 13 will rotate the movable parts of the switch in the opposite direction, and thereby break contact. The action of the key to make and breakcircuit is therefore similar to that of the ordinary gas-fixture. Greater safety is secured bythe location of the contacts on diametrically opposite sides of the blocks 5 and 16, whereby two breaks will be formed, and arcing thereby reduced.

It is to be noted that the slots 29 and 30 should be so proportioned that the cam may be turned against the tension of the spring to such an extent that the spring will begin to act to force it beyond the dead-point before the block 16 will receive any motion at all. By this means to permit the switch being either opened or closed the cam must be moved to such an extent that the contacts must be opened or closed entirely by the action of the spring.

Having now described my invention, what I claim is- 1. In a fixture-switch the combination with aframe, of a fixed block therein, a flanged bushing within the block, and means for securing the bushing to the frame, substantially as setforth.

2. In a fixture-switch, the combination with a frame, of a fixed block therein, a flanged,

bushing within the block, an offset on the bushing, and an engaging screw for the bushing for engaging the offset with the frame, substantially as set forth.

3. In a fixture-switch, the combination with a frame, a fixed block therein, a bushing within the block, means for securing the bushing to the frame, and a shaft engaging with the bushing, substantially as set forth.

4. In a fixture-switch, the combination with a frame, a fixed block therein, a bushing within the block, contacts thereon, means for securing the bushing to the frame, a shaft engaging with the bushing, and a contactcarrying block supported upon the shaft, substantially as set forth.

5. In a fixture-switch, the combination with a frame, a fixed block therein, having contacts thereon, a shaft, a contact-carrying block supported thereon, a bushing within the latter block, a pin thereon, a cam mounted on the shaft adjacent to the block, the said cam having a slot adapted to engage the pin, and connecting means between the shaft and cam, substantially as setforth.

6. In a fixture-switch, the combination with a frame, a fixed block therein, having contacts thereon, a shaft, a contact carrying block supported thereon, a bushing within the latter block, a pin thereon, a cam mounted on the shaft adjacent to the block, the said cam having a slot adapted to engage the pin, and a pin on the shaft and an engaging slot within the cam, substantially as set forth.

7. In a fixture-switch, the combination with a frame, a fixed block therein, having contacts thereon, a shaft, a contact-carrying block supported thereon, a bushing within the latter block, a pin thereon, a cam mounted on the shaft adjacent to the block, the said cam having a slot adapted to engage the pin, a pin on the shaft, and engaging the slot within the cam, and a spring engaging with the cam, substantially as set forth.

8. Inafixture-switch, the combination with a frame, a fixed block therein, having contacts thereon, a bushing within the block, a shaft, a contact carrying block supported thereon, a cam on the shaft, a second bushing within the contact-carrying block, pins on opposite faces thereof, one pin engaging within a slot on the first bushing, and a second pin engaging with a slot on the cam, and connecting means between the shaft and cam, substantially as set forth.

9. In a fixture-switch, the combination with a frame, a fixed block therein, having contacts thereon, a bushing within the block, a shaft, a contact carrying block supported thereon, a cam on the shaft, a second bushing within the contact-carrying block, pins on opposite faces thereof, one pin engaging within a slot on the first bushing and a second pin engaging with a slot on the cam, and a pin on the shaft engaging with' a second slot on the cam, substantially as set forth.

10. In a fixture-switch,the combination with a frame, and fixed contacts, of a shaft and contact-carrying block thereon, a pin carried by the. block, and a cam carried by said shaft, a recess within the cam, within which thepin engages, a spring engaging with the cam, and a key engaging with the cam, whereby the cam may be rotated beyond the dead-point by the key and snapped by the spring, substantially as set forth. 1

11. In a fixture-switch,the combination with a contact-carrying block having a depression therein, of a ring embedded within the depression, and headed contacts passing through the block and in engagement with the ring, substantially as set forth.

12. In a fixture-switch,the combination with a contact-carrying block having a depression therein, of a ring embedded within the depression and having contacts passing through the block and ring and riveted to the latter, substantially as set forth.

This specification signed and witnessed this 13th day of April, 1903.

JAMES T. ROBE. Witnesses: G. G. FERRIS,

NORMAN KING.

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