US 3708649 A
A control for an electrical appliance such as an electric blanket which is integrally formed with the blanket such that the temperature of the blanket may be controlled by the user without using conventional controls requiring electrical leads extending from the blanket to a control placed on a night stand. The control of the present invention is small and of light weight and does not interfere with the comfort of the user and is always handy for adjustment by the user. The control has waterproof seals so that the blanket may be washed or dry-cleaned without damaging the control and in a modified form the control is detachable connected to the blanket so that it may be removed for washing or dry-cleaning of the blanket.
Description (OCR text may contain errors)
United States Patent 91 [111 3,708,649 1 Jan. 2, 1973 Crowley et al.
 AUTOMATIC BLANKET INTEGRAL CONTROL  Inventors: George C. Crowley, Winnetka; Allen V. Berenson, Chicago, both of Ill.
[7 3 Assignee: Northern Electric Company,
 Filed: March 22, 1971  Appl. No.: 126,464
 US. Cl ..219/2l2, 219/529  Int. Cl. ..H05b l/00  Field of Search ..2l9/24, 212, 487, 528, 529, 219/549; 128/379, 402
 References Cited UNITED STATES PATENTS 2,508,101 5/1950 Crowley ..2l9/529 3,437,792 4/1969 Lauck ..2l9/2l2 X 2,215,042 9/1940 Howard et al.... ..2l9/529 2,588,926 3/1952 Holmes ..219/487 X 2,537,376 l/l951 Smith ..219/212 2,866,072 12/1958 Smith ....219/212 X 3 ,422,244 1/1969 Lauck "219/212 Primary Examiner-C. L. Albritton Attorney-Hill, Sherman, Meroni, Gross & Simpson [5 7] ABSTRACT A control for an electrical appliance such as an electric blanket which is integrally formed with the blanket such that the temperature of the blanket may be controlled by the user without using conventional controls requiring electrical leads extending from the blanket to a control placed on a night stand. The control of the present invention is small and of light weight and does not interfere with the comfort of the user and is always handy for adjustment by the user. The control has waterproof seals so that the blanket may be washed or dry-cleaned without damaging the control and in a modified form the control is detachable connected to the blanket so that it may be removed for washing or dry-cleaning of the blanket.
4 Claims, 7 Drawing Figures AUTOMATIC BLANKET INTEGRAL CONTROL BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to electric blankets and in particular to an integral control mounted in the blanket.
2. Description of the Prior Art Appliances such as electric blankets have used controls that attach to the blanket with electrical leads such that the control may be mounted on a night stand near the bed. The leads running to the control from the blanket require that the user avoid being entangled by the leads as the bed is entered or vacated. Furthermore, as the occupant of the bed turns and tosses the leads to the control may be pulled to cause the control to fall to the floor or to become entangled with the bed occupant.
SUMMARY OF THE INVENTION Thepresent invention eliminates the remote control of the conventional electric blanket in that the control is integrally formed with the blanket at a convenient location so that it is readily available to the user. The control may be mounted in one of the upper corners of the blanket, for example. Some double blankets require two controls and a pair of integral controls may be formed in the blanket and mounted in the upper portions where they are readily available to the user. The elimination of the extension cords between the blanket and the control provides a more compact, comfortable unit and removes the obstruction of the extension cord required in conventional electric blankets. The integral control of the invention may be permanently attached to the blanket and may be provided with an O-ring seal about the temperature regulating shaft so that the blanket may be washed or dry-cleaned with the control in place. A modified form of the invention provides a detachable control that may be removed for washing and dry-cleaning of the blanket.
Other objects, features and advantages of the invention will be readily apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of an electric blanket with the control of this invention mounted therein;
FIG. 2 is a partially cut-away and sectional view taken through the control;
FIG. 3 is a sectional view of the control of the tion;
FIG. 4 is a partially cut-away view of a modification of the invention;
FIG. 5 is a plan view of the connecter plate of the modified form of the invention; a
FIG. 6 is a sectional viewof a modification of the invention; and
FIG. 7 is a plan view of the control of the embodiment shown in FIG. 6.
inven- DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates an electric blanket designated generally as 10 according to this invention. The blanket has a fabric portion II which is formed in two layers as shown in the sectional view of FIG. 2 with a top layer 11a and a bottom layer 11b. Heating element 12 is mounted between the the top and lower layers 11a and 11b, respectively. A plurality of thermostats l3a-l3h are mounted in the heating'element 12 at various locations so as to prevent local overheating in the blanket. The integral control of the invention designated generally as 14 is mounted in the blanket as for example adjacent a corner as shown in FIG. 1. The integral control 14in addition to eliminating the need for a control attached to the blanket with an extension cord also replaces one of the thennostats which would normally be mounted in the portion of the blanket where the present invention is mounted.
