US1627875A - Electric water heater - Google Patents

Description

May 10, 1927. 7,875

J. J. UNDERWOOD ELECTRIC WATER HEATER Filed M12. 20, 1925 NIH:

Ill

Patented May 10, 1927.

UNITED STATES PATENT OFFICE.

31583 J'. UNDEBWOOD, OF TACOMA, WASHINGTON, AS SIGNOR 0F ONE-HALF TO JOSEPH B. ANTONETTE, 0F TACOMA, WASHINGTON.

nnncrmc WATER HEATER.

Application filed August 20, 1925, Serial No. 51,358.

This invention relates to devices for electrically heating service water and especially to that class adapted for domestic use in heating the water in the hot water tank. The invention further relates to that class of electric water heaters wherein the heating element is immersed in the water being heated.

The objects of this invention are to improve the construction of such a heater whereby, first, the heating element may be withdrawn from the device without, in any way, disturbing the plumbing thereof; second, the base of the water heating chamber is removable therefrom without disturbing the plumbing thereof; third, said base fixedly supports the heating element within t e heating chamber; and fourth, the electr c 'unction box is integral with the heater base.

urther objects are to improve the means of connecting the electric heating wire to thebinding osts whereby a cheap, efiicient and yet readily renewed electric connection is made; to improve the means of supporting the heating element from. the base whereby said element is held in rigid position in the heating chamber; to improve the construction of the insulating supporting means whereby no portion thereof is permitted to become overheated; to provide a novel means for attachin the heatin wire to the supporting insu ating body w ereb the heating wire is kept taut and is not al owed to sag thereon, and whereby the wires connecting the ends of said heating wire with the'respective binding posts are relieved of strain; and to improve the means for passing the electric current into the water chamber" without permitting leakage of the water therefrom. Another object is to provide an electric water heater which is simple and cheap to make, easily repaired, and 'eflicient in use.

I attain these and other objects by the devices, mechanisms, and arrangements illustrated in the accompanying drawings, in

,which- Fig. 1 is a vertical section of my improved water heater in use; and Fi 2 1s an elevation of the base and heatm element removed from the water cham er. Similar numerals of reference refer to similar parts throughout the several views.

Referring to the drawings it will be seen that the heater is constructed in two main parts, the water chamber land the removable base 2.

The water chamber 1 comprises a hollow body of such dimensions as to receive the heater element and a sufficient body of water. It is provided with an inlet passage 3, near its lower edge, into which the cold water pipe 4 is secured, and with an outlet passage 5, at the top, into which the hot water pipe 6 is screwed. ,These ipes 4 and 6, respectively, lead from and to a suitable water supply and tank, or other desired connections with the plumbing system, and an port the chamber. 1 in fixed posltion. readily seen from the drawings, the entire bottom of the chamber 1 is 0 en and is adapted to be closed by means 0 the removable base 2 which is screwed into theo 11 bottom thereof, suitable screw threads b eing formed in the lower end of theliam- The removable base 2 com rises an in chamber. A shoulder 8 is formed outside of. the said extension 7 and a suitable gasket 9 is mounted thereon, said gasket forming awatertight packing between the shoulder Send the lower edge of the water chamber 1 and preventing the leaks e of water from the chamber by means of t e screw threads connecting the two parts. The lower part of the base 2 is open, but'may be closed by a removable plate 10 secured thereto in any desired manner. p

The base 2 supports the heating element on its upper surface while the hollow box formed thereby forms the electric junction box wherein the conducting wires of the electric circuit are connected to the binding posts of the heatin element; said bindin posts passing throng the upper closure wal of said base by means of insulating stufiing boxes. v

