US1636369A - Electric heater - Google Patents

Description

July 19, 1927.

A. JOHNSON ELECTRIC HEATER 4Filed July 29. 1925. 2 sheets-sheet 1 l Ill Il .llllllllllz A 1,636,3 69 July 19 1927' A. JOHNSON ELECTRIC HEATER Filed July 29. 1925 2 Sheets-Sheet 2 1%, j 7 4. Hllilllmlllmnm v f P lj) 10 mlm.

Patented July 19, 1927.

- UNITED STA Tes PATENT oFFlcs.

AXEL .ToNs'om OFOAKLAND, CALFORNIA.

ELECTRIC HEATER.v

Application sied July' a9, 15525'. pseriai No; 46,705.

in providing a special framework construc- `tion for the` heating elements which removably mount the same therein in convenient and accessible relation. y

Another object ot the invention resides in providing a heating element of special construction having a substantially 'Hat rectann gular form provided with end recesses receiving the terminal connections for the heating element Which is `Wound in a conti'n` nous groove formed throughout the area of the element. j

The invention Y comprehends other im*- provementsresiding in the construction and arrangement of 'parts 'asinore particularly described in the 'following detaileddescrip-- tion and in the claimV direc'tedmto a' preferred construction of the invention7V it being understood, however, that various 'changes in the size, shape, and arrangement ol these parts may be made Without departing trom the spirit and scope ot the'rinvention as herein set forth; l

ln the drawings 'forming a part ot this application, f Y y l l ,m

Fig. l is a side elevation of awheating con duit showing the manner of mounting the heating unit therein and also showing dia'- grammatically the circuit connectionsand switches 'lor controlling the energy supply to the banks of heating units. y Fig. 2-is ran. enlarged plan view oiv the' rack showing the heating elements moun ed therein and the air conveying ,conduitv in section. y I Fig. 3 is a side elevation' ot'` therack and the heating elements,v portionsrof vvhich are broken away and shown in section.

Fig. 4 is an endelevation ot the structure shown in Fig. 3.

Fig. 5 is a detailed longitudinal section on a substantially large scale through one end of one of th'e heating elements.

ll indicates an air conduit adapted tosupply air Jfor any suitable purpose which is provided at 2 with an air intake and a'ta'n 3 for forcing air through the conduit. i door is provided at 4f giving access to a portion ofthe conduit adjacent to the tan 3 so that the heating unit indicated in dotted linesv bythe numeral 5A may be conveniently inserted or removed from said conduit in the rear ot the tan 3' and which is adapted for uniformly heating the airbeing forced therethrough by the fan. lu the zoru'e'olltliel conduit receiving the `heating unit jthe same is lined throughout .theV inner surface With insulating material indicated at 6.

The heating'unit includes' a main frame made up cfa plurality ot' longitudinal angle bars 7 connected by the vertical and hori zontal end bars 8 and-9', respectively. A-

plurality ot' supporting bars l0 are mounted on the end bars 8 and extend longitudinallyy a'long each side of the trame. :These bars are provided with notches in their upper edges, as indicated' at ll for receiving. and holding the spreader bars" 12 in position: These spreader bars are of inverted U-shape and extend transversely of the main frame" for support upon corresponding horiaontal supporting bars l0 at they opposite sides ot' the as clearly shoivn in Fig. Ll.' These i spreader bars mount a `plurality of pins 13, which project laterally from oneside thereof and receive and supportthe heating'elements 14 thereon. These spreader bars are L'rranged in pairs in Which the pins pro ject in opposed relation into the sockets 15 formed inthe upper edgesot the ends of the heating elements lll as clearly shovvnin 3;v In this Wayitjwill be noted that the spreader bars are removably mounted inthe notches inthe supporting bars l() and re'- movably but yet rigidly mount the heating elements le in j'nedetermined spaced rela*- tion Within the contines of the main frame.

vAs shown particularlyin Fig. 2 the heating elements in ditlerent banks or between dilitere'nt pairs of spreaderbars are mounted so as to be in staggered relation relative to the direction ot' tlow through thel traine.

