US2247231A - Electric switch - Google Patents

Description

lJune 24, 1941. B. E. GETCHELL ELECTRIC SWITCH 6, 1940 2 Sheets-Sheet l Filed Dec.

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"lilllml .June 24, 1941. B. E. GETCHELI.

ELECTRIC SWITCH 6, 1940 2 Sheets-Sheet 2 Filed Dep.

Patented June 24, 1941 ELECTRIC swrrcn Benjamin a. Gesehen, mamme, conn., signor tov The Trumbull Electric Manufacturing Company, Plainville, Conn., a corporation of Connecticut Application December 6, 19M), Serial No. 368,822

(Cl. 20o-50) l Claims. This invention relates generally to enclosed `electric switches and more particularly to front operated switches.

Such switches may be of the single throw, double throw or reversing switch type andthe form shown is for a three-wire system and has two sets of switch units, each unit having a pair of stationary 'contacts and a connecting movable switch member, all mounted on the front of a base member. Each set of switch units has an operating crank shaft at the rear of the base and an actuating rocker member is located at one side of the base and adapted to operate selectively the crank vshai'ts by movement in one direction or another. A lever on the inside ofthe box operated by an external handle is adapted to interlock with the rocker member for moving the latter and locking the cover. A separate spring is provided for biasing each crank shaft.

It is an object of my invention to provide switch actuating mechanism which` is positive in moving the operated parts of the switch,

Another object is to prevent closing of the switch cover unless the switch handle and operatingparts are in proper position. I

Another object is to prevent opening of the switch cover when the switch is in on" position.

Another object is to accelerate the breaking action of the switch. l

Fig. 1 is a front view of an enclosed switch embodying my invention, the handle being shown in the off or open circuit position and parts of 'the interior mechanism shown dotted.

Fig. 2 is a vertical sectional view of the casing and showing the switch mechanism in side view, in the open circuit position. g

Fig. 3 is a view similar to Fig. 2 but with one set of parts in the closed circuit position.

Fig. 4 is an end view partially broken away and showing the parts in the open circuit position.

Fig. 5 is an inside front view with the cover open and parts shown in section.

Fig. 6 is a detail view showing the throwing' throw, double throw or reversing type. The form shown is of the latter type.

'Ihe insulating body of the switch which carries the contacts, and the quick break mechanism are mounted on a plate Il which is detachably secured to the bottom of the box by screws I6 and I1. A

'I'he number of circuits controlled by the switch as shown is three but this is immaterial to the invention, and the switch contacts may be of the type shown in Hammerly Patent 1,889,515.

In the form shown there are two crank shafts I8 and I8', each having bearings I8 and I 9' carried by the plate I8 on opposite sides.

Each switch unit has a pair oi stationary contacts 20 and 2i between which an insulating carrier bar 22 is movable. This bar has a slotted projection 22 connected to a crank shaft I8 and carries a switch contact member 24 which is normally held in the open circuit position by the action of the spring 2B on the throwing rod 26. This rod has a slotted end 21 which engages a crank shai't I8 and the spring normally holds the crank shaft and the carrier in the off position where the inner end of the carrier 22 or the proiection 23 is pressed against the bottom plate I8 or some other nxed part of the device as shown in Fig. 2.

The end of the rod '26 opposite the slotted part 21 is guided in an aperture 28 in the support 28 so that the rod in eiIect is hinged and slides at one end. The spring 2i bears between the end 21 of the rod and a surface on the support 29.

In the form shown, the upper and lower parts of the device are alike except that the connections are inverted. Between the two parts and at one side of the box is a rocker plate pivoted at 8| to a bracket on plate l5. Two links 32 and 32 are hinged to this rocker plate and have slotted connections with the crank shafts I8 and i8', respectively, which connections normally hold the rocker plate in the central or off positions of Fig. 2.

'I'he operating handle or lever 35 is pivoted in the cover plate and normally hangs in the central position of Fig. 2 when the circuit is open. The lever 36 is hinged at l1 inside of the cover and has a slot and pin connection 38 with the hub 39 of the handle on the inside of 'the cover so that when the handle is moved from side to side the lever 36 is swung up and down. The outer end ill of the lever it is shaped and positioned to enter the notch II of the rocker plate 3i) when the parte are all in the open circuit or oif position.

To close the circuit, it is merely necessary to swing the handle 35 to the right or left whereupon the lever 36 is moved up or down and the rocker plate 30 turned on its axis so as to pull outwardly on one of the links 32 or 32 and thus turn a crank shaft, compress a spring, move a carrier and its contact and thus close the circuit, for instance as shown in Fig. 3.

'I'his places the spring 25 under compression slightly beyond center as shown in Figures 3 and 6, which is suillcient to hold this switch ln closed circuit position. When the parts are thus'positloned, it will be seen thatthe tip 40 of the lever 36 is in back of a hook-like part 42 `atone side of the notch 4I in the rocker so that the cover cannot be opened without returning the rocker plate to the "OiT position. This serves as a safety interlock of a very simple character.

