WO2010087033A1

WO2010087033A1 - Extrusion apparatus

Info

Publication number: WO2010087033A1
Application number: PCT/JP2009/054468
Authority: WO
Inventors: 正一星
Original assignee: 株式会社ニフコ
Priority date: 2009-02-02
Filing date: 2009-03-09
Publication date: 2010-08-05
Also published as: JP2010174599A; CN102301160A; KR20110112465A

Abstract

A thin extrusion apparatus is obtained. A worm gear (35) is linked to a drive motor (18), and a gear train (48) is meshed with the worm gear (35), thus making it possible to cause the axial center of the drive motor (18) and the axial center of the gear train (48) to intersect at a substantially right angle. In other words, the drive motor (18) need not be disposed in the direction of the axial center of the gear train (48).

Description

Extrusion equipment

The present invention relates to an extrusion device that assists the movement of a moving body that is pushed into and pulled out from a storage unit.

Conventionally, moving bodies such as drawers are manually pulled out or stored in system kitchens and furniture. When there are multiple drawers as in the system kitchen, the bottom drawer often stores heavy items, and when pulling out the bottom drawer while bent down, especially for elderly people Is a painful task.

For this reason, for example, as disclosed in Patent Document 1, the driving force of the motor is transmitted by a gear train, and the arm is rotated so that when the moving body such as a drawer is moved, the moving body is pressed and moved by the arm. Extrusion devices that move the body are known.
DE202007006884U1 publication

The present invention provides a thinned extrusion apparatus.

According to a first aspect of the present invention, in the extrusion apparatus, a worm gear provided in a housing and connected to a motor, a gear train that meshes with the worm gear, and a first rack that meshes with a final gear of the gear train are formed. A slide member slidably attached to the housing; a surface provided on the slide member; a surface intersecting a tooth row of the first rack; and a tooth row formed in a tooth row direction of the first rack. Two racks and a rotatable arm body having a gear meshing with the second rack.

In the above aspect, the casing is provided with the worm gear connected to the motor, and the gear train is engaged with the worm gear. The first rack meshes with the final gear of this gear train. The first rack is formed on a slide member that is slidably attached to the housing. The slide member has a surface that intersects the tooth row of the first rack and a tooth row in the tooth row direction of the first rack. A second rack in which is formed is provided.

The gear provided on the arm body meshes with the second rack, and the arm body rotates through the second rack and the gear by the sliding movement of the slide member. For example, when this push-out device is used in a housing portion that houses a moving body such as a drawer, the moving body can be easily and quickly pulled out with a low load by pushing out the moving body by rotating the arm body. .

Also, by connecting a worm gear to the motor and meshing the gear train with the worm gear, the shaft core of the motor and the shaft core of the gear train can be made substantially orthogonal. That is, since it is not necessary to arrange a motor along the axial direction of the gear train, the casing of the extrusion device can be made thin. Thereby, the installation space of an extrusion apparatus decreases and versatility expands.

Also, by engaging the last gear of the gear train and the first rack, the rotational force transmitted to the gear train can be converted into a driving force for sliding the slide member. And the 2nd rack by which the tooth row was formed in the surface which intersects the tooth row of the 1st rack of this slide member and the tooth row direction of the 1st rack is provided.

By forming the second rack tooth row in the first rack tooth row direction, the second rack tooth row also moves along the movement direction of the first rack tooth row moving through the slide member. By meshing the gear of the arm body with this second rack, when the tooth row of the second rack moves, the arm body rotates via the gear. By providing the second rack on the surface intersecting with the tooth row of the first rack, the transmission direction of the driving force of the motor can be changed by the angle (intersection angle) formed by the first rack and the second rack. .

In this way, by forming the first rack and the second rack on the slide member and changing the transmission direction of the driving force, for example, compared with the case where the transmission direction of the driving force is converted by a worm gear, The rotational center position of the arm body can be determined at a desired position, and the degree of freedom in design is expanded.

According to a second aspect of the present invention, there is provided a detection mechanism according to the first aspect of the present invention, wherein the detection mechanism is provided so as to be able to come into contact with a moving body pushed into or withdrawn from the storage unit, and the output voltage changes according to the position of the moving body And a control mechanism that drives the motor when the output voltage of the detection mechanism is equal to or higher than a predetermined value.

