GB2308414A

GB2308414A - Making a brake shoe

Info

Publication number: GB2308414A
Application number: GB9603210A
Authority: GB
Inventors: Haruo Komine; Masanao Takeuchi
Original assignee: Japan Brake Industrial Co Ltd
Current assignee: Japan Brake Industrial Co Ltd
Priority date: 1995-11-24
Filing date: 1996-02-15
Publication date: 1997-06-25
Anticipated expiration: 2016-02-15
Also published as: GB9603210D0; KR970027910A; JPH09144793A; AU676651B1; KR0170814B1; GB2308414B

Abstract

A friction lining 3 is bonded to a metallic brake shoe body 1, which comprises a shoe rim 11, parallel flanges 12, and substantially facing ends 13, by laminating the friction lining on the shoe rim with an adhesive 2 disposed therebetween, and electrically charging the brake shoe body through a pair of electrodes 51 pressed against both ends of the brake shoe body while the laminate-composite is pressed by means 6. The pressure applied to the electrodes is controlled so that the brake shoe body is heated uniformly to cure the adhesive. The brake shoe is locked in position by radially movable members 411 and is supported by lower and upper blocks (7, 91 Figure 9), which members and blocks are formed of steel flame-coated with ceramic.

Description

METHOD AND APPARATUS FOR PRODUCING BRAKE SHOE BACKGROUND OF THE INVENTION (a) Field of the Invention The present invention relates to a method of producing a brake shoe for drum brake assembly and to an apparatus suitable for the method.

(b) Description of the Related Art In prior art methods of producing brake shoes for drum brake assemblies by bonding friction linings to brake shoe bodies with adhesives, a thermosetting adhesive is applied on each of a brake shoe body and a friction lining, dried, and after the brake shoe body and the friction lining are pressed together with a pressure jig, cured in a thermosetting furnace by blowing hot blast on the brake shoe body and the friction lining pressed together.

The curing of the thermosetting adhesive by the hot-blast-heating involves the problems that rapid curing is difficult due to the low heat transfer efficiency thereof, and that efficient, local heating of the part coated with the adhesive is impossible since other parts including the pressure jig, conveyer devices and furnace walls are also heated. As a means of solving these problems and enabling the downsizing of apparatuses and rapid heat treatment, heating by high-frequency induction is proposed in Japanese Patent Application Kokai Koho (Laid-open) No. 61-153026.

This method enables rapid heat treatment but involves a problem of low heating efficiency due to the indirect heating by eddy current. There is another problem that coils of complicated forms and complicated apparatuses are required to heat brake shoe bodies of complicated shapes uniformly.

As a method of bonding brake shoe bodies with friction linings efficiently at a low cost by using a small and simple apparatus, in Japanese Patent Application Kokai Koho (Laid-open) No. 7-179824 is disclosed a method wherein when a friction lining and a metallic brake shoe body including a shoe rim are heated and pressed with an adhesive disposed therebetween to bond them into one body, the heating is performed by making the brake shoe body generate Joule's heat by electrically charging the brake shoe body through two electrodes pressed against both ends of the shoe rim.A problem with the method of making the brake shoe body generates heat by the directly electrical charging is that when the contact between the electrodes and the brake shoe body is insufficient, the parts near the contacting points generate such a high heat due to contact resistance that uniform heating cannot be performed. Even if the contact resistance is decreased as low as possible to the contrary, heating may also become ununiform due to the transfer of heat to the electrodes, or depending on the structure of the apparatus supporting the brake shoe body.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method wherein bonding of a friction lining to a brake shoe body having a shoe rim by heating and pressing them with an adhesive disposed between the friction lining and the shoe rim can be made in a short time with a high thermal efficiency, and uniform heating can be performed easily.

Another object of the present invention is to provide an apparatus suitable for the method.

