JP5108059B2 - Angle adjustment method - Google Patents

Description

  The present invention relates to an angle adjusting method capable of arbitrarily setting an angle formed by a member on one side and a member on the other side.

For example, a chair having a back portion 15 and a seat portion 16 as shown in the perspective view of FIG. 1 is a bracket having an angle adjusting function between the back portion 15 and the seat portion 16 so that the inclination angle of the back portion 15 can be adjusted. ──Equipped with angle adjustment bracket A───.
This conventional metal fitting pivotally supports the gear of the second arm on the other side (back portion 15 side) and the claw piece in the case portion of the first arm connected to one side (seat portion 16 side) By engaging the claw piece with the gear, the second arm is prevented from swinging in the deploying direction (the falling direction of the back portion 15) with respect to the first arm (see, for example, Patent Document 1).

The force acting between the first arm and the second arm (the force necessary to suppress the swinging) will support the human weight and is very large. The teeth of the gear become larger, and therefore the gear pitch of the gear becomes rough. In other words, the claw pieces and gears could not be reduced due to the required strength.
Accordingly, the case portion for storing the claw piece and the gear is increased, the number of gear teeth is small (the pitch is large), the number of angle switching steps is small, and fine adjustment cannot be performed.

Japanese Utility Model Publication No.59-20118

  The problem to be solved is that the number of angle switching steps cannot be increased. Moreover, since the component parts are large, the entire metal fitting becomes large.

In the angle adjusting method according to the present invention, the first arm and the second arm are pivotably pivoted about the first axis, and the first arm and the second arm are in the maximum expanded state and the maximum folded state. An angle adjustment method for maintaining an arbitrary inclination angle between the first arm and the second arm; and a gear portion having a plurality of teeth is formed on the second arm along an arc line centered on the first axis; On the first arm side, a wedge surface is formed at a position on the outer side of the gear portion with the first axis as the center, and between the wedge surface and the outer peripheral tooth surface of the gear portion. A floating wedge member having a tooth surface composed of a plurality of teeth on an inner surface is movably disposed in the space portion, and a plurality of tooth surfaces of the floating wedge member are arranged. The teeth are simultaneously meshed with the gear portion, and the contact surface on the outer side of the floating wedge member is the wedge surface. The first arm and the second arm are prevented from swinging around the first axis by the wedge action of the floating wedge member sandwiched between the gear portion and the wedge surface. and configured to maintain the tilt angle; Furthermore, the second arm, along the arc line having a projecting portion pushes back the one end of the gear portion having a plurality of teeth, and the gear portion When the second arm swings to the maximum folded state, the push-back protrusion comes into contact with the floating wedge member and presses the floating wedge member in the folding direction. When further swung in the folding direction from the folded state, the meshing state of the tooth surface of the floating wedge member and the gear portion is released, the floating wedge member is separated from the gear portion, and the first arm and the first arm 2 arms swing in the direction of deployment It can be freely returned to the maximum deployed state, and when it is deployed and swung to the maximum deployed state, the push-out protrusion pushes out the floating wedge member to return the tooth surface and the gear portion to the meshed state. Furthermore, the floating wedge member is moved in the left-right direction by the left and right side walls provided on the first arm side so as to correspond to the left and right end surfaces of the floating wedge member movable in the space portion. This is a method configured to prevent the dropout due to .

According to the angle adjusting method of the present invention, when the first arm and the second arm are to swing in the unfolding direction, the contact surface on the outer side of the floating wedge member is brought into contact with the wedge surface on the first arm side. As a result of the wedge action, the force acting as the compression force in the first axial direction acts on the meshing site between the plurality of teeth of the floating wedge member and the gear portion, so that both the first arm and the second arm move in the deployment direction. Never swing.
In addition, the swinging of the gear portion is not suppressed by the contact force of the floating wedge member with the wedge surface, the engagement with the gear portion, and the above-described compression force. Even if the teeth are small, they can handle a large load. Further, by reducing the teeth of the gear part, the number of teeth of the gear part can be increased, and the number of angle switching steps can be increased. Accordingly, the folding angle can be finely adjusted. In addition, since the floating wedge member is prevented from moving and dropping in the left-right direction by the left and right side walls, the above-described operation of the floating wedge member is performed reliably.