In the above configuration, the detection mechanism is provided so as to be in contact with the moving body, and the output voltage is changed according to the position of the moving body. When the output voltage by this detection mechanism is a predetermined value or more, the motor is driven by the control mechanism.

Here, it is detected that the moving body has moved from the storage position by moving the mobile body relative to the storage position with reference to the storage position, so that the output voltage by the detection mechanism changes. Further, when the output voltage by the detection mechanism becomes equal to or higher than a predetermined value, control by the control mechanism is performed to absorb an error in output voltage by the detection mechanism.

According to a third aspect of the present invention, there is provided the positioning mechanism according to the second aspect of the present invention, wherein a positioning mechanism is provided that contacts the moving body at the storage position of the moving body and allows the moving body to move backward from the storage position. good.

In the above configuration, the positioning mechanism hits the moving body and positions the moving body at the storage position. In this storage position, the moving body is allowed to move to the back of the storage unit. That is, the moving body can be pushed in or pulled out based on the storage position. For this reason, when the moving body is pushed in or pulled out based on the storage position, it is detected that the moving body has moved, so that the position of the moving body can be easily detected.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a final gear of the gear train includes a fixed shaft fixed to the housing, a large gear inserted through the fixed shaft and rotating around the fixed shaft, A gear member provided with a small gear, and the large gear and the small gear rotate together by mutual sliding resistance, and when a torque of a predetermined value or more acts on the arm body, Only the small gear that meshes with the first rack rotates.

In the above configuration, the final gear of the gear train includes a fixed shaft and a gear member that is inserted through the fixed shaft and rotates around the fixed shaft. The gear member is provided with a large gear and a small gear. ing. The large gear and the small gear are rotated together by mutual sliding resistance. When a torque exceeding a predetermined value is applied to the arm body, only the small gear is rotated.

When the moving body is pushed into the storage section even though the arm body is rotating, the slide member does not move through the first rack due to the locked state by the gear train, so the gear of the arm body rotates. There is a risk that the arm body may be damaged.

For this reason, when torque of a predetermined value or more acts on the arm body, the integration of the large gear and the small gear due to the sliding resistance is released, and the small gear can be rotated so that the arm can be rotated via the slide member and the gear. The body can be returned to the housing, and the arm body can be prevented from being damaged.

Since the present invention has the above-described configuration, the moving body extrusion device can be made thin.

It is a perspective view of the extrusion apparatus which concerns on embodiment of this invention. It is a schematic exploded perspective view of the extrusion device concerning an embodiment of the invention. It is a perspective view of the extrusion apparatus which concerns on embodiment of this invention, and is the state in which the arm body is accommodated. It is a perspective view of the extrusion apparatus which concerns on embodiment of this invention, and is the state which made the arm body protrude. It is a perspective view explaining operation | movement of the extrusion apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the effect | action of the extrusion apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the effect | action of the extrusion apparatus which concerns on embodiment of this invention, and FIG. 7B has shown the state which pushed in drawer | drawer from the storage position of FIG. 7A. It is explanatory drawing which shows the effect | action of the extrusion apparatus which concerns on embodiment of this invention, and FIG. 8B has shown the state which pulled out the drawer from the storage position of FIG. 8A. It is a flowchart explaining operation | movement of the extrusion apparatus which concerns on embodiment of this invention.

Next, the extrusion apparatus according to the embodiment of the present invention will be described.
1A and 1B show a box-shaped drawer 10 as a moving body, which can be pushed into or withdrawn into a storage portion 12 provided with an opening. Although not shown, a rail is disposed on the side wall of the storage portion 12 along the push-in or pull-out direction of the drawer 10, and the drawer 10 can move along the rail.

(Configuration of moving body extrusion device)
Here, the configuration of the moving body extrusion apparatus will be described.

As shown in FIG. 1A and FIG. 1B, the back wall 12A of the storage unit 12 is provided with an extrusion device 14 that reduces the load when the drawer 10 as a moving body is pulled out. As shown in FIGS. 2 and 3, the extrusion device 14 includes a substantially box-shaped casing 16, which is arranged so that the longitudinal direction thereof is a horizontal direction, and the base surface 17 of the casing 16 is accommodated. It is possible to face the rear wall 12A of the portion 12.

