JPS5989832A - Power transmission gear switching device - Google Patents

Abstract

PURPOSE:To decrease loss in torque, while securely disengage a switching member from a power tansmission gear member by enabling lost motion between a drive member and a relay member, and between the relay member and the switching member. CONSTITUTION:The force to engage switching members 28, 44 with either of a pair of power transmission gear members 22, 24, and the force to release this engagement are dependent on the energizing force of springs 52, 56, etc. Thereby the engagement between the switching members and the power transmission gear member is ensured, while their disengagement can be easily carried out by means of the small energizing force of the springs. Also, since the force that presses the power transmission gear members against their supporting parts 10, 12 is also reduced, the loss in torque is decreased, improving transmission efficiency. When the engaging force between the switching members and the transmission gear member is greater than the energizing force of the springs, etc., the engagement can be released by means of the direct transmission of force among a drive member 62, a relay member 46 and the switching member 44, ensuring the switching operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission switching device, and more particularly, to a power transmission member such as a gear, a clutch ring, etc., which is disposed on both sides of the switching part 1 and which contributes to power transmission. The present invention relates to a power transmission switching device that selectively engages and disengages.

The power transmission switching device described above is embodied, for example, as a clutch switching device in a camera lens. That is, conventionally, in automatic focusing mode, manual focusing mode, and gold-mounted nine autofocus lenses, in automatic focusing mode, driving force is transmitted from a driving device such as a motor to a gold lens driving member, and in manual focusing mode, driving force is transmitted manually to the gold lens driving member. A latch device that can be switched to transmit driving force from a focusing operation member to a lens driving member is disclosed in, for example, Japanese Utility Model Application No. 57-54116.

However, in these conventional examples, the clutch ring that is selectively engaged with either of the two gears is mechanically moved from the outside by a rigid body such as a lever.
o Therefore, if the engagement between the clutch ring and the gear is not strong, it becomes difficult for the clutch engaging portion to disengage during switching, resulting in poor switching operation.

Also, component tolerances and component area υ markings may occur if the relative positions of the components are shifted due to positional errors, etc.

If excessive force is applied to each part, switching malfunction may occur. Furthermore, since the gear is pressed against the support portion with a large force, there are disadvantages such as a large loss of torque and the need to prepare a motor with a large driving force. There are various types of power transmission switching devices other than clutch switching devices, but the situation is similar to that of I/I.

SUMMARY OF THE INVENTION Therefore, the present invention aims to eliminate the drawbacks in the prior art, namely, to minimize the pressing force of the switching member against the power transmission member to completely reduce torque loss, and to maintain the maintenance between the switching member and the power transmission member for switching. The purpose of this invention is to provide a force transmission switching device that can reliably disassemble alloys.

In order to achieve the above object 1, the present invention includes a drive member driven by an external force, a relay member operated by the drive member, and a switching member operated by the drive member, and a switch between the drive member and the relay member is provided. There is an opening between the relay member and the switching member.

In addition to making it possible to perform a straight motion, the switching member is biased in a predetermined direction by a biasing means such as a spring.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below based on an embodiment in which the present invention is applied to a clutch switching device for a camera lens.

1 and 2, a pair of substrates 10 and 12 are connected to each other at a portion not shown, and a rotating shaft 14t-
It is rotatably supported. An output gear 16 is non-rotatably fixed to one end of the rotating shaft 14 (the left end in both figures) with a through pin 1B. Manual gears 22 and 24 are fitted between the substrates 10 and 12 on @114 so as to be rotatable with respect to the shaft 14, respectively.

A recess 22a and a protrusion 24a are formed on the inner surfaces of the gears 22 and 24, respectively. In addition, gears 2-2 and 24
are driven by separate drive systems.

That is, for example, in the case of an autofocus photographic lens, the manual gear 22 is switched to the manual gear 24 by the manual focusing operation member.
are each rotated by a motor drive device.

A cylindrical member 26 is integrally fixed to the shaft 14 with a through pin 30 between the manual gears 22 and 24 on the shaft 14 . The cylindrical member 26 is provided with a groove 26at- extending in the axial direction.

A clutch ring 2B is fitted to the outside of the cylindrical member 26 so as to be movable in the axial direction.

