CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Chinese Patent Application No. 201010171640.0 filed on May 12, 2010 in the State Intellectual Property Office of China, the whole disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a transmission mechanism, more particularly, relates to a pure mechanical transmission mechanism that can convert a continuous straight-line motion of a driven member to an intermittent straight-line motion.

Description of the Related Art

With the development of the electrical control technology, persons have been used to adopting electrical mechanism to control or achieve an action of a driven member. In this way, the pure mechanical mechanism is disappearing in the modern industry.

Although the electrical mechanism has an advantage of simplicity of operation, it has many disadvantages compared with the pure mechanical mechanism, for example, electrical elements of the electrical mechanism may be often failed in some working conditions and need often be repaired or replaced.

Accordingly, in some applications, the pure mechanical mechanism may still be desirable, for example, in an application where a pneumatic needle is driven to intermittently move along a straight- line. The present invention is proposed mainly to provide a pure mechanical

transmission mechanism that can convert a continuous straight-line motion of a driven member to an intermittent straight-line motion.

SUMMARY OF THE INVENTION

The present invention has been made to overcome or alleviate at least one aspect of the above mentioned disadvantages.

Accordingly, it is an object of the present invention to provide a transmission mechanism with high reliability and high safety.

Accordingly, it is another object of the present invention to provide a transmission mechanism with simple structure.

According to an aspect of the present invention, there is provided a transmission mechanism, comprising: a driven member being movable in a route having three successive sections; a stationary member being fixed to a body frame; and an driven member. When the driving member is moving in a first section, the driving member is engaged with the driven member and the stationary member is disengaged with the driven member so that the driven member moves along with the driving member. When the driving member is moving in a second section, the driving member is disengaged with the driven member and the stationary member is engaged with the driven member so that the driven member does not move along with the driving member. When the driving member is moving in a third section, the driving member is engaged with the driven member and the stationary member is disengaged with the driven member so that the driven member moves along with the driving member again.

In an exemplary embodiment according to the present invention, the driving member comprises a movable guide block and a movable cam connected with each other; The stationary member comprises an unmovable guide block and an unmovable cam both fixed to the body frame; A first pin key is slidably received in a guide slot of the movable guide block, one end of the first pin key is slidably or turnably retained in an unmovable cam groove of the unmovable cam, the unmovable cam groove has three successive sections; A second pin key is slidably received in a guide slot of the unmovable guide block, one end of the second pin key is slidably or turnably retained in a movable cam groove of the movable cam; When the one end of the first pin key is moving in the first section of the unmovable cam groove, the other end of the first pin key is engaged with a first engaged portion of the driven member, and the other end of the second pin key is disengaged with the driven member so that the driven member moves along with the driving member; When the one end of the first pin key is moving in the second section of the unmovable cam groove, the other end of the first pin key is disengaged with the driven member, and the other end of the second pin key is engaged with the a third engaged portion of the driven member so that the driven member does not move along with the driving member; When the one end of the first pin key is moving in the third section of the unmovable cam groove, the other end of the first pin key is engaged with a second engaged portion of the driven member, and the other end of the second pin key is disengaged with the driven member so that the driven member moves along with the driving member again.

In another exemplary embodiment according to the present invention, the driving member continuously and linearly moves in the route, while the driven member intermittently and linearly moves in its route.

In another exemplary embodiment according to the present invention, under the control of the unmovable cam groove, the first pin key can slide in the movable guide block toward or away from the driven member to engage or disengage with the driven member; and under the control of the movable cam groove, the second pin key can slide in the unmovable guide block toward or away from the driven member to engage or disengage with the driven member.

In another exemplary embodiment according to the present invention, the unmovable cam and the movable cam are a pair of conjugate cams so that the unmovable cam groove and the movable cam groove are a pair of conjugate cam grooves that can cooperate with each other without any interference.

