US1813267A - Control device for electric irons and the like - Google Patents

Description

July 7; 1931. c, ARNEsEN 1,813,267

CONTROL DEVICE FOR ELECTRIC IRONS AND THE LIKE Original Filed June 22, 1925 2 Sheets-Sheet 1 1! a N s i .5 @si 07m z; T a r 672;

C. ARNESEN July 7, 1931.

CONTROL DEVICE FOR ELECTRIC IRONS ANID THE LIKE Original Filed June 22, 1925 2 Sheets-Sheet 2 T1100 midi? C an/M01156) flv'rwscvo,

OFF POSITION.

II \S .3 lllllw Patented July 7, 193 1 K PATENT OFFICE CHARLOTTE ARNESEN, OF CHICAGO, ILLINOIS i CONTROL DEVICE FOR ELECTRIC IRONS AND THE LIKE Application filed June 22, 1925, Serial No. 88,690. Renewed November 26, 1930.

This invention relates to electrically heated implements and particularly to a heat controlling and safety device therefor.

The invention has particular reference to 6 a control for electric flat irons and is herein shown and described with reference thereto.

It is well known that flat irons have been provided with switches controlled by the hand of the operator in graspin the handle and with switches thermostatlcal y opened at high heats. A thermostatic safety switch is of primary advantage to overcome fire hazard occasioned by forgetfulness on the part of the operator. Such a device also minimizes damaging the iron or the goods by use of an overheated iron through carelessness. Goods of coarse and of fine character require different degrees of heat in the iron. The moisture content of goods being ironed also 9 affects the temperature of the iron by coolingthe same more rapidly when the goods are very damp. Most thermostatic irons keep the temperature below a maximum degree which may be too high for some purposes. Such an iron cannot be readily kept at a lower temperature. Other irons have a hand controlled switch which keeps current on only while the handle is held. Without a thermostatic switch such an iron is inconvenien't to use because it may be cooled too rapidly while in use, requiring heating in the intermittent idle periods. It has been attempted to improve on such irons by providin a thermostatic lock for such handle switc es for the purpose of allowing them to open at a predetermined temperature, but as aforesaid, this arrangement will not permit of a lower temperature for the iron. Also, it has been found impracticable to operate the spring controlled lock for the handle by ther- 'mostatic means because of the substantial amount of power required in the thermostat. The present invention aims to provide an iron which can be used either as one having only a handle control or as one having a thermostatic safety shut-off. By providing one v switch which is a manual switch to open and 4 close the circuit and which is protected thermostatically against a continued closed position, in combination with a handle con .a heat when in use.

trolled switch which can be used at will, the operator can use the iron under all conditions with every degree of safety against overheatmg of the iron when idle or against too high Such a result is obtained by providing two independent switches in parallel, one being manually controlled to open or close the switch and being thermostatically opened,.and the other switch being manually closed, if desired, on grasping the handle and automatically opened on releasing the handle.

Another object is to provide the safety control mechanism wholly within a plug attachment so that it can be adapted for many irons now in use without being incorporated into their structure.

Still'other and ancillary objects and advantages of the invention and of the construction herein set forth and disclosed will be obvious from the following description of the drawings in which i I Figure 1 represents a general View of a fiat lron equipped with a controlling safety device.

' Fli. 2 is a. view along the line 22 of the attacment plug showing the rear section thereof in elevation.

Fig. 3 is a view of the plug and iron taken in cross section along the line 3-3 of Fig. 2.

Fig. 4 is a cross section taken along the line H of Fig. 2.

Fig. 5 is a view similar to Fig. 3 showing the parts in different positions.

Fig. 6 is a cross section of the plug along the line 6-6 of Fig. 5.

Figs. 7 and 8 are enlarged views of modi fied forms of contacts for the switch portions of the iron.

Fig. 9 is an enlarged detail View of parts of the thermostatic switch.

In the foregoing, it is to be understood that although the device is herein described with reference to fiat irons, its use is not limited to such articles nor is the construction limited to that which is herein disclosed. Other applications and constructions are herein contemplated as will appear from the scope of the appended claims.

