US1850206A

US1850206A - Thermostatic control

Info

Publication number: US1850206A
Application number: US219405A
Authority: US
Inventors: Hertzberg Harry
Original assignee: FRANK J KENT
Current assignee: FRANK J KENT
Priority date: 1927-09-14
Filing date: 1927-09-14
Publication date: 1932-03-22
Anticipated expiration: 1949-03-22

Description

March 22, 31932, Hf HERTZEERG THERMOSTATIC CONTROL `Original Filed Sept. 14. 1927 Patented Mar.. 22, 1932 STATES HARRY HERTZBERG, or BROOKLYN, Nnw YORK, Ass'IGNoR 'ro FRANK a'. KENT, or

/ NEW YORK, N. Y., .AND nnnsnrr, JOINTLY THEBMOSTATIC CONTROL Application led September 14, 192,7, Serial No. 219,405. Renewed June 10, 1931.

rlhis invention relates to a thermostatic control for electrical heating elements and provides a circuit breaker for preventing eX- cessive temperature in the heating elements. The invention is particularly useful in connection with electrical flat-irons, since the use of such irons creates peculiar problems that are most eciently solved by the apparatus disclosed herein.

An objectv of the invention is to provide a thermostat that will break the circuit positively and quickly after the temperature of the apparatus has passed above the critical point.

The invention also includes the provision of a heating relay for the thermostat, the relay being so arranged that a slight initial movement of the thermostatic element brings into operation the heating relay which applies heat directly tothe thermostatic element and hastens the operation of breaking the circuit to the heating element of the iron, or other apparatus.

Other features of theinvention cooperate to produce a-compact and simple device that is positive in operation and having a long useful life..

y While a preferred form of the invention has been disclosed for purposes of illustra- 30 tion, itl should be understood that various the thermostat has broken the circuit to the heating element.

`Fig. 5 is a section taken at right angles to Fig. 2.

F ig. 6 is a perspective of the thermostat.

Fig. 7 is an enlarged detail of one end of the thermostat.

Referring to the drawings more particularly, the reference numeral 1 designates the casing of the connector plug, which is formed of insulating material in a well-known manner. An aperture 2 provides entrance for the-

feed wires

3, 3, which are attached to binding

posts

4 and 5. The opposite end of the plug carries

spring sockets

6, 6, for cooperation with the

posts

7, 7 of the iron. One of the sockets is connected by a conductor 8 with binding post 4, and the conductor 8 carries a lip 9 projecting inwardly and downwardly from the binding post 1. The other socket 6 is connected by a conductor 10 with the post 11 on which is pivoted the knife switch 12. The outer end of the knife switch extends through a slot 13 in the casing and carries an insulating button 14. The inner end of knife switch 12 cooperates with a clip 15 mounted on-the binding post 5. A spring 16 engages a finger 17 formed on knife switch 12 and a finger 18 formed on the lower end of the conductor 10, and normally biases the switch arm 12 away from the clip 15. llihe switch arm 12 is held in contact with the clip 15 by a thermostat 19, which will now be described.

IThe thermostat, shown in detail in Figs. 6 and 7, comprises a strip 20 of any suitable structure, being preferably formed of two metals having dierent Vco-etli'cients of thermal expansion, according to well-known construction. rThis Strip 20 is formed so that when cold it assumes a V-shape as shown in Fig. 6. A heating element, which is attached to the inner side of an arm of the thermostat, includes a `Wire-wound resistance core 21 and insulating strips 22 of mica or other suitvable material. VMetallic rivets 23, and 23a secure the insulating strips' to the resistance core and each rivet is in contact with one end of the wire of the core. The heating element is secured to the strip 2O by a clip 24 and a band of insulation 25.y The strip 20 terminates at the outer end of insulation 25, as-

will be clear from Fig. 7, so that the circuit through the resistance core 21 passes from rivet 23 to winding 21, to rivet 23a, and thence to arm 20.

The thermostat is mounted in the connec-V tor plug by having the eyelet 2.6, formed at the juncture of its arms, pivotally engaged over a screw post 27 placed between the

spring sockets

6, 6, the parts being so arranged that in the normal/operating position (Fig.` 2) the left arm of the thermostat presses clip 24 against the conductor 8, while the right arm enga es a notch 28 in the lower side of the knife s 'tch 12 to hold the switch in contact with clip'15. In this position of the parts current iows to the

posts

7, 7 of the iron, but no current flows through the heating'element of the thermostat, due to the fact that the left arm of the thermostat is separated from the conductor 8 by the-insu- .lation 25.