As a result of researches for solving the problems, the inventors found that when a metallic brake shoe body is made to generate heat bydirectly electrical charging through electrodes pressed against the both ends of the brake shoe body, the brake shoe body can be heated uniformly by controlling the contact resistance at the contacting points by a proper control of the pressure under which the electrodes are pressed against the brake shoe body.The inventors further found that the heat transfer through the contacting surfaces and the difference in the temperatures of the parts near the contacting surfaces and other parts can be decreased by holding the brake shoe body during the heating and pressing treatment with holding devices of electrically and thermally insulating materials and by decreasing the contacting areas between the holding devices and the brake shoe body as small as possible. On the basis of these findings, the inventors have completed the present invention.

That is, the present invention provides a method of producing a brake shoe for a drum brake assembly by bonding a friction lining to a brake shoe body which is made of metal, is curved into a form of a substantially circular arc and comprises a shoe rim which is curved into a form of a substantially circular arc having substantially opposed two ends, and a pair of parallel flanges which project radially inwardly from both side edges of the shoe rim, the shoe rim, at each of the two ends thereof, being radially inwardly folded in two with the flanges brought into contact with the folded shoe rim, to provide the brake shoe body at two ends of the circular arc with two end surfaces which include their respective flat faces facing each other, which method comprises laminating at least one friction lining on a radially outer surface of the shoe rim with an adhesive disposed therebetween to form a laminate-composite, pressing a pair of electrodes against the two ends of the brake shoe body so that the electrodes are in contact at least with the two flat faces of the two end surfaces of the brake shoe body, and electrically charging the brake shoe body to make it generate heat while the laminate-composite is pressed and the pressure under which the electrodes are pressed against the two ends of the brake shoe body is adjusted so that every part of the brake shoe body generates uniform heat.

The present invention further provides an apparatus which is suitably used for performing an embodiment of the above-described method. That is, the apparatus of the present invention is an apparatus for producing a brake shoe for a drum brake assembly by laminating at least one friction lining on a brake shoe body with an adhesive disposed therebetween and heating and pressing the laminate-composite, the brake shoe body being made of metal, being curved into a form of a substantially circular arc and comprising a shoe rim which is curved into a form of a substantially circular arc having substantially opposed two ends, and a pair of parallel flanges which project radially inwardly from both side edges of the shoe rim, the shoe rim, at each of the two ends thereof, being radially inwardly folded in two with the flanges brought into contact with the folded shoe rim, to provide the brake shoe body at two ends of the circular arc with two end surfaces which include their respective flat faces facing each other, the friction lining being laminated on a radially outer surface of the shoe rim with the adhesive disposed therebetween to form the laminate-composite, which apparatus comprises a supporting means for supporting the laminate-composite horizontally with an outer surface of one of the flanges looking downward, the supporting means comprising plural supporting blocks of standing postures which are made of steel, are flame-coated with ceramic and have their respective upper surfaces coming, respectively, into contact with the outer surface of the flange looking downward and with an outer surface of the lining looking downward at plural parts of the laminate-composite;; a locking means for locking the supported laminated composition into place, the locking means comprising plural locking members made of steel and flame-coated with ceramic and a means for bringing the locking members radially outwardly from inside of the circular arc of the brake shoe body so that the locking members come into contact with the radially inner edges of the flanges, respectively, at plural parts of the brake shoe body and moving the locking members away from the edges of the flanges to release the locking; an electrically charging means comprising a pair of electrodes for electrical charging, a pressing device and a power supply means to which the electrodes are connected, the electrodes having their respective flat faces which, respectively, are able to be in contact with the flat faces of the end surfaces of the brake shoe body, the pressing device bringing the flat faces of the electrodes into contact with the flat faces of the end surfaces of the brake shoe body of the locked laminate composite, pressing the flat faces of the electrodes against the flat faces of the end surfaces of the brake shoe body at a controllable pressure and moving the electrodes away from the end surfaces of the brake shoe body to release the contact, the power supply means electrically charging the brake shoe body to make it generate heat while the flat faces of the electrodes are pressed against the flat faces of the end surfaces of the brake shoe body; and a pressing means which is located radially outside the circular arc of the brake shoe body of the locked laminate-composite and presses the friction lining of the laminate-composite against the radially outer surface of the shoe rim.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a plan view of a brake shoe body which is used in a method of an embodiment according to the present invention.

