JP2016169084A - Jack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jack capable of pressing up an object to be supported through a light operation without damaging the object to be supported and also setting a stroke thereof large, and enabling leveling adjustments to be easily and precisely made.SOLUTION: A jack is so constituted that a first elevation screw lever 3 in a barrel shape provided with an operation head 5 atop is threadably engaged with a male screw part 2 provided to a cylindrical body 1, and a second elevation screw lever 7 which has a smaller pitch than the first elevation screw lever 3 is threadably engaged with a female screw part 6 provided at a center part of the first elevation screw lever 3, and also configured to elevate a support head part 9 of an object to be supported, provided at an upper end of the second elevation screw lever 7, by a difference in pitch as the barrel part 5 is rotated.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a jack that supports a support object such as a workpiece or a table, and more particularly to a jack that includes a screw mechanism that performs leveling adjustment of the installation height of the support object.

  Conventionally, when machining a workpiece, for example, several positions on the lower surface of the workpiece are usually supported by small jacks called bean jacks, and the leveling of the workpiece is adjusted by these jacks, while the upper surface of the end portion of the workpiece is adjusted. Is held by one end of the clamp (holding metal fitting) and the lower surface of the other end of the clamp is supported by another jack. After adjusting the level of the clamp with this jack, it is passed through the through hole provided in the center of the clamp. The work is fixed by crimping the upper surface of the clamp with a nut screwed to the upper end of a bolt whose lower end is supported by a stand or the like.

  As such a jack, as described in Patent Document 1, as a conventional technique, a cylindrical main body provided with a female screw portion in the center portion in the vertical direction and a support head at the upper end are integrally provided. 2. Description of the Related Art A jack is widely known which is composed of an elevating screw 、 that is screwed into the female screw portion of the main body so as to be able to advance and retreat.

  Further, in Patent Document 2, a main body (fixed portion) provided with a screw portion in the center portion in the vertical direction, a lifting screw rod with a disc-shaped operation head integrally provided at the upper end, and an upper surface are provided. It consists of a disk-shaped head part formed on the work support surface, and the lifting screw 杆 is screwed into the female screw part of the main body so as to be able to advance and retract, and a bearing is mounted on the operating head of the lifting screw 杆. A jack is disclosed in which the head portion is rotatably supported around the central axis of the operating head.

JP 2002-87764 A JP 2011-131945 A

  When the jack described in Patent Document 1 is used to support a workpiece, the lifting screw rod screwed into the female screw portion of the main body is moved up and down by a rotation operation of the supporting head to support the workpiece supported on the supporting head. Since leveling adjustment is performed, friction may occur between the upper surface of the support head supporting the workpiece and the lower surface of the workpiece in contact with the upper surface, which may damage the workpiece. In addition, there is a problem that the support position of the jack itself shifts due to the frictional force, and the leveling adjustment cannot be performed accurately.

  Furthermore, since the leveling adjustment of the work is performed by rotating the support head that supports the lower surface of the work, the lower surface of the work obstructs the rotation operation of the support head, and the jack is connected to the work and this jack. There was a problem that leveling adjustment could not be smoothly performed in combination with being disposed in a narrow space between the base and the base.

  On the other hand, according to the jack described in Patent Document 2, since the head portion for supporting the workpiece via the bearing is disposed on the operating head of the lifting screw rod, the lifting screw is operated by rotating the operating head. If the leveling adjustment is performed by raising and lowering the heel, there is no possibility that the head portion supporting the workpiece will rotate, so that the possibility of damaging the lower surface of the workpiece or shifting the jack itself can be eliminated. .

  However, since the head portion that supports the workpiece is disposed so as to be always superimposed on the operating head of the lifting screw 杆 via a bearing, the operating head is also positioned at a height close to the lower surface of the workpiece. For this reason, there are cases where the operation head cannot be rotated smoothly, and when the operator grips the operation head of the lifting screw rod and rotates it, there is a possibility that the head portion may be grasped integrally. There is.