If at any time during the use of the flat iron its temperature goes above a certain pre-determined danger point, the arms of the thermostat immediately begin to converge, causing the left arm to move from the position of Fig. 2 to the position of Fig.. 3, causing the-rivet 23 to make contact with the lip 9. As soon as this occurs current flows through the resistance wire of the heating element 21, which applies a strong local heating eiect along the entire length of the` left arm of the thermostat, and quickly causes furtherV contraction-of the thermostat until the right arm becomes disengaged from the notch 28 and finally reaches the full line position of Fig. 4. This action, of course, breaks the circuit between binding post 5 and conductor 10, as well as that through the heating element 21. f

4Due to the fact that the arms of the thermostat are contracted against opposite sides of lip 9, the right arm is out Vof the path of the knife switch 12, and it is impossible to immediately reset the switch,to send current through the heating element of the iron. Before resetting itis necessary to permit the iron to cooluntil the thermostat relaxes to theldotted position of Fig. 4, at which time the switch can again be placed in the normal operative position of Fig.` 2.

The structure set forth above has a number of important advantages. The provision of a V-shaped pivoted thermostat ermits the use of a relatively longr length of t lermostatic material lwhile still preserving the proportions of the conventional connector plug. This arrangement of the thermostat also permits the location of its operative ends at points remote from the

sockets

6, 6, which is a factor making for a compact arrangement.

The provision of the heating relay 21 causes the thermostat to break the circuit after the temperature of the iron has risen only a short distance above the danger point. This is because only a small rise in temperature is needed to move the left arm of the thermostat from the position of Fig. 2 to that of Fig. 3.

From thisA point the heating relay rapidly boosts the temperature of the thermostat and causes prompt severance of the main circuit through the plug. 4

In addition to these advantages the device has certain features of rugged and simple construction andrease of assembly that will be evident to those skilled in the art.

I claim:

1. In combination, a switch for controlling passage of currentthrough a circuit, a thermostat for causing the switch to break the circuit, and a heating element associated with the thermostat for accelerating the action of the thermostat, said heating element being brought' into operation by the thermostat.

2. In combination, a switch for controlling passage of current through a circuit, and a V-shaped thermostat pivotally mounted with one of its arms in a position permitting it to hold the switch closed.

3. In combination, a switch for controlling passage of current through a circuit, a V- shaped thermostat pivotally mounted with one of its arms in a position permitting it to hold the switch closed, and a heating element associated with the ,thermostat for accelerating action of the thermostat. p

- 4. In combination, a switch for controlling `passage of current through a circuit, a V- shaped thermostat pivotally mounted with one of its arms in a position permitting it to hold the switch closed, and a heating element associated with the thermostat for accelerating action of the thermostat, said heating element being brought into operation by the thermostat. 5. In combination, a switch Jfor controllin .passage of current through a circuit, a spring biasing the switch to open position, a V- shaped thermostat pivotally mounted with one of its arms in a position permitting it to hold the, .switch closed, and a heating ele-` ment associated with the thermostat for accelerating action of the thermostat.

c 7. In combination, a switch for controlling passage of current through a circuit, a spring i biasing the switch 'to open. position, a V- shaped thermostat pivotally mounted with retirees one of its arms in a position permitting it to hold the switch closed, and a heating element associated with the thermostat for accelerating action of the thermostat, said heating element being brought into operation by the thermostat. Y.

8. A connector plug comprising a pair of sockets, a pair of conductors, each conductor being connected to a socket, a switch connected to one of the conductors, a spring biasing the switch to open position, a contact lip connected to the other conductor, a V- shaped thermostat pivotally mounted with one ot its arms in a position permitting it to hold the switch closed, a heating element associated with the thermostat for accelerating action of the thermostat., and a contact conductively connected with the heating element, said contact being adapted to be moved against the contact lip by initial movement of the thermostat.

d 9. A connector plug comprising a pair of sockets, a pair of conductors, each conductor being connected to a socket, a switch connected to one of the conductors, a spring thermostat, said means being brought into operation by the thermostat.

13. In combination a switch for controlling passage of current to a circuit, a thermostat for operating the switch, and means associated with the thermostat for accelerating the action of the thermostat, said means being brought into operation by the thermostat.

ln testimony whereof I affix my signature.

HARRY HERTZBERG.

biasing the switch to open position, a V- shaped thermostat pivotally mounted with one of its arms in a position permitting it to hold the switch closed, a contact lip connected to the second conductor and extending between the arms of the thermostat, a heating element extending along and insulated from the second arm of the thermostat, a contact conductively connected with the heating element, said contact being adapted to be moved against the contact lip by initial movement of the thermostat.

10. ln combination, a switch adapted to control passage of current through an electrical circuit, a thermostat for causing the switch to break the circuit, means comprising a heating coil for heating said thermostat to accelerate the action of the said thermostat, said coil being normally out of the circuit, and thermostatic means for causing current from the circuit to How through the said coil when said thermostat reaches a predetermined temperature.

1l. A switch comprising a pair of contactsadapted to be placed in an electrical circuit, one of contacts being movable relative to the other contact, a thermostatic member adapted to be heated by the current flowing in the circuit and thereupon permit the contacts to separate, and means comprising a thermostatic member for moving said lirst-named thermostatic member to close a heating circuit for the said first-named thermostatic member when the switch parts reach a predetermined temperature.

12. In combination, a switch for controlling passage of current through a circuit, a

thermostat for causing the switch to break the circuit, and means associated with the thermostat for accelerating the action of the izo