Fabricating machine for the surface of glass plates

Abstract: A machine for fabricating the surface of glass plates (6) to be fabricated, having an inlet section at which said glass plates are supplied and an outlet section from which the glass plates are taken out, said machine comprising means (1,9) for linearly conveying the glass plates from the inlet section to the outlet section, means (12) connected to the conveying means (1,9) for holding the glass plates (6), and a plurality of fabricating head devices (2) disposed in a row along the linear conveying direction of the conveying means, the fabricating head devices (2) execute different kinds of surface fabricating with respect to the glass plates held to the holding means (12), respectively.

Description: The present invention concerns a machine for preparing the surface of glass plates, for example a machine for preparing the surface of glass plates for producing rear view mirrors of automobiles by surface grinding and surface polishing. In previous machines for preparing the surface of glass plates for producing rear view mirrors, the surface of a glass plate after cutting into a predetermined shape (hereinafter simply referred to as a material mirror plate) has been put to grinding, smoothing and polishing machining and the material mirror plate has been finished to a shape of a rear view mirror, for example, a prismatic shape, by usually combining at least two kinds of fabricating machines as described below. In addition, for machining the material mirror plate, machining steps as described below have generally been required. At first, as the first machining step, a material mirror plate is roughly ground, for example, into a prismatic shape by means of a grinding machine. Then, as the second machining step, the roughly ground material mirror plate is further ground by lapping into a prismatic shape by means of a lapping machine capable of applying finer grinding than the grinding machine as described above. Then, if required, as the third machining step, finishing polishing is conducted by using a polishing machine which can apply a further finer finishing grinding than the lapping finishing as described above by using abrasives also as required. Each of the grinding machine, lapping machine and polishing machine as described above has a rotary plate capable of rotating and whereon the material mirror plate is secured horizontally. A fabricating head is positioned such that the material mirror plate secured to the rotary plate can be ground. The fabricating head is provided with a fabricating tool, such as a cup-shaped diamond wheel, a grindstone, etc. of roughness which is different depending on the degree of fabricating in each of the machining steps in the case of the grinding machine and the lapping machine, or attached with a felt wheel, etc. in the case of the polishing machine. Accordingly, in a known machine for fabricating the surface of glass plates for producing rear view mirrors as described above, the material mirror plate has to be put into and out of the fabricating machine on every machining steps for conducting the machining step, which is extremely inefficient and, as a result, brings about a drawback that it is difficult to increase the production speed for rear view mirrors. JP-A-63-62651 discloses a machine for fabricating glass plates according to the preamble of claim 1. The glass plates are conveyed past plural fabricating head devices while aligned transverse to the direction of motion. According to the present invention, there is provided a machine for preparing the surface of glass plates, each of which has a longitudinal direction, the machine having an inlet section at which said glass plates are supplied and an outlet section from which said glass plates are taken out, and comprising: conveying means for linearly conveying the glass plates along a linear conveying direction from said inlet section to said outlet section; holding means connected to said conveying means for holding the glass plates and including retaining members each having a horizontal direction and being so formed that a surface thereof retaining a respective one of said glass plates is inclined downwardly in substantially a single direction so that the surface of said glass plate to be fabricated is similarly inclined to the surface of said retaining member; and a plurality of fabricating head devices, including grinding and polishing wheels, for performing different fabricating steps, including grinding and polishing, on said glass plates, disposed in a row along said linear conveying direction of said conveying means, characterised in that: horizontal direction is arranged along said linear conveying direction and said surface is inclined in a direction transverse of said conveying direction such that said longitudinal direction of each glass plate is aligned with said linear conveying direction. The machine is preferably so adapted that each of the machining steps, which preferably include grinding, smoothing and polishing machining steps, can be applied successively and continuously without manual intervention at corresponding stages in the machine of the invention. With the machine according to the present invention glass plates which have already been cut into a predetermined shape (hereinafter simply referred to as material mirror plate) can be supplied successively in the course of producing for example rear view mirrors, means for grinding, smoothing and polishing and then the material mirror plates are