Spindle Support Assembly In A Glass Plate Edge Grinding Machine

Abstract

A spindle support assembly in a glass plate edge grinding machine comprises a support member provided on a spindle for a grinding wheel through a bearing, a resilient member fixed to the outer portion of said support member, a holding member adapted to hold said resilient member from the outside thereof, a clamp member disposed between said support member and said holding member, and a friction member inserted between the lower face of said clamp member and the upper face of said resilient member axially opposite to each other.

Description

The present invention relates to a support assembly, especially to a support assembly for a holding shaft or a spindle for a grinding wheel in a glass plate edge grinding machine.

The spindle in a glass plate edge grinding machine heretofore in use is provided with a grinding wheel fixed to the end thereof and rotatably mounted within a housing through a bearing, said housing being fixed to a movable mount for the grinding wheel, and consequently the axis of the spindle cannot substantially move in the radial direction.

The profiles of the glasses to be ground are various in shapes thereof such as a rectangle, a polygon or an ellipse. So, if the reaction force against the grinding resistance increases abruptly due to the movement of the grinding point of the grinding wheel, an abrupt shock will be given to the grinding wheel, whereby not only the grinding wheel itself is damaged but the surface of the glass plate to be ground is marred and poor in its finish.

The object of the present invention is to provide a spindle support assembly wherein if the reaction force against the grinding resistance increases abruptly due to the movement of the grinding point of the grinding wheel in grinding, the grinding wheel can escape in the direction of said reaction force, and consequently the grinding resistance is always maintained uniform and a very fine surface finish is obtained. The present invention will be more fully understood and the objects and the advantages thereof will be much appreciated from a consideration of the following detailed explanation with reference to the appended drawings.

FIG. 1 is a longitudinal sectional view of a spindle support assembly in a glass plate edge grinding machine according to the present invention;

FIG. 2 is an enlarged sectional view of a portion of the spindle support assembly as shown in FIG. 1;

FIG. 3 is a sectional view of the portion of the present machine as shown in FIG. 1 taken along the line III--III;

FIG. 4 is a partial front view of an automatic glass plate edge grinding machine provided with a spindle support assembly as shown in FIGS. 1 and 2; and

FIG. 5 is a sectional view of an automatic glass plate edge grinding machine as shown in FIG. 4 taken along the line V--V.

In FIG. 1, there is shown a view of a spindle support assembly in a glass plate edge grinding machine according to the present invention. Referring to the drawing, the reference number 10 indicates a spindle on the lower end of which is mounted a grinding wheel. On the said spindle 10, a support member 12 is rotatably mounted through a bearing 13, said support member being formed in a cylindrical shape.

The numeral 14 indicates a holder mounted on the cylindrical support member 12 through a ring-shaped resilient member 15, said holder holding the cylindrical support member and being fixed to the frame 20 of the mount B for the grinding wheel.

The resilient member 15 may be formed of elastic macromolecule material, for example, synthetic rubber, but it is preferably formed of silicon rubber excellent in elasticity in a wide range of temperature, heat-proof, oxidization-proof and water-proof.

The ring-shaped resilient member 15 is, as seen in FIG. 2, fitted to the annular groove 16 formed on the outer portion of the cylindrical support member, while being arranged so that the outer portion of said resilient member is supported by the inner face of the holder 14 and the upper face of the shoulder 14b extending in the radial direction. Between the holder 14 and the cylindrical support member 12 is provided a clamp plug 17 with an external thread for threaded engagement with an internal thread formed on the inner portion of said holder. The numeral 18 indicates a pressure ring, said pressure ring being provided with a tapered inner face 18a, at least the lower half of said tapered inner face 18a being in contact with the inclined face 15a formed on the upper portion of said resilient member 15 and shaped in correspondence with said tapered inner face. It is possible, of course, that the whole of the tapered inner face 18a is in contact with the inclined face 15a. When said clamp plug 19 is screwed into the holder 14, pressure in the axial direction is put upon the upper face of said pressure ring 18 through the friction ring 17 which is to be described below. The said pressure is divided into the axial component of force and the radial inward component of force through the function of the tapered inner face 18a, and therefore the resilient member 15 is pressed against the upper face of the shoulder 14b and the base of the annular groove 16. In other words, the said pressure ring 18 function to ensure the holding of the cylindrical support member by pressing the resilient member effectively.

As shown in detail in FIG. 2, between the lower face 17b of the clamp plug 17 and the upper face 18b of the pressure ring 18 is inserted a friction ring 19 formed of suitable wear-resisting metal material. The said friction ring 19 is disposed in such a manner as the inner face thereof is in contact with the outer face of said cylindrical support member 12, and the outer face thereof is suitably spaced from the inner face of said holder 14 to provide a floating space 19a for said friction ring 19 therebetween.

