A pin puller

Abstract

The application discloses a pin puller, which comprises a sleeve, a screw rod and a nut, one end of the sleeve is sequentially sleeved with a thrust ball bearing, the nut and a gland, the other end of the sleeve is provided with a cushion block, the nut is connected with the screw rod, the middle part of the screw rod is slidably connected with the sleeve through a spline, one end of the screw rod is sequentially provided with a spring, a sleeve and an axle stop ring, the sleeve can slide along the axial direction of the screw rod, the small end diameter of a bearing pin is matched with the radial small hole of the end part of a positioning pin to be disassembled, and the big end diameter is matched with the radial hole of the screw rod. The pin puller can quickly and safely pull out the positioning pin with the radial hole from the product shell, solves the problem of difficult disassembly, has compact structure, simple and convenient operation and stable and reliable function.

Description

Technical Field

[0001] This invention belongs to the field of mechanical assembly technology and relates to a pin puller. Background Technology

[0002] A pin is a common locating component, with common types including cylindrical pins, tapered pins, and slotted pins. The fit between the pin and the hole is generally an interference fit or a transition fit, and it is usually not disassembled after installation. In some applications requiring disassembly, a threaded hole is often made at the end of the pin for easier removal using a pin puller.

[0003] A pin puller is a tool used to remove pins with threaded holes at the ends. It generally consists of a pull rod, a stop block, and a pull head. The pull rod is the main body, with a handle and a stop block at one end, and a pull head at the other end. The pull head has external threads that correspond to the threaded holes at the pin ends. The stop block is fitted onto the pull rod and can slide on it. During operation, the external threads of the pull head are screwed into the threaded holes at the pin ends. Then, the stop block is held and forcefully struck against the stop block at the other end of the pull rod. The impact kinetic energy is instantly converted into pulling force, quickly pulling the pin out of the connector.

[0004] In the assembly of certain large products, multiple disassembly and reassembly operations are required for the transition fit locating pins. These locating pins are small in size and lack screw holes at the ends for disassembly, making them impossible to remove using conventional pin pullers. Due to the high value of the products, disassembly must be performed smoothly, safely, and reliably; methods such as hammering or shaking that could damage the product's size and shape are not permitted. Using tools such as wire cutters to clamp the head and pull it out could easily damage the surface, failing to meet product quality requirements and directly rendering the product unusable. Considering that the locating pin has a small radial hole at its end, the operator attempted to pull it out by threading a steel wire, but found it difficult to apply force, and the wire tip scratched the product surface. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a pin puller for removing locating pins with radial holes at the ends.

[0006] To achieve the above objectives, the present invention employs the following technical solutions:

[0007] A pin puller includes a sleeve, a screw, and a nut. A thrust ball bearing, a nut, and a pressure cap are sequentially fitted onto one end of the sleeve, and a pad is installed on the other end of the sleeve. The nut is connected to the screw, and the middle part of the screw slides into the sleeve via a spline. A spring, a retaining sleeve, and a shaft retaining ring are sequentially provided at one end of the screw. The retaining sleeve can slide along the axial direction of the screw. The small end diameter of the load-bearing pin is adapted to the radial small hole at the end of the positioning pin to be removed, and the large end diameter is adapted to the radial hole of the screw.

[0008] As a preferred embodiment, the gland and the sleeve are screwed together, the gland provides radial positioning for the nut shoulder through the inner hole, and restricts the axial displacement of the nut through the bottom of the hole.

[0009] As a preferred embodiment, one end of the screw is provided with a trapezoidal thread, and an external spline is formed on the outer edge of the middle flange; the other end of the screw is provided with two pins of different diameters, large and small.

[0010] Further preferably, the larger diameter pin is longer and is used to guide the retaining sleeve; the smaller diameter pin has a radial hole and a groove for installing a retaining ring for the shaft, and the center of the end face of the pin also has a flat-bottomed hole that matches the positioning pin to be disassembled.

