United States Patent
`
`[191
`
`[11]
`
`Patent Number:
`
`5,359,179
`
`Date of Patent:
`Oct. 25, 1994
`[45]
`Desloge et al.
`
`US005359179A
`
`[54]
`
`[75]
`
`[73]
`
`[21]
`
`[22]
`
`[63]
`
`[51]
`[52]
`
`[53]
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`[56]
`
`BAND AND STRIP HEATER
`CONSTRUCTION VVITH VARIABLE
`LEAD/TERMINAL CONNECTION
`CAPABILITY
`
`OTHER PUBLICATIONS
`
`Patent Abstracts of Japan-vol. 13, No. 24l—Jun. 1989
`Publication No. JP'l05 1460 on Feb. 27, 1989.
`
`Inventors: George B. Desloge, Frontenac;
`Raymond H. Fiehler, St. Louis; Keith
`M. Gegg, Bel-Nor; Steven M. Klump,
`St. Louis, all of Mo.
`
`Primary Examiner—Bruc_e A. Reynolds
`Assistant Examiner—Michael D. Switzer
`Attorney, Agent, or Firm-—Haverstock, Barrett &
`Roberts
`
`Assignee: Watlow Electric Manufacturing
`Company, St. Louis, Mo.
`
`App]. No.: 999,459
`Filed:
`Dec. 29, 1992
`
`Related U.S. Application Data
`Continuation of Ser. No. 608,242, Nov. 2, 1990.
`
`Int. Cl.5 .......................... H05B 3/58; HOSB 3/08
`U.S. Cl. ..............................
`219/535; 219/541;
`219/544
`Field of Search ............... 219/535, 528, 530, 541,
`219/544, 542, 93; 338/311, 314, 243, 247, 249,
`254, 255; 392/459
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`1,692,164 11/1928 Fromm ......................... 123/ 142.5 E
`2,029,075
`1/1936 Knight . ... .. .
`. ... .. 219/535
`2,707,507 5/1955 Tripp et al
`219/93
`2,845,522
`7/1958 Hall ...........
`219/93
`3,475,597 10/1969 Desloge
`219/535
`3,808,573 4/1974 Cappell
`338/249
`3,831,004
`8/1974 Wallstrom .. ...
`...... 219/535
`3,872,281
`3/1975 Krieg et al
`219/535
`3,889,362 6/1975 Tyler ... ..... .....
`..... ... 29/619
`3,912,907 10/1975 Lodi ........ ..
`.. 219/535
`4,203,197
`5/1980 Crandell ................................ 29/611
`
`
`
`FOREIGN PATENT DOCUMENTS
`
`364452 11/1922 Fed. Rep. of Germany ...... 219/535
`806270
`6/1951 Fed. Rep. of Germany .... .. 219/535
`394755 11/1910 France ................................ 219/535
`17538 of 1910 United Kingdom .
`
`[57]
`
`ABSTRACI‘
`
`A band and/or strip heater assembly which enables the
`terminal _end portions of the electrical heating element
`to be readily exposed so as to be easily accessible for
`later connection to any one of a wide variety of lead/-
`terminal connections. The assembly comprising a heater
`element having a plurality of end portions associated
`therewith, electrical insulation material positioned in
`surrounding relationship on at least two sides of the
`heater element, a housing member enclosing the heater
`element and insulation material, an opening extending
`through at least a portion of the insulating material
`located adjacent one side of the heater element and
`through at least a portion of the housing member, the
`heater element end portions extending through such
`openings so as to be readily exposed exterior of the
`housing member. This construction enables the basic
`heater unit to be fully fabricated and assembled without
`attaching a particular style of lead/terminal connection
`thereto. The present invention further includes the con-
`struction and operation of several embodiments of a
`specially adapted add-on lead/terminal cap or connec-
`tion member which facilitates the adaptation and join-
`der of a wide variety of lead/terminal options to the
`present heater assembly. The present construction is
`likewise adaptable for use with a wide variety of heating
`elements or winder constructions and likewise enables
`all electrical connections to the particular lead/terminal
`option selected to be accomplished by welding. This
`greatly improves the overall performance and reliabil-
`ity of such heater.