  In any of the above jacks, the height of the work support surface of the support head or the head is adjusted only by the lifting screw 杆 screwed into the female thread of the main body. The height of the support, that is, the stroke of the workpiece support surface moving upward from the main body is limited to a relatively short length, and when the lock nut is screwed to the lifting screw rod, the stroke is further shortened. There was a point.

  Furthermore, the load of the workpiece is directly supported by the screwed portion of the lifting screw rod and the female screw portion of the main body via the supporting head and head portion, and the pitch of the male screw portion of the lifting screw rod is adjusted by the pitch of the supporting screw and head portion. Since the lifting distance is set, the lifting distance when the lifting screw 杆 is rotated once becomes long, and when the workpiece is lifted by rotating the lifting screw 杆, a relatively large operating force is required. There is also a problem that the stroke and leveling cannot be easily fine-tuned.

  The present invention has been made in view of such problems, and the object of the present invention is to support a support object such as a workpiece without damaging it, as well as a light operation of the support object. Accordingly, it is possible to provide a jack which can be pushed up and its stroke can be set large, and leveling adjustment can be easily and accurately performed.

  In order to achieve the above object, a jack according to the present invention includes, as described in claim 1, a cylindrical body provided with an internally threaded portion opened upward, and an internally threaded portion of the tubular body on an outer peripheral surface. A screw-shaped male screw part is provided, an operation head is integrally provided at the upper end, and a female screw part that is open upward from the upper surface of the operation head is provided at the center. 1 lifting screw rod and a second lifting screw rod having an outer peripheral surface provided with a male screw portion screwed into a female screw portion of the first lifting screw rod and having a support head integrally formed at the upper end. The pitch of the male screw portion of the second lifting screw rod screwed into the female screw portion provided in the first lifting screw rod is set to be larger than the pitch of the male screw portion of the first lifting screw rod screwed into the female screw portion of the cylindrical main body. It is characterized by being small.

  In the jack configured as described above, in the invention according to claim 2, the cylindrical main body is formed with a female screw portion in which a first lifting screw rod is screwed to an inner peripheral surface of an upper end opening portion thereof. A screw hole penetrating between the inner and outer peripheral surfaces is provided in the upper end portion forming the female screw portion, and a pressing piece of a lock piece for locking the first elevating screw rod is screwed into the screw hole so as to freely advance and retract. It is a feature.

  According to a third aspect of the present invention, the axially-cylinder-shaped first elevating screw rod has a female screw portion penetrating in the vertical direction from the upper surface of the operating head to the inside of the first elevating screw rod in the center of the upper end. The second elevating screw 杆 is screwed into the female screw portion, and a circular hole is provided in the operation head between the inner and outer peripheral surfaces of the operation head. A pressing piece of a lock piece that locks the second lifting screw rod is screwed into a screw hole portion formed in the hole so as to be able to advance and retreat.

  According to the first aspect of the present invention, the axially-cylinder-shaped first lifting screw rod screwed to the female screw portion provided in the cylindrical main body so as to be able to advance and retreat in the vertical direction, and the center portion of the first lifting screw rod Since the second lifting rod is screwed to the provided female screw portion, the operation head is provided at the upper end of the first lifting screw rod, and the support head of the support object is provided at the upper end of the second lifting screw rod. Even if the stroke from the cylindrical main body to the support head can be set longer and the distance of the space between the support object and the base is larger than the length of the first lifting screw rod, the spacer, etc. The support object can be supported without intervening.

  Furthermore, the second lifting screw rod provided with a supporting head for the object to be supported protrudes upward from the first lifting screw rod, and the operating head moves the supporting head up and down on the upper end of the first lifting screw rod. Therefore, the operation head is disposed at an intermediate position between the support head and the cylindrical main body, and therefore, even in a narrow space between the support object on which the jack is installed and the base. The lower surface of the support object and the support head supporting the support object do not interfere with the work, and the leveling adjustment is facilitated by grasping the operation head and performing a smooth rotation operation. .

  Further, even when the operation head is rotated, the second lifting screw rod having the support head is fixed in a state where the support head supporting the support object is fixed by the frictional force with the support object. The female screw portion provided on one lifting screw rod is screwed and unscrewed according to the rotation of the operation head, and the occurrence of scratches on the lower surface of the support object due to the rotation of the support head can be prevented. .

