US2993978A

US2993978A - Baseboard heater

Info

Publication number: US2993978A
Application number: US762065A
Authority: US
Inventors: Morris L Markel; Grant Cuthbert
Original assignee: Markel Electric Products Inc
Current assignee: Markel Electric Products Inc
Priority date: 1958-09-19
Filing date: 1958-09-19
Publication date: 1961-07-25
Anticipated expiration: 1978-07-25

Description

July 25, 1961 'M. L. MARKEL ET AL 2,993,978

- BASEBOARD HEATER Filed Sept. 19, 1958 3 Sheets-Sheet 1 5:9 INVENTORS Maw-Q (2. mm 7 g; cum gu nt -69 8- Qfiowveys.

July 25, 1961 M. MARKEL ET AL BASEBOARD HEATER 3 Sheets-Sheet 2 Filed Sept. 19, 1958 INVENTORS C j a W wad W dzlFarww/s,

July 2 1951 M. L. MARKEL ET AL 7 BASEBOARD HEATER Filed Sept. 19, 1958 3 Sheets-Sheet 3 INVENTORS United States Patent 2,993,978 BASEBOARD HEATER Morris L. Markel, Kenmore, and Cuthbert Grant,

Eggertsville, N.Y., assignors to Markel Electric Products, Inc., Buffalo, N.Y., a corporation of New York Filed Sept. '19, 1958, Ser. No. 762,065 7 Claims. (Cl. 219-34) This invention relates to baseboard heaters and more particularly to electrically operated baseboard heaters and heater systems.

The baseboard heater and sy'stem of the invention represents an improvement over similar heaters of the prior art, and among other things, features greater flexibility, So that practically any type of heating pattern can be realized either at the time of original installation or at any time thereafter, thus providing optimum heating conditions for any given room. In addition, the heater system of the invention is extremely easy to install, and requires only one electric entry with a wire-way being built into each baseboard heater component. Another feature of the baseboard heater of the invention relates to the provision of air distribution arrangement whereby balanced air delivery with uniform heat is produced, and with no exposed surface of the heater exceeding 130 F., and in normal operation, never over 30 F. above room temperature. Still another feature is the unique extended surface heating structure and the means employed to mount the heater structures which facilitates installation and eliminates noise of expansion and contraction during heating and cooling.

A primary object of this invention is to provide an electric baseboard heater system that has great flexibility as to the amount and location of heat concentration so that practically any type of heating pattern may be realized to produce optimum heating conditions for any given room.

Another object is to provide such a baseboard heater which is exceptionally sturdy and which will withstand abuse and at the same time can be made and installed at low cost.

Another object is to provide such a heater system which can readily be rearranged to alter the heating pattern at any time and in which the amount of heat delivered by the system can be increased or reduced at any time.

Another object is to provide such a baseboard heater which provides a gentle even heat at floor level for balanced room heating free from cold air pockets or drafts.

Another object of the invention is to provide an electric baseboard heater system that is extremely easy to install, and which requires only one electric entry.

Still another object of this invention is to provide an electric baseboard heater system having a high wattage per lineal foot and a uniform heat distribution pattern, and with no exposed part of the heater exceeding 130 F., or over 30 F. above room temperature.

A further object of the invention is to provide an electric baseboard heater system which eliminates noise of expansion and contraction during heating and cooling.

Another object is to provide such a heating system which is of unconspicuous but pleasing appearance and can readily be fitted into any room, provision being made for corner sections and blank sections for this purpose.

Another object is to provide such a baseboard heater system which is complete in itself by the provision of a thermostat section, as Well as such convenience outlets as may be desired, in the line of heaters.

These and further objects and features of the invention will become more apparent from the following description and accompanying drawings wherein:

FIG. 1 is a perspective view of a room corner illustrating a baseboard heater system embodying the principles of the invention.

2,993,978 Patented July 25, 1961 FIG. 2 is a fragmentary front elevational view, with the cover panel and other parts removed, of a portion of the heater system illustrated in FIG. 1.

FIG. 3 is an enlarged vertical section taken generally on line 33, FIG. 2.

FIGS. 4, 5 and 6 are vertical sections taken generally on line 44, FIG, 2 and showing a baseboard heater in progressive stages of assembly.