`
`12 Claims, 3 Drawing Sheets
`
`64
`
`T1.12 :1;Q’: 1113 -146114#1:’: 30
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`32
`
`Euro-Pro Exhibit 1012
`Euro-Pro Exhibit 1012
`Euro-Pro v. Acorne
`36 Euro-Pro v. Acorne
`Page 1 of 12
`IPR2014-00186
`Page 1 of 12
`Page 1 of 12
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`

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` U.S.Patent
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`Oct. 25, 1994
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`Sheet 1 of 3
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`5,359,179
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`Page 2 of 12
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`U.S. Patent
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`Oct. 25, 1994
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`Sheet 2 of 3
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`5,359,179
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`39
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` 39 '
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`Page 3 of 12
`Page 3 of 12
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`32
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`

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`U.S. Patent
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`Oct. 25, 1994
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`Sheet 3 of 3
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`5,359,179
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`Page 4 of 12
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`

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`1
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`5,359,179
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`BAND AND STRIP HEATER CONSTRUCTION
`WITH VARIABLE LEAD/TERMINAL
`CONNECTION CAPABILITY
`
`This is a continuation of copending application(s) Ser.
`No. 07/608,242 filed on Nov. 2, 1990.
`The present invention relates generally to heaters
`and, more particularly, to an improved band and strip
`type heater construction which facilitates the attach-
`ment of a wide variety of lead/terminal connections to
`the finished unit depending upon the particular applica-
`tion and operating needs of the end user. The present
`heater construction enables a manufacturer to fabricate
`and assemble a band or strip heater without having any
`leads or terminal connections attached thereto. Advan-
`tageously, the present construction enables the terminal
`end portions of the electrical resistance wire or heating
`element housed within the unit to be readily exposed at
`an intermediate location exterior thereof so as to be
`easily accessible for later connection to the particular
`lead/terminal arrangement specified by the end user.
`Since the lead/terminal configuration may vary widely
`from one heater application to another,
`the present
`construction enables a manufacturer to fully assemble
`and stock such units without committing such units to a
`particular lead/terminal arrangement. Thereafter, such
`units can be easily and quickly equipped with the partic-
`ular lead/terminal configuration as specified by the end
`user. This facilitates reductions in the stock inventory
`requirements of the manufacture and speeds up delivery
`of the finished product to the end user. This also pro-
`vides the end user with a much broader selection of
`suitable heaters from available stock inventories. Al-
`though the present heater construction is specifically
`adaptable for use in the fabrication and assembly of
`band and strip type heaters, such construction may
`likewise lend itself to other heater applications.
`BACKGROUND OF THE INVENTION
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`Band and strip heaters are typically custom fabricated
`in accordance with the particular specifications of the
`end user. Besides specifying the particular performance
`characteristics and operating factors desired in a partic-
`ular heater unit, such as voltage, wattage, power sup-
`ply, dimensional and other special requirements, the end
`user also specifies the particular lead or terminal config-
`uration necessary for adaptation of the heater to the
`particular application in question. A wide variety of
`lead and/or terminal configurations are available and
`adaptable for use with band and strip type heaters and
`such configurations may vary considerably from one
`application to another. Typical of the known band and
`strip heater constructions including lead and/or termi-
`nal connections associated therewith are those shown
`and disclosed in U.S. Pat. Nos. 4,203,197; 3,872,281; and
`3,889,362.
`Since current manufacturing techniques usually man-
`date that the lead and terminal arrangement for a partic-
`ular band or strip heater be attached during the assem-
`bly process, manufacturers of such heaters have been
`somewhat reluctant to carry a large stock inventory of
`such heaters covering a wide variety of such lead/ter-
`minal variations. Instead, manufacturers typically wait
`until receiving a particular order from an end user be-
`fore manufacturing and assembling such heaters. Conse-
`quently, quick delivery of the end product is often times
`hindered due to the manufacturing process since the
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`manufacturer may not have a heater in stock meeting all
`of the specifications and requirements of the end user,
`particularly, the necessary lead and/or terminal config-
`uration as discussed above. As a result, often times, the
`manufacturer may attempt to modify the lead and/or
`terminal arrangement associated with heaters already in
`stock which otherwise meet all of the specifications and
`requirements of the end user so as to achieve a quicker
`delivery time. Such modification efforts often times
`reduce the overall performance and dependability of
`the modified heater due to disassembly and re-assembly
`of the lead and/or terminal portion of such heater as
`well as other factors. The present heater construction
`alleviates this particular problem by enabling the basic
`heater to be fabricated and assembled without any lead
`and/or terminal connection associated therewith as will
`be hereinafter explained.