Fig. 2 shows a side view of the brake shoe body of Fig. 1 from the direction of the arrow X.

Fig. 3 shows a partially expanded side view of the brake shoe body of Fig. 1 from the direction of the arrow Y.

Fig. 4 shows a plan view of a laminate-composite which is used in a method of an embodiment according to the present invention.

Fig. 5 shows a side view of the laminated composition of Fig. 4 from the direction of the arrow X.

Fig. 6 shows a perspective view of the laminatecomposite of Fig. 4.

Fig. 7 shows a side view of a brake shoe body which is used in a method of an embodiment according to the present invention.

Fig. 8 shows a plan view of an apparatus of an embodiment according to the present invention.

Fig. 9 shows a partially sectional view of the apparatus of Fig. 8.

Fig. 10 shows another partially sectional view of the apparatus of Fig. 8.

Fig. 11 shows a partially side view of the apparatus of Fig. 8.

Fig. 12 shows a bottom view of the apparatus of Fig. 10 from the direction of the arrow A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The brake shoe body used in the present invention is a part of a drum brake assembly and has a shape of a substantially circular arc extending close to a substantial circle.

Fig. 1 shows a plan view of a brake shoe body which is used in a method of an embodiment according to the present invention, and Fig. 2 shows a side view of the brake shoe body of Fig. 1 from the direction of the arrow X. The brake shoe body 1 includes a shoe rim 11 which is curved into a form of a substantially circular arc having substantially opposed two ends, and a pair of parallel flanges 12 project radially inwardly from both side edges of the shoe rim 11.

At each of the two ends, the shoe rim 11 is radially inwardly folded in two to come into contact with flanges 12. Fig. 3 shows a partially expanded side view of the brake shoe body 1 of Fig. 1 from the direction of the arrow Y and shows one end where the folded shoe rim 11 form an M-shape together with the flanges 12. Thus the brake shoe body 1 is provided at two ends 13 thereof with two end surfaces 14 which include their respective flat faces 141 facing each other.

In a drum brake assembly, the brake shoe produced by the method of the present invention is held in position in a drum by fitting the two ends 13 thereof into two end openings of a tubular sleeve. The tubular sleeve contains an actuating mechanism capable of expansion and contraction, and the actuating mechanism has at each end thereof a groove in which the ends 13 of the brake shoe body 1 locate, so that the brake shoe expands and contracts radially in response to the expansion and contraction of the actuating mechanism.

Expanding the actuating mechanism expands the brake shoe and brings the friction lining into contact with the inner surface of the drum to actuate the drum brake assembly, and contracting the actuating mechanism releases the expansion of the brake shoe and retracts the friction lining from its contact with the inner surface of the drum to release the brake-on conditions. The brake shoe body, therefore, is preferably made of a metal having a high rigidity and a sufficient elasticity, such as mild steel.

In the method according to the present invention, first, at least one friction lining is laminated on the radially outer surface of the shoe rim of a brake shoe body with an adhesive disposed therebetween, to obtain a laminatecomposite. Fig. 4 shows a plan view of a laminate-composite of an embodiment, Fig. 5 shows a side view of the laminatecomposite of Fig. 4 from the direction of the arrow X, and Fig. 6 shows a perspective view of the laminate-composite of Fig. 5.Although the laminate-composite of this embodiment comprises a brake shoe body 1 and two friction linings 3 which is laminated on the radially outer surface of the shoe rim 11 of the brake shoe body 1 with an adhesive 2 disposed therebetween, the numbers and shapes of the friction linings 3 may be varied according, for example, to the conditions and apparatuses which will be employed in the following heating and pressing treatment. Where the side edges of the shoe rim 11 are rounded, it is preferable to laminate the friction linings 3 only on the part not rounded, as shown in Fig. 7.