The housing 16 is provided with mounting

pieces

17A and 17B that can be mounted on the back wall 12A of the storage unit 12. The attachment pieces 17A extend from the lower ends on both sides of the base surface 17, and the attachment pieces 17B are provided at the lower end portion of the base surface 17 so as to be orthogonal to the base surface 17. Depending on the shape of the back wall 12A of the storage portion 12, at least one of the mounting

pieces

17A and 17B is attached to the back wall 12A.

In addition, a substantially box-shaped motor base 20 that houses the drive motor 18 and the like is provided at one end of the casing 16 in the longitudinal direction. A partition wall 22 is provided at the center of the motor base 20 in the width direction, and the housing 24 partitioned by the partition wall 22 controls the driving of the drive motor 18 that can rotate forward and backward. A control device (control mechanism) 26 (see FIG. 3) having a circuit board on which a microcomputer or the like that is not installed is accommodated.

In addition, a support wall 30 is provided at the center in the longitudinal direction (the height direction of the housing 16) of the storage portion 28 located next to the storage portion 24, and the drive motor 18 is provided below the support wall 30. Are accommodated in a standing state along the height direction of the housing 16.

The support wall 30 is provided with an arc-shaped notch 32, and the shaft 34 of the drive motor 18 passes through the notch 32. The drive motor 18 is in contact with the support wall 30 via a bush 37, and vibration due to the drive of the drive motor 18 is suppressed by the bush 37.

A worm gear 35 connected to the shaft 34 of the drive motor 18 is accommodated in the upper portion of the support wall 30 so that the drive force of the drive motor 18 is transmitted. On the other hand, fixed

shafts

36, 38, and 40 are fixed to the upper portion of the base surface 17 of the housing 16 at predetermined intervals along the longitudinal direction of the base surface 17.

Gear members

42, 44, 46 (a so-called gear train 48, and the gear member 46 is a final gear) are rotatably supported on the fixed

shafts

36, 38, 40. , 46 are respectively provided with

large gears

50, 52, 54 and

small gears

56, 58, 60 on the same axis.

Here, the large gear 50 of the gear member 42 meshes with the worm gear 35, and the driving force of the drive motor 18 is transmitted to the large gear 50 via the worm gear 35. The driving force of the driving motor 18 is transmitted to the gear member 42 through the large gear 50, and the gear member 42 rotates. For this reason, the small gear 56 provided in the gear member 42 rotates.

The small gear 56 meshes with the large gear 52, and the driving force of the driving motor 18 is transmitted to the gear member 44 via the large gear 52. Thereby, the gear member 44 rotates and the small gear 58 provided in the gear member 44 rotates.

The large gear 54 meshes with the small gear 58, and the driving force of the driving motor 18 is transmitted to the gear member 46 via the large gear 54. Thereby, the gear member 46 rotates and the small gear 60 provided in the gear member 46 rotates.

On the other hand, a storage space 62 is provided below the

gear members

42, 44, 46, and the slide member 64 and the arm body 66 can be stored. The base surface 17 of the housing 16 is provided with a holder 65 that is mounted so as to be movable along the longitudinal direction of the base surface 17, and the slide member 64 is interposed between the holder 65 and the base surface of the housing 16. 17 is slidable along the longitudinal direction.

Here, the slide member 64 is configured in two upper and lower stages, and the upper stage portion 68 of the slide member 64 is a rectangular tube body in which a long hole 68A penetrating along the depth direction of the housing 16 is formed in the central portion. It is. Further, the lower step portion 70 of the slide member 64 has a plate-like rectangle and is disposed in parallel with the base surface 17 of the housing 16.

A rack (first rack) 72 in which grooves are cut along the depth direction of the housing 16 (a tooth row is formed along the moving direction of the slide member 64) is provided on the upper surface of the upper step portion 68. Thus, the small gear 60 of the gear member 46 can be engaged. For this reason, as the small gear 60 rotates, the slide member 64 slides along the longitudinal direction of the base surface 17 via the rack 72.

Further, the upper step portion 68 is provided on one end side of the lower step portion 70, and a long hole 70 A penetrating along the depth direction of the housing 16 is provided in the lower step portion 70 at the lower portion of the upper step portion 68. A slot-like rib 65A provided in the holder 65 is fitted into the slot 70A, and the slide member 64 moves integrally with the holder 65. Further, a rack (second rack) in which a groove is cut along the height direction of the casing 16 (a tooth row is formed along the moving direction of the slide member 64) on the other end side of the lower step portion 70. 74 is provided.