finished into the shape of a rear view mirror, for example, to a prismatic shape while continuously applying grinding, smoothing and polishing to the surface of the material mirror plates. In order that the invention may be more clearly understood, the following description is given by way of example only, with reference to the accompanying drawings in which: Figure 1 is a front elevational view for one embodiment of a machine for fabricating the surface of glass plates according to the present invention. Figure 2 is a plan view for the embodiment of the machine for fabricating the surface of glass plates according to the present invention shown in Figure 1, Figure 3 is a side elevational view, in cross section, taken along line III - III for the embodiment of the fabricating machine according to the present invention shown in Figure 1, Figure 4 is an enlarged front elevational view for a portion of a machine for fabricating the surface of glass plates according to the present invention, Figure 5 is an enlarged perspective view for a portion of conveying means in the machine for fabricating the surface of glass plates according to the present invention, Figure 6 is an enlarged plan view for a portion of the conveying means in the machine for fabricating the surface of glass plates according to the present invention, Figures 7 and 8 are, respectively, partially cut away enlarged elevational views for a portion of suction means in the securing means for glass plates in the machine for fabricating the surface of glass plates according to the present invention, Figure 9 is an explanatory view for the suction means in the securing means for the glass plates in the machine for fabricating the surface of glass plates according to the present invention, and Figure 10 is a plan view for a material mirror plate applied with machining. Description is to be made for a preferred embodiment of the machine for fabricating the surface of glass plates according to the present invention referring to the drawings. As shown in Figure 1, the machine for fabricating the surface of glass plates of this embodiment comprises a machine frame 7, a conveyor device 1 as conveying means for linearly conveying a plurality of material mirror plates 6 in the state of applying machining, while arranging and securing them in a row in a predetermined direction, for example, in the right-to-left direction shown by the arrow 65, that is, in the advancing direction. A support frame 4 is mounted to the machine frame 7 and connected to the conveying device 1 for guiding the conveyor device 1 along the conveying direction. Suction devices 5 as securing means are connected to the conveyor device 1 for securing a plurality of material mirror plates 6 to the conveyor device 1 respectively, a plurality of fabricating heads 2 as fabricating head devices arranged in a row corresponding respectively to a plurality of material mirror plates 6 conveyed by the conveyor device 1 and fabricating wheels 3 are each mounted to the fabricating head 2 for applying a predetermined machining to each of a plurality of material mirror plates 6. The conveyor device 1 comprises a sprocket 8D and a sprocket 8T each disposed to the right and left ends of the machine frame 7 in Figure 1 and adapted to be rotatable around the axis in the direction crossing the conveying direction, an endless chain 9 laid over each of the sprocket 8D and the sprocket 8T and movable along the conveying direction and retaining members 12 each arranged along the conveying direction and attached through a mounting plate 11 to the endless chain 9. Shafts 8A and 8B disposed in the direction crossing to the conveying direction are fixedly connected to the sprocket 8D and the sprocket 8T respectively. The shafts 8A and 8B are supported in a canti-lever manner by means of bearings 36 and 36 mounted to the machine frame 7. Accordingly, the sprockets 8D and 8D can rotate by rotating of the respective shafts 8A and 8B. Particularly, the sprocket 8D is adapted for driving to convey the endless chain 9 and, as shown in Figure 2, a rotational driving force is transmitted from a motor 38 through a speed reducer 37. The endless chain 9 can be moved circulately by the rotation of the sprocket 8D in the direction shown by arrows 64 and 65. Further, each of the retaining members 12 is detachably mounted to a mounting plate 11 secured to each of the double-attachments 10A of a pair of ring plates 10 that constitute the endless chain 9 as shown in Figure 3 through Figure 5 respectively. Each of the mounting plates 11 is connected to the ring plate 10 at the double-attachment 10A of the ring plate 10 (refer to Figure 3). Further, as shown, particularly, in Figures 3 and 5, guide plates 13 and 13 disposed so as to put a pair of double attachments 10A respectively therebetween are mounted on both sides of the mounting plate 11. The guide plates 13 and 13 are arranged in a row along the conveying direction. Further, the guide plates 13 and 13 are supported by a pair of guide-way members 14 and 14 disposed on the support frame 4 at each of the lower faces 13A of the guide plates 13. The guide plates 13 are guided by a pair of side guide members 15 and 15 disposed on the support frame 4 on each of the side faces 13B. These guide-way members 14 and 14, and the side guide-members 15 and 15 are respectively disposed along the conveying direction, that is, along the endless chain 9. With such a constitution, the mounting plate 11 mounted with the guide plates 13 and 13 can be moved while being