Suitable bosses 11 are formed on theupper .wall of the base 2 and project downward into the junction box formed thereby. One of these bosses 11 is ositioned centrallyof said base 2, while t e other is separated therefrom to one side. The central boss forms the stuffing box and su port for the central binding post.12 on w lch the electric element is mounted, as hereinafter described, and to which one end of the said heating element is electrically connected, and the other boss 11 forms the stufiin box for the other binding post 13 to whic the other end of the said electric element is secured. Each boss 11 is bored with a hole 14 slightly larger than the respective binding post passing therethrough. Two pairs of insulatin sleeves 15, of fiber or other suitable insulatmg material, are slip ed over the conducting rods 12 and 13 wit in the hole 14 and a packing material 16, also of insulating material such as rubber or electric tape, is inserted between the two sleeves on such rod and is adapted to be compressed thereby to fill the hole 14 and prevent the leakage of water therepast. Each conductin rod 12 and 13 is provided with an insu ating washer 17 of mica, or other suitable material, and with a collar 18 engaging the said mica washer; said Washer 17 and collar 18 being on the side of the said stuiiingbox which is inside the water chamber 1. The ends of said conducting rods 12 and 13 which project through the stufiing boxes and into the junction box are screw-threaded and provided with mica insulation and washers and with two nuts 19 and 20. The nuts 19 are adapted to draw the respective rods tight against the top of the base 2 and to compress the packing 16, while the nuts 20 are adapted to clamp the respective electric conducting wires 21 to the said rods. The cable containing the wires 21 enters the junction box through a suitable insulated passa e. 22.

The central binding post 12 exten s a considerable distance fromthe base 2 into the water chamber 1 and supports the two concentric insulators 23 and 24. thereon, the insulator 23 being positioned inside the insulator 24 and'having an axial hole of larger diameter than the post 12. The central hole of the outer insiiator 24 is larger than the outside diameter of the insulator 23. Thus there is free space around the post 12 and between theitwo insulators for the circula zi tion of water, whereby all the several parts I are kept from excessive heat and therefore insured against breakage from this cause. The outer insulator 24 is provided with a groove 25 around it, near its u per end, and with a similar groove 26 near its lower end. A fastening wire 27 is tightly bound around the insulator '24,,within the groove 25 and is led therefrom 'to the binding post 12 to which it is secured. A similar wire 28 is tightly boundaround the lower end of said -to insure its holdin supported; a remova insulator 24 within the groove 26, and is'led therefrom to the binding a 13 to which it is secured. The above escribed wires 27 and 28 are secured to the respective bindin posts 12 and 13 by cutting a slit in the en of said binding post, inserting the wire therein and bending the sides of said slit end of the binding post together to clamp the said wire therein. Thus it will be seen that the said insulators 23'and 24 are\ firmly held in position by the binding posts 12 and 173 and by the wires 27 and 28 leading therefrom The heating wire 29 is preferabl first wound into a long helical spring 0 small diameter and then one end is attached to the said upper wire 27, above described, and the wire is coiled, helically, around the outside of the insulator 24, under suflicient tension itself in lace, and the other end is similar y attached to the lower supportin wire 28. Thus it will be seen that the internal tension on the wire 29, necessary for it to have in order to properly maintain its position on the insulator, is carried by the wires 27 and 28 where they are bound around the insulator and is not carried to the binding sts.

It will therefore e clear that, when it is desired to take the heating element out of the water for inspection, repair or replacement, it is only necessary to empty the said water chamber of its water, unscrew the base 2, and remove all the parts therewith, without disturbing the pipes 4 and 6 which hold the water chamber in position and connect it to the plumbing system: also, that, when so removed, it is a simple matter to remove the heating wire 29 and to replace it with a new wire, by simply disconnecting it with the wires 27 and 28; or the insulators may be removed by prying open the closed. slits in. the binding posts and removing the ends of the wires 27 and 28 therefrom.

Having, therefore, described my invention, whatl claim is An electric water heater com rising a fixed water chamber provided wit connections to the hot water tem, whereby it is 1:1: base closin the lower end of said water chamber an sup ported thereby, said base having a pair of passages therethrou h; a pair of terminals passin through sai passages, one such terminal ing longer than the other, and each provided with a collar within said chamber and with a screw-nut on its outer end; a V

water-tight insu latin packing in each said passage and surroun ing the respective termural, said peeking being compressed within said passage .b" the screw-nut and the collar whereby lea a e terminal is prevented; an inner insulating tube loosely surrounding the longer of said terminals whereby a free passage for water of water around the I is provided between the terminal and its mounted on said outer insulatin tube and insulator; an outer insulating tube loosely connections between the ends 0 Slidiflfilt- I surroundln said inner insulating tube, ing wire and said terminals respectively, 10 whereby a ree "passage for water is provided whereby electric energy may be conducted to 5 between said inner and outer insulating said heating wire.

tubes; a submerged electric heating wire v JESSE J. UNDERWOOD. 1

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