On the other hand, a fixing hole 75 is provided in the mounting piece 17B below the fixed shaft 38, and an arm shaft 76 is fitted into the fixing hole 75 and fixed to the mounting piece 17B. An arm gear 78 having a gear portion 78 A formed in a half in the circumferential direction is rotatably supported on the arm shaft 76, and the gear portion 78 A can mesh with the rack 74.

On the opposite side of the gear portion 78 A of the arm gear 78, a mounting portion 78 B that is attached to a notch portion 66 A formed at one end of the arm body 66 is provided. Here, the arm body 66 has a substantially rectangular parallelepiped shape, and has an arc shape that draws a gentle curved surface along the longitudinal direction, the other end portion is a free end, and the arc gear surface has a thickness of the arm gear 78 as a diameter. ing. The arm gear 78 and the arm body 66 may be integrally formed.

The notch portion 66A and the mounting portion 78B are formed with

shaft holes

66B and 78C, respectively. The arm shaft 76 is inserted into the shaft holes 66B and 78C, and the arm gear 78 and the arm body are centered on the arm shaft 76. 66 is rotatable.

When the rack 74 is moved by the sliding movement of the slide member 64 and the arm gear 78 is thereby rotated, the arm gear 78 is integrated with the arm gear 78, and the free end of the arm body 66 is centered on the arm shaft 76. It rotates in a direction away from or close to the surface 17.

Incidentally, a sensor housing 80 is fixed to the base surface 17 of the housing 16 at the lower portion of the shaft 36. The sensor housing 80 is provided with a through hole 80 A penetrating along the longitudinal direction of the housing 16, and the shaft portion 84 of the sensor (detection mechanism) 82 can be inserted therethrough.

The sensor 82 has a substantially fan shape, and can swing in the depth direction of the casing 16 around the shaft portion 84. A torsion spring 96 (see FIG. 6A; FIGS. 6 to 8 are schematic diagrams for explaining the operation of the sensor 82 and the like) is attached to the sensor 82, and the sensor 82 is attached to the base surface of the housing 16. It is biased in a direction away from 17.

The sensor 82 is connected to the control device 26 (see FIG. 3) housed in the motor base 20, and corresponds to the protrusion amount of the sensor 82 in the depth direction of the housing 16, that is, according to the rotation angle of the sensor 82. The output voltage is changed by a variable resistor whose resistance value changes.

Here, as shown in FIG. 2, a cover 86 can be attached to the housing 16, and the inside of the housing 16 is covered by the cover 86.

Openings

88 and 90 are formed in the lower part of the cover 86, the arm body 66 is exposed from the opening 88, and the sensor 82 can be exposed from the opening 90.

Further, a positioning pin (positioning mechanism) 92 is provided on the front surface of the cover 86 so as to protrude. As shown in FIG. 6B, the positioning pin 92 is provided with a compression spring (positioning mechanism) 94, and the drawer 10 is positioned in a state where the drawer 10 is in contact with the distal end portion of the positioning pin 92. This position is a so-called storage position P.

In this storage position P, as shown in FIGS. 6A and 6B, the drawer 10 is in contact with the sensor 82, and elastic energy is accumulated in the torsion spring 96. 7A and 7B, when the drawer 10 is positioned at the storage position P and is pushed into the drawer 10 with a pressing force of a predetermined value or more, the compression spring 94 is compressed and the positioning pin 92 is It is pushed.

That is, with reference to the storage position P, the drawer 10 can be moved in the pushing direction or the drawing direction (see FIGS. 8A and 8B). As the drawer 10 moves, the output voltage from the sensor 82 changes.

In the control device 26, when the output voltage is less than a predetermined value, it is not determined that the drawer 10 has moved. That is, when the sensor 82 is moved finely, it is determined that the drawer 10 has not moved, and the output voltage error due to the sensor 82 is absorbed.

(Operation of moving body extrusion device)
Next, the operation of the moving body extrusion apparatus will be described.

As shown in FIG. 8A, when the drawer 10 is in contact with the tip of the positioning pin 92 and positioned, the compression spring 94 provided on the positioning pin 92 is almost free. On the other hand, the sensor 82 is pressed by the drawer 10, and elastic energy is accumulated in the torsion spring 96.

