US3581753A

US3581753A - Limit switch connector

Info

Publication number: US3581753A
Authority: US
Inventors: Frederik J Ages
Original assignee: Honeywell Inc
Current assignee: Honeywell Inc
Priority date: 1969-10-14
Filing date: 1969-10-14
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01

Abstract

A thermocouple energized safety control having a housing enclosing a safety valve unit, an electrical terminal extending from said unit through a housing wall and terminating in a recess, a closure plate for the recess having a threaded opening therein to receive the terminals of a concentric lead type of thermocouple, a cup-shaped insulator member surrounding a slotted portion of the terminal, and a transversely slotted, cup-shaped electrical conductor member engageable by the central terminal of the thermocouple leads so that a first wire from a limit switch may be clamped between the valve unit terminal and the insulator member and a second wire from the limit switch may be clamped between the two cup-shaped members, to place the limit switch in series with the safety valve unit and the thermocouple.

Description

United States Patent [72] Inventor Frederik J. Ages Los Angeles, Calif. [21] AppLNo. 866,331 [22] Filed Oct. 14, 1969 [45] Patented June 1, 1971 73] Assignee Honeywell, lnc.

Minneapolis, Minn.

[54] LIMIT SWITCH CONNECTOR 6 Claims, 2 Drawing Figs.

[52] US. Cl 137/66, 126/351, 317/123, 339/174 [51] int. Cl ..ll01h 47/22 [50] Field of Search 126/351; 339/99, 174; 137/65, 66

[56] References Cited UNITED STATES PATENTS 3,467,893 9/1969 Jackson et a1. 126/351X Primary Examiner-William F. ODea Assistant ExqminerRichard Gerard Attorneys-Lamont B. Kootz and Alan M. Staubly ABSTRACT: A thermocouple energized safety control having a housing enclosing a safety valve unit, an electrical terminal extending from said unit through a housing wall and terminating in a recess, a closure plate for the recess having a threaded opening therein to receive the terminals of a concentric lead type of thermocouple, a cup-shaped insulator member surrounding a slotted portion of the terminal, and a transversely slotted, cup-shaped electrical conductor membe'rjehgageable by the central terminal of the thermocouple leads that a first wire from a limit switch may be clamped between the valve unit terminal and the insulator member and a second wire from the limit switch may be clamped between the two cup-shaped members, to place the limit switch in series with the safety valve unit and the thermocouple.

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INVENIOR.

FREDERIK J. AGES ATTORNEY.

- LIMIT SWITCH CONNECTOR The invention relates to a manifold valve of the type'which is adapted to control the flow of gas to a water heater. Such valves usually include a rod and tube actuated thermostat valve, a manual plug valve, a safety valve energized by a thermocouple responsive to the presence of a pilot burner flame and a highJimit switch in series circuit with the thermocouple and safety valve wherein the high-limit switch is located to sense the water temperature. More particularly, the invention is directed to the particular coupling between the high-limit switch and the safety valve unit and the thermocouple.

FIG. 1 of the drawing is a fragmentary and somewhat schematic view of the invention; and

FIG. 2 is a cross section of the coupling elements shown at right angle to the elements as viewed in FIG. 1.

The reference numeral 11 designates the housing of the manifold valve which has a valve seat 12 for the safety valve 13, has an opening 14 through which the supporting means for the valve unit extends and has a recess 15 in which the coupling means for the limit switch 16 and thermocouple 17 is located. A power unit 19, which is adapted to be energized by the thermocouple when the thermocouple senses a flame 18a from a pilot burner 18, is of conventional construction. lt is supported in the housing 11 by an insulating sleevelike member 20 which surrounds a central connector 21 to insulate and connect a coil 19a to a headed terminal portion 210. The insulating member is illustrated as being held in the opening 14 by means of a nut 22 of insulating material threaded onto the member 20. Connector 2! also has a slotted boss 21b extending into the recess 15 for the reception of the bared end 230 of a lead wire 23 from high-limit switch 16. A cupshaped insulator member 24 has an annular flange 240 that bears against the bared wire 23a'to clamp it against the head 21a. The boss 21b fits in the cavity of the member 24. A second cup-shaped electrical conductor 25 has diametrically opposed slots 25a and an inwardly struck abutment portion 25b which leaves a recess or socket 250 in the opposite face thereof for the reception of a head 26a of central thermocouple lead 26. A second bared end portion 27a of second lead 27 from the high-limit switch is clamped between the outer surface of the cup-shaped member 24 and the abutment portion 25b and the inner ends of the slots 25a.

