US1340919A - Thermal circuit-closer - Google Patents

Description

H. SIEBEN AND B. c HALDEMAN. THERMAL CIRCULT CLOSER.

APPLICATION FILED JUNE Il, 1917.

Patented May 25, 192()o 'A T To/e/VE Y UNITED STATES PATENT OFFICE.

`HENRY SIEBEN AND BERTRAND C. HALDEMAN, F KANSAS CITY, MISSOURI, ASSIGNORS, BY DIRECT AND MESNE ASSIGNMENTS, T0 CHARLES C. I-IOEFER,

0F KANSAS' CITY, MISSOURI.

THERMAL CIRCUIT-CLOSER.

Specification of Letters Patent.

Patented May 25, 1920.

A To all whom t may concern.'

s Be it known that we, HENRY SIEBEN and BERTRAND C. HALDEMAN, citizens of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Thermal Circuit-Closers; and we do declare the followingto be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, vreference being had to `the accompanying drawings, and to the letters and figures of reference marked thereon, which forma part of this specification.

Our invention relates to fusible plugs for electrical connections and more particularly to a device of that character' for domestic use in connection with sad irons, cookers, or with other devices utilizing electric heat or power in such relations that over heating, caused by neglect to disconnect the device v after use might cause damage by scorching or fire, the principal object of the invention being to provide a plug wherein the electrical circuit is automatically broken at a determined temperature but of suchl mechanical construction that, when the `plug has cooled, the parts may be returnedto functional relation without replacement of any of' the parts.

MoreV particularly the device comprises ycircuit making and breaking members normally yieldably held in functional relation by a fusible connection adaptable for fusing lat a determined temperature to permit separation of the contact makin members and of resetting whenthe circuit is broken to bers separated to show the switch mechan lism and wire connectlons.

.tion 3.

F ig. III is a longitudinal, central section lrough the plug, o n the line III-III, Fig.

Fig. IV is a transverse section of the same. Y

iFig. V is a sectional view on the line Vf-V, Fig. III.

Fig. VI is a transverse section through the plug on the line VI-VI, Fig. II.

Fig. VII is a perspective view of a modified form of switch actuating means.

Fig. VIII is a detail perspective view of the automatically releasable and resetting parts of the device.

Referring more in detail to the drawings:

1 designates'a plug constructed according to the present invention comprising coperating casing sections 2 3 of liber, hard rubber, or other non-conductive material wherein the circuit closing and releasing switch parts are housed and connections made therewith to the circuit wires and with the device to which the plug is to be applied; the sections 2-3each forming a face of the housing and being held together by screws or bolts 4 which extend through coperating projecting neckportions 5-6 at opposite sides of a central body portion 7 ,Revolubly carried by the housing section I s 2 is a switch control shaft 10, the inner end of which extends revolubly through the interior wall 11 of the section 2 and terminates in an interior circular chamber 12 in the sec- The opposite end of the shaft eX- tends from the housing through an overlying face plate 13 and through a plate 14 that is interposed between the edge of the section 2 and face plate 13, and is provided exteriorly of the housing with a turn button 15, whereby the .shaft may be operated to control the switch parts, as will presently be described.

The plate 14y has an extension or lip 14 at its inner end adapted for contacting the lbody of the iron when the plug is in place to conduct heat directly from the iron to the heat controlled element in the plug, so that said element may be affected more quickly and at a lower temperature than should it be necessary to conduct the heat throughthe entire body of the plug.`

In practice, I prefer to make the plate 14 o f aluminum, as the metal is a good conductor of heat and provides a more sensitive control.

Fixed within the section 3 to the base of the chamber 12 and at points diametrically opposite'the axial line of the shaft 10 are contact plates 1G-17, which are adapted to be simultaneously engaged by or disengaged Extended into the housing through an aperture 21, formed by grooves 21', 21 in the separate housing members forming the neck portion 5, are circuit wires 22-22; the wire 22 being attached to the binding post 23 on the plate 16 while the wire 22 is extended through the chamber to the base of the housing where it is attached to one of a pair of socket sleeves 25-25 located within cooperating pockets 26-26 in the opposite sections 2 3 and opening at their base ends to receive contact posts 27-27, or the like, on the iron, or other heating member, 28 (Fig. I), and which are the opposite terminals of a heating coil (not shown) located within the iron. The sleeve not connected with the wire 22l is in contact at its inner end with the plate 17 so that with the cross arm 18 in functional position a circuit may be completed through the circuit wires, plug and heating unit to heat the iron.

lVound about the portion of the shaft 10, exteriorly of the housing, is a coil spring 30, one end of which is fixed to the shaft and the opposite end to the housing so that the shaft is yieldingly urged to move the Across arm 18 from contact with the plates 16, 17 in the direction of the arrow, Fig. Il; movement of the shaft to set or operative position being limited by a stop ear 3l that is turned upwardly from the plate 17 to engage one end of the arm, and in the opposite direction after the arm is unseated from the contact plates by an arm 32 on a plate 33 that is fixed to the casing member 2. Rotation of the arm shaft 10 under tension of the spring 3() is prevented, under normal conditions, by engagement of the tooth 34, of a pawl 35, that is pivotally mount-ed on a pin in the Wall 11 of the housing member 2. A ratchet wheel 3G, that is rotatably mounted on the shaft 10 and comprises a cup 37 for containing a fusible solder 38 adapted for adherence to the cup and to a plate 39 that is fixed on the shaft 10 and serves as a cover for the cup, the facing sides of the cup and plate 39 being preferably separated to receive the solder and effectively connect the catcher cup with the shaft disk in order that when the ratchet is locked by its pawl, the shaft, 4is held in position to retain the cross arm 18 in Contact with the plates 1G and 17 and thereby maintain a closed'circuit through the heating member when the plug is on the member, or in position to complete the circuit when not on the member.