The friction linings provide the brake shoe with friction surfaces and are made of non-conductive, nonmetallic materials. For example, the friction linings are produced by mixing short fibers of asbestos, glass or plastics with a binder, such as a thermosetting resin, and heating and pressing the mixture into a curved plate which can be fit on the radially outer surface of the shoe rim.

The lamination is generally performed by applying an adhesive on the radially outer surface of the shoe rim of the brake shoe body and on the radially inner surfaces of the curved friction linings, drying the adhesive by blowing hot blast or the like, and then laminating the friction linings on the shoe rim with the adhesive layers disposed therebetween. Examples of suitable adhesives are thermosetting adhesives, such as phenolic resin or epoxy resin thermosetting adhesives which are highly resistant to impact, bending and peeling.

When carrying out the method of the present invention, it is preferable to lock the laminate-composite into place by using plural locking members made of steel and flame-coated with ceramic. In this embodiment, the laminatecomposite is locked into place by pressing the plural locking members against plural parts of the radially inward edges of the flanges. Locking by the contact of the plural locking members with the plural parts of the edges of the flanges minimizes the contacting areas between the locking members and the brake shoe body, thereby effectively preventing the ununiformity in the temperature of the brake shoe body due to the heat transfer to the locking members.The locking members made of steel is strong enough to stand the pressure applied to the laminate-composite during pressing, and the heat insulating and heat resistant ceramic coating prevents electric charging and heat transfer to the locking members.

A pair of electrodes for electric charging are pressed against the two ends of the brake shoe body so that the electrodes are in contact at least with the flat faces of the two end surfaces of the brake shoe body of the locked laminate-composite. Then the brake shoe body is electrically charged directly to generate heat, while the laminatecomposite is being pressed. The electrodes may be pressed against the ends of the brake shoe body so that the electrodes are in contact only with the flat faces of the two end surfaces of the brake shoe body. Thermosetting adhesives are cured by the'heat generated by the electric charging, and the friction linings are bonded strongly to the shoe rim.

If an electric current is passed through the brake shoe body in a state where the contact of the electrodes with the flat faces of the end surfaces of the brake shoe body is insufficient, the end parts of the brake shoe body 11 encircled by the chain line A in Fig. 4 will generate high heat, so that uniform heating cannot be performed. If the contacting area is too large, the overheating due to contact resistance will be decreased, but the temperature of the parts A will be lowered by the heat transfer to the electrodes and uniform heating cannot be made.

If the brake shoe body is not heated uniformly, the friction linings also cannot be bonded uniformly. Brake shoe bodies are generally coated with various coatings, such as corrosion-proof primer. Another problem which may arise in the overheated parts is the deterioration or discoloration of the coatings, which deteriorates the quality of the product brake shoe.

According to the present invention, the pressure under which the electrodes are pressed against the brake shoe body is controlled to control the contact between the electrodes and the flat phases of the end surfaces of the brake shoe body, thereby enabling uniform heating.

The brake shoe body used in the present invention is also advantageous in that it generates heat easily since its long thin shape curved into a substantially circular arc close to a circle provides the brake shoe body with a large resistance due to the long electric passage between the end surfaces of the circular arc shape through which an electric current is passed. Further, the folded end surfaces of the brake shoe body facilitate the formation of the flat faces which are used for making uniform contact with the electrodes.

The laminate-composite is pressed while the brake shoe body is made to generate heat by the directly electric charging.

The electric current passing through the brake shoe body may be varied depending on the material of the brake shoe body and the kind of the adhesive, and it is generally preferable to pass an electric current of 2 to 20 V and 800 to 1,500 A so that the whole brake shoe body is heated uniformly at 220 to 280 C. The pressure applied to the laminate-composite is generally 7 kg/cm2 or more, preferably 7 to 20 kg/cm2.

