US3626151A

US3626151A - Protector shield

Info

Publication number: US3626151A
Application number: US80908A
Authority: US
Inventors: Edward G Them; Bernard S Deubel
Original assignee: Therm O Disc Inc
Current assignee: Therm O Disc Inc
Priority date: 1970-10-15
Filing date: 1970-10-15
Publication date: 1971-12-07
Anticipated expiration: 1988-12-07

Abstract

A protective shield for the terminals of thermostats mounted on water heaters is disclosed. The shield is formed of heavy fish paper shaped to provide access to the thermostat controls while preventing accidental contact with the terminals and connecting leads. Mounting portions are provided on the shield for removably mounting the shield in place.

Description

United States Patent Inventors Edward G. Them; [56] References Cited A l N 33218:! S. Deubel, both of Mansfield, Ohio UNITED STATES PATENTS 'ff 15 1970 2,862,997 l2/l958 Veitch et al. 174/138 F Patented 7 1 3,435,189 3/1969 Manecke 2l9/330X Assignee Therm-O-DIsc Incorporated Primary Examiner-C. L. Albritton Mansfield, Ohio Attorney-McNenny, F arrington, Pearne and Gordon PROTECTOR SHIELD ABSTRACT: A protective shield for the terminals of therl0 Claims, 5 Drawing Figs. mostats mounted on water heaters is disclosed. The shield is U s 219 I328 formed of heavy fish paper shaped to provide access to the F 219/336 thermostat controls while preventing accidental contact with Int Cl 1' 1 1/00 the terminals and connecting leads. Mounting portions are i 952L330 provided on the shield forremovably mounting the shield in 31o-a12,321;174/s R, 138 r, 66, 1

*v- I i (r \V f 5 e 1/-.'

' 22 f I 4/ 4a '1 Q 34 8 J3 I 8 3 {7 .56 J I J 1 I i 53 J6 A 1 PROTECTOR SI-IIELD BACKGROUND OF THE INVENTION This invention relates generally to thermostatically controlled heaters and the like and more particularly to a combination of a control thermostat assembly and a removable protective shield which prevents accidental contact with electrically charged terminals and the like.

PRIOR ART Automatic electric water heaters are provided with temperature-sensing thermostats to control the operation of the resistance heaters. Generally, such water heaters include an inner tank in'which the water is heated and stored, thermal insulating material around such tank, and an outer casing en-. closing the tank and thermal insulating material. Usually, the thermostat is mounted against the inner tank in temperature sensing relationship therewith. An access opening is provided in the outer shell adjacent to the thermostat or thermostats which-is normally closed by a removable cover so that access can be obtained to the thermostat for adjusting of the operating temperature of the thermostat. In most instances, a highlimit thermostat of the manual reset type is also provided and access to such thermostat for resetting is also provided through the opening in the outer shell.

The thermostats are normally connected to the heaters and to the electrical supply by lead wires secured to terminals on the thermostats. Consequently, exposed wiring is located at a position substantially adjacent to the reset mechanism and the temperature-adjusting mechanism. Because the exposed wiring is adjacent to the'thermostat control mechanisms, there is a possibility of accidental contact with the exposed and charged wiring when the user either resets the thermostats or adjusts the operating temperatures thereof.

SUMMARY OF THE INVENTION The present invention is directed to a combination of a thermostat having operating controls and exposed terminals substantially adjacent thereto and a removable protective shield which limits access to the exposed wiring while providing access for the control of the thermostat. Such protective shield therefore, prevents accidental contact with the exposed wiring, but is removable to permit access thereto when the thermostat must be serviced or replaced.

The illustrated embodiments of this invention include a pair of thermostats of the type used to control the operation of an automatic electric water heater. One of the thermostats in the illustrated embodiment is a manual reset high-limit control thermostat and the other is a temperature-controlling thermostat which is manually adjustable. A protective shield formed of heavy fish paper or the like, which is relatively stiff but can be bent to a limited extent, is removably mounted on the thermostat in a position to prevent accidental contact with the exposed terminals and connecting lead wires while still providing access to the two thermostats for resetting or temperature ad- BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a typical electric hot water heater illustrating the mounting of thermostats thereon and the connection of the thermostats to the heater elements;

FIG. 2 is a view similar to FIG. I with the protective shield, in accordance with this invention, in place;

FIG. 2a is an enlarged view of the protective shield before installation;

FIG. 3 is a fragmentary perspective view of another typical installation of a thermostat and heaters on an electric hot water tank with another embodiment of a protective shield, in accordance with this invention, mounted thereon; and

FIG. 3a is an enlarged view of the protective shield illustrated in FIG. 3.

