US 3825407 A
Heating apparatus comprising at least one heating element for radiating heat to a material to be heated, bracket means for supporting the heating elements, the bracket means comprising a sufficiently large opening in the side thereof away from the material to be heated so that the amount of deformation of the bracket means is minimal upon heating by the heating element, the ratio of the area of the opening to the area of the side being 60-80 percent, a plate disposed over the opening and adjacent the heating element for reflecting radiant heat from the heating element to expedite the heating of the material to be heated and to lessen the amount of power consumed by the heating element, and means for loosely connecting the plate to the bracket means so that, upon heating by the heating element, the plate deforms independently of the bracket in spite of it being disposed adjacent the heating element.
Description (OCR text may contain errors)
United States Patent 1191 1 HEATER HOLDING BRACKET FOR A HEAT FIXER IN, A COPYING MACHINE OR THE LIKE v  lnventorsz .Yasuhiro Fujite; Hitoshi Fujiwarat Mitio Ynmasawa, all of Yamasawa, Japan 1 Y  Assignee: Fuji Xerox Co., Ltd., Tokyo, Japan  Filed? J Dec. 27, 1972 v 21] App1.No.:319',06 3-  Foreign Application Priority Data I Dec. 27, 1971' Japanm. 46 122575 1  US. Cl..' 432/227, 219/216, 432/251,
219/347,.432/175, 34/39  Int. Cl......; 1105b '1/00, F27b 9/00  Field oiSearch 432/59, 60, 61, 62,8,
216, 388, 347, 343; 250/65;ZE, 65 T, 70;
 References Cited UNITED STATES PATENTS 11,291,423 .1/1919 vCrary 219/461 1,622,663 3/1927 Mulholland... 432/ 31 1,910,549 5/1933 Junker 432/31 2,822,457 2/1958 Hatch 219/347 3,095,495 6/1963 Gvozdjak et al.. 219/461 3,155,812 11/1964 GreenhausL 219/347 3,204,939 9/1965 1psen....' 432/251 3,296,958 1/1967 Liepelt 219/216 l/1970 White et a1. 219/216v 1111 3, 25,407 1451 Ju1y23,1 974 3,629,555 12/1971 Herbert, Jr. ..219/347 3,648,019 3/1972 Brewitz 219/216 3,667,742 6/1972 Kamola 432/62 3,675,905 7/1972 Placek 432/24 FOREIGN PATENTS OR APPLICATIONS 1,032,790 6/1966 Great Britain 0.2191388 Primary Examiner- John J. Camby. AssistantlExamin er--Henry C. Yuen Attorney, Agent, or Firm-J. T. Martin; Gerald J L Ferguson, Jr.; Joseph J. Baker v 1 157] ABSTRACT Heating apparatus comprising at least one heating ele-' ment for radiating heat to a material to be heated, bracket means for supporting the heating elements,
, the bracket means comprising a sufficiently large opening in the side thereof away from the material to be heated so that the amount of deformation of the bracket meansis minimal upon heating by the heating element, the ratio of the area of the opening to the area of the side being 60-80 percent, a plate disposed over the opening and adjacent the heating element for reflecting radiant heat from the heating element to ex pedite the heating of the material to be heated and to lessen the amount of power consumed by the heating element,-and means for loosely connecting the plate to the bracket means so that, upon heating by the heating element, the plate deforms independently'of the bracket in spite of it being disposed adjacent the heat- V ing element. a
7 Claims, 3 Drawing Figures HEATER HOLDING BRACKET FOR A HEAT FIXER IN A COPYING MACHINE OR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved heater holding bracket for a heat fixer in a copying machine or the like wherein a developed image or the like is fixed on a copying paper.
2. Description of the-Prior Art 7 In the conventional heat fixer used in copying machines, it generally takes to minutes from the time when the fixer starts warming up to the time when the temperature of the fixer'is sufficiently high to fix the developed images. It'is apparent that the waiting time depends upon the heat capacity of the heater and the fixer body retaining the heater, and accordingly, it has usually been the practice to make the heater with a material of low heat capacity and to hold the'heater with a material of low heat capacity. Further, in conventional copying machines, only one side of the heater faces the copying paper and the opposite side (back side) is practically wasted in heating the paper.
lt has been provedv by experiments that a polished plate of aluminum or stainless steel may be effectively used'for reflecting the radiant heat generated from the back side of the heater to efficiently use the heat. Furthermore, it is apparent that thereflecting plate should be located as near. the heater as possible to effectively utilize theheat therefrom. By means of such an ar- 7 rangement, it can be expected that the time constant of temperature rise is made small becauseof the infinite reflection of the radiant energy between the back side of the heater and the inner surface of the bracket. Further, the electricpower consumption is reduced.
However, there are many problems from the viewpoint of safety in locating the heater holding bracket close to the heater since the thermal deformation of the bracket itself is quite substantial. Thus, the shape of the bracket is deformed due to the difference in deformation of various parts thereof whichresults in the possibility of electrical short circuit. Although the insertion of insulating material between the heater and the bracket together with the, utilization of a bracket comprising a thin plate of metal has been attempted, these attempts have not resulted in satisfactory radiant heat reflection characteristics nor in sufficiently rigid structures.
SUMMARY OF THE INVENTION V A further object of this invention is to provide an improved apparatus of the above type where the radiant heat reflecting plate is located close to the heater, and the fixing by heat is continuously repeated at a high speed so that the heater may be used in a high speed copying machine or the like.
A Other objects and advantages of this invention will become apparent upon-reading the appended claims in conjunction with the following detailed description and the attached drawing.
BRIEF DESCRIPTION 0E THE DRAWING FIG. 1 is an exploded perspective view of an illustrative embodiment of the invention.