For example, when an electric current of 3 V/1,000 A is passed through the brake shoe body while the laminatecomposite is pressed at a pressure of 10 kg/cm2, thermosetting adhesives are cured in two to five minutes by the heat generated by the brake shoe body and exhibit sufficient adhesion strength. Although the pressing and heating may be stopped simultaneously, it is preferable to continue the pressing for one to two minutes after the heating is stopped, to level the curing distortion of the adhesive.

During the heating and pressing treatment, the radially outer surfaces of the shoe rim of the parts bearing no friction lining may be covered with covering members of the same thermal conductivity as that of the friction linings to prevent the increase in temperature of the brake shoe body of this parts.

To prevent the slippage of the friction linings during the heating and pressing, stoppers having electrically and thermally insulating properties and heat resistance, such as stoppers made of ceramic or made of steel and flame-coated with ceramic, may be applied on the outside of one or both of the flanges of the laminate-composite and in contact with the friction linings, the exposed side of the adhesive layers and the flanges at least partially. In such cases, it is also preferable not to apply the stoppers completely along the flanges at the laminated parts, but to apply plural small stoppers per laminated part to minimize the total contacting area and to minimize the difference in the temperature of the brake shoe body due to the contact.

In the method according to the present invention, the energy efficiency is high since the brake shoe body alone is heated by the Joule'sheat generated by the directly electric charging, and the brake shoe body can be heated uniformly by controlling the pressure under which the electrodes for the electric charging are pressed against the brake shoe body. Further, the uniform temperature of the brake shoe body can be maintained during the heating and pressing treatment since the contacting area between the brake shoe body and the locking members is small and the locking members are coated with ceramic which is excellent in heat insulating property. The bonding of friction linings to brake shoe bodies, therefore, can be performed efficiently, uniformly and rapidly according to the method of the present invention.The method of the present invention is also excellent in operation efficiency since the pressing conditions can be made easily and maintained securely.

Fig. 8, Fig. 9, Fig. 10, Fig. 11 and Fig. 12 show various view of an apparatus of an embodiment according to the present invention, which is suitable for the method of the present invention.

Fig. 8 is a plan view of an apparatus of an embodiment according to the present invention, which includes a locking means 4 including plural locking members 411 flamecoated with ceramic, an electrically charging means 5 including electrodes 51 for directly electric charging, and two pressing means 6. Fig. 9 shows a partially sectional view of the apparatus of Fig. 8 for illustrating the locking means 4 and a supporting means for placing a laminatecomposite horizontally, wherein, for convenience of explanation, both a sectional view of the supporting means and a sectional view of the locking means 4 on different vertical sections are shown in one drawing. Fig. 10 is a partially sectional view for illustrating the electrically charging means 5.

The locking means 4 includes a central block 42 which is moved up and down by an air cylinder 43, and the block 42 has a standing cylindrical shall comprising a lower shell 421 of a larger diameter, an upper shell 423 of a smaller diameter and a taper shell 422 connecting the lower shell 421 with the upper shell 423. Around the block 42, plural pins 41 held in cylinders 43 are arranged radially, and each pin 41 has an end contacting to the shell of the block 42 and another end forming a locking member 411. The plural locking members 411 are in contact with the edges of the flanges of a brake shoe body 1 to lock the laminatecomposite into place. By moving the block 42 up and down, pins 41 move radially in the directions directed by the sliding thereof in the cylinders 43 as the diameter of the shell changes, to bring the locking members 411 into contact with or apart from the edges of the flanges.

The supporting mean in this embodiment comprises plural supporting blocks 7 of standing postures which are made of steel and arranged along the substantially circular arc shape of the laminate-composite. Each supporting block 7 has coating of flame-coated ceramic at least on an upper surface 71, and the laminate-composite is supported horizontally by the supporting members 7 with the friction lining 3, an exposed side of the layer of the adhesive 2 and one flange on the bottom side of the supported laminatecomposite being partially in contact with the upper surfaces 71. Also the upper surfaces 71 of the supporting blocks 7 which are in contact with plural parts of the bottom side of the laminate-composite prevent the friction linings from slipping or widthwise stretching during the heating and pressing treatment for curing the adhesive.That is, the supporting blocks 7 act also as the stoppers described above.