[0011] As a preferred embodiment, the nut has a shoulder at the bottom, an external hexagonal shape at the top, and a trapezoidal thread at the center. The shoulder has a groove at the bottom, and a thrust ball bearing is installed in the groove.

[0012] As a preferred embodiment, the gland is provided with an internal thread, a relief groove, a positioning hole, and an external hexagonal clearance hole in sequence inside.

[0013] As a preferred embodiment, the small end to the large end of the load-bearing pin adopts a tapered transition, and the large end of the load-bearing pin is provided with a radial hole.

[0014] As a preferred embodiment, the retaining sleeve is annular, with a stepped hole at the center and an inclined surface on the outer circumference of the retaining sleeve.

[0015] In a further preferred embodiment, the sleeve has an internal spline at its center that is compatible with the external spline of the screw.

[0016] As a preferred embodiment, the outer circumference of the large end of the sleeve is provided with an external thread that matches the gland, the end face of the large end of the sleeve is provided with a groove, the outer circumference of the sleeve is provided with a long groove, and a flat shape is formed on the groove.

[0017] The present invention has the following advantages:

[0018] This invention enables the quick and safe removal of the locating pin with a radial hole at the end from the product housing, solving the problem of difficult disassembly. It has a compact structure, is simple and convenient to operate, and has stable and reliable functions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the positioning pin structure to be disassembled;

[0020] Figure 2 This is a perspective view of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the present invention;

[0022] Figure 4 for Figure 3 AA section view;

[0023] Figure 5 for Figure 3 BB cross-sectional view;

[0024] Figure 6 This is a schematic diagram showing the installation state of the load-bearing pin of the present invention;

[0025] Figure 7 This is a schematic diagram of the drawing state of the present invention;

[0026] Figure 8 This is a schematic diagram of the screw structure;

[0027] Figure 9 This is a schematic diagram of the nut structure;

[0028] Figure 10 This is a schematic diagram of the gland structure;

[0029] Figure 11 This is a schematic diagram of the pad block structure;

[0030] Figure 12 This is a schematic diagram of a load-bearing pin structure;

[0031] Figure 13 This is a schematic diagram of the retaining sleeve structure;

[0032] Figure 14 This is a schematic diagram of the sleeve structure;

[0033] Figure 15 This is a three-dimensional view of the sleeve;

[0034] Figure 16 for Figure 14 AA sectional view.

[0035] In the diagram: 1-Screw, 2-Nut, 3-Thrust ball bearing, 4-Glander cap, 5-Spring, 6-Pan block, 7-Bearing pin, 8-Shaft retaining ring, 9-Sleeve, 10-Sleeve, 11-Product housing, 12-Positioning pin to be disassembled. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings.

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0038] Example:

[0039] A pin puller comprises components including a screw 1, a nut 2, a thrust ball bearing 3, a pressure cap 4, a spring 5, a pad 6, a load-bearing pin 7, a shaft retaining ring 8, a retaining sleeve 9, and a sleeve 10. The sleeve 10 serves as the base, with the thrust ball bearing 3, nut 2, and pressure cap 3 sequentially mounted on one end, and the pad 6 installed on the other end. The pressure cap 4 is screwed to the sleeve 10, providing radial positioning for the shoulder of the nut 2 through its inner hole and restricting axial displacement of the nut 2 through the bottom of the hole to ensure it does not come out. The screw 1 is mounted at the center of the nut 2, and its middle part slides into the sleeve 10 via a spline. When the nut 2 is rotated, the screw 1 only translates without rotating. The other end of the screw 1 is sequentially fitted with the spring 5, the retaining sleeve 9, and the shaft retaining ring 8. The retaining sleeve 9 can slide axially along the screw 1, while the shaft retaining ring 8 limits its movement. During operation, the two load-bearing pins 7 are symmetrically assembled. The small ends pass through the radial holes of the screw 1 from both sides and are inserted into the radial holes of the positioning pins to be disassembled. The large ends are restricted by the inner cavity of the retaining sleeve 9 and can only produce a very small radial displacement, and will not come out.