It is a perspective view of the seat chair to which the angle adjustment method of the present invention is applied. It is a perspective view of an angle adjustment metal fitting. It is a perspective view for explanation, and (a) is an exploded perspective view for explanation of an angle adjustment metal fitting, and (b) is a perspective view for explanation of an elongate drawing material for forming a floating wedge member. It is explanatory drawing explaining a floating wedge member, a gear part, and a wedge-shaped window part. It is a principal part perspective view for description. It is a side view which shows a drop-off prevention cover, Comprising: (a) is a side view which shows the positional relationship with a 1st arm, (b) is a cross-sectional side view which shows the positional relationship with the 2nd arm 2. It is a side view of the angle adjustment metal fitting in a maximum deployment state. It is a side view of the angle adjustment metal fitting made into the arbitrary inclination angles. It is a side view of the angle adjustment metal fitting in the maximum folding state. It is a side view of the angle adjustment metal fitting made into an angle maintenance release state. It is a side view of the angle adjustment metal fitting in the state which returns the 2nd arm to a deployment direction. It is a principal part side view explaining the operation | movement which performs angle setting from the maximum expansion | deployment state. It is a principal part side view explaining the operation | movement which returns a 2nd arm to the expansion | deployment direction from a maximum folding state. It is an explanatory front view which shows the plate for processing a 2nd arm. It is a principal part side view for description.

  The angle adjustment method according to the present invention is applied to a chair having a back portion 15 and a seat portion 16 as shown in the perspective view of FIG. That is, the angle adjusting bracket A is disposed between the back portion 15 and the seat portion 16 so that the inclination angle of the back portion 15 can be adjusted (angle adjustment). That is, the angle adjustment fitting A is a joint fitting (connecting fitting) having an angle adjustment function. In addition to the chair, this bracket A can be used for sofas, headrests, footrests, etc., and can be incorporated into one where two components swing, and in addition, the door swings. It can also be used for shelves that open and close.

FIG. 2 is a perspective view of an angle adjusting bracket A for performing the method according to the present invention, and FIG. 3 is an exploded perspective view thereof.
The angle adjusting bracket A is pivotally connected to the first arm 1 including the case portion 3, and swingable about the first arm 1 and the first axis C ₁ at the case portion 3, and the first axis C And a second arm 2 including a gear portion 4 centered at ₁ . That is, the first arm 1 and the second arm 2 are pivotally mounted around the first axis C ₁ so that they can swing relative to each other.

The first arm 1 has a case part 3 having a pair of facing walls 17 and 17 and a first attachment part 18 extending from the case part 3, and the first attachment part 18 is inserted in FIG. It has a cylindrical shape so that it can be fixed.
The second arm 2 includes two gear plate portions 45 and 45 that are parallel to each other, the gear portion 4 that is housed in the case portion 3, and a second attachment portion that extends from the gear portion 4. The second mounting portion 19 has a cylindrical shape so as to be inserted and fixed in FIG.

As shown in FIG. 14, the second arm 2 includes a single plate body 40 having two symmetrical left and right gear plate portions 45 and 45, and the gear plate portions 45 and 45 are parallel to each other with a predetermined interval. It is made by bending. Gear plate portions 45 is provided at its substantially central, is provided with a through-hole 22, when the plate member 40 and bending process, the through-holes 22, 22, around the first axis C ₁ A shaft hole is formed. The plate 40 is made of steel or the like.

The gear portion 4 is formed along an arc line centered on the first axis C ₁ , and as shown in FIG. 3, a range (100 to 30 °) slightly exceeding a quarter circle (90 °). ~ 120 °) with gears (teeth). The first and second attachment portions 18 and 19 may have a structure that can be connected by bolts or other structures.

  In FIG. 1, the frame of the seat portion 16 is attached to the first attachment portion 18 of the first arm 1, and the frame of the back portion 15 is attached to the second attachment portion 19 of the second arm 2. The back portion 15 swings with respect to the seat portion 16, and the back portion 15 reclines and is held at an arbitrary inclination angle.