As shown in Fig. 9, the apparatus of this embodiment includes an upper stopper 9 for insuring the prevention the slipping or widthwise stretching of the friction linings. Fig. 11 is a partially side view of the upper stopper 9, Fig. 12 is a bottom view of the upper stopper 9 of Fig. 11 from the direction of the arrow A. The upper stopper 9 includes plural stopper blocks 91 which are made of steel and are flame-coated with ceramic at least on the bottom surfaces 911 thereof which will come into contact partially with the friction linings 3 and the flange on the upper surface of the horizontally placed laminate-composite.

The upper stopper 9 is moved up and down by an air cylinder 92. When the upper stopper 9 is moved down, the bottom surfaces 911 of the stopper blocks 91 come into contact with plural parts of the laminate-composite to hold the friction linings into place, and the contact is released by moving the upper stopper 9 upward. In Fig. 12, the laminate-composite that will come into contact with the stopper blocks 91 are shown by chain lines.

The lower ends of the electrodes 51 of the electrically charging means 5 are connected to and held by a power supply means (not shown). At the upper end parts thereof, one side of each electrode is facing to the end surface of the brake shoe body, and the other sides of the electrodes opposed to each other are fixed, respectively, to two pressing jigs 52 of a plate-shape which are arranged in parallel to each other and extending toward the radially outside of the circular arc of the laminate-composite, with two insulating plates 56, respectively, disposed between the electrodes 51 and the pressing jigs 52. The two pressing jigs 52 are jointed with each other by a spring 54 which is loosely plugged in two cavities made, respectively, in the opposed positions of the pressing jigs 52.When the brake shoe body 1 is not electrically charged, the contact between the end parts of the electrodes 51 and the end surfaces 14 of the brake shoe body 1 is released by the spring force of the spring 54. When the pressing jigs 52 are pressed at a radially more outer position than the spring 54 toward each other by a pair of air cylinders 53 with a pressure perpendicular to the plate surfaces, two supporting blocks 55 acts as supporting points, and the electrodes 51 are brought into contact with the end surfaces 14 of the brake shoe body 1, respectively. In this embodiment, the pressing device of the apparatus of the present invention includes the pressing jigs 52, the insulating plates 56, the spring 54, the air cylinders 53 and the supporting blocks 55.The contact between the electrodes 51 and the flat faces 141 of the end surfaces 14 of the brake shoe body 1 can be controlled by controlling the pressure applied by the air cylinders 53.

Each pressing means 6 includes a pressing band 61 which is made of a spring material and has a part curved to form a surface corresponding to the radially outer surface of the friction lining 3 of the laminated-component, holders 62 for holding the pressing band 61, a hydraulic cylinder 63 for bringing the pressing band 61 held by the holders 62 from the radial outside of the brake shoe body into contact with the friction lining 3 to apply a pressure and moving the pressing band 61 away therefrom to release the pressure, and a pair of hydraulic cylinders 64 for supplementing the pressure applied to the both ends of the friction lining 3.While the laminate-composite is pressed by the pressing means 6, the brake shoe body 1 is directly electrically charged by the electrically charging means 5 to generate heat, and thus the brake shoe body 1 and the friction linings 3 are bonded strongly by the adhesive 2.

At a radial outside of the laminate-composite is provided a device 8 for bringing a contacting member 81 of approximately the same thermal conductivity with that of the friction linings into contact with the part of the radially outer surface of the shoe rim where no friction lining is laminated. The device 8 includes the contacting member 81 and an air cylinder 82 which brings a contacting surface of the contacting member 81 into contact with the radially outer surface of the shoe rim and moves it away to release the contact. During the heating and pressing treatment, the contacting member 81 is held in contact with the exposed part of the radially outer surface of the shoe rim, to prevent the temperature of this part from increasing than other laminated parts.

