Claims
- 1. A unitary frame of molded resinous material for a circuit protector comprising:
- a base adapted to provide support for at least a pair of terminals, a fixed contact and a movable contact support supporting a movable contact cooperating with the fixed contact;
- a relatively thin generally planar support frame transverse to and integral with the base for support of contact actuating structure;
- a back plane molded integrally with the support frame and the base at one end of the base; and
- supporting grooves in the support plane and the back plane positioned and adapted to engage and support a grid element arranged proximate to the edges and end of the movable contact support as it moves away from the fixed contact.
- 2. The unitary frame of claim 1 in which each supporting groove in the planar support frame is effectively extended by ridges extending outward from the groove on each side of the groove.
- 3. The unitary frame of claim 1 in which the generally planar support frame effectively divides the base in half and provides equivalent space for a complete circuit protector each side of the generally planar medial support frame wherein grid engaging and supporting grooves are provided on each side of the support plane and in the back plane on both sides of the support plane.
- 4. The unitary frame of claim 3 in which each supporting groove in the planar support frame is effectively extended by ridges extending outward from the groove on each side of the medial support plane.
BACKGROUND OF THE INVENTION
This is a continuation-in-part of U.S. application Ser. No. 337,578 filed Apr. 13, 1989, now U.S. Pat. No. 4,931,762.
The present invention relates to a circuit protector construction and more particularly to a circuit protector having a unique base and mounting frame and a few simple easily assembled mechanical parts, some of which may serve for both poles of a two pole circuit protector.
In the prior art circuit protectors of the general type of the present invention have been broadly disclosed in United States patents such as U.S. Pat. Nos. 4,167,720 and 4,258,349. These structures characteristically employ a rocker handle which is rotatably supported to a frame by a pin and provides a linkage crank which, in turn, is connected by a linkage to a switch actuating rocker. The linkage is connected to the linkage crank and rocker by rotatable pin connections parallel to the handle supporting pin. Characteristically the rocker which has a parallel pin trapped in a guide slot is engaged by a pivoted latch member also with a pin parallel to the others, which holds the latched end of the rocker in position as the rocker is moved by the handle member through the linkages against the movable contact arm to close the circuit protector contacts. The handle may be able to open the circuit protector contacts by rotation back the opposite direction. Upon overload, the contacts are opened as the latch member is moved releasing the latched end of the rocker to reposition so that the contacts will be able to open.
The applicant's assignee Heinemann Electric Company has manufactured thermally actuated circuit protectors using a rocker handle. Such a circuit protector has had a somewhat different configuration shown in U.S. Pat. Nos. 4,338,586 and 4,436,972.
The present invention provides a circuit protector actuator construction employing much structural resemblance to the prior art but in which important improvements over the prior art are introduced. A geometry which is quite simple lends itself to construction of many of the mechanical parts from molded resinous material, such as, for example, General Electric Company's ULTEM.RTM.. In particular the base preferably supports preassembled contact and external terminal assemblies which are easily assembled to the base by sliding them into preformed grooves in a base plate which preferably is of rigid molded resinous material. Slip-on adapters permit easy conversion of a conventional spade terminal to a screw type terminal. The device is particularly well suited to use a thermal actuator for tripping the switch of this circuit breaker, or circuit interrupter. A bi-metallic member preassembled, calibrated and stored as inventory before assembly into the base, may still be adjusted thereafter, even after assembly has been completed, and even after the cover has been put into place.
A novel arrangement for wiring and support of a lamp remote from a switch, which, for example, when actuated by the movable contact support arm, may by the illumination of the lamp show that the contacts are closed. Other switch arrangements may produce illumination under other conditions. Various types of bulbs may be employed. However, the arrangement permits a novel bulb support provided by the medial plane frame using wiring in alternating interconnected channels in the two sides of the medial plane frame.