The clutch ring 28 consists of a cylindrical portion 28m and flanges 28b and 28c on both sides thereof. It is inserted into one of the flange portions 28c and fitted into the groove 26a, and is made non-rotatable relative to the cylindrical member 26 and movable in the axial direction by the second pin 32. Each flange portion 28b and 2
Recesses 22 for the gears 22 and 24 are provided on the outer surface of the gears 8c, respectively.
protrusions 2B, d and recesses 28 that engage with m and protrusions 24a;
．． e is formed. Both flange parts 28b and 28c
The arm portion 4 of the clutch lever 44 is located in the space between
4b is inserted into the hole.

Fixed shafts 42 and 64 are provided near the shaft 14 and are arranged in a direction perpendicular thereto.A clutch lever 44 is pivotally supported on the shaft 42, and the lever engages with the clutch ring 28. It constitutes a switching member that switches power transmission. A switching lever 62 serving as a driving member that generates a driving force for the switching is supported on the shaft 64 . axis 4
A switching transmission plate 46, which is further provided between the two members and serves as a relay member for interlocking the two members, is pivotally supported on the switch 2.

The lever 44 has a fan-shaped portion 44m and extends from the arm portion 4.
4b, and the fan-shaped part 44m has a rectangular notch 4B.
is formed, and is biased in the right rotation direction (in the drawing M1) by a tension spring 52 disposed between the transmission plate 46 and the transmission plate 46. On the other hand, a rectangular notch 54 is formed in one side of the switching transmission plate 4B, and another spring 5G disposed between the tension spring 52 and the substrate 10. The notch 48 is biased in the counterclockwise direction.
A pin 58 is provided upright and can be held in place.

A pin 66 that can be engaged with the notch 54 is provided upright at the free end of the switching lever 62 .

This lever 62 rotates in conjunction with a changeover switch (not shown), and its rotation range is restricted by pins 68 and 70.

Next, the operation of this embodiment will be explained.

FIG. 11 shows a state in which the rotational force manually applied from the left hand gear 22 in the figure is transmitted to the output gear 16. At this time, the switching lever 62 is fixed in a right-handed state in contact with the pin 68 by the action of a mechanism not shown.

Further, the clutch lever 44 and the switching transmission plate 46 are connected to the spring 52.
The pin 58 is biased in the right-handed and left-handed directions due to the action of the pin 58 and is in contact (interference) with the abutment surface 48& of the notch 48, but the pin 66 is still not in contact with either of the abutment surfaces 54a and 54b. Not in contact. Therefore, the biasing force of the spring 56 causes the transmission plate 4 to
6 is rotated to the left, the lever 44 is rotated to the left through contact between the pin 58 and the contact surface 48a, and the actuating arm 44b pushes the inner surface 2Bf of the flange portion 28b to move the clutch ring 28 to the left. The groove 22a and the projection 28d are engaged. As a result, the output gear 16 is rotated via the manual gear 22, the clutch ring 28, the cylindrical member 26, and the rotating shaft 14. It is clear from the above explanation that the spring 52 is only a working metal that brings the pinot 58 into contact with the contact surface 48a of the notch 48, and the rotational force (left rotation force) to the transmission plate 46, that is, the lever 44 is This is applied by a spring 56.

Therefore, the biasing force of the spring 56 should be set to a value that does not disengage the groove 22m and the protrusion 28d, and the force pressing the human gear 22 against the board 10 does not become so large, so the friction loss can be kept small. Improves transmission efficiency.

Next, operate the changeover switch (not shown) to select the changeover lever 62.
When turning the pin 66 to the left on the shaft 64, first, the pin 66
collides with the contact surface 54a of the notch 54, and when the pin 66 is further rotated, the pin 66 resists the urging force of the contact surface 54af and the spring 56 and pushes upward in the figure WJ1. As a result, the fourth
As shown in the figure, the transmission plate 46 is pulled by the spring 52 and rotates to the right, so that the pin 58 and the contact surface 48b of the notch 48 come into contact with each other. As a result, the clutch ring 2 is moved by the actuating arm 44b.
8 is moved to the right, the groove 22& and the protrusion 28d are disengaged, come into contact with the manual gear 24, and stop at a fixed position.