FIG. 7 is a fragmentary horizontal section taken generally on line 77, FIG. 2.

FIG. 8 is a fragmentary vertical section taken generally on line 8-8, FIG. 7.

FIG. 9 is a fragmentary horizontal section taken generally on line 9-9, FIG. 2.

FIG. 10 is a perspective view of a baseboard heater unit and corner piece embodying the invention, with parts broken away to disclose the construction,

FIG. 11 is a perspective view of a hot air deflector plate used in the unit shown in FIG. 10.

FIG. 12 is a perspective view of the wireway cover used in the heating unit shown in FIG. 10.

FIG. 13 is a perspective view of the front cover plate used in the heater unit shown in FIG. 10.

FIG. 14 is a perspective view of one of the brackets used in the heater unit shown in FIG. 10, this also shows one of the wire hooks used to support the extended surface heater element,

FIG. 15 is a front elevational view, with parts broken away, of a heater embodying a modified form of the pressent invention.

FIG. 16 is a view similar to FIG. 15 with parts removed to disclose the construction of this modified form of heater.

FIG. 17 is a view similar to FIG, 16 but with the extended fin heating element reversed, end for end.

FIG. 18 is a view similar to FIG. 16 and showing the heater in a position for joint use with the reverse form of heater shown in FIG. 17,

FIG. 19 is a view similar to FIGS. 17 and 18 but showing the two heaters electrically joined together.

FIG. 20 is a view similar to FIG. 19 but with front cover plates and coupling members attached.

FIG. 21 is a vertical section through the extended surface heating structure used with the different forms of the invention.

Referring more particularly to the form of the invention shown in FIGS. 1-14 the numeral 21 refers to a baseboard heater system embodying the principles of the invention and which is arranged in a room 22 along the Walls and near the floor thereof as illustrated in FIG. 1.

The baseboard heater system 21 is shown as including a succession of baseboard heater units indicated generally at 23, a thermostat unit indicated generally at 24, an electric plug or convenience outlet unit 26, and an inside corner section indicated generally at 27. These various components of the system, together with blank units can be in various arrangements to suit the particular conditions encountered in the room and the use of such components as the convenience outlet unit 26 and the thermostat unit 24 is optional, the system being capable of being used, for example, with a conventional wall thermostat (not shown) and the convenience outlet units 26 being included wholly for the convenience in being able to serve floor lamps, vacuum cleaners, and other devices. In its preferred form the current supplied for heating purposes, that is, to the heater units 23 is at a voltage in the order of 240 volts whereas the convenience outlets 26 are supplied with the usual volt current.

Each heater unit 23 includes a horizontally elongated sheet metal housing or back panel 28, a sheet metal wire channel cover 29, having a forwardly projecting front edge 30, a pair of sheet metal support brackets 31, a sheet 3 metal deflector panel 32, a rigid extended surface heater structure 33, and a sheet metal front panel 34. The front panel 34 has its upper and lower horizontal edges bent rearwardly and toward each other, as indicated at 35, to form hookshaped edges providing opposing grooves or shoulders at the rear of the front panel. Thus it will be seen that the upper turned edge 35 provides a downwardly facing shoulder and the lower turned edge 35 provides an upwardly facing shoulder each extending the full length of the heater unit. The back panel 28 has an upper integral hood portion 36 projecting horizontally outwardly from its upper edge and an integral bottom flange or wire support portion 37 projecting horizontally from the lower edge of the back panel in generally parallel relation to the hood portion 36. The outboard edge of the hood portion 36 is reversely bent to form a channel 38 opening toward the back of the back panel, While the outboard edge of the bottom flange or wire support portion 37 is reversely bent to form a similar channel 39.

The back panel 28 is provided at each end with a hole near the bottom thereof to receive fastening means, such as screws 42, for securing the opposite ends of the wire channel cover 29 against the back panel 28, the outer edge 30 of this wire channel cover 29 fitting in the chan- ;nel 39 at the outboard edge of the wire support portion 37. The back panel 28 can be secured to the wall of the room by screws 44 or in any other suitable manner.