In this state, as shown in FIG. 8B, when the drawer 10 is pulled out from the storage portion 12 (see FIG. 1), the sensor 82 protrudes due to the urging force of the torsion spring 96. For this reason, the output voltage by the sensor 82 increases (the output voltage may be decreased). As a result, the control device 26 detects that the drawer 10 has moved, and the drive motor 18 is driven.

As shown in FIG. 5, the worm gear 35 is rotated by the rotation of the drive motor 18 in the direction of the arrow, the driving force of the drive motor 18 is transmitted to the gear train 48, and the

gear members

42, 44, and 46 are rotated in the direction of the arrow, respectively. .

The rotation of the gear member 46, which is the final gear of the gear train 48, causes the slide member 64 to slide in the direction of the arrow through the rack 72 that meshes with the small gear 60 provided on the gear member 46. As a result, the rack 74 provided on the slide member 64 also slides, and the arm body 66 rotates in the direction of the arrow via the arm gear 78 that meshes with the rack 74.

For this reason, as shown in FIG. 1B, the arm body 66 protrudes from the front surface of the cover 86 through the opening 88 (see FIG. 2) and presses the drawer 10. Thereby, the drawer 10 can be pulled out easily and quickly with a low load.

When the arm body 66 rotates in the arrow direction and a predetermined time elapses, the drive motor 18 is driven to rotate in the direction opposite to the arrow direction, and the arm body 66 rotates in the direction opposite to the arrow direction. In the housing 16.

On the other hand, when the drawer 10 is pressed toward the back of the housing 16 from the storage position P of the drawer 10 shown in FIG. 7A as shown in FIG. 7B, the positioning pin 92 is pressed in the direction against the urging force of the compression spring 94. Elastic energy is accumulated in the compression spring 94.

At the same time, the sensor 82 is pressed in a direction against the urging force of the torsion spring 96, and elastic energy is accumulated in the torsion spring 96. For this reason, the output voltage by the sensor 82 decreases (the output voltage may be increased). As a result, the control device 26 detects that the drawer 10 has moved, the drive motor 18 is driven, and the arm body 66 rotates in the direction of the arrow as described above (see FIG. 5).

Then, the arm body 66 protrudes from the front surface of the cover 86 and presses the drawer 10. At this time, the drawer 10 is also pressed by the positioning pin 92 by the urging force of the compression spring 94.

Here, a series of the above operations will be described with reference to the flowchart shown in FIG.

As shown in FIG. 9, in step 100, the control device 26 detects the output voltage from the sensor 82. Next, the routine proceeds to step 102 where it is determined whether or not the output voltage from the sensor 82 is equal to or higher than a predetermined value. If the output voltage from the sensor 82 is greater than or equal to the predetermined value in step 102, the process proceeds to step 104. In step 104, the control device 26 drives the drive motor 18 to project the arm body 66 from the front surface of the cover 86 via the gear train 48 and the like, and presses the drawer 10.

Next, in step 106, it is determined whether or not a predetermined time has elapsed since the drive motor 18 was driven. In step 106, the control device 26 is in a standby state until a predetermined time elapses after the drive motor 18 is driven. On the other hand, when the drive motor 18 is driven in step 106 and a predetermined time has elapsed, the routine proceeds to step 108. In step 108, the control device 26 drives the drive motor 18. At this time, the drive motor 18 is rotated in the reverse direction, and the arm body 66 is accommodated in the housing 16 via the gear train 48 and the like.

On the other hand, if the output voltage from the sensor 82 is less than the predetermined value in step 102, the process proceeds to step 100.

In the present embodiment, as shown in FIG. 5, the worm gear 35 is connected to the drive motor 18, and the gear train 48 is engaged with the worm gear 35, so that the shaft core of the drive motor 18 and the gear train 48 are substantially aligned. Can be orthogonal.

That is, since it is not necessary to arrange the drive motor 18 along the axial direction of the gear train 48, the casing 16 of the extrusion device 14 can be made thin. Thereby, the installation space of the extrusion apparatus 14 decreases and versatility expands.

Further, by engaging the small gear 60 of the gear member 46 which is the final gear of the gear train 48 and the rack 72, the rotational force transmitted to the gear train 48 can be converted into a driving force for sliding the slide member 64. it can.