  In addition, the male screw of the second lifting screw rod screwed into the female screw portion provided in the first lifting screw rod than the pitch of the male screw portion of the first lifting screw rod screwed into the female screw portion of the cylindrical main body. Since the pitch of the parts is reduced, the support head of the second lifting screw rod supporting the object to be supported is the first even if the first lifting screw rod is moved up and down by rotating the operation head. Only the distance obtained by subtracting the pitch of the male screw portion of the second lifting screw rod from the pitch of the male screw portion of the lifting screw rod can be raised and lowered, and therefore the operation head rotation for raising and lowering the supporting head with a relatively light operation force Not only can the operation be performed, but the stroke of the support head relative to the cylindrical body and the leveling of the support object can be finely adjusted, and the support object can be fixed with high accuracy.

  According to the second aspect of the present invention, the cylindrical main body 1 is formed with an internal thread portion in which the first elevating screw rod is screwed onto the inner peripheral surface of the upper end opening, and this internal thread portion is formed. Since a screw hole penetrating between the inner and outer peripheral surfaces is provided in the upper end portion of the upper end and a pressing piece of a lock piece for locking the first elevating screw 杆 is screwed into the screw hole so as to freely advance and retract, It is possible to lock the first lifting screw rod by pressing the lock piece against the first lifting screw rod by screwing the pressing piece screwed into the screw hole provided in the upper end portion of the main body without using it. The stroke of the first lifting screw rod can be used effectively.

  According to the third aspect of the present invention, the shaft-cylinder-shaped first elevating screw rod has a female screw penetrating in the vertical direction from the upper surface of the operation head to the inside of the first elevating screw rod at the center of the upper end. A second elevating screw 杆 is screwed into the female screw portion, and a circular hole is provided in the operating head between the inner and outer peripheral surfaces of the operating head, Since the pressing piece of the lock piece for locking the second elevating screw 杆 is threadably engaged with the screw hole formed in the circular hole, a lock nut is used as in the case of the first elevating screw 杆. Without rotating the pressing piece screwed into the screw hole provided in the operating head, the second lifting screw rod can be locked by pressing the lock piece against the second lifting screw rod. 2 Stroke of lifting screw 杆 can be used effectively Kill.

The front view of this invention jack. The longitudinal front view. Perspective view. FIG. The perspective view of the state shrunk. The longitudinal cross-sectional front view of the contracted state. The simplified front view which shows a use condition. The front view of the state which is performing leveling adjustment. The front view of the state which is performing lock operation.

  Referring to the drawings, specific embodiments of the present invention will be described. In FIGS. 1 to 4, the jack J has a cylindrical main body 1 provided with an internal thread portion 2 opened upward from the upper surface thereof at the upper end portion; A male screw part 4 screwed into the female screw part 2 of the cylindrical main body 1 is provided on the outer peripheral surface, and a disk-shaped operating head 5 is integrally provided on the upper end, and the operating head is provided on the inner peripheral surface of the upper end part. A first cylindrical lifting screw rod 3 provided with a female screw portion 6 opened upward from the upper surface of 5 and a male screw portion screwed onto the outer peripheral surface of the female screw portion 4 of the first lifting screw rod 3. And a second elevating screw rod 7 integrally provided with a disk-shaped support head 9 at the upper end, and is screwed into the female screw portion 2 of the cylindrical main body 1. The above-described first lifting screw rod 3 has a pitch higher than the pitch of the male screw portion 4 of the lifting screw rod 3. The pitch of the male screw portion 7 of the second lifting screw rod 7 screwed on the threaded portion 6 is made smaller.