Claims

What is claimed is,

1. A method of producing a brake shoe for a drum brake assembly by bonding a friction lining to a brake shoe body which is made of metal, is curved into a form of a substantially circular arc and comprises a shoe rim which is curved into a form of a substantially circular arc having substantially opposed two ends, and a pair of parallel flanges which project radially inwardly from both side edges of the shoe rim, the shoe rim, at each of the two ends thereof, being radially inwardly folded in two with the flanges brought into contact with the folded shoe rim, to provide the brake shoe body at two ends of the circular arc with two end surfaces which include their respective flat faces facing each other, which method comprises laminating at least one friction lining on a radially outer surface of the shoe rim with an adhesive disposed therebetween to form a laminate-composite, pressing a pair of electrodes against the two ends of the brake shoe body so that the electrodes are in contact at least with the two flat faces of the two end surfaces of the brake shoe body, and electrically charging the brake shoe body to make it generate heat while the laminate-composite is pressed and the pressure under which the electrodes are pressed against the two ends of the brake shoe body is adjusted so that every part of the brake shoe body generates uniform heat.

2. The method of claim 1, comprising laminating the friction lining on a radially outer surface of the shoe rim with the adhesive disposed therebetween to form the laminate-composite, locking the laminate-composite into place by bringing plural locking members into contact with plural parts of the radially inner edges of the flanges, the locking members being made of steel and flame-coated with ceramic, pressing the electrodes against the two flat faces of the two end surfaces of the brake shoe body, and electrically charging the brake shoe body to make it generate heat while the laminate-composite is pressed and the pressure under which the electrodes are pressed against the two flat faces of the two end surfaces of the brake shoe body is adjusted so that every part of the brake shoe body generates uniform heat.

3. An apparatus for producing a brake shoe for a drum brake assembly by laminating at least one friction lining on a brake shoe body with an adhesive disposed therebetween and heating and pressing the laminate-composite, the brake shoe body being made of metal, being curved into a form of a substantially circular arc and comprising a shoe rim which is curved into a form of a substantially circular arc having substantially opposed two ends, and a pair of parallel flanges which project radially inwardly from both side edges of the shoe rim, the shoe rim, at each of the two ends thereof, being radially inwardly folded in two with the flanges brought into contact with the folded shoe rim, to provide the brake shoe body at two ends of the circular arc with two end surfaces which include their respective flat faces facing each other, the friction lining being laminated on a radially outer surface of the shoe rim with the adhesive disposed therebetween to form the laminate-composite, which apparatus comprises a supporting means for supporting the laminate-composite horizontally with an outer surface of one of the flanges looking downward, the supporting means comprising plural supporting blocks of standing postures which are made of steel, are flame-coated with ceramic and have their respective upper surfaces coming, respectively, into contact with the outer surface of the flange looking downward and with an outer surface of the lining looking downward at plural parts of the laminate-composite;; a locking'means for locking the supported laminated composition into place, the locking means comprising plural locking members made of steel and flame-coated with ceramic and a means for bringing the locking members radially outwardly from inside of the circular arc of the brake shoe body so that the locking members come into contact with the radially inner edges of the flanges, respectively, at plural parts of the brake shoe body and moving the locking members away from the edges of the flanges to release the locking; an electrically charging means comprising a pair of electrodes for electrical charging, a pressing device and a power supply means to which the electrodes are connected, the electrodes having their respective flat faces which, respectively, are able to be in contact with the flat faces of the end surfaces of the brake shoe body, the pressing device bringing the flat faces of the electrodes into contact with the flat faces of the end surfaces of the brake shoe body of the locked laminate composite, pressing the flat faces of the electrodes against the flat faces of the end surfaces of the brake shoe body at a controllable pressure and moving the electrodes away from the end surfaces of the brake shoe body to release the contact, the power supply means electrically charging the brake shoe body to make it generate heat while the flat faces of the electrodes are pressed against the flat faces of the end surfaces of the brake shoe body; and a pressing means which is located radially outside the circular arc of the brake shoe body of the locked laminate-composite and presses the friction lining of the laminate-composite against the radially outer surface of the shoe rim.