The thermocouple 17 is adapted to be electrically connected to the high-limit switch 16 by threading the conventional connector nut 28 into a closing plate 29 for the cavity 15, so as to bias the head 26a into engagement with the member 25, bias the member 25 against wire 27a, and to connect the switch 16 to the terminal 21 by having the same force bias the insulator member 24 against the wire 23a, which, in turn, is biased against the head portion 210. As coil 19a is grounded at 19b to the metallic housing of the unit 19, the grounding of the outer lead 30 from the thermocouple to the housing 11, through nut 28 and plate 29, completes the electrical circuit between the thermocouple, the high-limit switch and the coil.

It is thus seen that with the safety valve 13 opened by a conventional manual operator for the manifold valve and the pilot burner ignited and having a flame playing on the thennocouple 17, current will flow from the thennocouple 17 through the central lead 26 to the connector member 25, through the lead 27 to the high-limit switch, back through the lead 23 to central terminal 21 of the power unit, through the coil 19a of the power unit, through the valve body including plate 29 to the clamping nut 28, and outer lead 30 back to the thermocouple. As long as there is current flowing to the coil 19a, the armature will be held and the valve 13 connected thereto kept in an open position. Should either the pilot flame 18a become extinguished or the water temperature surrounding the high-limit switch 16 approach the boiling temperature so as to open the switch, the current flow to the coil will cease and cause the valve 13 to close under the bias of its return spring 13a. It is thus seen that a compact and easy to assemble terminal arrangement is provided for connecting a hi h-limit switch into the circuit of a thermocouple-energize safety valve that will obviously provide reliable operation.

The embodiments of the invention in which I claim an exclusive property or right are defined as follows:

1. In a thermocouple-energized gas flow control device including a housing therefor, the combination comprising headed electrical terminal means extending through a wall of said housing with the head thereof resting in the bottom of a recess in said housing, insulation means electrically separating said terminal means from said housing, said head having an axially extending and transversely slotted boss of smaller diameter than said head and shaped to receive a first wire therein, a cup-shaped insulating means having an inside cavity adapted to receive said boss and to press said wire against said head, a cup-shaped electrical conductor means having a transverse slot through the sidewalls thereof for the reception of a second wire and having an inside cavity adapted to receive said cupshaped insulating means and having abutment means thereon adapted to press said second wire against said insulating means, and a wall member closing said recess and having a threaded opening therein in axial alignment with said conductor means and positioned so that upon threading the nut of the connector terminals of a conventional concentric leads type of thermocouple into said threaded opening the central terminal head of said connector terminals will clamp said second wire between said cup-shaped connector means and said cupshaped insulating means and will clamp said first wire between said cup-shaped insulating means and said headed electrical terminal means.

2. A control device as defined in claim 1 wherein said wires are the bared ends of lead wires connected to a temperatureresponsive high-limit switch.

3. A control device as defined in claim 2 wherein said lead wires extend through an opening in a sidewall of said recess.

4. A control device as defined in claim 1 wherein said cupshaped insulating means has an annular flange around the open end thereof for engagement with said first wire.

5. A control device as defined in claim 4 wherein said cupshaped electrical conductor means has an inwardly struck closed end portion that internally provides a small area portion for engagement with said second wire and an external socket portion for the reception of the central terminal head of said connector terminals of the thermocouple leads.

6., A control device as defined in claim I in combination with a safety valve means operably connected to said terminal means.

Claims

1. In a thermocouple-energized gas flow control device including a housing therefor, the combination comprising headed electrical terminal means extending through a wall of said housing with the head thereof resting in the bottom of a recess in said housing, insulation means electrically separating said terminal means from said housing, said head having an axially extending and transversely slotted boss of smaller diameter than said head and shaped to receive a first wire therein, a cup-shaped insulating means having an inside cavity adapted to receive said boss and to press said wire against said head, a cup-shaped electrical conductor means having a transverse slot through the sidewalls thereof for the reception of a second wire and having an inside cavity adapted to receive said cup-shaped insulating means and having abutment means thereon adapted to press said second wire against said insulating means, and a wall member closing said recess and having a threaded opening therein in axial alignment with said conductor means and positioned so that upon threading the nut of the connector terminals of a conventional concentric leads type of thermocouple into said threaded opening the central terminal head of said connector terminals will clamp said second wire between said cup-shaped connector means and said cup-shaped insulating means and will clamp said first wire between said cupshaped insulating means and said headed electrical terminal means.

2. A control device as defined in claim 1 wherein said wires are the bared ends of lead wires connected to a temperature-responsive high-limit switch.

4. A control device as defined in claim 1 wherein said cup-shaped insulating means has an annular flange around the open end thereof for engagement with said first wire.

5. A control device as defined in claim 4 wherein said cup-shaped electrical conductor means has an inwardly struck closed end portion that internally provides a small area portion for engagement with said second wire and an external socket portiOn for the reception of the central terminal head of said connector terminals of the thermocouple leads.

6. A control device as defined in claim 1 in combination with a safety valve means operably connected to said terminal means.