DE20010345U1 - Elastic jaw lining - Google Patents

Description

[FilerANMVCCOSOIBI.DOC] 08.06.00 ·♦**:*! JJ J * J J J Elastic jaw chuck ** ** " ** *· *"

Chai, Cheng-Chung

Description Elastic cheek lining

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The invention relates to a jaw chuck of a clamping device, in particular to an elastic jaw chuck which has an elastic housing and is provided with weights, whereby the centrifugal force is balanced and high elasticity, strength and precision are achieved, so that the clamping force is increased.

Figure 1 shows a conventional jaw chuck comprising a draw tube 60 of the rotary cylinder, a thrust piece 61, a base 62, a nozzle 621 and several jaw sets 63, wherein the nozzle 621, the thrust piece 61 and the draw tube 60 of the rotary cylinder are inserted into the base 62, on which the jaw sets 63 are evenly distributed by 120°, wherein

the base 62 has an axle hole 622 and cross-shaped sliding guides 620 which are evenly distributed by 120°,

the jaw set 63 has a cross-shaped slider 630 which is provided on the lower side with a T-shaped projection 632 having an inclined bottom surface and on the front side with a T-shaped groove 631 into which a T-shaped piece 634 is pushed, onto which a jaw 633 is screwed, whereby the jaw 633 can be adjusted by sliding in the T-shaped groove 631,

the thrust piece 61 has T-shaped grooves 6Ti on the circumference, which have an inclined bottom surface, and an axle hole 612 in the middle, and the pull tube 60 of the rotary cylinder is provided with a driver 601.

When the jaw set 63 slides into the sliding guide 62&Oacgr;, the T-

shaped projection 632 of the slider 630 is pushed into the T-shaped groove 611 of the thrust piece 61. To release the workpiece, the pull tube 60 of the rotary cylinder with the driver 601 pushes the thrust piece 61, whereby the T-shaped projection 632 along the oblique

[FilerANMNCCODOIBLDOC] 08.0600 I Elastic jaw chuck ·

Chai, Cheng-Chung

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bottom surface of the T-shaped groove 611 so that the jaw set 63 is pushed outwards along the sliding guide 620 and the jaws 633 thus release the workpiece. To clamp a new workpiece, the draw tube 60 of the rotary cylinder must be retracted, whereby the thrust piece returns and the T-shaped projection 632 slides down again along the inclined bottom surface of the T-shaped groove 611 so that the jaw set 63 is pushed inwards again along the sliding guide 620 and the jaws 633 thus clamp the workpiece. Therefore, the workpiece is clamped and released by the back and forth movement of the draw tube 60 of the rotary cylinder.

However, this conventional chuck has the following disadvantages

on:

1. The structure is relatively complicated, with the jaw set consisting of a T-shaped groove, a T-shaped projection, a T-shaped piece and a jaw, the thrust piece having T-shaped grooves and the pull tube of the rotary cylinder being provided with a driver, so that the production is costly and the assembly is time-consuming and labor-intensive.

2. The T-shaped piece and the jaw, the slider and the sliding guide, the T-shaped projection and the T-shaped groove as well as the driver and the thrust piece must take into account a tolerance during production, so that a tight connection is not possible and thus the precision cannot be guaranteed.

3. After a long period of operation, the moving parts may suffer wear, affecting precision and shortening the service life.

4. There is no space for weights. To arrange the weights, the length must be increased, which may reduce the rigidity. Therefore, the rotation speed is limited by the centrifugal force.

5. The clamping force for a thin workpiece can be balanced by the centrifugal force.

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Elastic cheek lining Chai, Cheng-Chung

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The invention is therefore based on the following objects:

1. The elastic casing has symmetrically and evenly distributed thicker rigid zones and thinner elastic zones as well as auxiliary elastic zones, thereby increasing the strength and elasticity;

2. Weights are provided behind the elastic housing to balance the weight and compensate for the centrifugal force so that the clamping force is not affected by the centrifugal force;

3. manufacturing does not have to take tolerance into account, which increases precision;

4. There are no moving parts, which prevents wear and tear and ensures that precision is not affected.

The invention thus achieves an increase in precision, an extension of the service life and a reduction in manufacturing costs.

