US2863960A - Control for electrical start and stop switch - Google Patents

Description

Dec. 9, 1958' T. A. MARTIN 2,363,960

CONTROL FOR ELECTRICAL START AND STOP SWITCH Filed July 1, 1957 THOMAS A. MART/N INVENTOR.

A T TORNE Y Unlted States PatentO ce Patented Dec. 9, 1958 In examining the details of construction, the frame 2 is seen to include a pair of side plates 8, and an end plate 9 which serves as a mounting base for the switch 3 and 2,863,960 cooperates with one side plate 8 to support the solenoid CONTROL FOR ELECTRICAL START AND STOP 4. The frame and all of its attached components may SWITCH be supported at its point of installation by a bottom flange or flanges 10 to a base or mount (not shown); however, it Thomas A. Martin, Fort Worth, Tex. will be obvious that the complete switch assembly may be mounted in any desired manner so long as the push Apphcatmn July 1957 Sena} 669221 10 rod 11 of the control linkage 5 is permitted a gravity fall. 3 Claims. (Cl. 200-18) The switch 3 may be of any suitable commercial type, of which there are several, and reference is made to one such type, Cutler-Hammer Bul. 10250H653, for the purpose of example and not of limitation. The switch 3 in- This inventionrelates generally to electrical control cludes a rocker shaft 12 by which the internally located apparatus and more specifically to a unique start and stop switch contacts 13 and 14 (Figure 5) are operated. The switch for circuits containing electrically operated equiprocker arm referred to generally at 6 actually consists of ment. a basic L-shaped arm 15 which is supplied with the The primary object of this invention is to provide a commercial switch 3, and an additional arm actuator 16 novel combined electrical and mechanical switch assemwhich is added to this arm for the purposes of this invenbly wherein a single pull from a remote location will tion. Actuator 16 is attached to arm 15 in any suitable close the switch and energize an electrical circuit, and at manner such as by screws 17 which pass through an unthe same time place the switch assembly in condition to derturned lip extending in overlapping relation to the upbe opened upon the next successive pull. per and lower ends of the arm 15; and the actuator 16 in- Another object is to provide a switch assembly which cludes another larger lip which extends in a direction includes means whereby a second successive pull on the away from arm 15 and defines an operating sector 18 remote control equipment may be caused to re-close the against which the push rod 11 may operate. A conduit switch rather than open it as in normal procedure in the 19 threads into the top of switch 3 and provides the means event of a momentary power failure in the main power through which the incoming and outgoing leads are opsupply source. eratively connected internally to the switch 3.

Another object is to provide a switch assembly for elec- Solenoid 4 is supported by end wall 9 and from side trical circuits which is rugged enough to withstand a heavy walls 8 in any suitable manner and includes a downwardly operating pull by shop personnel and yet accurate enough projecting armature 20 which normally drops to the posito provide positive operation under the various conditions tion shown in Figure 1 under its own weight and which is of use. raised to the position shown in Figure 3 when the solenoid A still further object is to provide a switch assembly 4 is energized. A tension spring 21 is attached at its which includes a mechanically actuated switch push rod upper end to the lower end of armature 20, and at its and includes automatic means by which the push rod is lower end to ring 22 which pivotally engages rod 11; and shifted from a starting to a stopping control position. the tension of this spring is set so that when armature 20 An additional object is to provide a switch assembly is in its uppermost position, the spring will lift rod 11 which includes a mechanically actuated switch push rod from its lower or start control position (as shown in solid having automatic means which is adapted to first shift the lines in Figure 1) up to its upper or stop control position push rod from a starting to a stopping control position (as shown in dotted lines in Figure 1). and then shift the push rod back to the starting position The control linkage 5 is made up of a main lever 23 in the event of a power failure. rigidly attached to a transverse shaft 24 which is pivotal- Another object is to provide a switch assembly of the 1y supported in side plates 8, and a short lever 25 attype described which is reliable and durable in operation tached to the shaft 24 at a position on the opposite side and yet which is simple and compact in design and ecoof plate 3 from the main lever 23, and a push rod 11 nomical in construction. which is pivoted to short lever 25 at the desired radial These and other objects and advantages will be apdistance from shaft 24. Numeral 11 is the reference numparent from an examination of the following specification ber used to identify the functional push rod member and drawing, in which: which in actual construction is made up of a tube 26 into Figure 1 represents a side elevational view of the comwhich an end rod 27 telescopes. A compression spring plete switch assembly of this invention. 28 is anchored at one end to the rod 27 and at its other Figure 2 is a fragmentary end elevational view of the end to tube 26 so that in order to transmit a longitudinal push rod linkage shown in Figure 1. force, rod 27 must first slightly compress spring 28; this Figure 3 is a fragmentary detail view of the push rod feature will prevent damage to the rocker arm 6 and will of Figure 1 shown in its start control position. permit lever 23,to be pulled with substantial force against Figure 4 is a partial view of the push rod of Figure 3 its stop bolt 29 without endangering the sensitive operashowing the rod in its stop control position. tional parts of this switch assembly. That por ion of rod Figure 5 is a circuit diagram partly in schematic showend 27 which pivotally engages short lever 25 is curved ing the electrical operation of the switch of this invention. and at right angles to the balance of the rod end. A