In the present embodiment, a rack 72 having a groove cut along the depth direction of the housing 16 is provided on the upper surface of the upper step portion 68 of the slide member 64, and is arranged in parallel with the base surface 17 of the housing 16. A rack 74 having grooves cut along the height direction of the housing 16 is provided in the lower step portion 70 (a tooth row is formed in a surface orthogonal to the tooth row of the rack 72 and in the tooth row direction of the rack 72. Rack 74).

By forming the tooth row of the rack 74 in the tooth row direction of the rack 72, the tooth row of the rack 74 also moves along the moving direction of the tooth row of the rack 72 that moves through the slide member 64. By meshing the arm gear 78 of the arm body 66 with the rack 74, when the tooth row of the rack 74 moves, the arm body 66 rotates via the arm gear 78. By providing the rack 74 on a surface orthogonal to the tooth row of the rack 72, the transmission direction of the driving force of the driving motor 18 can be changed by about 90 degrees.

Thus, by forming the rack 72 and the rack 74 on the slide member 64 and changing the transmission direction of the driving force, for example, although not illustrated, the case where the transmission direction of the driving force is converted by a worm gear In comparison, the rotation center position of the arm body 66 can be determined at a desired position, and the degree of freedom in design is expanded.

Further, here, when the drawer 10 hits the positioning pin 92 and the drawer 10 is pushed with the positioned position at the storage position P, the compression spring 94 is urged through the positioning pin 92, and the storage portion 12 of the drawer 10. Is allowed to move to the back. That is, since the push-in of the drawer 10 or the movement in the pull-out direction can be detected based on the storage position P, the position detection accuracy of the drawer 10 is improved.

By the way, the rack 74 does not move due to the locked state by the gear train 48 when the drawer 10 is pushed into the storage portion 12 even though the arm body 66 is in the middle of rotation, and therefore the arm gear 78 of the arm body 66. Cannot rotate and the arm body 66 may be damaged.

For this reason, the large gear 54 and the small gear 60 provided on the gear member 46, which is the final gear of the gear train 48, are formed as separate parts, and the disc gear (not shown) is fitted in the large gear 54. Omission) prevents the small gear 60 from coming off. The large gear 54 and the small gear 60 are rotated together by mutual sliding resistance, and when a torque of a predetermined value or more acts on the small gear 60, only the small gear 60 is rotated.

As a result, when a torque greater than a predetermined value acts on the arm body 66, a torque greater than a predetermined value acts on the small gear 60 via the arm gear 78 and the rack 72 of the slide member 64, and the small gear 60 rotates. To do. Thereby, the slide member 64 can be slid through the rack 72, the arm body 66 can be returned into the housing 16 through the rack 74, and damage to the arm body 66 can be suppressed.

As described above, in this embodiment, the extruding device 14 of the drawer 10 has been described, but any moving body for reducing the load can be applied. For this reason, for example, it may be used for a drawer for nursing care or a drawer for infants.

Claims

A worm gear provided in the housing and connected to the motor;
A gear train meshing with the worm gear;
A first rack that meshes with a final gear of the gear train, and a slide member that is slidably attached to the housing;
A second rack provided on the slide member, a surface intersecting with a tooth row of the first rack, and a tooth row formed in a tooth row direction of the first rack;
A rotatable arm body having a gear meshing with the second rack;
Extrusion device having
A detection mechanism provided so as to be able to come into contact with a moving body that is pushed into or withdrawn from the storage unit, and in which an output voltage changes according to the position of the moving body;
A control mechanism for driving the motor when the output voltage by the detection mechanism is a predetermined value or more;
The extrusion apparatus of Claim 1 which has these.
The extrusion apparatus according to claim 2, further comprising a positioning mechanism that is positioned by hitting the moving body at the storage position of the moving body, and that allows the moving body to move backward from the storage position.
The final gear of the gear train includes a fixed shaft fixed to the housing, and a gear member provided with a large gear and a small gear that are inserted through the fixed shaft and rotate around the fixed shaft.
The said large gear and the said small gear rotate integrally by mutual sliding resistance, and when the torque more than predetermined value acts on the said arm body, only the said small gear which meshes with the said 1st rack will rotate. The extrusion apparatus as described.