  Specifically, the cylindrical main body 1 is formed in a cylindrical shape whose upper and lower surfaces are formed as flat surfaces and can function as a pedestal, and the length (height) of the cylindrical main body 1 is the first ascending and descending. A circular hole 10 that is longer than the length of the screw rod 3 and penetrates between the upper and lower surfaces is provided at the center thereof, and the upper end opening of the circular hole 10 is formed to have a smaller diameter than the circular hole 10. The female screw portion 2 having a small diameter is formed on the inner peripheral surface. As shown in FIG. 6, the first elevating screw rod 3 is screwed along the female screw portion 2 so that the lower surface of the operation head 5 is The first elevating screw rod 3 is configured to be accommodated in the cylindrical main body 1 over the entire length when it is lowered until it comes into contact with and is received by the upper surface of the cylindrical main body 1.

  Furthermore, a small-diameter screw hole 11 that penetrates horizontally between the inner and outer peripheral surfaces of the upper end portion is provided at the upper end portion of the cylindrical main body 1 forming the female screw portion 2. A lock piece 12a having a diameter smaller than that of the screw hole 11 is loosely fitted on the back side of the screw piece 11, and a press piece 12b is provided on the back side of the lock piece 12a. The first elevating screw is formed by pushing the lock piece 12a forward by screwing the piece 12b and crimping the front end surface thereof to the outer peripheral surface of the first elevating screw rod 3 screwed into the female screw portion 2 of the cylindrical body 1. The hook 3 is configured to be locked. The first elevating screw rod 3 is in contact with the lower end surface of the female screw portion 2 connected to the upper end of the screw hole 11 of the cylindrical main body 1 on the outer peripheral surface of the lower end portion of the first elevating screw rod 3. A retaining ring 13 is provided for preventing the slipping out of the retaining ring 13.

  As with the cylindrical main body 1, the first elevating screw rod 3 has a circular hole 14 having a smaller diameter than the circular hole 10 of the cylindrical main body 1 extending between the upper and lower surfaces. At the same time, the upper end opening of the circular hole 14 is formed to have a smaller diameter than the circular hole 14, and the female screw portion 6 is formed on the inner peripheral surface thereof. Further, a female screw having the same diameter as the female screw portion 6 and a lower end continuing to the upper end of the female screw portion 6 is provided at the center of the operation head 5 provided integrally with the upper end of the first lifting screw rod 3. Part 6 'is engraved. That is, the female screw portions 6 and 6 ′ into which the second lifting screw rod 7 is screwed from the center of the upper surface of the operation head 5 to the upper end portion of the circular hole 14 at the center of the first lifting screw rod 3 are provided. Engraved.

  The length of the first lifting screw rod 3 from the upper surface of the operating head 5 to the lower end of the circular hole 14 is longer than the length of the shaft portion on which the male screw portion 8 of the second lifting screw rod 7 is provided. Accordingly, as shown in FIG. 6, the second elevating screw rod 7 is screwed along the female screw portions 6 and 6 'of the first elevating screw rod 3 so that the lower surface of the supporting head 9 is the first. When the first elevating screw rod 3 is lowered until it is joined so as to overlap the upper end operating head 5, the shaft portion of the second elevating screw rod 7 extends over the entire length in the circular hole 14 of the first elevating screw rod 3. It is configured to be stored.

  Further, similarly to the cylindrical main body 1, the operation head 5 of the first lifting screw rod 3 extends between the outer peripheral surface of the operation head 5 and the inner peripheral surface provided with the female screw portion 6 ′. A small-diameter circular hole 15a penetrating horizontally is provided, and an inner peripheral surface on the back side of the circular hole 15a is formed in the screw hole portion 15b, and the screw hole is formed on the back side of the screw hole portion 15b. A lock piece 16a having a diameter smaller than that of the portion 15b is loosely fitted, and a press piece 16b screwed into the screw hole portion 15b to be freely advanced and retracted is provided on the back side of the lock piece 16a, and the press piece 16b is screwed. Then, the lock piece 16a is pushed forward, and the tip surface thereof is pressed against the outer peripheral surface of the second lifting screw rod 7 screwed into the female screw portions 6 and 6 'of the first lifting screw rod 3, thereby causing the second lifting screw The bag 7 is configured to be locked. Also in the second elevating screw rod 7, the second elevating screw rod 7 comes into contact with the lower end surface of the female screw portion 6 connected to the upper end of the screw hole 14 of the first elevating screw rod 3 on the outer peripheral surface of the lower end portion. A retaining ring 17 is provided for preventing the first lifting screw rod 3 from coming out.