However, in reality, the manual gear 22 may be in the process of being driven, or the output gear 16 may be stopped due to a rotation limit of a member that is electrically driven by the output gear 16. Since a circumferential force acts between the clutch ring 28 and the flange portion 2&b, the groove 2
The friction or engagement force between the protrusion 2a and the protrusion 28d is large, and it may be difficult to release the engagement between the protrusion 2a and the protrusion 28d only by the biasing force of the spring 52. This state is shown in FIG. 3. Therefore,
When the switching lever 62t is further turned to the left from the state shown in FIG. 3, the pin 66 pushes against the contact surface 54 and the pin 58 pushes against the contact surface 48b', so that the clutch lever 44 turns to the right. As a result, the actuating arm 4 of the clutch lever 44
4b presses the inner surface 28g'r of the flange portion 28c, so
The force that rotates the switching lever 62 acts as a force that moves the clutch ring 28 to the right. Then, if you operate the switching lever 62 with sufficient force, the clutch ring 2
8 moves to the right to engage the groove 22a and the protrusion 28d.
Even if the friction is large, the clutch ring 28 is released, and thereafter the clutch ring 28 moves to the right on the shaft 14 by the force of the spring 52, and stops at the position where it collides with the input gear 24, as shown in FIG.

In the state shown in FIG. 4, the angular positions (phases) of the groove 2[1e and the protrusion 24a do not match, so they cannot be held together.
The outer surface of the flange portion 28c is pressed against the protrusion 24a by the biasing force of the spring 52. In this state, the lever 62 is in its most left-handed rotation [7], and the pin 66 and contact surface 54m are
Upon contact with the lever 46, the lever 46 is in its most right-handed state. However, since there is a gap between the pin 5B and the contact surfaces 4B& and 48b, the switching lever 62 transfers the force of the transmission plate 46, that is, the pin 58, to the operating arm 4 of the clutch lever 44.
4b to the flange portion 28c of the clutch ring 28.

If the manual gear 24 is rotated from this state, the clutch ring 28 will not rotate due to the load acting on the output gear 16, so the spring 52 will stop when the groove 280 and the protrusion 24m are in phase.
When the ring 28 moves, the two engage for the first time, and as shown in FIG. 5, a rotation transmission system from the manual gear 24 to the output gear 16 is completed.

In FIG. 5, the switching lever 62 is prevented from turning to the right by the biasing force of the spring 56 by means such as a click (not shown), so the force exerted by the spring 56 is canceled and the force acting on the clutch lever 44 is reduced. Only the biasing force (rightward turning force) of the spring 52 is applied. That is, the clutch ring 28 is connected to the manual gear 24.
The only force pressing against it is the biasing force generated by the spring 52. Therefore, similar to the spring 56 described above, the spring 5
The biasing force of step 2 only needs to be enough to prevent the engagement between the groove 28e and the protrusion 24a from coming loose.
Only a small force is required to press on the contact point 2, and a state of low friction loss and high transmission efficiency can be achieved.

In order to move the clutch ring 28 to the left, the lever 62, ie, the transmission plate 46, is completely released from the lock by the click means. Then, the transmission plate 46 moves to 11 due to the action of the spring 56.
1142 rotation to the left, the pin 58 and the contact surface 48a
The lever 44 is rotated to the left through contact with the actuating arm 44.
b pushes the inner surface 28f of the flange portion 28b. As a result, the clutch ring 28 is moved to the left and the grooves 2B, e are disengaged from the protrusion 24a.

At that time, even if the engagement between the groove 2841 and the protrusion 24a is difficult to disengage, the pin 66 pushes the contact surface 54b'i by operating the switching lever 62 (clockwise rotation), and the pin 5B pushes the contact surface 48b'i.
By pressing, the operating arm 44b of the clutch lever 44 pushes the inner surface of the flange portion 28b. Therefore, if the switching lever 62 is operated with enough force, the clutch ring 28
can be moved to the left. When the engagement between m28e and the projection 24a is released, the transmission plate 46 and the lever 44 are rotated to the left by the biasing force of the spring 56, but the projection 28
d and the groove 22a are not always in phase, and the protrusion 28
d comes into contact with the inner surface of the output gear 22. Then gear 22
is rotated, and when the protrusion 28d and the groove 22a are in phase, they engage, resulting in the state shown in FIG. 1.

In the embodiment described above, the rotation 11Q114 of the three members of the switching lever 62, the switching transmission plate 46, and the clutch lever 44
2 and 64 are set parallel to each other, however, in mounting, a three-dimensional configuration may be possible, such as by orthogonal rotation axes. Although the springs 52 and 56 are tension coil springs, other spring members such as torsion springs may also be used. Furthermore, the manner in which it is hung is not limited to the embodiment, and it may be hung between the members 62 and 46, such as the spring 56t-52, or between the member 44 and the fixed member, such as the spring 52 =', r56. You can also hang it on.