In the following, the structure, features and mode of operation of the invention are explained in more detail with reference to the accompanying drawings.

The drawings show:

Figure 1 shows an exploded view of the conventional solution.

Figure 2 shows a perspective view of the elastic housing according to the invention.

Figure 3 shows an exploded view of the invention.

Figure 4(A) shows a plan view of the invention.
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Figure 4(B) shows a sectional view of the invention along the line A-A.

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Elastic cheek lining *· *· ··**··*"

Chai, Cheng-Chung

Figure 5(A) shows a sectional view of the invention for releasing the workpiece.

Figure 5(B) shows a sectional view of the invention for clamping the

workpiece.

Figure 2 shows the structure of the elastic housing 70. As can be seen, the inner surface of the elastic housing 70 has symmetrically and evenly distributed rigid zones 73 and elasticity zones 75. The rigid zones 73 have a greater thickness in the inner region and are provided with a thinner auxiliary elasticity zone 74 on the outer edge, while the elasticity zones 75 have a smaller thickness and are provided with grooves 76 which adjoin the rigid zone 73 and the auxiliary elasticity zone 74, whereby the elasticity zone forms an uneven surface.

In Figures 3 and 4 the entire structure of the invention is shown, which comprises a base 10, a hollow cylinder 43, several weights 50 and an elastic housing 70. The base 10 has a central hole through which the hollow cylinder 43 can be connected to the draw tube of a rotary cylinder. The weights 50 are provided with bores 51, each of which receives a screw bushing 42 for a screw 30, whereby the hollow cylinder 43 is held between the weights 50. The elastic housing 70 has jaw holders 701, T-shaped pieces 703 and jaws 702 on the outer surface and is connected to the base 10 by means of the screws 30 and 31, the screw 30 being rotated by the screw bushing 42 which is received in the bore 51 of the weight 50.

The functionality of the invention is described below:

In turning work, the workpiece 1 usually has a fixed dimension and is machined in masses, so that the time and type of turning work are also fixed.
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As can be seen from Figures 5(A) and 5(B), the workpiece 1 to be machined is placed between the jaws 702 of the elastic housing 70

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[File:ANM\CC0901 B1 .DOC] 08.06.00 Elastic jaw chuck

Chai, Cheng-Chung

Then, the T-shaped piece 703 in the jaw holder 701 is adjusted by sliding to clamp the workpiece 1. Then, the movement time of the draw tube of the rotary cylinder is adjusted according to the processing time of the workpiece 1 (the draw tube of the rotary cylinder is not part of the subject of the invention and is therefore not described in detail). After processing the workpiece T, the rotary cylinder stops and causes its draw tube to move axially outward, whereby the draw tube presses against the hollow cylinder 43; so that the elastic housing 70 bulges outward and the jaws 702 thus tilt. Gaps are therefore formed between the jaws 702 and the workpiece 1, whereby the workpiece 1 is released and can be removed. To clamp a new workpiece 1, the workpiece 1 must be placed between the jaws 702 and the draw tube of the rotary cylinder must be pulled axially inward, whereby the curved elastic housing is released and returns to its original state due to its restoring force, so that the jaws 702 clamp the workpiece 1 again. In this way, rapid clamping and release of the workpiece 1 is achieved.

Based on the above facts, the invention has the following

Benefits on:

1. Increasing the elasticity and strength of the elastic jaw chuck

As shown in Figure 4, the stress points when the housing is warped are evenly distributed and do not concentrate on the two sides as usual, since the rigid zone 73, the elastic zone 75, the auxiliary elastic zone 74 and the groove 76 have different thicknesses and are symmetrical and evenly distributed.