  A tip of a handle shaft (not shown) for rotating the second lifting screw rod 7 is provided on the outer peripheral portion of the upper end supporting head 9 of the second lifting screw rod 7 with a predetermined interval in the circumferential direction. A locking hole 19 for inserting and locking the part is formed. The circular hole 15a drilled in the outer peripheral surface of the operating head 5 is used as the locking hole provided on the first lifting screw rod 3 side. The operation head 5, the support head 9, and the outer peripheral surface of the cylindrical main body 1 are knurled to prevent slipping of fingertips and the like.

  Next, the usage mode of the jack J configured as described above will be described. Between the lower surface of the support object A (shown in FIGS. 7 and 8) such as a table to be supported and a workpiece to be processed, and the base B. A plurality of jacks J are interposed in the space. At this time, if the second lifting screw rod 7 having the supporting head 9 in each jack J protrudes upward from the operating head 5 of the first lifting screw rod 3 by an appropriate length, the support by the supporting head 9 is supported. The supporting operation of the object A can be efficiently performed, and the operation head 5 of the first lifting screw rod 3 is disposed at an intermediate position of the space between the supporting object A and the base B, so that the supporting object A Rotation can be performed without obstructing the lower surface or the like.

  Thus, after arrange | positioning the jack J in the space part between the support target A and the base B, the said operation head 5 of the upper end of the 1st raising / lowering screw rod 3 is rotationally operated, and the 1st raising / lowering screw rod 3 is used. When the cylindrical body 1 is screwed in the ascending direction, the second lifting screw rod 7 screwed into the female screw portion 6 (6 ′) of the first lifting screw rod 3 is also raised integrally. The support head 9 comes into contact with the lower surface of the support object A. First, the first elevating screw rod 3 is raised and its supporting head 9 is lightly brought into contact with the lower surface of the supporting object A, and then the operating head 5 is rotated to move the supporting head 9. You may make it crimp on the lower surface of the support target A. FIG.

  In this way, the operation head 5 is rotated to press the upper surface of the support head 9 against the lower surface of the support object A, and the second lifting screw rod 7 having the support head 9 is made non-rotatable. When the upper end operating head 5 of the first lifting screw rod 3 is rotated to adjust the leveling of the object A, the first lifting screw rod 3 causes the male screw portion 4 to move with respect to the female screw portion of the cylindrical body 1. While the second elevating screw rod 7 is raised while being screwed, the second elevating screw rod 7 is not rotatable due to the crimping force between the upper surface of the supporting head 9 and the lower surface of the supporting object A. The first elevating screw rod 3 in which the female screw portion 4 is screwed to the male screw portion 8 is screwed on the male screw portion 8 of the second elevating screw rod 7 by the rotation operation of the operation head 5 and is moved up and down. The male screw portion 8 of the screw rod 7 is relatively screwed into the female screw portion 6 (6 ′) of the first lifting screw rod 3. It becomes Rukoto.

  At this time, it is screwed into the female screw portion 6 provided in the first lifting screw rod 3 rather than the pitch of the male screw portion 4 of the first lifting screw rod 3 that is screwed into the female screw portion 2 of the cylindrical main body 1. Since the pitch of the male screw portion 7 of the second lifting screw rod 7 is made small, even if the first lifting screw rod 3 is raised with respect to the cylindrical main body 1 by the rotation operation of the operation head 5, the support object A The support head 9 of the second lifting screw rod 7 that supports the height rises only by a distance obtained by subtracting the pitch of the male screw portion 8 of the second lifting screw rod 7 from the pitch of the male screw portion 4 of the first lifting screw rod 3. .