In another exemplary embodiment according to the present invention, the movable cam groove of the movable cam has three successive sections; when the one end of the first pin key is moving in the first section of the unmovable cam groove, the one end of the second pin key is moving in a third section of the movable cam groove; when the one end of the first pin key is moving in the second section of the unmovable cam groove, the one end of the second pin key is moving in a second section of the movable cam groove; when the one end of the first pin key is moving in the third section of the unmovable cam groove, the one end of the second pin key is moving in a first section of the movable cam groove.

In another exemplary embodiment according to the present invention, the one end of the first pin key is fitted in the unmovable cam groove by a slidable pin or a turnable roller.

In another exemplary embodiment according to the present invention, the one end of the second pin key is fitted in the movable cam groove by a slidable pin or a turnable roller.

In another exemplary embodiment according to the present invention, the movable guide block and the movable cam are connected with each other by a plate.

In another exemplary embodiment according to the present invention, the transmission mechanism is a pure mechanical transmission mechanism.

In various exemplary embodiments of the present invention, the transmission mechanism includes only mechanical elements without any electrical elements, increasing the reliability and safety. Further, the transmission mechanism controls the driven member to intermittently move mainly by an unmovable cam and a movable cam, therefore, the transmission mechanism is very simple in structure.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.1 is an illustrative view of a transmission mechanism according to an exemplary embodiment of the present invention;

Fig.2 is a cross section view of the transmission mechanism shown in Fig.1 , wherein the driving member is engaged with the driven member and the stationary member is disengaged with the driven member; and

Fig.3 is a cross section view of the transmission mechanism shown in Fig.l, wherein the driving member is disengaged with the driven member and the stationary member is engaged with the driven member.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE

IVENTION

Exemplary embodiments of the present disclosure will be described hereinafter in detail with reference to the attached drawings, wherein the like reference numerals refer to the like elements. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art.

Fig.1 is an illustrative view of a transmission mechanism according to an exemplary embodiment of the present invention.

As shown in Fig. l, in one exemplary embodiment of the present invention, the transmission mechanism mainly comprises a driven member 10, 200, a stationary member 20, 100, and an driven member 30.

With reference to Fig.l, in one exemplary embodiment of the present invention, the stationary member 20, 100 is fixed to a body frame (not shown) and is unmovable. The driving member 10, 200 can reciprocally move along a straight line in a direction Y-Y shown in Fig.l . The driven member 30 may be connected to an actuation member (not shown) to drive the actuation member to acts a predetermined action, for example, to drive the actuation member to acts an intermittent and linear movement, so that a workpiece, for example, a pneumatic needle, can be driven in position by the actuation member.

Referring to Fig.l, in one exemplary embodiment of the present invention, the stationary member 20, 100 comprises an unmovable guide block 20 and an unmovable cam 100. The unmovable guide block 20 and the unmovable cam 100 both are fixed to the body frame and held unmovable.

As shown in Fig.l, in one exemplary embodiment of the present invention, the driving member 10, 200 comprises a movable guide block 10 and a movable cam 200 that are connected with each other and can move together. In the exemplary embodiment shown in Fig.l, the movable guide block 10 and the movable cam 200 are fixed to a plate 40 and are connected with each other by the plate 40.

In one exemplary embodiment of the present invention, the movable guide block 10 and the movable cam 200 can move along a straight line in the direction Y-Y relative to the unmovable guide block 20 and the unmovable cam 100.

Fig.2 is a cross section view of the transmission mechanism shown in Fig.l, wherein the driving member is engaged with the driven member and the stationary member is disengaged with the driven member.

As shown in Fig.l and Fig.2, in one exemplary embodiment of the present invention, a guide slot is formed in the movable guide block 10, and a first pin key 11 is slidably received in a first guide slot of the movable guide block 10. In the illustrative exemplary embodiment shown in Figs.1-2, the first pin key 11 can slide in a direction X-X perpendicular to the direction Y-Y, and can move in the direction Y-Y along with the movable guide block 10.

With reference to Fig.l and Fig.2, in one exemplary embodiment of the present invention, the unmovable cam 100 is located at left side of the movable guide block 10, and the driven member 30 is located at right side of the movable guide block 10. That is, the movable guide block 10 is located between the unmovable cam 100 and the driven member 30.