It will be seen that when the parts are moved to actuate one of the switches, the other switch is not actuated because the crank shaft is not affected. This isdue to the slotted connection of its link, and to the fact that the outer end of the link moves on an arc, a tangent of some point of which is substantially perpendicular to the line joining the pivot of the rocker plate and the inner end of the link. 'I'he relation of parts for best results is shown in Figure 7 where it will be noted that the slot is made long enough to prevent moving of the yoke when the switch is operated through this inactive position. Obviously, the slotted connection might be made at the rocker plate end of the link instead of at the yoke end, lf desired.

When the handle and rocker plate are turned to ctuate the yoke and switch,movement of the outerA end of the link is on an arc of the same length as before, but this arc begins and ends at points such that a substantially straight pull outward is obtained on the inner end of the link in a direction toward a tangent to both the arc of movement of theyoke and the arc of movement of the link pivot on the rocker plate.

It will be seen that the construction of the lever 36 and the rocker prevents the closingv of the cover until the switch is o i and the handle is in its central position. Likewise the cover cannot be opened with the circuit on.

Iclaim:

l. .An enclosed switch including a box having a cover hinged at one edge, switching means in the box including an element pivoted adjacent the side of the box opposite the hinge of -the cover and having an interlocking notch opening toward the front of the box, a lever hinged tothe inside of the cover adjacent the hinge of the cover and having its opposite end adapted to interlock with the notch in said pivoted element, an operating crank member pivoted to the inside of the cover and having a hinged connection with said lever and an external handle on the front of the cover and constituting a part of the operating crank member.

2. In an electric switch, two spring pressed switch units, a rocking member pivoted at one side, a link connecting each switch unit with said rocking member, said rocking member having an undercut notch in one edge, and an actuating lever hinged at one end and having its opposite end adapted to interlock with the notch in said rocking member.

3. An enclosed switch including a box having a hinged cover, a switch unit in the box having a rocking piece with a slot in one edge thereof a shoulder formed on a wall of said slot and an actuating lever carried by the cover for' rocking said piece, a portion of said lever being adapted to interlock with the shoulder upon partial rocking of the piece when the cover is closed.

4. A front operated enclosed switch including a box having a hinged cover, a movable handle K on the front of the cover, an actuating lever on the inside of said cover having one end connected to said handle and having an inwardly depending lug on its free endh a switch unit in the box having a rocking plate with -a slot in the edge thereof positioned in the path of the lug of said lever upon closing movement 'of the cover `.and adapted to receive said lug upon closure of the cover and a shoulder on a wall of said slot adapted to be interlocked with the lug on the lever uponl rocking of said plate by the lever when the cover is closed.

5. An enclosed switch including a box, a cover therefor, an operating handle on the front ofthe cover, a lever on the inside of said cover having one end connected to said handle, two switch units in the box, each unit including movable switch members and a yoke for actuating said movable switch members, and a rocking plate having a slot in its edge normally positioned centrally of said switch units and when in such position adapted to receive the free end of said lever when the cover is closed for actuating the plate, a separate lost motion link connection between said plate and said yokes whereby movement of the plate is imparted to eitherof said yokes and its respective movable switch members to on position, the other yoke remaining stationary, and a shoulder Aon a wail of the slot of said plate' adapted to interlock with the free end of saidlever when said plate is moved to either side of its center to prevent opening of the cover.

6. An enclosed switch including a box, a cover therefor, an operating handle on the front of the cover, a lever on the inside of said cover having one end connected to said handle, a switch unit in the box including movable switch members, a

. yoke for actuating said movable switch members and a rocking plate having a link connectionvwith `said yoke, said plate having a slotV adapted to receive the free end of said leverfor moving the plate when the cover is closed. 'j

7. An enclosed switch including "a box, a cover therefor, an operating handle on the front of the cover, a lever on the inside of said cover having one end connected to said handle, two switch units in the box, each unit including movable switch members and a yoke for actuating said movable switch members, and a rocking plate having a separate lost motion link connection with each of said yoke members and having a slotted connection with said lever when the cover isA closed, said plate when rocked'to either side of its center being adapted to move either of said yokes and its respective movable switch members to on position, the other yoke member remaining stationary.

8. In an electric switch. a pivoted crank shaft, a reciprocable switch member having a slotted connection with said crank shaft, a spring pressed throwing member having a slotted connection with said crank shaft, a support for said throwing member at the end opposite said slotted connection, a rocking plate, and a link having a slotted connection with said shaft and hinged to said plate so that when the rocking plate is moved from a neutral position with the circuit of the switch open toward a closed circuit position ofl the switch the crank and the link move the switch member toward the closed circuit position against the spring bias of the `throwing member.

9. A- switch having two switch units, each unit including movable switch members normallyv 10. In an electric switch, two pivoted crank shafts, a switch member separately connected to each Acrank shaft to be moved thereby, a spring pressed throwing member for each shaft, a single rocking member, and links having separate slotted connections with each of said shafts and hinged to said rocking member'so that when the rocking member is moved from a neutral position with the circuit of the switch open, to a closed circuit position of the switch, one crank and its throwing member hold one switch member in the ofP position while the other crank is moved by its link to place its switch member in the on position.

BENJAMINE. GETCHELL.

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