DETAILED. DESCRIPTION OF THE DRAWINGS Referring to FIGS. 1 through 3, a typical electric water heater includes an inner tank l0 surrounded by thermal insulation 11 which is, in turn, enclosed within an outer case 12. An access opening 28 is provided in the outer case. Mounted on the inner tank 10, within the access opening, are one or more resistance-type electric heaters 13 which operate to heat the water within the tank 10 when supplied with electrical power. Automatic temperature control is provided by a pair of thermostats l6 and 17. In the illustrated embodiment, the upper thermostat 16 is a high-limit thermostat of the manual reset type, and the lower thermostat 17 is the temperaturecontrolling thermostat. The high-limit thermostat 16 does not operate under normal conditions, but opens to shut off the heaters 13 whenever excessive temperatures are encountered. Such thermostat is of the manual reset type wherein the thermostat switch remains open until the thermostat is manually reset by pressing the reset button 18.

The lower thermostat I7 is the thermostat which controls the operation of heaters 13 in normal operation of the water heater. Such thermostat is manually adjustable to a desired temperature by turning an adjustment element 19. Once adjusted, the thermostat turns the heaters 13 on and off to maintain the desired water temperature. Thermostats of the type illustrated are disclosed in the US. Pat. No. Des. 203,945.

Each of the thermostats is provided with terminals 21 for connection to power leads. These terminals are in the forward faces of the thermostats so that they are easily accessible for connecting and disconnecting the leads during installation and servicing of the system. However, such terminals, since they are adjacentto the reset button 18 and the adjusting element 19, are susceptible to accidental contact when the thermostat 16 is reset or the thermostat I7 is adjusted.

In the illustrated embodiment, the two leads 22 and 23 connect the high-limit thermostat 16 to a source of power. The

leads

24 and 26 connect the thermostat assembly to the terminals 27 of the heaters 13; Aremovable cover (not illustrated) is normally mounted over the opening 28 and is removed when access is required to the thermostats or the heaters.

FIG. 2 illustrates the same electric water heater with a protective shield 31 in place. The protective shield is preferably formed of a relatively stiff sheet material which is electrically insulating in character such as l/32-inch-thick fish paper. Such paper is sufficiently flexible, however, to permit the shield to be slipped into place and to be removed when necessary for servicing of the thermostats or heaters.

The shield includes a main body portion 32 formed with an opening 33 therein proportioned to closely fit around the reset projection 34. Also, the main body portion is also formed with an opening 36 positioned over the adjusting element 19 and providing access thereto when the shield is in place. A laterally projecting portion 37 is proportioned to cover the heaters 13 and extends at its end 38 under the outer case 12 adjacent to the opening 28. Because of the cylindrical shape of the tank 10 and case 12, the lateral projection 37 tends to assume a curved shape when the shield is mounted in position.

In order to secure the shield to the thermostats l6 and 17, the shield is formed with spaced mounting

portions

41 and 42. The mounting portion 41 is formed by two

cuts

43 and 44 and is provided with a hinge line 46 so that it can bend back from the plane of the shield. The hinge line is provided by scoring the shield material with a shallow cut partially through the material from the forward face. The cut 43 is shaped so that the mounting portion 41 provides a lateral extension 47 which fits behind the lead 22 and engages the backside thereof, as illustrated in FIG. 2. Adjacent to the mounting portion 41 is a projection 48 which extends up behind the outer shell 12.

The lower mounting portion. 42 is formed along the lower edge of the opening 36. This mounting portion has a semicircular recess 51 shaped to fit against the shaft 52 on which the adjusting element 19 is mounted.

Projections

53 and 54 are provided on each side of the groove 51 to extend behind the adjusting element 19 to hold the lower section of the shield substantially against the adjacent surface 56 of the thermostat 17. A notch 57 is provided to receive the stop pin 58.

The two mounting

portions

41 and 42, because they engage rearwardly facing surfaces on this thermostat assembly, securely hold the shield 31 against the forward face of the thermostats. These portions, in cooperation with the engagement between the edge of the opening 33 and the reset projection 34, provide exact proper location of the shield with respect to the thermostats. Consequently, access to the reset button 18 and the adjustment element 19 is insured.

The shield is installed by inserting the projection 37 behind the outer case 12 with the main portion 31 slightly below the ultimate mounting position. The shield is moved upwardly while holding the mounting portion 42 back against the thermostat until the

projections

53 and 54 are properly positioned behind the adjusting element 19. The projection 48 is preferably positioned behind the outer case 12 by this movement. As soon as the lower mounting portion 42 properly engages the adjusting element, the opening 33 is in proper registry to slip down over the reset projection 34. The upper mounting portion is then bent back and positioned behind the lead wire22 to complete the mounting of the shield. When the shield is in position, accidental contact with any of the terminals is prevented. However, in the event that servicing of the heaters or the thermostats is required, the shield is easily removed to provide full access. After the servicing is completed, the shield is replaced in the same manner as it is originally installed. The material forming the shield should be sufficiently heat resistant and resistant to moisture or the like to prevent its deterioration in use;