The preferred application of the invenl at the top of its slot.

tion is shown in Fig. 1 as embodied in a plug attachment 10 for an ordinary electric iron 11 having a handle 12. The iron has projecting contact fingers indicated genera ly at 13 which are received by the plug in suitable recesses provided therefor, thus providing both mechanical and electrical connection between the plug and the iron. In the present instance the handle has a vertical bracket 14 at the rear of the iron alongside of which the plug 10 is adapted to lie. A hand lever 15 carried by the plug 10' is arranged to lie over the handle 12 when the latter is grasped by the hand as indicated generally at 16. WVires 18 lead into the plug at any convenient place.

The plug proper is preferably composed of two sections 19 and 20 of material such as molded bakelite. Bolts 21 secure. the two sections together. The rear section 20 (Fig. 2) carries the principal parts of the mechanism. In the lower portion of the plug are two pairs of spring clips 22 which. provide the recesses to'receive the contact fingers 13 of the iron. One such pair of clips is connected directly to one of the wires 18., The other pair of clips 22 is connected to the other wire 18 through two independent switches, one of which is both a manually and an automatic thermostatically controlled switch, and the other of which is a semiautomatic manually' controlled switch.

Reference first will be made to the thermostatic cut-out switch which is provided by a construction preferably as follows: The casing sect-ion 20 has spaced brackets 23 therein through one of which there isa fixed pin or shaft 24 screwed fixedly into the other and headed in the side of the'casing. Adjacent the bracket carrying the end of the shaft lies an operating member in the form of a disk 25 which is freely rotatable on the shaft 24. The disk (Figs. 3 and 5) is provided with an extension or a lug 26 which projects through a rear slot 28 in the casing. The slot and the lug serve to limit the motion of the disk in its rotation about the shaft. The disk has a wide arc-uate slot 29 therein which is at the top of the disk when the lug 26 is horizontal The slot narrows towardone end by providing the lower side of the slot as a cam 30'more particularly referred to hereinafter. On the lower side of the disk there is a. pin 31 projecting therefrom toward the bracket pierced by the shaft 24.. Adjacent to the left hand side (Figs. 2 and 4) of the disk 25 there is a dog 32- pivoted into the left hand bracket 23 at the point 35 tends to move down as shown in the drawings. In the position shown in Fig. 3, the pin 36 can rise in the slots on moving the tail 34 of the dog to the left. Moving the disk 25 clockwise in Fig. 3 will cause cam 30 to raise the detent by action on the pin 36.

A spring actuated contact element is arranged to be operatively moved against the force of the spring into circuit closing position on raising the lug 26 and to be released on raising the detent 35. The spring contact lies adjacent the disk 25 and in t 1e present instance is in the form of a disk 38 pivoted loosely on the pin 24. The whole disk 38 nests into the dog 32, as clearly shown in Figs. 4 and. 9. both being snugly adjacent the large disk 25; Small *disk 38 is provided with a contact arm 39. On the periphery of the disk there is a shoulder or stop 40 which is engaged by the detent 35 to prevent counter clockwise motion of the contact arm 39 (Fig. 3). A spring 41 between the arm 39 and the bracket 23 tends to move the contact arm into its open position shown in Fig. 5

from the closed position shown in Fig. 3. A

thermostatic element 42 fixed in the casing 20 is movable forward from the rear inside face of the plug. A metal plate 43 carried by the plug has a spring end 44 contactingv the iron 11 to conduct a sufiicient quantity of heat to the thermostat to provide for its operation. A layer of insulating material such as mica 43* provided between the metal plate 43 and the casing in order'to avoid overheating the casing by the plate 43. The moving of the thermostaticelement is arranged to move the tail 34 of the dog 32 in order to raise the detent 35 thus releasing the contact arm 39. In the present. instance the tail 34 is bent to engage'with the thermostat. In order to decrease the pressure-to be exerted by the thermostat on the dog, the contact pressure between shoulder 40 andthe detent is made light by providing a light pressure spring 41. For the same reason the contact arm 39 is arranged to have a, wiping action in operating as a switch.