Referring to Fig.2, in one exemplary embodiment of the present invention, the unmovable cam 100 is formed with an unmovable cam groove 110 therein. One end (left end shown in Fig.2) of the first pin key 11 is slidably or turnably retained in the unmovable cam groove 1 10 of the unmovable cam 100.

Although it is not shown, in one exemplary embodiment of the present invention, the one end of the first pin key 11 may be fitted in the unmovable cam groove 1 10 by a slidable pin or a turnable roller so that the first pin key 11 can slide or turn along the unmovable cam groove 110 of the unmovable cam 100.

Accordingly, the unmovable cam groove 110 of the unmovable cam 100 can control the first pin key 11 to slide in the first guide slot of the movable guide block 10. In this way, under the control of the unmovable cam groove 110, the first pin key 11 can slide in the movable guide block 10 toward or away from the driven member 30 to engage or disengage with the driven member 30.

Please referring to Fig.1 and Fig.2 again, in one exemplary embodiment of the present invention, the unmovable cam groove 110 of the unmovable cam 100 includes three successive sections al-a2, a2-a3, a3-a4. In this way, the three successive sections al-a2, a2-a3, a3-a4 limit a route al-a4 along which the driving member 10, 200 can moves through the first pin key 11.

As shown in Fig.l and Fig.2, in one exemplary embodiment of the present invention, a second guide slot is formed in the unmovable guide block 20, and a second pin key 21 is slidably received in the second guide slot of the unmovable guide block 20. In the illustrative exemplary embodiment shown in Figs.1-2, the second pin key 21 can slide in the direction X-X perpendicular to the direction Y-Y, and can not move in the direction Y-Y under the limitation of the unmovable guide block 20. With reference to Fig.1 and Fig.2, in one exemplary embodiment of the present invention, the movable cam 200 is located at right side of the unmovable guide block 20, and the driven member 30 is located at left side of the unmovable guide block 20. That is, the unmovable guide block 20 is located between the movable cam 200 and the driven member 30.

Referring to Fig.2, in one exemplary embodiment of the present invention, the movable cam 200 is formed with a movable cam groove 210 therein. One end (right end shown in Fig.2) of the second pin key 21 is slidably or turnably retained in the movable cam groove 210 of the movable cam 200.

Although it is not shown, in one exemplary embodiment of the present invention, the one end of the second pin key 21 may be fitted in the movable cam groove 210 by a slidable pin or a turnable roller so that the second pin key 21 can slide or turn in the movable cam groove 210 of the movable cam 200.

Accordingly, the movable cam groove 210 of the movable cam 200 can control the second pin key 21 to slide in the second guide slot of the unmovable guide block 20 in the direction Y-Y. In this way, under the control of the movable cam groove 210, the second pin key 21 can slide in the unmovable guide block 20 toward or away from the driven member 30 to engage or disengage with the driven member 30.

Please referring to Fig.1 and Fig.2 again, in one exemplary embodiment of the present invention, the movable cam groove 210 of the movable cam 200 includes three successive sections b2-bl, b3-b2, b4-b3.

As shown in Fig.l and Fig.2, in one exemplary embodiment of the present invention, the unmovable cam 100 and the movable cam 200 are a pair of conjugate cams so that the unmovable cam groove 110 and the movable cam groove 210 are a pair of conjugate cam grooves that can cooperate with each other without any interference.

Please be noted that the trajectory of the unmovable cam groove 110 or the movable cam groove 210 is not limited to the trajectory shown in the exemplary embodiments of the present invention, it may be any kind of trajectory that can achieve a same function as the exemplary embodiments of the present invention.

Fig.3 is a cross section view of the transmission mechanism shown in Fig.l, wherein the driving member is disengaged with the driven member and the stationary member is engaged with the driven member.