`During the fabrication and assembly of conventional
`band and strip heaters, it is also common practice to
`crimp or stake the terminal end portions of the electrical
`winding or heater element to the insulation sheet mate-
`rial and/or other components associated therewith for
`ultimate connection to the particular lead/terminal ar-
`rangement utilized. This staking of the electrical resis-
`tance means to the particular insulation material utilized
`within the heater often times causes cracks or other
`damage to such insulation material. This is particularly
`true when the heater is curved into a band type heater.
`This cracking and damage around the staking point
`decreases performance and reliability of the heater since
`the winding lead attached thereto has a tendency to
`loosen, short out, oxidize during operation, and/or
`cause other performance problems. This problem is
`likewise alleviated by the present heater construction as
`will be hereinafter explained.
`
`SUMMARY OF THE INVENTION
`
`The present heater construction overcomes the afore-
`mentioned problems and other disadvantages and limi-
`tations associated with the construction and assembly of
`known band and strip heaters and teaches the construc-
`tion and operation of an improved heater assembly
`whereby the basic heater unit can be fully fabricated
`and assembled without attaching a particular style of
`lead/terminal connection thereto. Contrary to current
`manufacture, the present heater construction allows the
`terminal end portions of the heater element located
`therewithin to be readily exposed outside the metal
`sheath enclosing the heater components at an intermedi-
`ate location therealong. This is accomplished by routing
`the heater element end portions through slot means
`formed in certain portions of the insulator material
`housed therewithin as well as through slot means
`formed in the outer metal sheath associated with such
`heater. The present heater is assembled and constructed
`using known techniques, the end result being that a
`band or strip heater is formed having the two terminal
`end portions of the heater element extending therefrom
`for easy accessibility and later connection to a particu-
`lar lead/terminal configuration.
`The present invention further includes the construc-
`tion and operation of several embodiments of a specially
`adapted add-on lead/terminal cap or connection mem-
`ber which can be easily attached, both electrically and
`structurally, to the protruding heater element end por-
`tions and the outer metal sheath of the heater. By vary-
`ing the construction and design of the lead/terminal
`connection member, all of the various terminal and lead
`Page 5 of 12
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`

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`3
`designs available for use with band and strip heaters can
`be adapted for attachment to the basic heater unit. This
`is extremely important. and beneficial to the manufac-
`turer of such heaters since such heaters can now be
`easily stocked in inventory without physically attaching
`a particular type of lead/terminal connection thereto.
`Thus, when an end user requests a particular 1ead/ter-
`minal configuration, the specified termination arrange-
`ment can be quickly adapted and attached to the already
`completed basic heater unit. This greatly improves
`turnaround time and delivery of the product to the end
`user. Such heater termination options typically include
`the use of any plurality of post terminals, upright leads,
`upright leads housed within either a loose or a tight
`stainless steel braid sleeving, upright
`leads housed
`within a flexible conduit, upright leads housed within a
`fiberglass sleeving,-terminal box protection, and many
`other lead and post terminal variations. The present
`lead/terminal connection members are therefore an
`important link between the various lead/terminal op-
`tions and the basic heater construction. The only fea-
`tures of the basic heater unit that are subject to change
`are the size of the unit, the wattage and/or voltage
`output, and the attachment location for the add-on
`lead/terminal cap member, all of which variable fea-
`tures can be easily stocked in inventory.
`Besides improving delivery time, the present heater
`construction also eliminates the need for staking the
`opposite end portions of the heater element to the insu-
`lation material or other heater components. Instead,
`since the terminal end portions of the heater element are
`fully exposed and easily accessible outside the unit, all
`electrical connections to the particular lead/terminal
`option selected are accomplished by welding. This
`therefore eliminates the cracking and damage problems
`at the staking points as previously explained, thereby
`improving the overall performance and reliability of
`such heaters. Also, the present heater construction in-
`cludes clamping or attachment means which simplifies
`installation and provides for a more uniform load distri-
`bution over the heating element. When used as a band
`heater,
`the present construction also facilitates the
`opening or spreading apart of the unit so as to more
`easily position such unit around the particular cylindri-
`cal object or surface to be heated. This can be accom-
`plished without detrimentally affecting the heater itself;
`without otherwise using a two-piece type band con-
`struction; and without utilizing a more expensive ex-
`pandable type band construction.