The back panel 28 is also provided at each of its ends with .a hole which receives fastening means such as a screw 47 for an electrical ground strap 48, this strap serving to ground the rigid heater structure 33 to its back panel 28. For this purpose each ground strap 48 is suitably aflixed to one of a plurality of fins 49 which provide the .extended surface of the rigid heater structure 33. The back panel 28 as well as the wire channel cover 29 is formed with circular knockouts 51, any one of which can be removed to provide a hole for bringing wires into the wireway 52 provided by the wire channel cover 29 and the bottom of the back plate 28.

The form and purpose of each of the supporting brackets 31 is an important feature of the invention. Each supporting bracket is made of a single piece of sheet metal and is formed to provide a vertical back attaching portion 53 from the top of which a horizontal hood engaging arm 54 projects outwardly. Both the back and top or hood engaging arm of the bracket are preferably grooved to provide a common stiifening rib 55, and an integral vertical flange 56 extends outwardly -from one edge of the attaching portion 53 in the same general'direction as the horizontal hood engaging arm 54. The upper end of the flange 56 is continued to form a supporting arm 58, the outer extremity of which is formed to provide an upstanding hook 59. The bottom of the flange 56 is extended to provide a stop 60. The

bottom of the stop 60 is formed to provide ahorizontal and transversely extending flange or shelf 61 to which a leaf spring 62 is secured. The outer extremity of this leaf spring is formed to provide a yielding book 63 having a downward opening channel for a purpose hereinafter described. The flange 56 is also formed to provide a pair of tabs 64 arranged one above the other adjacent to back 53 and which tabs ser e as stops limiting the movement of the rigid heater structures 33 into the housing or back panel 28.

To secure the heating unit to the bracket, a doubleended wire hook 65 is arranged to hang down from the inboard end of the arm 58 for the support of the corresponding end of the rigid heater structure 33, as hereinafter described, the depending part of this hook being formed to provide an upwardly directed hookshaped end 66 for this purpose.

The back attaching portion 53 of each bracket 31 has a hole 67 adapted to receive a screw 67' which secures each bracket to the back panel 28. The upper horizontal hood engaging arm 54 hooks into the channel 38 of the 4 hood 36 so that only one screw 67' is required to secure each bracket 31 to the back panel 28. Conversely, the hood engaging arm 54 supports and strengthens the hood 36.

The back attaching portion 53 of each bracket is also provided near its upper end with a hole 68 for receipt of a screw 68' for securing the deflector panel 32 to each pair of brackets 31 immediately beneath the hood portion 36.

The rigid extended surface heater structure 33 includes the metal fins or plates 49 arranged in spaced parallel relation to one another and each brazed to a pair of rigid heater tubes 69. While these fins can be of any suitable form, for this purpose each fin is shown as provided with a pair of parallel horizontal slots 70 extending inwardly from the rear vertical edge thereof, the inner end of each slot being offset to provide an integral boss or flange 71. The metal heater tubes 69 are passed through the slots 70 into engagement with these offset bosses or flanges 71 and hence these offset bosses or flanges 71 provide extended contract area between each fin and the tubes. The fins are brazed to the tubes.

The heater element tubes 69 are of the electrical range type which have an internal electrical resistor 72 which is completely sheathed in a body 73 of magnesium oxide, or other electrical insulating material, which is introduced into each tube 69 as a powder cement which sets to provide the rigid body 73. Each end of each tube is provided with a low resistance electrical terminal 74 projecting axially from the body 73 of insulation and to which the electrical connections to the resistance heating element 72 are made.

The rigid heater structures 33 are coupled in parallel with one another and in the installation shown in series with the thermostat unit 24. To this end the two terminals 74 at one end of each rigid heater structure 33 are electrically connected by a conductor 75, FIG. 2, preferably welded to these terminals. These terminals 74 so connected by the conductor 75 are preferably housed within a two-part ceramic case 76 of any suitable design. The opposite terminals 74 of each heating element are severally electrically connected by metal clips or electrical connectors 78 with buss bars 79 mounted on a ceramic base 80. These electrical connectors are in line with the terminals 74 so that the terminals can be moved lengthwise into these connectors which are then tightened. The base 80 is provided with a protective cover 81 and wires 82 can be secured to the buss bars 79 which lead to the next succeeding baseboard heating unit 23 for the purpose of connecting the two heating units in parallel. These wires 82 are shown as passing through a hole provided by the removal of the adjacent knockout 51 and as extending along the wireway 52 to the next succeeding baseboard heading unit 23. These wires 82 are also shown as passing through the inside corner section 27 as hereinafter described. A pair of supply wires 83 are also shown as connected to the two buss bars 79 and as extending through the same hole to the wireway 52. These supply wires 83, however, are shown as leading to the thermostat unit 24.