A power plug 18 is connected to the heating element 12 by leads 22 and 23 and has connecting terminals 19 and 21 that are adapted to be received in' a plug of a power cord that may be connected to a suitable power source as for example 1 I0 volts. It is to be realized that the plug 18 may be mounted near the portion of the blanket which is received over the foot of the bed so that the power cord which attaches'to the plug 18 is not in the way of the occupant of the bed. As a matter of fact, the power cord may pass from the foot of the bed under the bed to a power plug near the head of the bed.
The lead 22 from the plug 18 connects to the heating element 12 and the lead 23 of the plug 18 connects to the control 14 through the thermostat 13c. Lead 24 connects to the control 14 and provides power for an indicating light window 16 that might be a small neon bulb. The control 14 has an on-off switch and temperature regulating knob 15. The top of the control 14 is designated by numeral l7.
FIGS. 2 and 3 illustrate the control 14 in section. It is to be noted that the lower layer 11b of the blanket is continuous beneath the control 14 and the upper layer Ila is formed with a generally rectangular opening and the control 14 is received in the opening and attaches to the upper layer Ila about the opening. In FIG. 2 it is seen that the top 17 of the control is attached to a flange 27 which bears against the layer 11a and a bottom portion 51 of the control is formed with a flange 26 and an upwardly extending portion 28 which is received within the downwardly extending portion 50 of the top member 17 and is sealed thereto. The flanges 27 and 26 clamp the edge of the upper layer 1 la of the blanket to lock the control 14 to the blanket.
The conductors 23, 24 and 20 pass through openings formed in the lower portion 51 and into the confines of the control as shown. It is to be realized that the heating elements and the conductors 23, 24 and 20 lie between the upper and lower layers 11a and 11b of the blanket. As shown in FIG. 3, the knob 15 is supported on a shaft 36 which passes through a sleeve 31 formed with a groove 32 in which an O-ring seal 33 is mounted so as to provide a liquid seal to prevent liquid from passing through the sleeve about the shaft 36. .A cam 37 is mounted on the lower end of the shaft 36 and engages a bi-metallic strip 46 which has one end attached to a suitable support connected to the housing of the control and carries a contact 48 on a free end thereof. A mating contact 49 is connected to the bottom 51 of the housing and conductor 20 is connected to the contact 49. Conductor 24 passes through the lower portion 51 of the housing and is connected to an indicator light 41 mounted to the upper portion 17 of the housing. The other side of the indicator light socket is connected to a lead 42 which is connected to an on-off switch 39 that has an actuating button 44 engageable with a projection 38 connected to the cam 37. The other side of the on-off switch 39 is connected to the bi-metallic strip 46. Lead 25 which is connected through the thermostat l3e to lead 23 is connected to the bi-metallic strip 46.
In operation, power is applied to plug 18 through terminals 19 and 21 by suitable extension cord (not shown) and the blanket may be turned on by moving the knob so that the projection 38 of cam 37 moves out of engagement with the projection 44 of switch 39. The contact 48 engages the contact 49 when the blanket is cool and has been off so power will be applied to the heating element 12 through the power leads 25 and through the contacts 48 and 49 of the bi-metallic switch. The indicator light will be visible through the transparent window 16 and will be on when the power is applied to the blanket and the switch 39 is closed. Current will flow through the indicator bulb to the lead 24 and through the switch 39 to the power lead 25. The indicator 16 will be on at all times except when the projection 38 opens the switch 39 by engaging the switch actuator 44. The heating element 12 will be cycled on and off in response to the action of the bi-metallic strip 46 which when heated moves the contact 48 out of engagement with contact 49. The temperature of the blanket is controlled by the position of the cam 37 which controls the position of the bi-metallic strip 46. Thus, by moving the knob 15 the blanket may be set at high, low or medium temperature settings.
The integral control of this invention eliminates one or more of the protective thermostats installed in the blanket because it monitors the temperature of the blanket at a location where a thermostat would normally be installed in a conventional blanket having a control attached with an extension cord. Thus, at least one of the thermostats is eliminated with the present invention.
FIGS. 4 and 5 illustrate a modification of the invention which allows integral controls to be detachably removed from the blanket as for example during washing or dry-cleaning. A generally rectangular plate of insulating material 55 is attached to the upper layer 11a of the blanket by suitable brads 52 and 53. Female connecters 54, 56 and 57 are mounted in the plate 55 and receive leads 20, 24 and which are mounted between the upper and lower layers 11a and 111;, respectively. The control 58 of the invention is formed with a flange 61 and has a lower plate 69 in which snaps 62 and 63 are mounted which may be detachably connected to the upper ends of the rivets 52 and 53. The upper ends of the rivets may comprise male snap members which snap into the female snap members 62 and 63. The control 58 also has male contacts 64, 66 and 67 which are receivable in the female contacts 54, 56 and 57 of the plate 51.