controlled and guided along the conveying direction. Accordingly, the retaining member 12 attached to the mounting plate 11 can also be guided and moved along the conveying direction, that is, in a linear way. Further, in the present embodiment, as shown in Figure 5, each of the retaining members 12 is so formed that a mirror suction face 16, onto which the material mirror plate 6 is secured by vacuum suction, is gradually inclined from above to below in Figure 2 and along the direction in perpendicular to the plane of the drawing sheet in Figure 1. Accordingly, the mirror suction face 16 is so formed as to have saw teeth shape as viewed from the front each in Figure 1 and Figure 4. The angle of inclination for the mirror suction face 16 is preferably determined depending on the prismatic angle in the prismatic shape of a rear view mirror to be fabricated (in the case of fabricating a prism). A rubber sheet 17 is appended on the surface of the mirror suction face 16. As shown in Figures 5 and 6 respectively, a perforation 18 is formed to the central portion of the rubber sheet 17. The rubber sheet 17 is so arranged and appended onto the mirror suction face 16 that a suction valve device 19 of a suction device 5 described later is situated to the portion of the perforation 18. As shown in Figure 5, a space 18A having a height corresponding to the thickness 17A of the rubber sheet 17 is defined with the perforation 18 and a partial surface 16A of the mirror suction face 16 exposed externally by the perforation 18, between the plate face 6A of the material mirror plate 6 and the retaining member 12 when the material mirror 6 is placed on the retaining member 12 (refer to Figure 8). The suction device 5 connected to the conveyor device 1 as described above is connected at the retaining member 12 so as to secure each of a plurality of material mirror plates 6 to the corresponding retaining member 12 under vacuum suction. The suction device 5 has a suction valve device 19 as shown in Figures 7 and 8 respectively. Further, the suction valve device 19 comprises a suction aperture 22 formed to the mirror suction face 16, and rod 23 contained vertically movably, in Figures 7 and 8, in the inside of the suction aperture 22, a valve body 24 connected to the rod 23 such that it can seal the suction aperture 22, a spring 25 for resiliently urging the valve body 24 upwardly in Figures 7 and 8, and a cover member 26 for supporting the spring 25. The valve body 24 and the spring 25 are contained to the inside of a valve chamber 27 in communication with the suction aperture 22. Further, the diameter of the valve chamber 27 is made greater than that of the suction aperture 22 and the valve chamber 27 is in communication with an ventilation aperture 20. As shown in Figure 7, in the suction valve device 19 having thus been constituted, if the material mirror plate 6 is not placed on the upper surface of the retaining member 12, that is, on the mirror suction face 16, the rod 23 is resiliently urged upwardly by the spring 25 and the top 28 of the rod 23 protrudes from the mirror suction face 16 and, as a result, the valve body 24 is in contact under pressure with the ceiling at the inside of the valve chamber to interrupt the communication between the suction aperture 22 and the valve chamber 27. As shown in Figure 8, in the suction valve device 19, if the material mirror substrate 6 is placed on the mirror suction face 16 of the retaining member 12, the rod 23 is pressed downwardly against the resilient urging force of the spring 25 by the weight of the material mirror plate 6 and, as a result, the valve body 24 is aparted from the ceiling at the inside of the valve chamber 27 to communicate the suction aperture 22 with the valve chamber 27. Accordingly, the suction aperture 22 is also in communication with the ventilation aperture 20 which is in communication with the valve chamber 27. Furthermore, as shown in Figure 2, a vacuum pump device 29 is connected through a vacuum hose 34 of the suction pipe device 21 to the ventilation aperture 20. Accordingly, when the material mirror plate 6 is placed on the mirror suction face 16 of the retaining member 12 and the rod 23 is depressed downwardly against the resilient urging of the spring 25 by the weight of the material plate 6, a space 18A is formed with each of the perforation 18 in the rubber sheet 17, the partial face 16A of the mirror suction face 16 exposed by the perforation 18 and the plate face 6A of the material mirror plate 6 in a case where the material mirror plate 6 is placed on the retaining member 12. Since each of the space 18A, suction aperture 22, the valve chamber 27 and the ventilation aperture 20 are in communication with each other and the space 18A is evacuated as shown by an arrow 66, the material mirror plate 6 can be sucked and secured on the retaining member 12. In this way, each of the material mirror plates 6 can be conveyed integrally with the retaining member 12 in a state being sucked and secured on the retaining member 12. As has been described above, the suction device 5 comprises a suction valve device 19, a ventilation aperture 20, a suction pipe device 21 and a vacuum pump device 29. Furthermore, as shown in Figures 5, 6 and Figure 9, the suction pipe device 21 comprises a plurality of T-shaped pipes 30 each connected to the opening 20A of the ventilation aperture 20 disposed on the side 12A for each of the retaining members 12 and a plurality of vacuum hoses 34 that constitute a flexible suction pipe loop 32 over the