Referring now more particularly to the characters of cotter 30 then locks the rod end 25 in its operational posireference on the drawing it will be observed that the comtion. A slot 31 in end plate 9 permits push rod 11 to explete switch assembly of this invention consists basically tend from short lever 25 to sector 18 in both a guided of a frame 2 which supports a heavy duty electric switch and protected manner. The slot 31 also positively limits 3 and a holding solenoid 4 and on which frame a control the upper and lower positions of the push rod 11 to insure linkage identified generally at 5 is installed in operational a continual contact with sector 18. relation to the switch rocker arm 6. A flexible cord 7 From the above description it will be recognized that provides the means by which linkage 5 may be operated the switch 3 may be installed at a remote location from from a remote location to trip rocker arm 6 to selectively start or stop switch '3.

the operator, and the operator may pull the cord -7 with a substantial force without fear of damage to close the switch and operate the electrical equipment such as motor M shown in Figure 5. After the normally open start switch 13 has been closed by the action of push rod 11 which rotates shaft 12 as previously described to move internal actuator arm 32 against its proper contact members l3 and 14', then solenoid 4 is energized simultaneously with contactor holding interlock 33 and main contactor 34, and armature 2t) raises the push rod 11 to its upper position so that the neXt pull of cord '7 will operate shaft 12 in the stop direction (Figure 5). However, if a power shortage occurs in the main supply lines 35 then solenoid 4 is de-energized and armature 20 and push rod 11 fall to the lower or start position, so that the next successive pull on cord 7 will restart the cycle of operation.

The invention is not limited to the exemplary construction herein shown and described, but may be made in various ways Within the scope of the appended claims.

What is claimed is:

1. A control for an electrical start and stop switch having a switch rocker arm shaft, said control comprising a frame mounted on one side of said switch, a lever pivotal- 4, 1y mounted on said frame, a generally vertical operating plate mounted intermediate its ends on said shaft, a gen erally horizontal push rod pivotally connected at one end thereof with said lever, the remaining end of said rod being in sliding contact with a face of said operating plate, a solenoid mounted above said push rod, said solenoid having a depending armature, means connecting said armature with said push rod, means limiting the up and down movement of said push rod, and means actuating said solenoid when said switch is in a closed position.

2. A control for an electrical start and stop switch as defined in claim 1, and wherein said means connecting said armature with said push rod is a tension spring.

3. A control for an electrical start and stop switch as defined in claim 2, and wherein said push rod is of telescoping construction and includes spring means normally urging the rod toward an extended position.

References Cited in the file of this patent UNITED STATES PATENTS 2,580,905 Foster Jan. 1, 1952

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