[0040] One end of the screw 1 is provided with a trapezoidal thread, and an external spline is formed on the outer edge of the middle flange. The other end is provided with two pins of different diameters, one large and one small. The larger diameter pin is longer and is used to guide the retaining sleeve 9. The smaller diameter pin has a radial hole and a groove for mounting a shaft retaining ring 8. At the same time, the center of the end face of this pin also has a flat-bottomed hole that matches the locating pin to be disassembled.

[0041] Nut 2 has a shoulder at the bottom, an external hexagon at the top, and a trapezoidal thread in the center. A groove is made at the bottom of the shoulder for installing the thrust ball bearing 3.

[0042] The pressure cap 4 is shaped like a hexagonal nut, and its interior is provided with internal threads, a relief groove, a shoulder positioning hole for the nut 2, and an external hexagonal clearance hole.

[0043] The pad 6 is made of nylon, which can effectively protect the surface of the product shell during operation. It is also cut in half from the middle for easy disassembly and assembly.

[0044] The small end diameter of the load-bearing pin 7 is adapted to the radial hole at the end of the positioning pin to be disassembled. The transition from the small end to the large end is made of a tapered surface. The diameter of the large end is adapted to the radial hole of the screw 1, with the outer part being slightly smaller, and a radial hole is also made there. As the main load-bearing component, it is made of high-strength special steel due to its small size and large load.

[0045] The retaining sleeve 9 is annular with a stepped hole in the center. The smaller diameter of the hole is adapted to the long cylindrical section of the screw 2 used for guidance, while the larger hole is used to limit the radial displacement of the load-bearing pin 7 during operation. In addition, a bevel is provided on the outer circle to facilitate the installation and removal of the load-bearing pin 7.

[0046] The sleeve 10 has an internal spline at its center that matches the external spline of the screw 1 to prevent the screw from rotating. The outer diameter of the large end has an external thread that matches the gland 4. A groove is made on the end face of the large end for mounting a thrust ball bearing. For easy gripping, a long groove is made on the outer diameter, and a flat shape is made on the groove. When the disassembly force is large, tools such as wrenches can be used for clamping and fixing.

[0047] During operation, hold the pin puller sleeve 10 and first reverse-tighten the nut 2 to extend the screw 1 to the right. Once sufficient space is exposed for installing the load-bearing pin 7, push the inclined surface of the retaining sleeve 9 to move it to the left, compressing the spring 5. Then, insert the head of the screw 1 into the end of the locating pin to be removed, aligning the radial hole of the screw 1 with the radial small hole at the end of the locating pin. Next, pass the small ends of the two load-bearing pins 7 through the radial holes of the screw 1 from both sides and insert them into the radial small holes at the end of the locating pin to be removed. Release the retaining sleeve 9, which moves to the right under the rebound force of the spring 5 until the bottom surface of its inner cavity abuts against the shaft retaining ring 8. The inner cavity of the retaining sleeve 9 restricts the radial displacement of the load-bearing pin 7, ensuring that the load-bearing pin 7 will not come out during operation. Then, install the pad 6 and forward-tighten the nut 2, causing the sleeve 10 to slowly move to the right and abut against the pad 6. Install the ratchet wrench and continue forward-tightening the nut 2. Under the pulling force, the locating pin slowly detaches from the product housing until it is completely removed. Tighten nut 2 again in the opposite direction to extend screw 1 to the right. After the retaining sleeve 9 is exposed with enough space, push the retaining sleeve 9 to move diagonally to the left. Then the load-bearing pin 7 can be removed, and finally the positioning pin can be removed.