entire area of the conveyor device 1 while connecting the T-shaped pipes 30 with each other. Among such plurality of the T-shaped pipes 30, a T-shaped pipe 30A disposed, for example, as shown in Figure 9 (Figure 2) is attached with a rotary joint 33 (Figure 2) that can freely rotate around the axis in the direction crossing the conveying direction. The vacuum pump device 29 is connected to the rotary joint 33 through a flexible vacuum hose 34. Further, the vacuum hose 34 has such a sufficient length as capable of always controlling the operation of the suction valve device 19 through the rotary joint 33, that is, always capable of operation for fixing each of the material mirror plates 6 under vacuum suction and operation for releasing the vacuum fixing by means of each of the retaining members 12 even if the rotary joint 33 is moved over the entire circumference of the conveyor device 1. As shown in Figure 9, an excess portion of the vacuum hose 34 is taken-up to a take-up drum 35 so that the change of the relative distance, if resulted, between the rotary joint 33 and the take-up drum 35 due to the conveying operation of the conveyor device 1 can be resiliently absorbed by the taking-up or delivering operation of the take-up drum 35 to the vacuum hose 34. As shown in Figures 1 and 2 respectively, a plurality of fabricating heads 2 are arranged in a row above each of the retaining members 12 of the conveyor device 1 in Figure 1 corresponding to the position for each of the retaining members 12 in a row along the conveying direction of the conveyor device 1 in order to conduct different kinds of fabricatings, and they are connected respectively to a common bed device 40 laid above the machine frame 7 in Figure 1. As shown in Figures 1 and 3 respectively, each of the fabricating heads 2 comprises a motor spindle 41 serving as a motor and also as a spindle, and a shaft 43 for the motor spindle 41. A fabricating wheel 3 as a fabricating tool is mounted by way of an adaptor 42 to the shaft 43. Each of the fabricating heads 2 has a vertical slide device 39 so that the fabricating wheel 3 mounted to the fabricating head 2 can be brought closer or aparted from the upper surface for each of the retaining members 12 supported on the support frame 4, that is, the mirror suction face 16. Each of the vertical slide devices 39 is mounted to the common bed device 40. The vertical slide device 39 can conduct fine adjustment for the cutting degree by each of the fabricating wheels 3 mounted to each of the fabricating heads 2. Further, as shown in Figures 1 and 9, the fabricating head 2 attached with a felt wheel 3C, e.g., for polishing to be described later is so adapted that the shaft 43 of the motor spindle 41 is freely movable relative to the axial direction of the shaft 43. The shaft 43 is connected to an air cylinder device 45 attached to a bracket 44 mounted on the motor spindle 41. By the operation of the air cylinder device 45, the shaft 43 can be moved in the axial direction as described above and, for instance, in a case where polishing is applied by the felt wheel 3C of the fabricating head 2, the operation of the air cylinder device 45 is preferably controlled such that the felt wheel 3C is pressed against the material mirror plate 6 while being kept at an optimum state for conducting the polishing operation. It will be apparent that such an air cylinder device 45 can also be used to other machining steps as required. In addition, it is desirable to control operation of the air cylinder device 45 such that when the material mirror plate 6 has passed the machining region by the felt wheel 3C of the corresponding fabricating head 2, the felt wheel 3C returns in the direction opposite to that described above. In addition, it is desirable to conduct these control operations by a numerical value control device such as a microcomputer (not illustrated). Further, it is desirable that each of the fabricating heads 2 is set vertical from just above each of the corresponding retaining members 12 toward the retaining member 12. As has been described above, the fabricating wheel 3 is attached to each of the fabricating heads 2. Different kinds of fabricating wheels 3 are selected for mounting to the respective fabricating heads 2 corresponding to each of the machining steps, that is, grinding, smoothing, polishing, etc. as has been described above. For example, as shown in Figures 1 and 2 respectively, four diamond wheels 3A for grinding are at first disposed in a row from the right to the left in each of the drawings, that is, in the conveying direction of the conveyor device 1, then, four resin-diamond wheels 3B for smoothing which is finer grinding machining than the grinding described above and, further, four felt wheels 3C for applying finishing lustering, that is, for polishing are successively disposed to the portions machined by grinding and smoothing. Although the fabricating heads 2 are disposed each by four on every machining steps in this embodiment, the machine for fabricating the surface of glass plates according to the present invention is not necessarily limited only thereto and the number of the fabricating heads for each of the machining steps is preferably selected depending on the requirement. Further, although three machining steps are disposed in this embodiment, the machine for fabricating the surface of glass plates can also be constituted by properly combining the machining steps as required, for example, two machining steps e.g., a grinding step and a polishing step, or