FIG. 2 is a partial elevational sectional view illustrating the assembled bracket, radiant heat reflecting plate and heater of FIG. 1.
FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2.
DESCRIPTION oFTnE PREFERRED EMBODIMENT The present invention will be described with reference to the drawing. A bracket 1 for the heat fixer preferably comprises a material having good radiant heat reflectance such as a polished plate of stainless steel. The bracket 1 includes four side plates and an-upper' face which has a central part cutout to form anopening 2. Disposed below the opening 2 are heater members 3 having a substantially V-shaped cross section ,as can be seen in FIG. 3. The heater members 3 are supported by support bars 4 disposed lengthwise to the opening 2 of the bracket 1. One side 3a of each of the heater members 3 facing the copying paper 5 is made black so as to effectively generate radiant energy. The heater members 3 are connected to a plug to provide electric current thereto either serially orin parallel in this invention.
Each corner of the upper face of the bracket 1 is provided with a bolt hole 6 as can be seen in FIGS. 1 and 2. A radiant heat reflecting plate 7 is "typically com prised of a polished plate of stainless steel or aluminum, the respective corners of which being provided with holes 8 having a diameter larger than that of the bolt holes 6. A spacer 9, a washer 10, a spring Washer 11, a bolt 12, and a nut 13 comprise a plate securing means 14 which is used at each of the bolt holes 6to secure the radiant heat reflecting plate 7 tothe bracket 1.
In securing the plate 7 to the bracket 1, the plate 7 is placed on the bracket 1 with the bolt holes 6 aligned with the holes 8, the spacers 9 are inserted intothe holes 8, the washers 10 are placed on the spacers 9, the bolts 12 are inserted into the bolt holes 6 from the washer 10 side, the spring washers 11 are set to the bolts 12, and the nuts 13 are screwed to the bolts 12 to fix tightly the washers 10 and the spacers 9 to the bracket, as can beseen in FIG. 2, whereby the radiant heat reflecting plate 7 is secured and mounted to the bracket 1. The outside diameter of the spacer 9 is less than the diameter of the hole 8 so that the reflecting plate 7 may move in any direction with respect to the bracket 1 so that the plate 7 does not have any effect on the bracket 1 when the plate is deformed by heat.
Thus, the heat irradiated from the heater 3 is rapidly multiplied because of a substantially infinite number of reflections which are repeated between the reflecting plate 7 and the heater members 3. The efficiency of heating the copying paper 5 is thus increased. At this time, the bracket 1 and the radiant heat reflecting plate 7 are expanded by heat as the temperature of the heater members 3 rises. However, because of the open- 3 ing 2, the deformation of bracket 1 is, quite small. Further, the radiant heat reflecting plate 7 is not deformed at all by heat because it is not tightly fixed to the bracket 1 as mentioned above.
Thus, since the bracket 1 holding the heater members 3 has an opening 2 in its central portion and since opening 2 is covered with a radiant heat reflecting plate 7 which is loosely mounted on bracket 1 by plate securing means 14 so that the plate 7 may extend freely, thermal deformation of the bracket 1 and the radiant heat reflecting plate 7 is substantially prevented. Ac-
I cordingly, the reflecting plate 7 can be located close to the heater 3 and therefore the time constant of temperature rise can be made quite small which results in considerable shortening of the waiting time and decrease of electric power consumption. Consequently, it becomes possible for the device of this invention to be used with a high speed copying machine or the like in which the operation of rapid heating fixation is repeated continuously under high temperature.
It has been determined that the ratio of the area of the opening 2 with respect to the area of the upper face of the bracket 1 should preferably be about 70 percent and may be from 6080 percent in order that minimum deformation of the bracket occurs.
Numerous modifications of the invention will become apparent to one of ordinary skill in the art upon reading the foregoing disclosure. During such a reading it will be evident that this invention provides an improved heater holding bracket for a heat fixer for accomplishing the objects and advantages herein stated.
What is claimed is:
1. Heating apparatus comprising; at least one heating element for radiating heat to a material to be heated;
bracket means for supporting said heating element, said bracket means comprising a sufficiently large opening in the side thereof away from said material to be heated so that the amount of deformation of said bracket means is minimal upon heating by said heating element, the ratio of the area of said opening to the area of said side being 6080 percent;
a plate disposed over said opening and adjacent said heating element for reflecting radiant heat from said heating element to expedite the heating of said material to be heated and to lessen the amount of power consumed by said heating element; and
means for loosely connecting said plate to said bracket means so that, upon heating by said heating element, said plate deforms independently of said bracket in spite of it being disposed adjacent the heating element.
2. Heating apparatus as in claim 1 where said ratio is approximately percent.
3. Heating apparatus as in claim 1 where said material to be heated is copying paper for use in a copying machine.
4. Heating apparatus as in claim 1 where said heating element comprises a longitudinally extending element having a V-shaped cross section with the top of the V facing toward said heat reflecting plate and with the bottom portion of one of the sides of the V blackened to generate heat.
5. Heating apparatus as in claim 4 where said bracket means includes at least two vertically extending side members and where said apparatus includes at least one support member extending longitudinally between said side members for supporting said heating element.
6. Heating apparatus as in claim 1 where said heat reflecting plate has a plurality of holes of a first diameter and where said connecting means includes a plurality of members connected to said bracket of a second diameter less than said first diameter, said members being disposed in said holes to effect said loose connection of the heat reflecting plate to the bracket means.
7. Heating apparatus as in claim 6 where said members connected to said bracket comprise a plurality of spacers respectively disposed about a plurality of bolts respectively connected through a plurality of holes disposed about said opening in said bracket means.