`The present heater construction is likewise adaptable
`for use with all of the various known heating elements
`or winder constructions presently employed in band
`and strip type heaters. This includes the conventional
`single wound element arrangement which comprises a
`single resistance wire wrapped around a sheet of insula-
`tor material; the parallel or bifiler wound arrangement
`which comprises two resistance wires wrapped around
`a sheet of insulator material; a sinuated wire arrange-
`ment wherein the sinuated wire is sandwiched or other-
`wise embedded between two or more sheets of insulator
`material; and still other heating element and winder
`constructions. Also,
`importantly,
`the present heater
`construction is adaptable for use in constructions which
`utilize any number of insulating layers of material adja-
`cent the opposite sides of the heating element. Such
`internal heating element and insulator configurations
`are usually dependent upon the performance character-
`istics of the heater as well as the particular construction
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`5,359,179
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`4
`associated with the heating element utilized therein.
`Also, importantly, the present heater construction is
`adaptable for use with any type of insulator material
`such as mica, sheets of organically bound ceramic parti-
`cles such as aluminum oxide and/or magnesium oxide,
`and any combinations thereof. Regardless of the inter-
`nal workings and material composition of such heater,
`all of the features and capabilities afforded by the pres-
`ent heater construction represent important advance-
`ments in the manufacture of band and strip heaters.
`It is therefore a principal object of the present inven-
`tion to teach the construction and operation of an im-
`proved band and strip heater construction wherein a
`wide variety of lead and/or terminal configurations can
`be easily attached thereto.
`Another object is to improve the performance and
`reliability of band and strip type heaters by eliminating
`the need to crimp or stake the terminal connection end
`portions of the heating element to the insulation mate-
`rial or any other component of such heater.
`Another object is to teach the construction and oper-
`ation of several embodiments of a lead/terminal con-
`nection member which will facilitate the adaptation and
`joinder of a wide variety of lead and terminal configura-
`tions to the present heater construction.
`Another object is to teach the construction and oper-
`ation of a heater construction which will enable manu-
`facturers of band and strip type heaters to reduce their
`stock inventory yet still offer their customers a broad
`selection of such heaters including a broad selection of
`lead/terminal configurations associated therewith.
`Another object is to teach the construction and oper-
`ation of a heater construction which will reduce and
`improve the time needed to deliver such heaters to the
`end user.
`Another object is to teach the construction and oper-
`ation of a heater construction wherein all of the electri-
`cal connections associated with such heater are welded
`connections.
`Another object is to teach the construction and oper-
`ation of a heater construction having clamping means
`associated therewith which not only provides for a
`more uniform load distribution over the heating element
`housed therein but also simplifies the installation of such
`heater by eliminating the need to align straps and termi-
`nals.
`
`Another object is to provide a heater construction
`that is structurally and operationally relatively simple to
`make.
`
`Another object is to provide a band heater construc-
`tion which can be more easily expanded to fit around
`the particular cylindrical surface to be heated without
`detrimentally affecting or otherwise interfering with or
`hindering the overall performance and reliability of
`such unit.
`Another object is to provide a more responsive and
`reliable heater and one which is not easily susceptible to
`premature heater failure, erratic, or less than fully de-
`pendable performance.
`These and other objects and advantages of the pres-
`ent invention will become apparent to those skilled in
`the art after considering the following detailed specifi-
`cation in conjunction with the accompanying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective view of a band heater con-
`structed according to the teachings of the present in-
`Page 6 of 12
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`5,359,179
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`5
`vention, said heater being shown without a lead/termi-
`nal connection and without clamping means;
`FIG. 2 is an exploded perspective view of one em-
`bodiment of the present heater construction showing
`the various components associated therewith;
`FIG. 3 is a cross-sectional view of an assembled
`heater unit taken, for example, along line 3—3 of FIG.