Each ofthe heating elementsare of similarV construction and comprise a substantiallyV liat molded body of suitable insulating material. These elements are of substantially rectangular kformation and have the upper ly extending grooves 19 1n and lower edges rounded as illustrated in the drawings. The end portions are provided with cut out sections or recesses 16 which provide end lugsfl? for receiving the terminals 18 for the heatin element. Y These molded bodies are provide with transversethe faces thereof which are interconnected around the curved edges so that `a continuous substantially s iral groove is formed from end to end of t e elements in which the grooves in one side and at one end are. arranged in a substantially vertical or transverse relation in the body of the element while the grooves pro-v gressing towards the opposite end on the same side of the body are formed therein at successively increasing angles. The grooves on the opposite side of the body are formed in the same manner with substantially vertical or transversely extending grooves while at the opposite end the saidV grooves incline successively, these grooves being arranged in the reverse relation to the grooves in the other side. The heating element 20 is formed of a substantially helical resistance wire laid in said grooves 19 and secured therein by suitable fireproof material which firmly cements the heating coil in the grooves for the purpose of preventing sagging and the like. The particular formation of they grooves permits the use of the entire area of the body of the element for receiving portions of the heating element therein in order that a heating coil having a maximumlength may be wound over substantially the entire area in order that the element may at the same time be made of small size. The particular relation of the grooves as above described aids in providing a heating element structure of minimum slze. and at the same time carrying the maximum length of heating coil. The heads of the bindmo` posts 18 are slotted and receive the ends ofp the heat-k ing element 2O from the end portion ofthe groove in the body ofthe element which head portionv is swagedover the endv of the wire 20 of the heating coil for effectively retaining the heating coil in direct electrical cfmnection with the binding post without other securing means. Lock nuts 21 secure the binding posts 18 in the body of the'element while the bus bars 22 having a plurality of openings in spaced relation lit over the ends of the binding'posts 18 andare rigidly connected thereto by the use of additional lock nuts so that the several heating coils on the heating elements are connected in the circuits made with the bus bars in parallel. The ends of the bus bars 22 are formed with sockets 23 which receive the ends of the cables 24 used for connectin the several banksof heatin elementswit the icontrolmotely to the main framework and the heating unit. A main control switch 26 may also be provided for controllin the connection of thel-heat'ing'elements w1th sources of power of Vdifferent voltage or from different sources. As shown particularly in Fig. 2 the cables 24 extend through insulating sleeves 27 mounted in the side of the conduit 1 and :extending through insulating section 6.

As shown in the drawing a plurality of heating elements 14 are mounted between each pair of spreader bars to form a bank of heating elements which are removably supported on the bars 10 and opposite sidesl of themain frame. As shown there arc a plurality of banks arranged horizontally in which the heating elements of each adjacent bank are mounted in staggered relation to produce even heating of air lowingthrough the frame. It will also be noted that there are a plurality of vertically arranged banks of heating elements su orted by different pairs of bars 7 in spaced)liorizontal planes.

n this way a substantially open and readily disassembled structure is provided for a plurality of banks of heating units in which the units themselves are removably mounted between pairs of spreader bars while the spreader bars are removably seated in the notches of the supporting bars 10. A further feature of the invention resides in the construction of the heating element which is provided with recesses for removably receiving the pins of the spreader hars and provided with cut out ortions in the ends mounting the terminals or the heating coil while at the same time utilizing the entire surface of the body for receiving a heating element in a predetermined manner.

What is claimed is: i

A heating unit comprisin an open frame work having a plurallty o parallel spaced horizontal bar members dis sed in superimposed pairs at opposite side0 pairs of parallel supporting barsfremovably resting in predetermined spaced relation at opposite ends on opposing bar members of the respective pairs, a plurality of elongated heating elements disposed in parallel spaced relation vbetween sa1d pairs of supporting bars and secured at their ends thereto forming with said supporting bars horizontal and vertical rows of batteries of heating units, each horizontal row being independently rcmovable from said frame, the heating element between each adjacent pair of su porting bars being positioned in staggere rela-` tion with one another. y

In testimony whereof I have signed` my yname to this specification.

AXEL. JOHNS@ s of the frame,

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