4. A method of producing a brake shoe for a drum brake assembly substantially as herein described with reference to the accompanying drawings.

5. Apparatus for producing a brake shoe for a drum brake assembly substantially as herein described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS 1. A method of producing a brake shoe for a drum brake assembly by bonding at least one friction lining to a brake shoe body which is made of metal, is curved into a form of a substantially circular arc and comprises a substantially circular shoe rim having two substantially opposed ends, and a pair of parallel flanges each of which projects radially inwardly from a respective side edge of the shoe rim, the shoe rim, at each of the two ends thereof, being radially inwardly creased with the flanges brought into contact with the folded shoe rim, to provide the brake shoe body with two, substantially opposed, flat-faced ends;; which method comprises laminating at least one friction lining onto a radially outer surface of the shoe rim with an adhesive disposed therebetween to form a laminate-composite, pressing a pair of electrodes against the two ends of the brake shoe body so that the electrodes are in contact with the flat faced ends of the brake shoe body, and electrically charging the brake shoe body such that it generates heat whilst the friction lining of the laminatecomposite is pressed against the radially outer surface of the shoe rim and the pressure under which the electrodes are pressed against the two ends of the brake shoe body is adjusted so that the brake shoe body is heated uniformly.

2. The method of Claim 1, further comprising locking the laminatecomposite into place by bringing a plurality of locking members into contact with the radially inner edges of the flanges, the locking members being made of steel and being flame-coated with ceramic.

3. An apparatus for producing a brake shoe for a drum brake assembly by laminating at least one friction lining onto a brake shoe body with an adhesive disposed therebetween and heating and pressing the laminate-composite, the brake shoe body being made of metal, and comprising a substantially circular shoe rim having two substantially opposed ends, and a pair of parallel flanges each of which projects radially inwardly from a respective side edge of the shoe rim, the shoe rim, at each of the two ends thereof, being radially inwardly creased with the flanges brought into contact with the folded shoe rim, to provide the brake shoe body with two, substantially opposed, flat-faced ends;; the friction lining being laminated on a radially outer surface of the shoe rim with the adhesive disposed therebetween to form the laminate-composite, which apparatus comprises a supporting means adapted to supporting the laminate-composite horizontally with an outer surface of one of the flanges directed downwardly, the supporting means comprising a plurality of supporting blocks which are flame-coated at least on an upper surface thereof with ceramic and have their respective upper surfaces contacting respectively the downwardly directed outer surface of the flange and a corresponding downwardly directed outer surface of the lining at a plurality of points of the assembled laminate-composite;; a locking means adapted to lock the supported laminate-composite into place, the locking means comprising a plurality of locking members flame-coated with ceramic and a means for extending the locking members radially outwardly from inside of the circular arc of the brake shoe body so that the locking members come into contact with the radially inner edges of the flanges, and moving the locking members away from the edges of the flanges to release the locking;; an electrical charging means comprising a pair of electrodes for electrical charging, a pressing device and a power supply means to which the electrodes are connected, the electrodes having flat faces which, respectively, are able to contact the flat faced ends of the brake shoe body, the pressing device bringing the flat faces of the electrodes into contact with the flat faced ends of the brake shoe body of the locked laminatecomposite, pressing the flat faces of the electrodes against the flat faced ends of the brake shoe body at a controllable pressure and moving the electrodes away from the ends of the brake shoe body to release the contact, the power supply means electrically charging the brake shoe body to generate heat while the flat faces of the electrodes are pressed against the flat faced ends of the brake shoe body; and a pressing means which is located radially outside the circular arc of the brake shoe body of the locked laminatecomposite and presses the friction lining of the laminatecomposite against the radially outer surface of the shoe rim.