Further, as shown in FIGS. 2 and 3, through holes 21 and 21 are provided in the central portions of the wall portions 17 and 17 of the case portion 3 of the first arm 1.
The first arm 1 and the second arm 2 are pivotally connected by a shaft member 20. That is, with the gear portion 4 of the second arm 2 sandwiched between the wall portions 17 and 17 of the first arm 1, the shaft member 20 is passed through the through holes 21 and 21 of the first arm 1 and the second arm 2. The second arm 2 can be swung around the first axis C _{1 with} respect to the first arm 1 by being inserted into the holes 22 and caulking.

Further, as shown in FIGS. 3, 4, and 5, the angle adjusting bracket A includes a wedge-shaped window portion 5 formed in the case portion 3 of the first arm 1. The wedge-shaped window portion 5 is formed in the same shape on the wall portions 17 and 17 of the case portion 3, respectively, and the case portion 3 has a penetrating shape.
The wedge-shaped window portion 5 is a through hole formed in an arc shape so as to be concave toward the first axis C ₁ side, outside of the through hole in the case where the first axis C ₁ as the center side An arcuate wedge surface 8 is formed on the surface on the outer side and is located on the outer side of the gear portion 4. The surface on the inner side is an arc having a smaller diameter than the gear portion 4 with the first axis C ₁ as the center. A surface 23 is formed. Therefore, the teeth of the gear portion 4 are visible from the wedge-shaped window portion 5.

The wedge surface 8 is formed in an arc shape centering on the second axis C ₂ that is eccentric with the first axis C _1, and as shown in FIG. 4, the first arm 1 is on the left hand side and the second arm When 2 is on the right hand side, the wedge-shaped window portion 5 shrinks in the clockwise direction --- the wedge surface 8 approaches the gear portion 4--to form a wedge-shaped hole.
That is, a space portion is formed between the outer wedge surface 8 and the outer peripheral tooth surface of the gear portion 4, and a floating wedge member 6 described later is disposed in the space portion.

Further, the angle adjusting bracket A is provided with a floating wedge member 6, which is disposed so as to be movable in the wedge-shaped window portion 5, and one surface side (inner side surface) is a gear portion. 4, the other surface side (outer surface) is a contact surface 9 that contacts the outer wedge surface 8 of the wedge-shaped window portion 5.
The contact surface 9 is (substantially) the same as the radius of curvature of the wedge surface 8 of the wedge-shaped window portion 5. The tooth surface 7 has a plurality of teeth formed on the same surface as the radius of curvature of the pitch circle of the gear portion 4, and these teeth all mesh with the gear portion 4 at the same time.

The wedge-shaped window portion 5 has a retracting space portion 11 that accommodates the floating wedge member 6 pushed back by the second arm 2 and releases the meshing state between the tooth surface 7 and the gear portion 4.
The second arm 2 has a push-back protrusion 10 that presses the floating wedge member 6 in the folding direction on one end side (upper side) of the gear portion 4, and the retracting space portion 11 of the wedge-shaped window portion 5. The other end side (lower side) of the gear part 4 is provided with an extrusion protrusion 12 for pushing out the floating wedge member 6 accommodated in the gear part 4.

Further, the width dimension of the floating wedge member 6 is substantially the same as the width dimension of the case portion 3. That is, the surfaces of both side edges of the abutting surface 9 of the floating wedge member 6 can abut on the wedge surface 8 of the wedge-shaped window portion 5 (wall portions 17, 17).
The floating wedge member 6 is formed by cutting a long drawing material 43 made of a steel material as shown in FIG. 3B into a predetermined length.

  Further, the case portion 3 of the first arm 1 has a resilient member 13 that resiliently biases the floating wedge member 6 in a direction of pressing the floating wedge member 6 against the gear portion 4 of the second arm 2. The elastic member 13 is a spring member formed by folding a steel wire into a U shape, and both end portions are fixed to the case portion 3 between the wall portions 17 and 17 and the central portion is a contact surface 9 of the floating wedge member 6. Abuts on the central region of The floating wedge member 6 is elastically biased toward the gear portion 4 (see FIG. 5).