This thermostat unit is shown as comprising a boxlike metal casing 85 of any suitable form, a cover 86 which preferably conforms to the exterior of the hood 36, bottom flange 37 and front plate 34 of the adjacent heater unit 23, and a ceramic block 88. To secure the thermostat unit in place the metal case 85 has ears 89 struck out from its end walls and which ears are arranged against the back or housing panel 28 of the adjacent heater units 23. These cars can be secured by self-tapping screws 90 or the like to the housing panels 28.

The ceramic block 88 of the thermostat unit carries a pair of buss bars 91 to which the supply wires 83 to the heating system are connected, FIG. 2, showing the thermostat unit 24 as serving a pair of heater units 23 at each side thereof. The buss bars '91 are supplied with current through a thermostat 92 under control of a bulb 92 which can be located at the air inlet side of the next heater unit 23 as illustrated in FIG. 2. The thermostat 92 is adjusted by means of a knob 93 projecting from the front face of the cover 86. The supply wires 94 to this thermostat connect with the 240 volt wiring system for the house.

120 volt wires 95 are also brought into the system along with the 240 volt Wires 94, as illustrated in FIG. 2. These 120 volt wires are shown as passing directly to a convenience outlet unit 26 in FIGS. 1, 2 and 9.

Each of these convenience outlet units 26 is shown as including a box-like casing 96. A cover 98 conforming to the cover 86 of the thermostat unit is provided for the casing 96, and a Bakelite block 99 is suitably secured within the box-like casing 96 and has a pair of electrical sockets 100 projecting through the cover 98 in the conventional manner. The box-like casing 96 can be secured in the same manner as the box-like casing 85 for the thermostat unit, that is, it can be provided with ears 101 stuck outwardly from its end wall and secured by self tapping screw 102 to the back of the housing panel 28 of the adjacent baseboard heater unit 23. The 120 volt wires 95 connect to suitable terminals 103 at the bottom of the ceramic block 99.

Where the line of baseboard heater units 23 and

components

24, 26 are required to go around an inside corner of the room 22, the inside corner unit 27 is included in the line as shown in FIGS. 1, 2, 7, 8 and 10. This unit comprises a rectangular metal box 105 of approximately the same height as the housing panels 28 and having two open sides which fit against the wall of the room. This box can be secured in position in the same manner as with the thermostat unit 24 and convenience outlet unit 26, that is, it can be provided with attached ears 106 projecting from its side walls and which can be secured by self tapping screws 108 to the adjacent housing panels 28 of the baseboard heater units 23 between which the corner unit is interposed. The box 105 is preferably internally reinforced by a diagonally disposed vertical plate 109 and top plate 110, these plates not only reinforce the box 105 but also provide a wireway 111 for the wires which extend around the corner of the room.

At the ends of the system the outboard extremities of the end baseboard heater unit 23 are shown as provided with end caps 112 which are shaped and flanged to snugly fit over the corresponding panels 28 and cover plates 34. Also, to provide a finished appearance, the meeting ends of the succession of baseboard units 23 can have their hoods 36 connected by a cover joint or finish strap or clip 113 of any suitable form. Similarly the meeting ends of the corresponding front plates 34 can be concealed by a cover joint, a finish strap or clip 114.

All of the back panels 36 are electrically connected by ground straps 115 which ground straps are also connected with the

cases

85, 96 and 105 of the thermostat, con venience outlet and inside

corner units

24, 26 and 27 as illustrated in FIGS. 7; 8 and 9.