By screwing said clamp plug 17 into the holder 14, said friction ring 19 is pressed against the pressure ring 18 and then fitted between said two faces 17b and 18b. In operation of the glass plate edge grinding machine with said support assembly, if an abrupt increase of the reaction force against the grinding resistance acting on the grinding wheel is caused by the movement of the grinding point of the work to be ground, the spindle 10 and the cylindrical support member 12 will move radially in the direction of said reaction force subject to the escape of the grinding wheel. The pressure caused by said movement of the spindle 10 and the cylindrical support member 12 is tramsmitted to the resilient member 15 and presses the resilient member 15 and is absorbed in it. Then the pressed resilient member 15 restores to the original state.

The said compression and restoration of the resilient member causes in practice some vibration of the spindle and the grinding wheel. As the speed of the movement of the resilient member in the said compression and restoration increases, the said vibration becomes all the more severe, so that the balance of the rotation of the grinding wheel is disturbed and the grinding wheel is partially deformed and worn and the surface finish of the work is roughened and at the same time the life of the grinding wheel is shortened. The said friction ring 19, by making use of the friction against the lower face 17b of the clamp plug and upper face 18b of the pressure ring 18, slows down and minimizes such speed of the movements of said resilient member 15 in the said compression and restoration, and obviates the above-mentioned disadvantages.

With reference to FIGS. 3 and 4, an embodiment of an automatic glass plate edge grinding machine with a spindle support assembly according to the present invention will be explained in the following.

Referring to the drawings, the letter A indicates a spindle support assembly of the same construction as shown in FIGS. 1 and 2, the said spindle support assembly being fixed to the frame 20 of the mount for the grinding wheel.

The numeral 21 indicates the glass plate to be ground which is absorbedly held by means of a plurality of vacuum chuck suction members 21a provided on the upper face of the profile plate 22 formed in a shape similar to the profile of the glass plate. The profile plate 22 is fixed to the fixing plate 24 mounted on the upper portion of the rotating shaft.

The numeral 25 indicates a cam follower which rotates following the peripheral edge of the profile plate 22, said cam follower being fixed to the shaft rotatably mounted on one end of the lever 26 fixed to the lower end of the mount for the grinding wheel. On the other end of the lever 26 is provided a differential transducer 34 which detects the quantity of the displacement of the grinding wheel through the medium of the cam follower 25.

The mount B for the grinding wheel is mounted on the guide rail 28 provided on the upper face of the bed 27.

On the lower side of the mount for the grinding wheel is mounted a nut means 29 which is in threaded engagement with a feed screw stock 31 whose both ends are rotatably supported by bearings 30. Said feed screw stock 31 is rotated by a belt transmission means 32 and a pulse motor 33, and by said rotation the grinding wheel 20 is horizontally driven (as shown by the letter H or H' in FIG. 5). The numeral 35 indicates a controlling assembly which controls the horizontal movement of the mount for the grinding wheel, while said controlling assembly being connected with the pulse motor 33 and the differential transducer 34 respectively.

On the other hand, a shaft 23 supporting the fixing plate 24 is rotatably supported by a bearing 36 provided on the bed 27, on the lower end of said shaft there being provided a bevel gear 37. The shaft 23 is rotated by a driving gear 44 through the medium of an intermediate drive shaft 40. The drive shaft 43 is operatively connected with the intermediate shaft 40 through a pulley 42, a pulley 39 and a belt 45 provided therebetween. The said intermediate drive shaft 40 is operatively connected with the shaft 23 through the bevel gear 38 and another bevel gear 37 engaging therewith.

Further, the spindle 10 is rotatably driven by an electric motor 46 provided on the upper portion of the mount for the grinding wheel. The output shaft 47 of said electric motor 46 is operatively connected with the spindle 10 through a pulley 48, a pulley 49 and a belt 50 provided therebetween.

In operation of the glass plate edge grinding machine with the above-mentioned unique structural arrangement, the grinding wheel 11 grinds the glass plate edge in following the peripheral edge of the glass plate under the control of the controlling assembly 35.

As the cylindrical support member 12 rotatably supporting the spindle 10 is surrounded by the resilient member 15 uniformly throughout the periphery thereof, if subject to the movement of the grinding point of the grinding wheel 11 caused by the turn of the glass plate 21 the reaction force against the grinding resistance acting on the grinding wheel 11 increases abruptly, or the direction of said reaction force suddenly changes, the grinding wheel 11 can escape quickly in the direction of said reaction force against the grinding resistance.

And further, as the speed of the displacement of the resilient member in compression and restoration is reduced to the minimum by the friction ring 19, it is avoidable that the balance of the rotation of the grinding wheel is disturbed by the abrupt severe vibration of the grinding wheel.

Therefore, the glass plate with a profile formed in any shape is always ground with an even grinding pressure, and the depth of grinding is always uniform, whereby the fine surface finish can be obtained.

Further in the glass plate edge grinding machine of the above-mentioned embodiment the spindle 10 and the cylindrical support member 12 being held by the resilient member 15, if an abrupt reaction force against the grinding resistance acts on, the grinding wheel 11 can quickly follow the radial movement of the glass plate and consequently can escape in the direction of the grinding reaction force. Therefore, when the cam follower 25 follows the peripheral edge of the profile plate 22 which moves with uneven acceleration, the pulsating of the mount 20 for the grinding wheel occurring in the horizontal movement of the mount driven by the pulse motor of usually uniform acceleration starting is not transmitted to the grinding wheel.