Next, as shown in FIGS. 2, 3, 6, and 15, the angle adjusting bracket A includes a drop prevention cover 33 that prevents the floating wedge member 6 from dropping from the wedge-shaped window portion 5. To do. The drop-off prevention cover 33 is disposed so as to surround the case portion 3 from the left and right outer sides, and is a thin plate body having an approximately U-shaped shape with an upward opening in a side view when viewed from the front.
Specifically, the fall prevention cover 33 includes left and right side walls 34, 34, a bottom wall 35 that bridges the lower edges of the left and right side walls 34, 34 so as to surround the case portion 3 from below, and a rear wall 35 And a corner wall portion 36 that is connected to the end and is formed in a curved shape upward.
The corner wall portion 36 is formed such that the upper end thereof is at a height that does not contact the lower side when the second arm 2 is expanded by approximately 180 ° (see FIG. 6B). ). With this configuration, the corner wall portion 36 does not prevent the second arm 2 from swinging in the deployed state.

Further, each side wall 34 has a small stepped portion at a position corresponding to the wedge-shaped window portion 5 of the case portion 3 and a separation surface portion 34a that forms a slight gap with the outer surface of the wall portion 17 of the case portion 3. It is formed. Due to the spacing surface portion 34 a, the frictional force between the left and right end surfaces of the floating wedge member 6 and the left and right side walls 34 and 34 is low, and the floating wedge member 6 can move smoothly in the wedge-shaped window portion 5.
Further, each side wall 34 is provided with a hole portion 37 for passing the shaft member 20 at a position corresponding to the through holes 21 and 22.

Next, as shown in FIGS. 2, 3, and 7 to 9, the angle adjusting bracket A includes a foreign matter intrusion prevention member 26 that surrounds the gear portion 4 and the floating wedge member 6 from above. The foreign matter intrusion prevention member 26 is pivotally mounted between the wall portions 17 and 17 of the first arm 1 so as to be swingable about the first axis C ₁ .
Specifically, the foreign matter intrusion prevention member 26 includes a front and rear direction strip plate-shaped umbrella head 29 and a flat plate-shaped swing plate piece 30 extending below the umbrella head 29. The swing plate piece 30 is formed in a square shape so that the tip protrusion 32 side is inclined forward and a hole 31 for passing the shaft member 20 is provided at an intermediate position. Has been. The lateral width of the umbrella head 29 is set slightly smaller than the distance between the wall portions 17 and 17 of the first arm 1.
The foreign matter intrusion prevention member 26 swings in a state in which the tip protrusion 32 of the swing plate piece 30 is disposed below the floating wedge member 6 (see FIGS. 7 to 9). In the process of swinging, the umbrella head 29 always surrounds the gear portion 4 and the floating wedge member 6 from above to prevent foreign matter from entering.

Next, an angle adjustment function (angle adjustment method) of the first arm 1 and the second arm 2 that performs folding and unfolding swinging operations will be described.
FIGS. 7 to 11 are front views of the angle adjusting bracket A for explaining the operation, and a view in which the wall portion 17 on one side (front side) of the case portion 3 is omitted (omitted) for the sake of explanation. It is said.
FIGS. 12 and 13 are principal part front views for explaining the operation of the floating wedge member 6 in the gear portion 4 and the wedge-shaped window portion 5.

The first arm 1 and the second arm 2 are in a maximum unfolded state (FIG. 7). The state where the first arm 1 and the second arm 2 are linear (180 ° phase). The second arm 2 gradually oscillates around the first axis C ₁ from ─, and is folded (inclined) at an arbitrary folding angle with the first arm 1 (FIG. 8). A predetermined maximum folded state is obtained (FIG. 9).

Referring to FIGS. 12 and 13, FIG. 12 (a) corresponds to the state of FIG. 7, the floating wedge member 6 engages with the gear portion 4 and abuts against the wedge surface 8, and the second arm 2 is shown in FIG. No more rocking around (locked).
When the second arm 2 is swung in the standing direction as shown in FIG. 8 from this state, the elastic member 13 (see FIG. 5) is used to make an impact on the gear portion 4 as shown in FIG. 12 (b). The contact surface 9 of the floating wedge member 6 that is urged and meshed is separated from the wedge surface 8 of the window portion 5, and a slight gap d is formed between the contact surface 9 and the wedge surface 8. Then, as shown in FIG. 12 (c), the guide gradient surface (stepped surface) 27 of the floating wedge member 6 abuts against the contact stepped portion 28 of the wedge-shaped window portion 5 by the standing operation of the second arm 2. Thus, the tooth surface 7 of the floating wedge member 6 can be separated from the gear portion 4 by the gap d, and the tooth surface 7 of the floating wedge member 6 can get over the gear portion 4 with a click.