  For example, if the pitch of the male screw portion 8 of the second elevating screw rod 7 is formed to be 2/3 the pitch of the male screw portion 4 of the first elevating screw rod 3, as shown in FIG. , And the first elevating screw rod 3 is raised by 3 pitches, the second elevating screw rod 7 is lowered by 2 pitches. Therefore, the support head 9 is raised by 1 pitch to lift the support object A. Will push up. Similarly, when the operation head 5 is rotated in the opposite direction from the state in which the support target A is supported by the support head 9 and the support head 9 is lowered, the first lifting screw rod 3 The pitch can be lowered by subtracting the pitch of the male screw portion 8 of the second lifting screw rod 7 from the pitch of the male screw portion 4.

  In this way, while raising or lowering the first elevating screw rod 3 by rotating the operation head 5, the support head 9 supporting the support object A is lowered or lowered by a distance shorter than this elevating distance. Since the operation head 5 is raised, the rotation operation of the operation head 5 can be performed with a relatively light force, and the stroke from the cylindrical main body 1 to the support head 9 and the fine adjustment of the leveling of the support object A are easy and accurate. Can be done well. When the load applied to the support head 9 from the support object A side is large and it is difficult to manually rotate the operation head 5, the circular hole 15 a provided in the operation head 5 or the support head 9 is provided. The operating head 5 and the supporting head 9 may be rotated by inserting and locking the tip end of a handle shaft (not shown) for rotation operation into the locking hole 19 provided in the operating hole.

  Further, after the leveling adjustment of the support object A, as shown in FIG. 9, the pressing piece 12 b screwed into the screw hole 11 provided in the upper end portion of the cylindrical main body 1 is screwed by a hexagon wrench or the operating rod 20. The first elevating screw rod 3 is locked by pressing the lock piece 12a at its tip end surface and pressing it onto the outer peripheral surface of the first elevating screw rod 3 screwed into the female screw portion 2 of the cylindrical main body 1. Similarly, the locking piece 16a is pushed forward by screwing the pressing piece 16b screwed into the screw hole portion 15b provided in the operation head 5 of the first lifting screw rod 3, and the tip surface thereof is moved to the first lifting screw. The second elevating screw rod 7 is locked by being crimped to the outer peripheral surface of the second elevating screw rod 7 screwed into the female screw portions 6 and 6 ′ of the rod 3.

J Jack A Support object 1 Cylindrical body 2, 6, 6 'Female thread part 3 First lifting screw rod 4,8 Male screw portion 5 Operation head 7 Second lifting screw rod 9 Support head
11 Screw hole
15a round hole
12, 16 Lock piece

Claims (3)

  A cylindrical main body provided with an open female screw portion facing upward, a male screw portion screwed into the female screw portion of the cylindrical main body on the outer peripheral surface, and an operating head integrally provided at the upper end; and A shaft-cylinder-shaped first lifting screw rod provided with a female screw portion that opens upward from the upper surface of the operation head at the center, and a female screw portion of the first lifting screw rod on the outer peripheral surface. The second elevating screw rod is provided with a male screw portion and a support head is integrally provided at the upper end. The pitch of the male screw portion of the first elevating screw rod screwed into the female screw portion of the cylindrical body is larger than that of the first elevating screw rod. A jack characterized in that the pitch of the male screw portion of the second lifting screw rod screwed into the female screw portion provided on the first lifting screw rod is reduced.   The cylindrical main body 1 is formed with an internal thread portion in which a first elevating screw rod is screwed on the inner peripheral surface of the upper end opening, and the upper end portion forming the internal thread portion extends between the inner and outer peripheral surfaces. The jack according to claim 1, wherein a screw piece penetrating through is provided, and a pressing piece of a lock piece for locking the first elevating screw rod is screwed into the screw hole so as to freely advance and retract.   The shaft-cylinder-shaped first lifting screw rod is formed with a female screw portion penetrating in the vertical direction from the upper surface of the operation head to the inside of the first lifting screw rod in the center of the upper end thereof, and the second lifting and lowering portion is formed on the female screw portion. A screw hole is screwed together, and a circular hole penetrating the inner and outer peripheral surfaces of the operation head is provided in the operation head, and a second hole is formed in the screw hole formed in the circular hole. The jack according to claim 1, wherein a pressing piece of a lock piece that locks the lifting screw rod is screwed forward and backward.

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