The electrical circuit through the iron is completed from the left hand pair of contacts 22 (Fig. 2) to the wire 18 through means including the contact arm 39. This arm in its motion has a wiping action on two contacts 45 and 46 to open and close the circuit as a switch in the two positions of: the contact arm. Contact 45 is one leg of a U-shaped strip of material of which the other leg 48 is also a switch contact, both being connected to part of the spring contacts 22 as shown at 49 in Fig. 3. The contact 46 is a part of the strip 50 shown in the rear inside face of the plug. A second switch contact .51 on the strip 50 is provided opposite the contact 48.

Independently of the thermostatic switch,-

above'described, I provide a second switch for p closing the circuit at contacts 48 to 51. Set into the casing and pivoted about the shaft 24 is a collar 52 carrying an external arm 53.

Loosely pivoted on the pin 24 is a contact arm 54 similar to the contact arm 39 and disk 38 of the other switch.- A spring 54 (Fig. 2) 5 between the arm 54 and the bracket 23 serves normally to open the switch with a wipin action away from a brid 'ng position witfi respect to contacts 48 an 51. The face of collar 52 has a relation to the contact arm 54 generally similar to the relation of the disk 25 to the contact arm 39. Accordingly there is provided in the collar 52 a pin 55 engaging the edge of the arm 54 to close the switch on moving the hand lever 15 down onto the handle 12. A slot or recess 56 (Fig. 2) is provided on the collar 52 and a pin 57 rigid in the disk portion of the contact arm 54 moves in the slot. A spiral spring 57 a between the arm 53 and the casing 20 holds the lever 15 normally in open position (Fig. -5) It will be observed that in the open position the handle is well back to permit one to use the iron without closing this switch.

In Figs. 7 and 8 there is shown a modified .construction for the switches. Instead of rigid contact arms provided for a wiping action across two opposed contacts the modified construction comprises a drum 58 of insulated material rotatable on the pin 24. The drum carries a metallic band 59 about the periphery which is extended to form a resilient contact finger 60 having a loop at its end. A curved contact '61 providing a depression 62 therein normally receives the loop end of contact finger 60. A brush contact 63 from the casing completes contacts to the ring 59. This type of switch operates more as a snap switch because of the resiliency of the contact finger 60. l 1

In the operation of the preferred form of iron described, the operator attaches the plug 10 to the iron by plugging it onto the contact fingers 13.- The spring heat-conducting strip 44 serves to hold it firmly in place. The lever arm 15 is normally in the up position (Fig. 5) and the switch operated thereby is opened. If the lug 26 is down the thermostatic switch is open and no current flows. By raising the lug 2.6 the disk 25 is turned counter clockwise. Its pin 31 engages with the contact arm 39 moving the same against s ring 41 to close the switch. Detent 35 rops or may be moved by a spring so that it rests against shoulder 40 preventing operation of the switch to open the circuit. With the detent holding the switch in closed position the opening may be accomplished manually or thermostatically. In the first instance the lug 26 may be moved down causing the cam 30 to raise pin 36 thus releasing the contact arm and opening the switch. In the second instance the thermostat on excessive heat in the iron will raise the detent by moving forward and acting upon the tail 34 of 65 the dog The contact arm will thus be heat will be supplied only when the iron is in use provided, of course, the rear lug 26 is in the down and off position. Should the iron be too cool while in use the lug 2-6 may be moved to its on. position, from which it will automatically move to off position when the maximum temperature has been obtained irrespective of whether the iron is in use or out of use.

While other constructions may be employed in carrying out the invention, it is to be observed that the present construction is embodied entirely in the plug and, of course, is adapted to the particular iron. As many irons of the illustrated type are now in use, it is readily seen that the invention can be adapted to particular types of irons and be provided as a valuable safety attachment. It is likewise contemplated that the principles of the invention can be incorporated directly in the iron structure as well as in the plug. Furthermore, since flat irons are not the onlyv form of heated implements in common use, the application of the invention is not herein limited to flat irons. The scope of the invention as to structure and as to its application in the arts will become apparent from the appended claims.

I claim as my invention:

1. A control device for electrically heated implements having an electrical heating circuit, two switches in parallel in said circuit, means to close one switch 'whenthe implement is held for use, said means and said switch being arranged to open automatically when not held in use, manual means to close the other switch, and thermostatic means to open the other switch automatically at a predetermined maximum temperature of the'implement.