  The guide slope surface 27 of the floating wedge member 6 is formed at the rear edge of the tooth surface 7 of the floating wedge member 6, and the stepped portion 28 of the wedge-shaped window portion 5 is located on the inner side of the wedge-shaped window portion 5. The arc surface 23 is formed so as to be in contact with the gradient surface 27.

Therefore, the floating wedge member 6 has the tooth surface 7 meshed with the gear portion 4, the abutment surface 9 abutted on the wedge surface 8, and the floating wedge member 6 sandwiched between the gear portion 4 and the wedge surface 8. The wedge action prevents the second arm 2 from swinging in the deployment direction with respect to the first arm 1.
That is, the first arm 1 and the second arm 2 can be maintained at an arbitrary folding angle (inclination angle).

Then, as shown in FIG. 13 (d), when the second arm 2 swings to the maximum folded state (FIG. 9) beyond the predetermined folding angle with respect to the first arm 1, the push-back projection 10 floats wedge. The member 6 is pressed in the folding direction.
That is, the push-back protrusion 10 is formed on one end side of the gear portion 4 (tooth forming portion). In this state, the push-back protrusion 10 contacts the front edge of the tooth surface 7 of the floating wedge member 6.

  Then, as shown in FIGS. 10 and 13 (e), when the second arm 2 is further swung in the folding direction from the maximum folded state, the floating wedge member 6 (inductive gradient) pushed back by the push-back projection 10 is obtained. The surface 27) gets over the stepped portion 28 and is accommodated in the retracting space portion 11 of the wedge-shaped window portion 5 to release the meshing state between the tooth surface 7 of the floating wedge member 6 and the gear portion 4. That is, the floating wedge member 6 accommodated in the retreat space portion 11 is in a state of being separated from the gear portion 4.

Accordingly, the second arm 2 becomes free (swingable) with respect to the first arm 1 and can swing in the unfolding direction as shown in FIG. 11, and can be returned to the maximum unfolded state in FIG.
Then, when the second arm 2 is deployed and swung to the maximum deployed state of a predetermined angle (180 °) with respect to the first arm 1, as shown in FIG. 13 (f), the second arm 2 is accommodated in the retreat space 11. It has an extrusion protrusion 12 that pushes out the floating wedge member 6 to bring the tooth surface 7 and the gear portion 4 into meshing state.

  The push-out protrusion 12 is formed on the other end side of the gear part 4 (on the opposite side to the one end side where the push-back protrusion 10 is formed), and when the fully expanded state is obtained, the protrusion 12 is a floating wedge. The floating wedge member 6 can be pushed out from the retreat space 11 by pressing the guide gradient surface 27 of the member 6 and returned to the state shown in FIG.

That is, the operation of the floating wedge member 6 in the wedge-shaped window portion 5 is performed by the wedge action between the gear portion 4 and the wedge surface 8 by the wedge action from the maximum expanded state to the maximum folded state. The first arm 1 on the surface 8 side and the second arm 2 on the gear unit 4 side can be adjusted to an arbitrary folding angle (inclination angle), and the angle can be maintained. When the maximum folding state is exceeded, the floating wedge The member 6 is pressed by the push-back protrusion 10 and is accommodated in the retracting space 11 of the wedge-shaped window 5 so that the first arm 1 and the second arm 2 are in a freely swinging state.
Then, when returned to the maximum deployed state, the floating wedge member 6 is pressed by the pushing projection 12 and pushed out of the retracting space portion 11, and is brought into meshing state with the gear portion 4 again.

In addition, when the seat is tilted so that the front part of the seat part floats obliquely upward and the angle adjusting bracket A is in a state as shown in FIG. 15, the corner wall part 36 of the fall prevention cover 33 is The floor surface F is brought into contact with a gentle curved surface, so that the surface pressure acting on the floor surface F is prevented from being excessive and damage to the floor surface F is prevented.
Although not shown in the drawings, even if the seat is manufactured so that the angle adjusting bracket A is surrounded by a cushioning material or a covering cloth, the surface pressure applied to the covering cloth or the like by the bracket A is not limited. It can be prevented from becoming excessively large, damage such as tearing of the covering cloth hardly occurs, and long-lasting can be achieved.