FIGS. 3 and 3a illustrate a second embodiment of this invention wherein the physical arrangement of the mounting of the thermostats and the heaters on the water heater is different than illustrated in FIG. 1. in this embodiment, similar reference numerals will be utilized to designate similar parts with a prime added to indicate that reference is being made to the second embodiment. The high-limit thermostat 16 and the temperature controlling thermostat 17' are again mounted within an access opening 28 in the outer case 12' of the water heater. in this instance, however. the electric heaters 13' are mounted on the inner tank directly below the thermostats. The protective shield 31' is again formed with an upper mounting portion 41 having the same shape as the mounting portion in the first embodiment, and a lower mounting portion 42' proportioned to fit behind the adjusting element 19'. The mounting of the shield against the thermostats 16 and 17 is exactly the same as in the first embodiment. However, in this instance, the shield is provided with a downwardly extending projection 61' which extends over the heaters 13' and under the outer case 12 at its lower end. The upper projection 48' also extends up under the outer case 12'.

The principal difference between this embodiment and the first embodiment is that the downwardly projection portion 61' is utilized to cover the heaters 13' and the leads connected thereto, instead of the lateral projecting portion 37.

With a protective shield incorporating the present invention a low-cost device is provided which is easily installed to protect the user against accidental contact with terminals and connected leads while providing access for operating the thermostats. The protective shield, however, is easily removed when access to the thermostats or heaters is required for servicing. After servicing, the shield can be replaced. Since the shield is accurately located with respect to the thermostats, the access for controlling the operation of the thermostats is insured.

in both embodiments the reset button projection 34 provides opposed surfaces which are engaged to accurately locate the upper end of the shield. Similarly, the

projections

53 and 54 and the notch 57 engage opposite sides of the shaft 52 and the pin 57, respectively, and cooperate with the reset button 34 to position the lower end of the shield. Because the notch 57 extends below the lower edge of the opening 36, the shield will not fit into place unless it is properly aligned with the thermostat assembly.

Although the shield incorporating this invention is illustrated in use in a typical electric water heater, it is equally useful for protecting the terminals of thermostats or the like in other thermostatically controlled, temperature changing devices.

Although preferred embodiments of this invention are illustrated, it is to be understood that various modifications and rearrangements of parts may be resorted to without departing from the scope of the invention disclosed and claimed herein.

What is claimed is:

1. A temperature-controlling system comprising a device having electrically controlled temperature changing means, thermostat means mounted on said device having a forward face, control means on said forward face, said thermostat means also including terminal means accessible from said forward face and lead wires connecting some of said terminals to said temperature changing means for controlling the operation thereof, said thermostat means providing at least two spaced surfaces facing in a direction opposite said forward face, and a protective shield removably mounted against said forward face formed of a relatively stiff bendable electrical insulating material, said shield providing; a portion covering said terminals and the connections thereof to said lead wire for limiting access thereto, opening means providing access to said control means, and mounting portions engaging said spaced surfaces operating to secure said shield in position against said forward face.

2. A temperature-controlling system as set forth in claim 1 wherein said thermostat means provides opposed surfaces extending substantially normal to said forward face, and said shield engages said opposed surfaces to provide location thereof with respect to said forward face.

' 3. A temperature-controlling system as set forth in claim 2 wherein at least one of said operating means is located on a boss projecting from said forward face, said boss providing said opposed surfaces, said opening means closely fitting said boss and locating said shield with respect to said forward face.

4. A temperature-controlling system as set forth in claim 3 wherein at least one of said spaced surfaces is provided by a lead wire.

5. A temperature-controlling system as set forth in claim 4 wherein said device is an electric water heater, said temperature changing means is an electric resistance heater controlled by said thermostat means located substantially adjacent to said thermostat means, said resistance heater having a heater terminal connected to a lead wire, and said shield provides an extension extending over said heater terminal and limiting access thereto.

6. A temperature-controlling system as set forth in claim 5 wherein said water heater is provided with an outer shell, and the end of said extension extends under said outer shell.

7. A temperature-controlling system as set forth in claim 6 wherein said thermostat means includes an adjustable thermostat and a manual reset high-limit thermostat, said control means includes temperature adjusting means on said adjustable thermostat and reset means on said high-limit thermostat spaced from said adjusting means, and said opening means includes separate openings for said adjusting means and said reset means.

8. A temperature-controlling system as set forth in claim 7 wherein said adjusting means provides another of said spaced surfaces.

tension extending over said heater terminal and limiting access thereto.

10. A temperature-controlling system as set forth in claim 9 wherein said water heater is provided with an outer shell, and the end of said extension extends under said outer shell.

ll 'l i

Claims

3. A temperature-controlling system as set forth in claim 2 wherein at least one of said operating means is located on a boss projecting from said forward face, said boss providing said opposed surfaces, said opening means closely fitting said boss and loCating said shield with respect to said forward face.

9. A temperature-controlling system as set forth in claim 1 wherein said device is an electric water heater, said temperature changing means is an electric resistance heater controlled by said thermostat means located substantially adjacent to said thermostat means, said resistance heater having a heater terminal connected to a lead wire, said shield providing an extension extending over said heater terminal and limiting access thereto.