lith this arrangement, under normal conditions, the solder forms a union between the ratchet member and shaft which, when the shaft is set against tension of thespring, enables the pawl to hold the shaft, but should the heating unit become over heated to the fusing point of the solder, the latter will melt and break the connection between the ratchet wheel and shaft disk, thereby releasing the shaft so that tension of its spring will throw the shaft around and move the ends of the bar 18 off' of its contact plates to break the circuit and thereby prevent excessive heating of the iron that might cause damage to any article with which it might be in contact and a possible conf-lagration. i

To determine whether or not the parts are in connected or disconnected relation, we provide the shaft 1() with a pointer 40, preferably constituting one end of the spring 3f), that is adapted to register with on and off marks on the face of the housing according to the relative position of the switch parts.

lVith the plug containing the heat controlled element separate from the iron or other body, when the iron has reached a temperature sufficiently hot to melt solder and the current has been automatically cut off,

4the plug may be removed from the iron and,

being a relatively small body, cools quickly so that the contacts may be reset if desired and operation with the iron continued without unnecessary delay.

lith this arrangement the iron may be heated to a temperature of 600 degrees F. the solder or heat controlled element in the plug adapted to melt at 15() degrees, and the conductor plate 11 of a resistance to operatively affect the solder or heat controlled element when the iron oi' other body has reached the determined temperature, so that the lug or the heat controlled element therein does not need to reach the temperature of the iron before it may opel'- ate.

As the plug cools much more quickly than the iron, it may be repeated and the iron again put to use much quicker than if it were necessary for the iron to cool to a temperaperature at which the solder or heat controlled element would return to operative condition.

Assuming that the plug is so constructed and that the switch parts are .normally closed as shown in Fig, Il, the plug is applied to the iron, or other device, by seating the plug sleeves 25, 25 over the contact posts 27-27 to close a circuit through the A iron.

It is not the intention that the plug should be left on the iron until the fusion takes place, asa primary switch may be used to lcontrol the circuit, but should the person using the iron forget to turn olf the circuit, when the iron reaches a certain temperature, heat conducted along the plate 14, through the ratchet wheel, melts the solder so that the shaft 10, being freed and under presisure of the spring 30, it will move the cross \arm from the contact plates to break the circuit through the heating unit.

After the iron vhas become sufficiently cooled the solder sets and the ratchet wheel is again locked relative to movement of the shaft and the parts again placed in set position by revolving the shaft against the tension of the spring. I

It will be seen that by so constructing the plug, automatic means is provided for breaking a circuit to prevent overheating of the iron, or other device, to which the invention is applied.

Having thus described our invention, what we claim as new therein, and desire to secure by Letters-Patent, is:

l. In an electrical plug connector for electrically heated bodies, contacts adapted to coperate with complementary contacts on the body, means for closing a circuit through the plug contacts and normally urged to break the contact, a heat-responsive element in the plug normally opposing the actuation of the circuit closing means to break the contact, the heat-responsive element being effective to permit the breaking of the contact when subjectedto a determined heat, member for conducting heat from the heated body to said element.

2. In an electricalv plug connector for heated bodies having contacts coperative with complementary contacts of the heated body, means for closing acircuit through the plug contacts and normally' urged.'to

' move to open position to break the circuit,

a heat-responsive element normally holding said means in circuit closing position, and a conducting member for conducting heat from the heated body to said device.

3. A circuit closer, adapted to be used o.n

` a heated body, having contact points, `comprising a removable plug having contacts cooperative` with those of said body, a normally closed switch in the removable plug for closing a circuit through the plug contacts, said switch having automatic opening movement in response to heat generated in the heated body and conducted to said plug, and' a conducting member for conducting the heat from the heated body to said plug. p

4. A circuit closer, adapted to be used on a heated body, having contact points, comprising a removable plug having contacts cooperative withthose of said body, means for closing a circuit through the plug contacts and normally urged to break the circuit through the contacts, a heat-controlled element in the plug, means operating through the heat-controlled element to set said means, and a conducting member for conducting heat from the heated body to said element. 5. A circuit closer, adapted to be used on an electrically heated body, having contact points, :comprising a plug removable from the body and having contact points coperative with those on the body, a movable circuit closer adapted for closing or opening a contact through said points, means normally urging the circuit closer to open the circuit, an actuator, an element variable under the infiuence of heat, forming a union between the circuit closer and actuator at a determined temperature and changeableto release the circuit closer under a higher temperature but permitting the circuit closer and actuator to be automatically reunited upon return, of the element to low temperature condition, a latch for the actuator op- -erable -to effect setting and holding of the circuit closer, and a heat conductor leading from said' variable element to contact with said body.

tures.

HENRY SIEBEN. p BERTRAND C. HALDEMAN.

In testimonywhereof we affix our signa-

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