US1391469A

US1391469A - Electromagnetic trip mechanism

Info

Publication number: US1391469A
Application number: US343066A
Authority: US
Inventors: Benjamin E Getchell
Original assignee: Trumbull Electric Manufacturing Co
Current assignee: Trumbull Electric Manufacturing Co
Priority date: 1919-12-06
Filing date: 1919-12-06
Publication date: 1921-09-20
Anticipated expiration: 1938-09-20

Description

B. E. GETCHELL.

ELECTROMAGNETIC TRIP MECHANISM.

APPLICATION FILED DEC-6| 1919.

Patented Sept. 20,1921.

UNITED STATES PATENT OFFICE.

BENJAMIN E. GETCHELL, OF PLAINVILLE, CONNECTICUT, ASSIGNOR TO THE TRT J'M- BULL ELECTRICMANUFACTURING 00.,

RATION OF CONNECTICUT.

nnnc'rnormennric TRIP MECHANISM.

OFPLAINVILLE, CONNECTICUT, A CORPO- Specification of Letters Patent. Pate t d S t 20 1921 Application filed December 6, 1919, Serial No. 343,066.

T all whom it may concern:

Be it known that I, BENJAMIN E. GETCH- ELL, a citizen of the United States of America, residing at Plainville, Connecticut, have invented -a new and useful Electromagnetic Trip Mechanism, of which the following is a specification.

My invention relates to mechanism which is particularly adapted for a low voltagewho voltage release for an inclosed electric switch.

In. such constructions it has been custo: mary to provide mechanism for holding the switch in the closed circuit position and for releasing it automatically in case the circuit is broken or in case the voltage decreases. Such devices customarily employ springs and naturally the moving parts require more or less force to start their move.

2 mentj Sometimes, if the voltage decreases slowly the release apparatus fails to work, particularly as regards the operation of the armature of a solenoid such as shown in this application.

The main object of my invention is to make the release action more ositive and certain even under such conditions and insure a positive drop of the armature rather than a gradual settling down of same. Another object is to prevent the chattering or humming of the parts which sometimes occurs when operating on alternating current.

In the preferred form of my invention I have illustrated it as applied to an inclosed switch with a spring actuated operating handle and a solenoid release with intermediate. latch and trip levers. The core of thesolenoid is formed in two parts, one of which is auxiliary or supplemental to the main part and is longtudinally movable with relation thereto. The trip lever is actuated by the dropping of the main part of the core.

Figure 1, is a side .view of apparatus embodying my invention, part of the coil and its housing being broken away to show the core and the trip mechanism, the parts being in the position they would occupy when operating under normal conditions with circuit ON.

Fig. 2 is a vertical sectional view on a plane at right angles to the view of Fig. 1,

the parts being in the position momentarily interior operating arm 6 in any suitable occupied in case the voltage decreases slowly and allows the plunger and core to descend until the flange of the auxiliary armature rests upon the upper part of the coil frame. A further drop of the core from this position causes the automatic tripp ng of the levers and release of the swltc Fig. 3, is a perspective view showing separate parts'of the core and plunger.

I have indicated a part of the switch box by the reference 5. This box contains the switch mechanism which of course has a movin contact member as usual (not shown% adaplted to be opened andclosed by an arm 6. his arm is under tension of a spring 7 which tends to open the circuit in the switch.

Exterior of the box is the operating handle or lever 8 which is connected to the manner.

A pivoted latch member 9 is adapted to engage the stud or projection 10 on the handle 8 to hold the handle with the switch in the closed circuit position. A trip lever 11 co-acts with one end of the latch 9 so as to normally oppose the action of the spring 12-which tends to disengage the latch from the handle projection 10. A spring 13 holds the trip lever 11 under tension towardthe position in which it is shown in Figs. 1 and 2, that is, with the latch 9 engaging the handle projection 10.

A releasing member 14 normally raised by the spring 15 is adapted to be pushed down by the finger piece 16 so as to release the tri lever 11 from the latch 9 when it is desire to manually open the switch.

The coil 17 is provided with a core having the plunger rod 18. This core consists of a main body 19 and the auxiliary part 20 both of which are of magnetic material. The rod is preferably of non-magnetic material so ,that it does not enter into the magnetic circuit. At the upper end of the rod 18 is a disk 24 which overstands the horizontal arm of the trip lever 11 so that when the core of the solenoid descends it strikes the horizontal arm of the trip lever and thus upward movement until the flange 22 of the auxiliary core is free of the coil so as to prevent chattering of the flange against the coil under normal conditions; the disk 24 is also carried upward so asto free it from contact with the trip lever 11.

When the voltage is reduced or decreased, the two-part core descends until the flange 22 of the auxiliary core rests upon the coil and in this position, the magnetic condition of the two parts of the core tends to hold them together until the Volta e has been so much further reduced that t e magnetic influence is no longer strong enough to hold up the main part of the core which then drops suddenly and trips the switch.

The magnetic attraction of the two parts of the core holds them together for a period during which the voltage has been considerably reduced so that when the main part of the core does separate from the auxiliary part, the separation is sudden and causes a positive tripping of the lever 11 which in turn releases the switch.

This interrupted dropping of the main part of the core occurs whether the voltage is suddenly or gradually reduced and this sudden initial drop causes the disk 24 to strike the trip lever 11 with a comparatively powerful blow. It will be obvious that if the core descended slowly the friction of the parts of the latch lever and trip lever might be suflicient to sustain the entire weight of the core and plunger. g

For convenience in manufacture and assembling, the parts of the solenoid and trip and latch-mechanism are preferably mounted in an auxiliary housing consisting of the body part 25 which surrounds the coil and the cover part 26 which surrounds the upper end of the core and the trip lever and carries the latch member and the manual releasing device 14 and button 16. The body part 25 is open at the bottom to ermit ventilation and access to the core. he latch 9 has a shoulder 27 adapted to be engaged by the projection 10 when resetting the handle so as to thus reset the latch 9 and allow the spring 13 to reset the trip lever -11.

I claim 1. In an electro-magnetic trip device, a coil, a vertically movable core consisting of a main body, a plunger rod, an auxiliary core slidable on said rod, means for limiting the vertical descent of the auxiliary core and a trip member operated by said plunger rod when the voltage falls below a prede- 3. In an electro-magnetic trip device, a

coil, a core to be moved in one direction by and movable within said coil, an auxiliary core movable within saidcoil and co-acting with said first mentioned core when the latter is moved to one position by the. coil under normal voltage, a trip member, means on said first mentioned core for actuating said trip member when the voltage in the coil falls below a predetermined point, said means'and trip member being out of contact with each other under normal voltage conditions, means for arrestin the movement of said auxiliary core wl ereby when the voltage falls below a predetermined point both cores will move and upon the arresting of the movement of the auxiliary core the other core will move away therefrom and deliver a sharp blow to said trip member.

4. In an electro-magnetic trip device, a coil, a core movable within said coil, a plunger rod of smaller diameter than said core and movable therewith, a flange on said plunger rod at the end remote from said core, an auxiliary core slidable on said plunger rod and adaptdd to co-act with said first mentioned core, a flange upon said auxiliary core for stopping against a part of the device for arresting the movement of the auxiliary core in one direction, and a trip member having a part extending between said flanges and adapted to be operated by one of said flanges when the voltage in the coil drops below a predetermined point.

BENJAMIN E. GETCHELL.