`1;
`'
`FIG. 4 is a side elevational view of the band heater
`construction illustrated in FIG. 1 showing the clamping
`means and one embodiment of a terminal arrangement
`associated therewith;
`FIG. 5 is an enlarged fragmentary View of one of the
`clamping bars shown in FIG. 4 illustrating its attach-
`ment to one of the tab members associated with the
`outer metal sheath of the present construction;
`FIG. 6 is an exploded cross-sectional view showing
`one embodiment of a terminal connection adaptable for
`use with the heater assembly of the present invention;
`FIG. 7 is a perspective view of the terminal cap mem-
`ber illustrated in FIG. 6;
`FIG. 8 is an exploded cross-sectional view showing
`another embodiment of a lead/terminal connection
`adaptable for use with the heater assembly of the pres-
`ent invention;
`FIG. 9 is a perspective view of the lead cap member
`illustrated in FIG. 8;
`FIG. 10 is an exploded perspective view similar to
`FIG. 2 showing another embodiment of a heater assem-
`bly constructed according to the teachings of the pres-
`ent invention; and
`FIG. 11 is an exploded perspective view of still an-
`other heating element/insulator arrangement
`con-
`structed according to the teachings of the present in-
`vention.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`Referring to the drawings more particularly by refer-
`ence numbers, wherein like numerals refer to like parts,
`number 10 in FIGS. 1 and 2 identifies one embodiment
`of a basic band or strip heater assembly constructed
`according to the teachings of the present invention, the
`heater assembly 10 being manufactured and assembled
`without termination and attachment means associated
`therewith. As best shown in FIG. 2, the present heater
`assembly 10 includes a channel-shaped upper sheath or
`cover member 12 having a pair of downwardly extend-
`ing opposed side wall portions 14 associated therewith.
`The channel-shaped member 12 is generally made of a
`metallic material and further includes a tab member 16
`associated with each respective opposite end portion
`thereof as well as an elongated slot or opening 18 posi-
`tioned at an intermediate location therebetween. The
`heating element 20 is a conventional bifiler winder con-
`struction which includes a pair of electrical resistance
`wires 22 and 24 helically wrapped or wound in parallel
`relationship around a sheet of insulator material 26. The
`bifiler wound construction is achieved by first winding
`the resistance wires 22 and 24 in parallel around the
`insulator strip 26 from one end to the other in accor-
`dance with known techniques and thereafter welding
`together the respective opposite ends thereof so as to
`create a closed loop therebetween. This joined wire
`arrangement is then severed at a predetermined inter-
`mediate location as desired thereby forming an electri-
`cal circuit having terminal end portions 28 and 30 as
`shown in FIGS. 1 and 2. The resistance wires 22 and 24
`
`6
`are generally formed of a ribbon of nichrome wire,
`although any suitable high temperature electrical resis-
`tance means can be utilized. The terminal wire end
`portions 28 and 30 are each preferably doubled over and
`welded respectively to themselves so as to form a dou-
`ble layer construction at end portions 28 and 30. This
`lowers the resistance of the wire end portions 28 and 30
`and allows such end portions to operate at cooler tem-
`peratures at the point of connection to a particular
`lead/terminal arrangement.
`The heating element 20 is sandwiched between two
`strips or sheets of insulation material 32 and 34 which
`effectively insulate the heating element 20 from the
`metallic heat conducting parts 12 and 36 as will be
`hereinafter explained. The upper insulator sheet 34 like-
`wise includes an elongated slot 38 positioned thereon so
`as to receive the terminal end portions 28 and 30 of the
`heating element 20 when positioned in overlaying rela-
`tionship thereto. Slot 38 is also located so as to lie in
`registration with slot 18 associated with the cover mem-
`ber 12. Insulator sheets 26, 32 and 34 are typically com-
`prised of either mica or high density ceramic particles
`bound together by a suitable binder, or any other suit-
`able insulating material. The ceramic particles typically
`include particles of aluminum oxide, magnesium oxide,
`boron nitride, or silicon dioxide. All of these materials
`have excellent dielectric strength, the ceramic materials
`being capable of operating at somewhat higher temper-
`atures as compared to mica and some other known
`suitable materials. When fully assembled, the terminal
`end portions 28 and 30 of the heating element 20 extend
`through the respective slot means 38 and 18 as best
`shown in FIGS. 1 and 3. A bottom cover plate 36 com-
`pletes the components of the basic heater unit 10. The
`plate member 36 is likewise generally made of a metallic
`material and is dimensioned so as to be received within
`the charmel—shaped cover member 12.