The installation of the system as above described is as follows:

Assuming the several baseboard heater units 23 to be in separate cartons, with the extended surface heater structures 33 separately packed, after unpacking these units 23, pressure is exerted on the bottom of each front panel 34 so as to move it upwardly against the resistance of the pair of springs 62 until the hook shaped top flange 35 is released from the points 59 of the pair of bracket arms 58. The covers of all terminal boxes for the several uni-ts are then removed together with the wire covers 29 and deflector plates 32.

If required, an appropriate knockout 51 would be removed from one back panel 28 for supply connection. For ease of installation where end caps 1 12 are to be used, these end caps are attached to the corresponding ends of two back panels 28 before these back panels are mounted on the wall. The location of the back panels against the wall is then determined as well as the wall stud locations. Holes can be drilled in the back panels 28 for receiving wood screws 44 which are used to secure each back panel 28 to the studs of the wall.

After the first back panel 28 has been attached to the wall, the remainder of the back panels are carefully aligned with the one previously installed. Each joint is then covered with a top connection or strip or joint cover 113 and the successive back panels 28 are screwed in position and the deflector panels 32 attached by screws 68'.

Where inside corners 27, convenience outlet units 26, thermostat unit v24 or blank sections are required, each part is installed into the system as planned. The mounting of the

units

24, 26 and 27 is through their

ears

89, 101 and 106, respectively, and the self tapping screws 90, 102 and 108 which anchor in the adjacent back panels 28.

The ground straps for the several back panels 28 are then secured to electrically connect the several back panels with sheet metal screws. These ground straps are also attached to the

casings

85, 96 and 105 of the thermostat convenience outlet and inside

corner units

24, 26 and 27.

The higher voltage power supply lines 94 are then attached to opposite sides of the thermostat 92 as shown in FIG. 2. The adjacent heater unit or units 23 are then connected with the buss bars 9.1 of the thermostat unit 24, such as by the wires 83, which are placed in the wireway 52 and are connected at their other ends to the buss bars 79 of the adjacent baseboard heater units 23. Any additional baseboard heater units 23 are connected in parallel with one or the other of these baseboard heater units 23 opposite sides of the thermostat unit 24 by means of wires 82 set into the wireway 52 and interconnecting the buss bars 79 of the baseboard heater units 23 these units being connected in parallel. The volt power supply lines 95 are then brought from the supply through the wireway 52 and suitably connected with the convenience outlet or outlets 26 by means of the terminals 103.

The wire channel covers 29 are then replaced, the lower edges 30 of these covers being caught under the reversely formed or book shaped edges 39 of the back panels 28 and the upper parts of these wire covers being secured by screws 42 to the corresponding back panel 28.

The extended surface or finned heater structures 33 are then inserted into the bracket supports 31 so that the

arms

58 and 60 pass between corresponding fins '49 and so that the heater tubes 69 abut against the tabs 64 of the supporting brackets 31. The hook shaped lower ends 66 of the wire hook 65 are then caught under the upper heating tube 69 so that each extended surface or finned heater structure 33 is secured in position but is able to expand and contract lengthwise with reference to the brackets 31 and back panels 28 so that popping or other expansion and contraction noises do not result from the heating and cooling of the several extended surface heater elements 33.

The conductors 75 have already been welded to the corresponding pair of terminals 74 and enclosed in the two-part ceramic box case 76. Accordingly to electrically connect each extended surface heater structure 33, the other terminals 74 are placed in the electrical connectors 78 which are tightened so as to electrically connect these terminals with the buss bars 79. The electrical ground straps 48 are then attached through the screws 47 to ground the rigid heater structures 33 to the back panels 28.

The covers for the terminal boxes are then attached. The front panels 34 are remounted by catching the lower shoulder of channel 35 under the ends 63 of the leaf springs 62 and moving the cover panels upward and then back so that when released, the upper shoulders or channels 35 of these panels are caught between the points 59 of the bracket arms 58 and its leaf springs 62. The joining or finish

pieces

113, 114 for the hoods 36 and front plates 34 are placed between the several baseboard heater units 23. Accordingly the system is ready for operation through the adjustment of the thermostat 92 which can also be the on and ofi switch for the system.