The spindle support assembly according to the present invention can be applied to the grinding of a work of a triangular, rectangular or polygonal profile. For example, in grinding the edge of a rectangular glass plate, the reaction force does not increase abruptly in grinding the rectilineal portion, but increases abruptly at the beginning of the grinding, at the intersecting point of the rectilineal portions or the corners and at the point of the work coming off the grinding wheel.

Further, if the feed of the grinding wheel is not accurate the direction of the reaction force against the grinding resistance changes irregularly and abruptly, so that not only the finish of the work becomes poor but the grinding wheel itself is damaged. In the meantime, in the spindle support assembly according to the present invention, as clearly shown in the above-mentioned explanation of the embodiment thereof, the cylindrical support member 12 which supports the spindle 10 provided with the grinding wheel through the bearing is held by the holder 14 through the ring-shaped elastic member 15 fitted into said cylindrical support member, and further, said resilient member 15 is surrounding the periphery of the cylindrical support member with uniform resiliency, so that if the reaction force against the grinding resistance acting on the grinding wheel increase abruptly and the direction of said reaction force changes suddenly the spindle 10 and the cylindrical support member 12 move in any direction, such as axial or radial, against the resiliency of the resilient member 15 and therefore the abrupt reaction force against the grinding resistance is absorbed.

Further, between the upper face of the pressure ring 18 in contact with the inclined face 15a of the ring-shaped resilient member 15 and the lower face of the clamp plug 17 engaged with the holder 14 there being inserted the friction ring 19, the speed of the restoration of the resilient member 15 after being pressed is controlled at its minimum, so that the vibration of the resilient member 15 can be prevented, and consequently the balance of the rotation of the grinding wheel is not disturbed, and a fine surface finish of the work is obtained, and damage of the grinding wheel is avoided, and the life of the grinding machine is not lengthened.

Further, the resilient member 15 is disposed in such a manner as the inner portion thereof is fitted into the annular groove formed on the outer portion of the cylindrical support member 12, the outer portion thereof is abutting against the shoulder formed on the inner portion of the holder 14, and said resilient member is clamped to a required extent by the clamp plug 17 through the friction ring 10, so that the resilient member 15 is surely supported and if axial force acts on the spindle 12, the grinding wheel is scarcely influenced thereby. And further, by adjusting the clamp plug 17, the resiliency of the resilient member is controlled.

In the grinding with strong grinding pressure, therefore, by clamping the clamp plug 17, the resiliency of said resilient member 15 is strengthened, and at the same time, the force thereof for holding the cylindrical support cylinder is strengthened, whereby the grinding wheel can escape quickly.

Claims

What I claim is:

1. A spindle support assembly in glass plate edge grinding machine comprising a cylindrical support member provided on a spindle for a grinding wheel through a bearing, an annular-shaped resilient member formed of elastic material of suitable elasticity, said resilient member being disposed in such a manner as the inner portion thereof is fitted to an annular groove formed on the outer portion of said cylindrical support member, a holder which holds said resilient member from the outside thereof, a clamp plug disposed between said cylindrical support member and said holder, the outer portion of said clamp plug being in threaded engagement with the inner portion of said holder, the inner face of said clamp plug being suitably spaced from the outer face of said cylindrical support member, a pressure ring having a tapered inside which is gradually enlarging towards the resilient member, said pressure ring being disposed in such a manner as said tapered inner face is in contact with the corresponding inclined face of said resilient member, and a friction ring inserted between the lower face of said clamp plug and the upper face of said resilient member axially opposite to each other, the inner face of said friction ring being in contact with the outer face of said cylindrical support member, the outer face thereof being spaced from the inner face of said holder to provide a floating space for said friction ring therebetween.

2. A spindle support assembly in a glass plate edge grinding machine comprising a spindle, a support member rotatably supporting the spindle, a resilient member mounted on the outer portion of said support member, a holding member engaging said resilient member from the outside thereof, a clamp member mounted between said support member and said holding member for axial movement relative thereto, a pressure ring mounted between the clamp member and the resilient member and having a tapered inner surface engaging the resilient member, the pressure ring being movable axially by the clamp member whereby the resilient member is forced against the support member as the clamp member is moved toward the resilient member, and a friction ring mounted between the support member and the holding member, the friction ring having an inner periphery engaging the support member and an outer periphery spaced from the holding member.

3. The structure of claim 2 in which a portion of the resilient member has an inclined surface engaging the tapered surface of the pressure ring.

4. The structure of claim 2 in which said support member is cylindrical and is provided with an annular groove on the outer portion thereof, the resilient member being received in the annular groove.

5. The structure of claim 2 in which said support member is cylindrical and the inner periphery of the friction ring is circular.