Since the elastic zone 75, the auxiliary elastic zone 74 and the groove 76 have a smaller thickness, the elasticity is increased. The rigid zone 73 with a larger thickness serves for reinforcement. Therefore, the best elasticity and strength are achieved. The groove 76 can particularly reduce the surface tension and thus contributes to increasing the elasticity.

[FiIeANIMCCOSOIBLDOC] 08.06.00 Elastic jaw chuck Chai, Cheng-Chung

2. Stable clamping force at high speed

As shown in Figures 2 and 3, the elastic housing 70 is provided with weights 50 on the rear side, which can balance the weight of the workpiece at high speed, thereby allowing the workpiece to be rotated stably. When the jaw chuck is rotated at high speed, a centrifugal force is generated which acts outwards and can thus influence the clamping force of the jaws. The weights according to the invention generate a rear centrifugal force which can balance the front centrifugal force, thereby preventing a reduction in the clamping force.

3. High precision

Since the workpiece is clamped and released by the elastic deformation of the elastic housing, the moving parts of the conventional solution (Figure 1) can be dispensed with, thus avoiding wear and ensuring precision. In addition, tolerance of the moving parts is not required, which also contributes to increasing precision.

Therefore, the invention, in terms of its availability, progressiveness and novelty, fully meets the requirements for a utility model.

In summary, the invention relates to an elastic jaw chuck having an elastic housing, by the elastic deformation of which the workpiece can be clamped and released, thereby avoiding wear of the moving components, so that precision is ensured. The inner surface of the elastic housing has symmetrically and evenly distributed thicker rigid zones and thinner elastic zones, the rigid zones being provided with an auxiliary elastic zone on the outer edge and the elastic zones being provided with grooves, thereby increasing elasticity and strength. The weights can compensate for the centrifugal force by rotating at high speed, thereby ensuring the clamping force. Therefore, an increase in precision,

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Elastic cheek lining *'

Chai, Cheng-Chung

a reduction in manufacturing costs and an extension of the service life.

The jaw chuck according to the invention is particularly suitable for turning work and can achieve very high machining precision.

Claims (2)

1. Elastic jaw chuck comprising a base ( 10 ), a hollow cylinder ( 43 ), a plurality of weights ( 50 ) and an elastic housing ( 70 ), the base ( 10 ) having a central hole through which the hollow cylinder ( 43 ) can be connected to the draw tube of a rotary cylinder, the weights ( 50 ) being provided with bores ( 51 ) each receiving a screw bushing ( 42 ) for a screw ( 30 ), whereby the hollow cylinder ( 43 ) is held between the weights ( 50 ), and the elastic housing ( 70 ) has jaw holders ( 701 ), T-shaped pieces ( 703 ) and jaws ( 702 ) on the outer surface and is connected to the base ( 10 ) by means of screws ( 30 , 31 ), the screw ( 30 ) being rotated by the screw bushing ( 42 ), which is received in the bore ( 51 ) of the weight ( 50 ), whereby an elastic jaw chuck is created which clamps and releases the workpiece by the elastic deformation of the elastic housing ( 70 ), enables adaptation to the dimensions of the workpiece by adjusting the position of the jaws and ensures the clamping force by compensating the centrifugal force. 2. Elastic jaw chuck according to claim 1, characterized in that the inner surface of the elastic housing ( 70 ) has symmetrically and evenly distributed rigid zones ( 73 ) and elastic zones ( 75 ), the rigid zones ( 73 ) having a greater thickness in the inner region and being provided with a thinner auxiliary elastic zone ( 74 ) at the outer edge, while the elastic zones ( 75 ) having a smaller thickness and being provided with grooves ( 76 ) which adjoin the rigid zone ( 73 ) and the auxiliary elastic zone ( 74 ), whereby the elastic zone forms an uneven surface, which can evenly distribute the stress points during arching.