The internal structure of the control 58 may be the same as the internal structure of the control illustrated in FIGS. 2 and 3 with male contact 67 electrically connected to one contact of the bi-metallic control and contact 66 connected to the other contact of the bimetallic control and to the on-off switch and with con tac\t 64 connected to the indicator light 59 of the contro The control .58 may be removed from the blanket when it is desired to wash or dry-clean the blanket by merely pulling upwardly relative to FIG. 4 so that the female snaps 62 and 63 disengage the upper ends of the members 52 and 53. The electrical contacts 64, 66 and 67 move out of their mating sockets 54, 56, and 57. After washing or dry-cleaning has occurred, the control 58 may be reconnected to the blanket by merely inserting the contacts 64, 66 and 67 into their mating sockets and snapping the snaps 62 and 63 onto the upper ends of the members 52 and 53.
The control illustrated in FIGS. 2 and 3 need not be removed during washing or dry-cleaning because the O-ring seal 33 prevents liquid from passing intothe control as it is laundered or dry-cleaned.
The controls of this invention-may be small and thin so that they do not interfere with the comfort of the user. The user may turn the blanket on or off with the knob 15 at any time by merely rotating the knob 15 until the desired temperature is obtained. The indicator 16 indicates if the blanket is on at all times.
In the blanket illustrated in FIG. 1, only a single COI'I' trol and a single heating element is illustrated but it is to be realized that in certain double bed blankets it is desirable to have two controls so that each user may control his side of the blanket. Such blankets have two heating elements and it is to be realized that a pair of controls according to this invention may be installed in the blanket with one control in each heating element so as to individually control the heating elements.
FIGS. 6 and 7 illustrate a further modification of the invention wherein the control may be removed from the blanket. A generally rectangular-shaped member is mounted between upper and lower blanket layers 11a and 11b. Opening 81 is formed in member 80 at one end thereof and an aligned opening 82 is formed in upper blanket layer 11a and conductors 20', 24 and 25 extend therethrough.
A U-shaped member 83 has end portions 84 and86 and fits over the top blanket layer 11a and locks into the rectangular member 80.
An electrical female socket 87 is attached to portion 86 and conductors 20, 24 and 25 are connected thereto.
The removable control 88 is rectangularly shaped and has three male prongs 89, 90 and 91 that mate with the female socket 87.
A notch 92 is formed in the other end of control member 88 and portion 84 has a lip 93 which is receivable within the notch 92. A spring 98 biases the control away from member 83. The upper end 94 of portion 84 extends above the blanket layer 11a for a distance sufficient to allow an operator to engage it with his thumb and unlock the control 88 from the member 83.
The control 88 has an on-off and thermostat setting knob 96. A window 97 provides light to index the knob In use, the member 88 is inserted into the member 83 with the prongs 89, 90 and 91 in engagement with the socket 87 and thus are connected to leads 20, 24 and 25. The lip 93 engages notch 92 to hold the control in place.
The control may then be used to control the heating element of the blanket. When it is desired to remove the control, the end 94 is moved so that the lip 93 is removed from notch 92 and the control is lifted from the blanket.
It can be seen that this invention provides new and novel integral control and eliminates the conventional controls of the prior art which were connected to the blanket by an extension cord.
Although the invention has been described with respect to preferred embodiments it is not to be so limited as changes and modifications may be made therein which are within the full intended scope as defined by the appended claims.
1. An electrical appliance comprising:
an electric blanket formed having two layers with a heating element mounted therebetween;
a control for said heating element attached to one of said two layers of said blanket, said one layer formed with an opening;
a outer portion of said control having a downwardly extending portion and formed with a flange which bears against the outer surface of said one layer about said opening;
an inner portion of said control mounted between the other of said two layers and said outer portion of saidcontrol and formed with an upwardly extending portion which is received in said downwardly extending portion of said outer portion and sealed thereto;
said inner portion formed with a flange which bears against the inner surface of said one layer about said opening so that said outer and inner portions clamp said control to said one layer;
a temperature control shaft rotatably supported by said outer portion;
an O-ring seal between said control shaft and said outer portion to provide a seal;
a cam formed with a projection mounted on said control shaft within said control;
a bi-metallic temperature responsive switch in said control and engageable with said cam;
an on-off switch mounted in said control and engageable with said projection; and
said heating element electrically connected to said on-off switch and said bi-metallic switch.
2. An electrical appliance according to claim 1 including a recess formed between said shaft and said control means and said O-ring mounted in said recess.
3. An electrical appliance according to claim 1 including an indicator mounted in said outer portion and connected to said on-off switch and said bi-metallic switch within said control. I
4. An electrical appliance according to claim 1 comprising a control knob mounted on said control shaft.