In the above description, the clutch ring 28 is connected to the rotating member 44.4.
6 and 62), but this is not essential; the ring 28 is moved by a linearly moving member. It's okay if it looks like this. Figure 6 and lf, 7
Such an embodiment is shown in the figure, but in order to simplify the explanation, portions corresponding to those in the above embodiment are shown with numerals added by 100', and detailed explanation will be omitted. In short, groove 22
The engagement between m and the protrusion 28d cancels the biasing force by the spring 156; when the engagement force between the two is small at -, the spring 152 is applied, and when the engagement force is large, the pin is activated by the rightward movement of the drive plate 162. The contact (interference) between the pin 166 and the abutting surface 154b and the contact between the pin 158 and the abutting surface 148b cause the groove 28e to be held in place by the spring 15.
When the engagement force between the two is small, the spring 156 cancels out the biasing force exerted by the drive plate 1, and when the engagement force is large, the drive plate 1
Pin 158 and contact surface 14 based on leftward movement of 62
8a and the contact between the pin 166 and the contact surface 154a. In addition, in the above embodiment, we explained that two systems of manual gears 'z22 and 24 are arranged and switched, but conversely, with the same structure, gear 16 is replaced with manual gear and gear 22.
and 24 as the output gear, switching to two output systems J
It is also possible to do both.

As stated above, according to the present invention, the switching member 2B
, 44:28,144 as a pair of power transmission members 22.24
The force to engage one of the two and the force to completely eliminate this engagement are the biasing forces of springs, etc. In addition to being more reliable, the locking can be easily removed with a small biasing force such as a spring, and the force to press against the support part 10.12 of the power transmission part hammer is also reduced, so torque loss is reduced. This has the effect of improving transmission efficiency. Further, if the engagement force between the switching member and the power transmission member is greater than the urging force of a spring or the like, the driving a member 62;
The direct transmission of force between the relay member 46: 146 and the switching members 44, 144 can remove engagement metal debris, thereby ensuring reliable switching operation.

[Explanation of symbols of main parts]

22.24...Power transmission member 28.44...Switching member 46...Relay member 48a, 48b, 54a, 54b
... Q surface 58.66 ... Bin 62 ... Drive member 56 ... First biasing means 52 ... Second biasing means Applicant 2 Nippon Kogaku Kogyo Co., Ltd.

Claims (1)

[Claims] 1. First@first direction and second direction for engaging with the force transmitting member
a front switching member capable of reciprocating in a second direction for engaging the power transmission member; the switching member reciprocating in a third or fourth direction by an external force to displace the switching member in the first or second direction; a movable driving member; a ninth first biasing member that biases the switching member in the #g1 direction; a second biasing member that biases the switching member in the second direction; A relay member is provided between the switching member and the driving member to interlock the two members, and when the driving member is located at an end in the third direction in the reciprocating stroke, the relay member is configured to switch the switching member. The member is engaged with the first power transmission member by the biasing force of the Is1 force member, and when the drive member is located at the end in the fourth direction in the reciprocating stroke, the relay member engages the switching member. When the second power transmission member is engaged by the biasing force of the second biasing member and the drive member is displaced from the third direction end toward the fourth direction by an external force, the relay member engages with the second power transmission member. The biasing force of the biasing member is deenergized, and when the engagement force between the first power transmission member and the switching member is smaller than the biasing force of the second biasing member, the biasing force of the second biasing member is used. , the switching member is displaced in the forward Mtl! second direction by direct transmission of the external force applied to the thick driving member, and the driving member is moved from the fourth direction end to the third direction by the external force. When the relay member is displaced to The power transmission switching is characterized in that when the biasing force of the first force member is large, the switching member is displaced in the first direction by direct transmission of the external force applied to the drive member. Apparatus. 2. The relay member is capable of relatively reciprocating motion with each of the switching member and the driving member in a non-interfering state, and is capable of interfering with each other at both ends of the reciprocating stroke and being integrally displaced. The first biasing member biases the switching member via the relay member, the second biasing member directly biases the entire switching member, and the driving member pushes the switching member at the end in the third direction in the reciprocating stroke. When the relay member is located at
The biasing force of the biasing member is deenergized, and the switching member is biased in a first direction by the biasing force of the first biasing member to engage with the filter 1 # force transmission member, When located at the end in the fourth direction of the reciprocating stroke, the relay member interferes with the drive member, thereby deenergizing the first biasing member and disengaging from the switching member. In the interference state, the switching member is biased in the 22nd direction by the biasing force of the second biasing member and engaged with the f, QwJ force transmitting member. A power transmission switching device according to claim 1.