`In assembling the basic heater 10, the sandwich sub-
`assembly or heater core body comprising heating ele-
`ment 20 and insulator sheets 32 and 34 is placed within
`the channel-shaped cover member 12 such that the
`heating element terminal end portions 28 and 30 extend
`through slot means 38 and 18 and are readily exposed
`exterior of the member 12. Plate member 36 is now
`positioned within the charmel-shaped member 12 in
`abutment with the insulator sheet 32. In this regard, the
`plate member 36 and the insulator sheets 32 and 34 are
`of about the same length and width as the channel-
`shaped cover member 12 so as to fit snugly therewithin.
`0n the other hand, the insulator sheet 26 associated with
`the heating element 20, while about the same length as
`the cover member 12, is preferably somewhat narrower
`than insulator strips 32 and 34 so as to provide a small
`gap 39 (FIG. 3) for electrical clearance between the
`resistance means 22 and 24 and the channel side portions
`14. When so positioned, the channel side portions 14 are
`folded tightly inwardly over plate member 36 to close
`the assembly as shown in FIG. 3. The members 12 and
`36 thereby form a sheath totally enclosing and encasing
`the internal components of the heater. The closed as-
`sembly is then rolled flat or is formed into a curved
`finished shape in accordance with known procedures.
`The assembly may be shaped, for example, into the
`configuration of a curved band heater as shown in FIG.
`1, or the assembly may be left in its extended form so as
`to be completed as a strip heater (not shown). After the
`forming step, the assembly is normally fired at an ele-
`vated temperature sufficient to vaporize and bake out
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`the binder materials associated with the insulator sheets
`26, 32 and 34.
`The sheath members 12 and 36 are typically con-
`structed of selected metals to provide high reflectivity,
`high emissivity and good conductive characteristics to
`efficiently transmit heat from the core element 20
`towards the plate member 36 which lies adjacent to the
`particular object or surface to be heated. For example,
`the channel-shaped cover member 12 is typically made
`of aluminized steel which has a highly reflective surface
`thereby directing the heat from the heater element 20
`back towards the part or surface to be heated. In con-
`trast, the plate member 36 is typically made of a zinc
`coated metal which has good emissivity. This increases
`the heat transfer rate through this relatively thin layer
`of metal to the part or surface to be heated. Also, the
`thickness of the insulation material positioned between
`the outer sheath member 12 and the heating element 20
`can be made greater as compared to the thickness of
`insulation sheet 32 so as to further direct the heat gener-
`ated by the heater element 20 towards the plate member
`36. Also, the insulator strips 26, 32 and 34 can be com-
`prised of different material compositions to further en-
`hance the heat transfer capabilities of the unit. All of
`these various combinations contribute to the overall
`efficiency of the heater.
`As can be seen from FIGS. 1 and 3, the terminal end
`portions 28 and 30 of the heater element 20 are readily
`exposed exterior of the upper cover member 12 for easy
`access and later connection to any one of a plurality of
`lead/terminal configurations as will be hereinafter ex-
`plained. The heater construction 10 can be fully manu-
`factured and stocked in such manner. Once an end user
`specifies a particular lead/terminal arrangement, such
`heaters can then be easily and quickly equipped to fill
`such order. This is extremely advantageous for all of the
`reasons previously explained.
`FIGS. 4 and 5 illustrate the construction and design
`of an improved clamping means 40 particularly adapt-
`able for use on a band type heater such as the basic band
`heater construction 10 illustrated in FIG. 1. More par-
`ticularly, clamp or attachment means 40 includes a pair
`of clamp bar members 42 and 44 each having an elon-
`gated slot 46 extending the full length thereof. The
`members 42 and 44 are each respectively attached to the
`outer cover member 12 through use of the tab members
`16, each slot 46 being dimensioned so as to insertably
`receive the tab 16 as best shown in FIG. 5. Once the tab
`members 16 are engaged with the bar members 42 and
`44, such members are then attached to each other by a
`staking or crimping process as illustrated in FIG. 5.