As described above, the angle adjusting bracket is pivotally connected to the first arm 1 including the case portion 3 and swingable around the first arm 1 and the first axis C ₁ at the case portion 3. A second arm 2 having a gear portion 4 composed of two parallel gear plate portions 45, 45, a wedge-shaped window portion 5 formed in the case portion 3 of the first arm 1, and a wedge-shaped window portion 5 The tooth surface 7 is a tooth surface 7 that is movably arranged and meshes with the gear portion 4 on one surface side, and a contact surface 9 that abuts the wedge surface 8 on the outer side of the wedge-shaped window portion 5 on the other surface side. 7 includes a floating wedge member 6 that meshes with the gear portion 4, and the contact surface 9 contacts the wedge surface 8 and prevents the second arm 2 from swinging in the deployment direction with respect to the first arm 1. Therefore, when the first arm 1 and the second arm 2 are about to swing in the unfolding direction, the contact surface 9 on the outer side of the floating wedge member 6 is a wedge. Since the floating wedge member 6 that abuts on the wedge surface 8 of the window portion 5 and meshes with the gear portion 4 of the second arm 2 acts as a pressing force toward the center of the gear portion 4, Both of the two arms 2 never swing in the deployment direction.

In addition, the rocking is not suppressed only by the catch of the gear portion 4 but is swung by the contact force of the floating wedge member 6 with the wedge surface 8, the meshing with the gear portion 4, and the compression force. In order to suppress, even if the tooth (module) of the gear part 4 is small, it can carry a big load and can have sufficient intensity | strength. Further, by reducing the teeth of the gear unit 4, the number of teeth of the gear unit 4 can be increased, and the number of angle switching steps can be increased. Therefore, the pitch of the folding angle is reduced and fine adjustment can be performed. That is, when applied to a chair or a sofa, the back portion 15 having a comfortable inclination angle can be obtained.
In addition, since the gear portion 4 is composed of two gear plate portions 45 and 45 that are parallel to each other, the floating wedge member 6 stably meshes with the gear portion 4 without rattling from side to side and is smoothly wedge-shaped. There is no possibility of malfunction due to movement in the window 5.
Furthermore, the case portion 3 can be made small, so that the entire metal fitting can be reduced in size, and when the metal fitting A is disposed in the cover when used for a chair or a sofa, the cover is not likely to be broken.

  The second arm 2 is formed by bending a single plate body 40 having two symmetrical left and right gear plate portions 45 and 45 so that the gear plate portions 45 and 45 are parallel to each other at a predetermined interval. As a result, the number of parts can be reduced, and the molding effort can be reduced.

In addition, a foreign matter intrusion prevention member 26 is provided so as to be swingable about the first axis C ₁ in the case portion 3 and disposed so as to cover the gear portion 4 of the second arm 2 from above. As a result, it is possible to efficiently prevent foreign matter such as dust from entering between the gear portion 4 and the floating wedge member 6 so as not to operate, thereby preventing the occurrence of a failure.

  Further, since the floating wedge member 6 is formed by cutting the long drawn material 43 made of a steel material, the forming becomes easy and mass production is possible.

  In addition, since the case portion 3 is disposed so as to surround the left and right outer sides and includes a drop prevention cover 33 that prevents the floating wedge member 6 from falling off the wedge-shaped window portion 5, the floating wedge member is used in use. 6 is reliably prevented from falling off the wedge-shaped window portion 5, and the malfunction and failure of the floating wedge member 6 can be prevented.

The fall prevention cover 33 is connected to the left and right side walls 34, 34, the bottom wall 35 that bridges the lower end edges of the left and right side walls 34, 34 so as to surround the case portion 3 from below, and the rear end of the bottom wall 35. The corner wall portion 36 is formed in a curved shape upward and rearward, so even when the seat wall 16 is tilted so that the front portion of the seat portion 16 floats obliquely upward, the corner wall portion 36 is Contact with the floor surface F with a gentle surface can prevent the surface pressure acting on the floor surface F from becoming excessive, and damage to the floor surface F can be suppressed.
Alternatively, if the chair is manufactured by surrounding the metal fitting A with a cushioning material or a covering cloth, the surface pressure acting on the covering cloth is prevented from being excessive, and the covering cloth or the like is damaged. It is difficult and can last a long time.