As shown in Fig.2 and Fig.3, in one exemplary embodiment of the present invention, because the unmovable cam 100 and the movable cam 200 are a pair of conjugate cams, the first section al-a2 of the unmovable cam groove 110 corresponds to the third section b4-b3 of the movable cam groove 210, the second section a2-a3 of the unmovable cam groove 110 corresponds to the second section b3-b2 of the movable cam groove 210, and the third section a3-a4 of the unmovable cam groove 110 corresponds to the first section b2-bl of the movable cam groove 210. That is, when the one end of the first pin key 11 moves into the first section al-a2 of the unmovable cam groove 110, the one end of the second pin key 21 moves into the third section b4-b3 of the movable cam groove 210; when the one end of the first pin key 11 moves into the second section a2-a3 of the unmovable cam groove 110, the one end of the second pin key 21 moves into the second section b3-b2 of the movable cam groove 210; and when the one end of the first pin key 11 moves into the third section a3-a4 of the unmovable cam groove 110, the one end of the second pin key 21 moves into the first section b2-bl of the movable cam groove 210.

Hereinafter, the operation process of the mechanical transmission mechanism will be described in detail with reference to Fig.2 and Fig.3.

Please refer to Fig.2, in one exemplary embodiment of the present invention, during the one end of the first pin key 11 is moved in a range of the first section al-a2 of the unmovable cam groove 110 in the direction Y-Y, the other end of the first pin key 11 is pushed to engage with a first engaged portion 31 of the driven member 30 under the control of the first section al-a2 of the unmovable cam groove 110. Meanwhile, the other end of the second pin key 21 is pulled to disengage with the driven member 30 under the control of the third section b4-b3 of the movable cam groove 210. Accordingly, as shown in Fig.2, the driven member 30 is moved with the driving member 10, 200 together in the direction Y-Y during the one end of the first pin key 11 is moved in the range of the first section al-a2 of the unmovable cam groove 110.

Please refer to Fig.3, in one exemplary embodiment of the present invention, during the one end of the first pin key 11 is moved in a range of the second section a2-a3 of the unmovable cam groove 110 in the direction Y-Y, the other end of the first pin key 11 is pulled to disengage with the first engaged portion 31 of the driven member 30 under the control of the second section a2-a3 of the unmovable cam groove 110. Meanwhile, the other end of the second pin key 21 is pushed to engage with a third engaged portion 33 of the driven member 30 under the control of the second section b3-b2 of the movable cam groove 210. Accordingly, as shown in Fig.3, during the one end of the first pin key 1 1 is moved in the second section a2-a3 of the unmovable cam groove 1 10, the driven member 30 is not moved with the driving member 10, 200 together, and is held by the unmovable guide block 20 and the second pin key 21 so that the driven member 30 is prevented from being moved back its original position due to any external force.

Although it is not shown, in one exemplary embodiment of the present invention, during the one end of the first pin key 1 1 is moved in the third section a3-a4 of the unmovable cam groove 110, the other end of the first pin key 11 is pushed to engage with a second engaged portion 32 of the driven member 30 under the control of the third section a3-a4 of the unmovable cam groove 110, and the other end of the second pin key 21 is pulled to disengage with the driven member 30 under the control of the first section b2-bl of the movable cam groove 210. Accordingly, the driven member 30 is moved with the driving member 10, 200 together again during the one end of the first pin key 11 is moved in the third section a3-a4 of the unmovable cam groove 110. As the above description, it has been discussed the operation process during the driving member 10, 200 moves from the start point al to the end point a4.

Obviously, the operation process during the driving member 10, 200 moves from the end point a4 to the first point al is reversed to the operation process during the driving member 10, 200 moves from the start point al to the end point a4. Accordingly, herein is omitted a further description to the operation process during the driving member 10, 200 moves from the end point a4 to the first point al .

In the above various exemplary embodiments of the present invention, during the driving member 10 is continuously moved along a straight-line in the direction Y-Y, the driven member 30 is driven to intermittently move along another straight- line in the direction Y-Y, so that the transmission mechanism according to the present invention can achieve conversion of a continuous straight-line motion of a driven member 10 to an intermittent straight-line motion of the driven member 30 and a workpiece, for example, a pneumatic needle, can be driven in position by the driven member 30. Furthermore, the transmission mechanism includes only mechanical elements without any electrical elements and is a pure mechanical transmission mechanism.

Although several exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that various changes or modifications may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.