=In operation air enters below each front panel 34 and flows up through the extended surface heater structure 33 and is then deflected outwardly by the corresponding deflector panel 32 which prevents the hoodv36 of the housing panel from being overheated. This permits the use of higher wattage heater structures 33 and in par ticular permits the use of the electric range types of heater tubes 69 containing the resistance elements 72 and body 73 of hardened insulation material, with these tubes brazed to the fins 49 to provide rigid heater structures.

Theserigid heater structures 33 are easily hung from the brackets 31 and when in place can expand and contract noiselessly because of the double ended hook hangers 65.

With such rigid extended surface heater structures 33 and the housing panels 34, the brackets 31 have a number of functions and provide a number of advantages. Thus only one attaching screw 67 is required for each bracket, the top being held by the hood 36 of the housing plate. In turn it supports the hood 36 in case the hood should be stepped on. The brackets also support the front panels 34 in such manner that they cannot be kicked oif but can be removed by the housewife without difliculty. The brackets 31 not only support the extended surface heater structures 33, free from expansion noises but also locate these structures, the tabs 64 providing back rests for locating the heating structures. These brackets also support the baffies 32 so as to thermally isolate these hot baffies from the rest of the heater parts. In this connection it would be noted from FIGS. and 6 that the spacing of the baffle 32 from the hood 36 provides a passageway therebetween which is open at the opposite longitudinal edges of the baffle plate. Each of these brackets 31 is also a low cost one-piece stamping.

The form of the invention shown in FIGS. -l520 is designed for use where only one or two baseboard heaters are required as compared with the succession of heaters, blanks, thermostat, convenience outlet plugs and inside corner units of the form of the invention shown in FIGS. l-l4.

With the form of the invention shown in FIGS. 15-20, instead of the terminal boxes with the ceramic bases 80 and buss bars 79, a simple metal terminal box 120 with the suitable knockouts is provided into which the corresponding ends of the heating tubes 69 project and are connected with the supply wires 94 through conventional wire connectors 121. If two units are to be used, jumper wires 122 can be employed between the two terminal boxes 120 as shown in FIG. 19. Also the rear wall of each terminal box 120 is provided with a pair of holes which are adapted to mate with a pair of holes 123 at each end of the housing panel 28. Accordingly the terminal box 120 can be arranged at either the right hand end of the housing panel 28 as at the left of FIG. 19, or at the left hand end as in the FIGS. 1548 and the right hand end of FIG. 19. Since in other respects the form of the invention shown in FIGS. 1520 is identical with the form of the invention shown in FIGS. l-l4, the same reference numerals have been employed and the description will not be repeated.

From the foregoing it will be seen that the baseboard heater of the present invention accomplishes the various objectives previously set forth.

We claim:

1. A baseboard heating unit, comprising a pair of rigid, vertically spaced, generally horizontal and parallel heating tubes, an electrical resistance heating element extending through each of said tubes, a plurality of transversely extending fins arranged in spaced relation along said heating tubes and each fixed to and embracing said pair of heating tubes to provide a unitary, rigid heating structure, a housing panel for said unitary heating structure adapted to be secured to the wall of a room, horizontally spaced brackets secured to said housing panel and each having an upper and a lower arm projecting horizontally outwardly from said housing panel between a corresponding pair of fins to a point beyond said unitary heating structure, means arranged to support the upper part of said unitary heating structure from the upper arms of said brackets, a front panel generally coextensive in horizontal length to said housing panel and arranged in front of said unitary heating structure to form a lower opening allowing an upward flow of cool air past the unitary heating structure and an upper opening allowing an outward flow of warm air from the unitary heating structure, an upwardly directed hook formed on the extremity of each of said upper arms and adapted to catch under downwardly facing shoulders on the upper part of said front panel, means providing abutting engagement between the end of each lower arm and the back face of said front panel, and a downwardly directed spring hook on each of said lower arms and adapted to engage upwardly facing shoulders on the lower part of said front panel whereby said front panel can be removed by displacing it upwardly against the resistance of said spring hook to free its upper parts from said upwardly directed spring hooks.

2. A baseboard heating unit as set forth in claim 1 wherein said shoulders comprise reversely bent upper and lower edges on said front plate extending the full length thereof and of hook shaped form in cross section.