  The second arm 2 has a push-back protrusion 10 that presses the floating wedge member 6 in the folding direction when the second arm 2 swings over a predetermined folding angle with respect to the first arm 1, and the wedge-shaped window portion 5 pushes back. The retraction space part 11 which accommodates the floating wedge member 6 pushed back by the protrusion 10 and releases the meshing state of the tooth surface 7 and the gear part 4 is provided. Furthermore, the second arm 2 is a first arm. 1 has a push-out projection 12 that pushes out the floating wedge member 6 accommodated in the retreat space portion 11 and engages the tooth surface 7 and the gear portion 4, so that the floating wedge member 6 Due to the movement in the wedge-shaped window portion 5, the meshing with the gear portion 4 can be released or the meshing can be resumed, and the angle adjusting operation between the second arm 2 and the first arm 1 is very simple. .

The gear portion 4 is formed around the first axis C _1, and the wedge surface 8 of the wedge-shaped window portion 5 is an arc centered on the second axis C ₂ that is eccentric from the first axis C _1. Since it is formed in a shape, an effective wedge action is exhibited, and the movement of the floating wedge member 6 and the engagement / disengagement operation with the gear portion 4 become smooth.

DESCRIPTION OF SYMBOLS 1 1st arm 2 2nd arm 4 Gear part 6 Floating wedge member 7 Tooth surface 8 Wedge surface 9 Contact surface
10 Push-back protrusion
12 Extrusion protrusion
34 (Left and right) side wall C ₁ first axis

Claims (1)

The first arm (1) and the second arm (2) are pivotably pivoted about the first axis (C ₁ ), and the first arm (1) and the second arm (2) are In an angle adjustment method for maintaining an arbitrary inclination angle between the maximum expanded state and the maximum folded state,
The second arm (2) is formed with a gear portion (4) having a plurality of teeth along an arc line centered on the first axis (C ₁ ).
On the first arm (1) side, a wedge surface (8) is formed on the outer side of the gear portion (4) with the first axis (C ₁ ) as the center, and the wedge is formed. Forming a space between the surface (8) and the outer peripheral tooth surface of the gear portion (4);
A floating wedge member (6) having a tooth surface (7) composed of a plurality of teeth on the inner surface is movably disposed in the space portion, and the tooth surface of the floating wedge member (6) ( 7) simultaneously meshing the plurality of teeth with the gear portion (4) and bringing the contact surface (9) on the outer side of the floating wedge member (6) into contact with the wedge surface (8) Due to the wedge action of the floating wedge member (6) sandwiched between the portion (4) and the wedge surface (8), the first arm (1) and the second arm (2) are moved to the first axis (C ₁ ). It is configured to suppress swinging in the deployment direction around and maintain the above-mentioned arbitrary inclination angle ,
Furthermore, the second arm (2) has a push-back protrusion (10) on one end side of the gear part (4) having a plurality of teeth along the arcuate line, and the gear part (4 ) On the other end side, and when the second arm (2) swings to the maximum folded state, the push-back protrusion (10) abuts on the floating wedge member (6). When the floating wedge member (6) is pressed in the folding direction and further swung in the folding direction from the maximum folded state, the tooth surface (7) and the gear portion (4) of the floating wedge member (6) The floating wedge member (6) is separated from the gear portion (4), and the first arm (1) and the second arm (2) are swingable in the unfolding direction. Can be returned to the maximum deployed state, and the above-mentioned Rust member (6) the extrusion projection (12) is extruded and configured to return the tooth surface (7) and the gear unit (4) in mesh with,
Moreover, the floating wedge is provided by the left and right side walls (34) (34) provided on the first arm (1) side so as to correspond to the left and right end surfaces of the floating wedge member (6) movable in the space. It was configured to prevent the member (6) from falling off due to movement in the left-right direction.
A characteristic angle adjustment method.

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