a smoothing step and a polishing step. Further, as shown in Figures 2 and 3 respectively, two coolant tanks 47 are disposed behind the machine frame 7. The coolant tanks 47 are disposed for recovering cooling water supplied during a series of machining operations as described above by a coolant supply device 60 comprising a spray nozzle 61, a spray pipe 62 and a spray pump 63 between the fabricating wheel 3 mounted to the fabricating head 2 and a portion to be machined of the material mirror plate 6 which is machined with the fabricating wheel 3 (refer to Figure 3), in the route shown by the arrow 47A and circulately delivering the recovered water again to the coolant supply device 60. The operation of the machine for fabricating the surface of glass plates in this embodiment is to be explained next. At first, each of the fabricating heads 2 connected with the common bed device 40 is adjusted by way of each of the vertical slide devices 39 connected to each of the fabricating heads 2 so that the relative distance for each of the fabricating wheels 3 mounted on each of the fabricating heads 2 to the portion of the material mirror plate 6 to be machined is aligned with each other. Then, the machine for fabricating the surface of glass plates is put under the operated state. When the machine for fabricating the surface of glass plates is put under the operation state, as the conveyor device 1 starts its conveying operation, the motor spindle 41 for each of the fabricating heads 2 is also put into operation, that is, the shaft 48 is started to rotate and, accordingly, the fabricating wheel 3 mounted to the shaft 43 is also started to rotate. In this state, material mirror plates 6 are successively supplied so that the material mirror plates 5 are placed on the mirror suction faces 16 of the successive retaining members 12 of the conveyor device 1. The material mirror plates 6 are conveyed linearly in a state being secured and placed on the mirror suction faces 16 of the retaining members 12 by the suction device 5 and successively undergo various kinds of surface machinings by various kinds of fabricating wheels 3 of fabricating heads disposed along the linear conveying direction in each of the machining steps. Figure 10 shows a material mirror plate 6 after undregoing machining. As has been described above, since the machine for fabricating the surface of glass plates according to the present invention has the foregoing constitution, glass plates to be machined, when merely supplied successively to the inlet section of the machine for fabricating the surface of glass plates, can be discharged continuously from the take-out section each in a state finished into a predetermined product. That is, since no operator's labour is required, production speed of the products can effectively be improved.

Claims: A machine for preparing the surface of glass plates, each of which has a longitudinal direction, the machine having an inlet section at which said glass plates (6) are supplied and an outlet section from which said glass plates are taken out, and comprising: conveying means (1) for linearly conveying the glass plates along a linear conveying direction from said inlet section to said outlet section; holding means (5) connected to said conveying means for holding the glass plates and including retaining members (12) each having a horizontal direction and being so formed that a surface thereof retaining a respective one of said glass plates is inclined downwardly in substantially a single direction so that the surface of said glass plate to be fabricated is similarly inclined to the surface of said retaining member; and a plurality of fabricating head devices (2), including grinding and polishing wheels, for performing different fabricating steps, including grinding and polishing, on said glass plates, disposed in a row along said linear conveying direction of said conveying means, characterised in that: said horizontal direction is arranged along said linear conveying direction and said surface is inclined in a direction transverse of said conveying direction such that said longitudinal direction of each glass plate is aligned with said linear conveying direction. A machine according to claim 1, wherein said conveying means includes an endless chain (9) which is circulated. A machine according to claim 1 or 2, wherein said holding means is adapted to hold said glass plates by means of a vacuum suction device. A machine according to any one of claims 1 to 3, wherein said plurality of fabricating head devices includes a grinding wheel, a smoothing wheel and a polishing wheel. A machine according to claim 3 or 4, wherein said holding means includes means for applying reduced pressure to the lower sides of the glass plates, and said applying means is activated when the plate is laid on said holding means. A machine according to claim 5, wherein said holding means includes a valve (19) actuable by a pin (23) which is depressed when the plate is laid on said holding means. A machine according to any one of claims 1 to 6, wherein said holding means is provided with a resilient surface (17). A machine according to any one of claims 1 to 7, wherein said fabricating head devices are vertically movable. A machine according to any one of claims 1 to 8, including guide plates (13) for said holding means on each side of said conveying means.

Inventors: BANDO SHIGERU, BANDO, SHIGERU
Applicants: BANDO KIKO CO, BANDO KIKO CO., LTD
Application year: 1989
Main classification: B24B7
IPC codes: B24B7