[0048] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A pin puller characterized by: The application relates to a sleeve, a screw rod, a nut, a bearing pin, one end of the sleeve is sequentially sleeved with a thrust ball bearing, a nut and a gland, and a cushion block is arranged at the other end of the sleeve; the nut is connected with the screw rod, an outer spline is arranged in the middle of the screw rod, and the outer spline is slidably combined with an inner spline of the sleeve to prevent the screw rod from rotating; a trapezoidal thread is arranged at one end of the screw rod, a flange is arranged in the middle of the screw rod, and the other end of the screw rod is formed into two coaxial pin columns with different diameters, the pin column with the larger diameter is used for axially guiding a sleeve, a radial hole and a groove for mounting an axle check ring are arranged on the pin column with the smaller diameter, a flat-bottom hole matched with a to-be-removed positioning pin is arranged at the center of the end face of the pin column with the smaller diameter; the sleeve is a ring-shaped part, a stepped hole is arranged at the center of the sleeve, the smaller hole of the stepped hole is matched with the pin column with the larger diameter, the larger hole of the stepped hole is used for limiting the radial displacement of the large end of the bearing pin, the sleeve is sleeved on the pin column with the larger diameter and can axially slide along the screw rod, a spring, the sleeve and the axle check ring are sequentially arranged at one end of the screw rod, and the spring is used for pushing the sleeve to reset towards the end of the screw rod; the small end of the bearing pin is matched with the radial small hole at the end of the to-be-removed positioning pin, and the large end of the bearing pin is matched with the radial hole of the screw rod, the two bearing pins are symmetrically arranged, the small ends of the two bearing pins respectively pass through the two sides of the radial hole of the screw rod and are inserted into the radial small holes at the end of the positioning pin, and the large end of the bearing pin is located in the larger hole of the stepped hole of the sleeve and is radially limited by the larger hole, so that when the nut rotates relative to the sleeve, the axial movement of the screw rod relative to the sleeve is transmitted to the positioning pin through the two bearing pins, and the positioning pin is pulled out. When working, the sleeve of the pin puller is held by hand, the nut is first twisted in the reverse direction to make the screw rod stretch out to the right, the sleeve is moved to the left by pushing the inclined surface of the sleeve with the hand after enough space for installing the bearing pin is exposed, the spring is compressed, then the head of the screw rod is sleeved at the end of the to-be-removed positioning pin, the radial hole of the screw rod is aligned with the radial small hole at the end of the positioning pin, the small ends of the two bearing pins are respectively passed through the radial hole of the screw rod and are inserted into the radial small holes at the end of the to-be-removed positioning pin, the sleeve is loosened, the sleeve moves to the right under the spring rebounding force until the inner cavity hole bottom surface of the sleeve abuts against the axle check ring, the inner cavity hole of the sleeve can limit the radial displacement of the bearing pin and ensure that the bearing pin does not fall out during work, then the cushion block is installed, the nut is twisted in the forward direction to drive the sleeve to slowly move to the right and abut against the cushion block, the ratchet wrench is installed and the nut is continuously twisted in the forward direction, the positioning pin slowly separates from the product shell under the pulling force until the positioning pin is completely taken out.

2. A pin extractor according to claim 1, wherein: The gland is screwed between the sleeve, the gland provides radial positioning for the axial shoulder of the nut through the inner hole, and the nut is limited in the axial displacement through the hole bottom.

3. A pin extractor as defined in claim 1, wherein: The lower part of the nut is provided with an axial shoulder, the upper part of the nut is provided with an outer hexagonal part, and the center of the nut is provided with a trapezoidal thread, a recess is arranged at the lower part of the axial shoulder, and a thrust ball bearing is arranged in the recess.

4. The pin extractor of claim 1, wherein: An inner thread, a tool withdrawal groove, a positioning hole and an outer hexagonal avoiding hole are sequentially arranged in the inside of the gland.

5. The pin extractor of claim 1, wherein: The small end to the large end of the bearing pin adopts a taper transition, and the large end of the bearing pin is provided with a radial hole.

6. The pin extractor of claim 1, wherein: An inclined surface is arranged on the outer circle of the sleeve.

7. The pin extractor of claim 1, wherein: An outer thread matched with the gland is arranged on the outer circle of the large end of the sleeve, a recess is arranged on the end face of the large end of the sleeve, a long recess is arranged on the outer circle of the sleeve, and a flat potential is formed on the recess.

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