3. A baseboard heating unit as set forth in claim 2 additionally including a finished clip adapted to attach to abutting ends of the front plates of adjacent baseboard heating units to bridge the gap therebetween.

4. A baseboard heating unit, comprising a pair of rigid, vertically shaped generally horizontal and parallel heating tubes, an electrical resistance heating element extending through each of said tubes, electrical terminals projecting from each end of each of said tubes and connected by the corresponding electrical resistance heating element, a plurality of transversely extending fins arranged in spaced relation along said heating tubes and each fixed to and embracing said pair of heating tubes to provide a unitary, rigid vertically symmetrical electrical heating structure, a housing panel for said heating structure, an electrical conductor connecting said termina-ls at one end of said heating structure, a terminal box housing the opposite terminals of said heating structure and adapted to house the ends of current supply wires for connection to said opposite terminals, means removably supporting said heating structure at spaced intervals on said housing panel, and means to secure said terminal box to either end of said housing panel whereby said heating unit with said terminal box can be mounted in said housing panel with said terminal box at either end.

5. A baseboard heating unit, comprising a pair of rigid, vertically spaced, generally horizontal and parallel heating tubes arranged one above the other, an electrical resistance heating element extending through each of said tubes, a plurality of transversely extending fins arranged in spaced relation along said heating tubes and each fixed to and embracing said pair of heating tubes to provide a unitary, rigid heating structure, a sheet metal housing panel for said unitary heating structure adapted to be secured to the wall of a room, horizontally spaced brackets secured to said housing panel and each having an upper arm projecting perpendicularly horizontally outwardly from said housing panel between a corresponding pair of has above the upper of said heating tubes and a lower arm, projecting perpendicularly horizontally outwardly from said housing panel between said pair of fins, a double-ended hook arranged Wholly between each said pair of fins and having its upper end swingably supported from the corresponding upper arm and its lower end hooking under and swingably supporting said upper of said heating tubes for movement of said rigid heating structure lengthwise of said heating tubes, and a front panel generally coextensive in length to said housing panel removably supported on the outboard ends of said arms. 6. A baseboard heating unit as set forth in claim wherein each bracket includes a back rest having an outwardly facing generally vertical face arranged intermediate said arms and engageable with said lower of said heating tubes between the corresponding pair of fins.

7. A baseboard heating unit, comprising a pair of rigid, vertically spaced, generally horizontal and parallel heating tubes arranged one above the other, an electrical resistance heating element extending through each of said tubes, a plurality of transversely extending fins arranged in spaced relation along said heating tubes and each fixed to and embracing said pair of heating tubes to provide a unitary, rigid heating structure, a sheet metal housing panel for said unitary heating structure adapted to be secured to the wall of a room, horizontally spaced brackets secured to said housing panel and each having an upper arm projecting perpendicularly horizontally outwardly from said housing panel between a corresponding pair of fins above the upper of said heating tubes and a lower arm projecting perpendicularly horizontally outwardly from said housing panel between said pair of fins below the lower of said heating tubes, a double-ended hook arranged wholly between each of said pair of fins and having hook shaped ends arranged in planes at right angles to each other with the upper end of each hook mounted directly on the corresponding upper arm and the lower end of each hook hooking under and swingably supporting the upper of said heating tubes for movement of said rigid heating structure lengthwise of said heating tubes, and a front panel generally coextensive in length to said housing panel removably supported by the outboard ends of said arms.

References Cited in the file of this patent UNITED STATES PATENTS 1,709,505 Vedder Apr. 16, 1929 2,064,389 Smith Dec. 15, 1936 2,450,921 Smith Oct. 12, 1948 2,662,963 Wessel Dec. 15, 1953 2,733,049 Carter Jan. 31, 1956 2,793,007 Reynolds May 2-1, 1957 2,796,238 Sjoden June 18, 1957 2,799,763 Hicks July 16, 1957 2,815,431 Paley Dec. 3, 1957 2,855,186 Brinnen Oct. 7, 1958 2,861,167 Wick Nov. 18, 1958 2,872,162 Marini Feb. 3, 1959 FOREIGN PATENTS 1,089,262 France Sept. 29, 1954