2.. A control device for an electrically heated implement comprising an electrically heated member a handle and electrical con tacts, said device comprising an electric attachment plug adapted for connection to said contacts, a switch in said plug, a switch operating element carried by the plug and arranged to overlie said handle in the closed position of said switch, said element being adapted to open the switch when the element is released from its position overlying the handle, and a thermostatic switch in said plug, a thermostat arranged for opening the thermostatic switch at a predetermined maximum heat in the heated member, and a heat conducting element carried by the .plug and contacting the heated member to heat the thermostat.

3. An attachment plug for an electrically heated implement comprising, in combination, a casing adapted for mechanical and electrical connection to the implement, two

[switches connected in parallel in said casing,

a thermostat in said casing arranged to open one switch at a predetermined heat of the thermostat, said implement and plug in the mechanical connection being adapted to transfer heat from the implement to the thermostat, an' operating member for the second switch outside of the casing, the second switch being arranged for closing when its operating member is held by the hand as in using the implement, and means to hold said second switch normally opened.

4. An attachment plug for an electrically heated implement comprising, in combination, a casing adapted for mechanical and electrical connection to the implement, two switches connected in parallel in said casing, a thermostat in said casing arranged to open one switch at a redetermined heat of the thermostat, said lmplement and casing in the mechanical connection being adapted to transfer heat from the implement to the thermostat, means to openand close said switch independently of the thermostat below the predetermined temperature, an operating member for the second switch, the second switch being arranged for closing when its operating member is held by the hand as in using the implement, and means to hold said second switch normally opened.

5. A control device for a member to be heated electrically, 'said device having means for controlling the flow of electric current comprising a pair of independent switches, one of said switches including a movable contact element having a normal open position and a locking closed position, a detent normally positioned to lock the contact element, a thermostat arrangedfto move the detent to release said contact element, and an operating member having an on position and an off position arranged in moving to the on position to move the contact element to its locked position, and in moving to the of! position to move the detent to release the contact element.

6. In a device of the class described, a

. thermostatic switch comprising, in combination, a contact element, means tending to move said element into a normal opened positron for the switch, means for locking said element in a closed position for the switch,

. said locking means being normally actuated to lie in its locking position, a thermostat to moveathelocking means out of locking position, andmanual means adapted to move vthe locking ineans out of locking position,

said manual means bein also arranged to move the contact element om its normal position into its locked position.

7. In a device of the class described, a thermostatic switch comprising, incombination, a casing, a shaft in said casing, a contact element pivoted on said shaft, means normally tending to move said element into an. 0 en position of the switch, an operating mem er on said shaft freely rotatable to on and ofr" positions, said member having a wide and long slot therein, a projection from said operating member having an engaging relation with the contact element to move it out of its normal position into a closed position of the switch, a detent adjacent the operating member arranged to hold the contact element in the closed position of the switch, a pin on said detent lying in said slot, a thermostatic element adapted on heating to trip the detent moving said detent pin across the width of the slot and releasing the contact element, said element engaging the pin of the operating member to move the latter to its off position, the length of the slot permitting the motion of the operating member past the pin of the detent.

8. In a device of the class described, a thermostatic switch comprising, in combination, a casing, a shaft in said casing, a contact element pivoted on said shaft, means normally tending to move said element into an 0 en position of the switch, an operating mem ber on said shaft freely rotatable to on and off positions, said member having a wide and long slot therein, a projection from said operating member having an engaging relation with the contact element to move it out of its normal position into a closed position of the switch, a detent adjacent the operating member arranged to hold the contact element in the closed position of the switch, a pin on said detent lying in said slot, a thermostatic'elementadapted on heating to trip the detent moving said detent pin across the width of the slot and releasing the contact element, said element engaging the pin of the operating member to move the latter to itsoff position, the length of the slot permitting.

,the motion of the operating member past the pm of the detent, said slot being somewhat,

the contact element in a position for closing the switch, an oper ting element movable to on and foflf posi ions, said member in moving to its on position being arranged to move the contact element to close the switch, and in moving to the off position to release the detent to open the switch, and other means operable in the on position of the operating member to release the detent, thereby permitting return of the contact element to normal position, said contact element on return engaging the operating member to move it to the off position.

In testimony whereof, I have hereunto affixed my signature.

CHARLOTTE ARNESEN.

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