`Each bar member 42 and 44 likewise includes an
`opening 48 extending transversely therethrough at an
`intermediate location therealong, each such opening 48
`being in registration with each other and at least one of
`such openings 48 being adaptable to threadably receive
`a threaded fastening member such as the member 50
`(FIG. 4). Threading the fastener member 50 through at
`least one threaded bore 48 such as the threaded bore 48
`extending through the bar member 42 (FIG. 5) will
`draw the respective terminal end portions 52 and 54 of
`the heater 10 towards each other thereby securely fas-
`tening and clamping the heater 10 around the cylindri-
`cal object over which it is positioned. Although only
`the opening 48 extending through bar member 42
`(FIGS. 4 and 5) need be threaded in order to accom-
`plish this task, it is also recognized that the opening 48
`extending through bar member 44 may likewise be
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`60
`
`65
`
`5,359,179
`
`8
`threaded if so desired. When fully secured around the
`object to be heated, the tab members 16 carry and dis-
`tribute the load over the entire unit by means of the
`outer sheath member 12, thus eliminating the use of
`straps and other clamping mechanisms. This provides a
`more uniform load distribution over the internally
`housed heating element 20 and draws the heater tightly
`and evenly to the cylindrical surface to which it is at-
`tached. This assures a critical mating of the heater sur-
`face to the cylindrical surface to which it is attached
`thereby eliminating air gaps that can cause early fail-
`ures. Depending upon the overall width of the particu-
`lar band heater involved, each bar member 42 and 44
`may include any plurality of openings 48 spaced along
`the length thereof, each such opening on bar member 42
`being in registration with a corresponding opening posi-
`tioned on bar member 44 and each such respective pairs
`of openings 48 being adaptable to receive a threaded
`fastening member as previously described. This will
`provide sufficient clamping means to securely and
`evenly fasten wider heater units around the surface over
`which they are positioned along their entire width. The
`clamp mechanism 40 also simplifies the installation of
`such heaters by eliminating the need to align straps and
`terminals commonly associated with other clamping
`means.
`
`FIGS. 6 and 7 illustrate one embodiment of a spe-
`cially adapted add-on terminal connection member 56
`specifically adaptable for use when the termination
`option calls for a post terminal arrangement. The termi-
`nal connection or cap member 56 is somewhat oval in
`shape and includes a pair of openings 58 extending
`therethrough as best shown in FIG. 7. The cap member
`56 is formed of an aluminized steel material and likewise
`includes a downwardly extending peripheral flange or
`skirt portion 60 having a pair of triangularly-shaped
`weld projections or dimples 62 located respectively on
`at least two opposite sides thereof as best illustrated in
`FIG. 7. A pair of post terminals 64 each having a
`flanged head portion 65 associated respectively there-
`with are insertably positioned through the openings 58
`of the cap member 56 in such a way that both the termi-
`nals and the cap member are electrically isolated. This is
`accomplished by positioning a pair of insulator mem-
`bers 66 and 68 between the flanged head portions 65 of
`the post terminals 64 and the inside portion of the cap
`member 56 as shown in FIG. 6. Each of the insulator
`members 66 and 68 is preferably oval in shape so as to fit
`within the formed flange portion of the cap member 56
`and each includes a pair of openings extending there-
`through adapted to receive the post terminals 64 when
`inserted therethrough. The openings associated with
`insulator members 66 and 68 are positioned and located
`thereon so as to be in registration with the openings 58
`associated with the cap member 56. Once the post ter-
`minals 64 are shielded by the insulator members 66 and
`68 and are thereafter inserted through the openings 58
`as shown in FIG. 6, such terminals are held in engage-
`ment with the cap member 56 through use of the lock-
`ing nut members 70 or other suitable locking means. To
`further insulate the post terminals 64 from the upper
`surface portion of the cap member 56, any number of
`suitable insulating washers may be positioned therebe-
`tween such as the respective pairs of washers 72 illus-
`trated in FIG. 6. Although a particular construction and
`arrangement of insulator members 66, 68 and 72 are
`disclosed and described with respect to th