The same medial plane frame enables a symmetrical actuator structure on both sides of the medial plane for a two pole configuration. Parallel crank arms of the handle are connected to parallel arms of the rocker on opposite sides of the medial plane preferably using novel integral pin linkages which provide rotatable pins parallel to the axis of the rotatable pin supporting the handle. These pins are sized and configured to snap into prepared holes in the handle linkage crank and the rocker. The rocker itself is not directly pinned to the frame, but preferably uses has a single molded resinous pin extending between its parallel arms on opposite sides of the medial plane. The pin which may be inserted into a subassembly positioned on the frame by the handle pin positions the parallel rocker pin to ride in a guide slot in the medial plane frame in order to limit the movement of the rocker. When the circuit protector is tripped because overload occurs in a single pole, the latch lever is moved out of position to retain the latch surface of the rocker and both poles are opened. The rocker, which is normally engaged and positioned by the latch keeper, moves to upset the over-center equilibrium achieved when the link pin to the handle link moves between the other link pin to the rocker and the handle pin. The force of a spring between frame and handle is now sufficient to restore the off position of the handle because of movement of the intermediate link pin over center between the handle pin and the rocker link pin. The camming surface on the rocker actuating the switch arm into the closed contact position is released in the process. The stability of the linkage is disturbed and the handle spring returns the handle to off position, assuring that the contacts remain open.
A back plane attached to the medial plane is spaced from the casing and supplied with a vent slot to afford controlled venting of gases generated, for example, by arcing of the contacts. The vent passage is continued by providing spacing between the back plane and the housing. The medial plane frame and the back plane also provide slots to carry a gradient plate to aid in suppressing arcs at the contacts.
The latch lever itself has a unique structure and orientation in the present invention. It is pivotally supported on a pin parallel to the other pins. A spring between the frame and the latch lever holds the latch keeper in engagement with the transversely oriented rocker except for the times when thermal overload occurs moving the latch lever against the bias of the spring and releasing the rocker. Latching can be restored when off position of the switch handle is achieved since the handle spring through the linkage moves the rocker back into position to be latched. A cam surface is provided on either latch lever or rocker to move the latch lever out of the way of rocker movement against its light spring bias. Once past the latch keeper, the latch bias holds the rocker and latch lever in contact until the handle is again moved to close the contacts of both poles.
More broadly, the present invention relates to a circuit protector construction employing a support base having a support frame arranged generally transverse thereto. At least a pair of terminals are supported on the base. One of the pair of terminals is connected directly to a circuit protector switch contact and the other is connected through an overload actuator element to a second movable contact on a movable arm. A circuit protector actuating handle is rotatably supported on the frame by a pin and provides a linkage crank arm. A handle spring between the handle and the frame urges the handle into its open contact position. A link is connected to the linkage crank arm of the handle by a rotatable pin connection and connected to the rocker by a parallel pin whereby movement of the handle will cause movement of a switch actuator portion of the rocker in contact with a latch lever to close the circuit protector switch contacts when the latch is engaged. The rocker pin parallel to the handle pin is guided by a slot in the frame. The latch lever is pivotably supported on the frame by a pin parallel to the aforesaid pins and provides a latch keeper to engage and hold the rocker. The latch spring extends between the latch lever and the frame to urge the latch lever into engagement with a latch surface of the rocker. When the handle rotates to close the contacts of the circuit protector, it moves the linkage pivot point to the linkage arm over center between the handle pin and other linkage pin to stably hold the switch in closed contact condition. Release of the latch lever by overload forces releases the rocker latch surface from the latch keeper and allows movement of the rocker to an unstable position such that the handle spring moves the lever arm pin back over center to allow the rocker switch actuator to free the movable contact.
US Referenced Citations (4)
| Number |
Name |
Date |
Kind |
|
3211860 |
Stephenson, Jr. et al. |
Oct 1965 |
|
|
3341791 |
Leonard |
Sep 1967 |
|
|
4075446 |
Aadahl |
Feb 1978 |
|
|
4757294 |
Todaro et al. |
Jul 1988 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
| Parent |
337578 |
Apr 1989 |
|
Patent Grant
5064977
