Adjustable mold clamp equipment
By designing an adjustable mold clamping device including a porous bottom plate, a strip-shaped limit support seat, a support column and a detachable clamping unit, the problem of low positioning accuracy of metal blocks in the existing technology is solved, and the close contact of the metal blocks is achieved. Hehe high-precision positioning.
Patent Information
- Application Number
- CN202421235327.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-03
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2034-06-03
AI Technical Summary
In the prior art, a pair of strip limit support seats and a movable adjustable positioning clamp have low positioning accuracy, resulting in a gap between the metal block and the strip limit support seat, affecting the metal block. Positioning accuracy and mold matching.
An adjustable mold clamping device is designed, including a porous bottom plate, a strip limit support seat, a support column and a detachable clamping unit. The clamp unit is composed of a first strip plate, an installation mechanism and a clamp mechanism. The installation mechanism realizes the adjustment of the clamp unit through a rotating rod and a limit plate, and the clamp mechanism realizes the close fit of the metal blocks through gears and adjustment mechanisms.
Through this equipment, the metal block can closely fit the corresponding bar-shaped limit support seat to improve positioning accuracy, and the clamp unit can adjust the installation position according to the specifications of the metal block. The operation is simple and convenient, and the disassembly of the support column is avoided.
Smart Images

Figure CN222370994U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field related to mold processing, and in particular to an adjustable mold clamp device. Background Art
[0002] Molds refer to various molds and tools used in industrial production to obtain the desired products by injection molding, blow molding, extrusion, die casting or forging, smelting, stamping and other methods. Molds are tools used to make molded objects. This tool is composed of various parts. Different molds are composed of different parts. The mold mainly realizes the processing of the shape of the object by changing the physical state of the molded material.
[0003] There are many ways to manufacture a mold. Processing a whole piece of metal blank to form a mold is the most common method. Because the specifications of the metal blanks used in molds of different products are different, an adjustable clamping method is required. In cutting processing, the most common clamping method is a pair of strip limit support seats matched with a clamping block with a movable adjustable position. A stepped groove is formed on the strip limit support seat. The pair of strip limit support seats includes a first strip limit support seat and a second strip limit support seat. The metal block can be clamped under the action of the clamping block and the first strip limit support seat corresponding to the clamping block. The second strip limit support seat plays a positioning role, but there is no other force to push the metal block to fit tightly with the second strip limit support seat, that is, there is still a gap between the side wall of the stepped groove of the second strip limit support seat and the metal block. Because the gap is not convenient for human eyes to observe, and the gap will affect the positioning accuracy of the metal block, thereby affecting the matching degree of the upper mold and the lower mold after processing, it is necessary to design an adjustable mold clamp device. Utility Model Content
[0004] In view of the above technical problems, the purpose of the utility model is to overcome the problem of low positioning accuracy of a metal block in the prior art in which a pair of strip-shaped limit support seats and a clamping block with a movable position adjustment are matched.
[0005] In order to achieve the above-mentioned purpose, the utility model provides an adjustable mold clamp device, which comprises: a horizontal porous bottom plate, a pair of horizontal strip-shaped limit support seats both mounted on the porous bottom plate and with their length directions perpendicular to each other, a plurality of support columns distributed in a matrix and mounted on the porous bottom plate, and a clamp unit detachably mounted on two adjacent through holes of the porous bottom plate and capable of abutting against a metal block away from a corner of the pair of strip-shaped limit support seats;
[0006] The clamp unit includes a first strip plate that can fit and contact the upper surface of the porous bottom plate, a pair of mounting mechanisms that are symmetrically arranged and respectively installed on the two ends of the first strip plate, and a clamp mechanism that can abut against the corner of the metal block. The mounting mechanism includes a vertical mounting sleeve that is installed on the first strip plate and can fit and pass through the through hole on the porous bottom plate, a rotating rod that passes through the mounting sleeve with an eccentric axis and can rotate around its own axis, and a limiting plate that is fixedly installed at the lower end of the rotating rod and can fit with the lower surface of the porous bottom plate. When the rotating rod is rotated, the limiting plate can be driven to rotate so as to be misaligned or completely overlapped with the mounting sleeve.
[0007] Preferably, the clamping device also includes a connecting plate fixedly mounted on a pair of mounting sleeves, a mounting plate located above the support column is fixedly mounted on the connecting plate, each of the rotating rods is axially connected to the connecting plate through a bearing, the upper end of each of the rotating rods is coaxially connected to a gear, and an adjustment mechanism is installed on the mounting plate for synchronously driving a pair of gears to rotate in the same direction.
[0008] Preferably, the mounting plate is recessed with a first strip slide groove whose length direction is parallel to the length direction of the first strip plate, the adjustment mechanism includes a rack which is slidably inserted into the first strip slide groove in the same length direction and meshes with the two gears, and a finger ring fixedly mounted on the end of the rack, the rack has two recessed positioning holes arranged at intervals along its own length direction, the mounting plate is protruded with a screw-on portion which can slide in contact with the upper surface of the rack, the screw-on portion is threadedly penetrated by a positioning bolt whose end can be inserted into the corresponding positioning hole.
[0009] Preferably, the clamp mechanism includes a vertical first rotating shaft axially connected to the connecting plate, a second strip plate fixedly connected to the first rotating shaft and located above the supporting column, a guide sleeve fixedly installed at the end of the first strip plate away from the first rotating shaft, an axle seat fixedly installed at the end of the second strip plate away from the guide sleeve, a connecting sleeve arranged in the same length direction as the second strip plate and sliding through the guide sleeve along its own length direction, an adjusting screw arranged coaxially with the connecting sleeve and threadedly connected to the inner wall of the connecting sleeve, a connecting piece fixedly installed at the end of the connecting sleeve away from the adjusting screw, and an L-shaped clamp hinged to the connecting piece through a vertical hinge shaft, and the hinge shaft is located at the bending part of the clamp.
[0010] Preferably, two limiting bolts are fixedly mounted on the rack and are spaced apart along the length direction of the rack and are respectively located on both sides of the rotational connection portion.
[0011] Preferably, the strip-shaped limit support seat is formed with a stepped portion for placing the metal block, and a second strip-shaped slide groove with the same length direction is recessed on the side of the strip-shaped limit support seat away from the support column, and at least one safety mechanism that can press on the metal block is slidably arranged in the second strip-shaped slide groove.
[0012] Preferably, the mounting mechanism includes a slider slidably mounted in the second strip-shaped slide groove, a sliding arm vertically slidably connected to the slider, a pressure arm fixedly connected to the top of the sliding arm and capable of pressing on the metal block, and a vertical adjustment bolt threadedly passing through the pressure arm and having its lower end connected to the slider axis.
[0013] According to the above technical scheme, the utility model provides an adjustable mold clamp device, which has the following beneficial effects when in use: first, a metal block is placed on a pair of strip-shaped limit support seats and corresponding support columns, so that the strip-shaped limit support seats corresponding to two adjacent side walls of the metal block fit in with each other, because the clamp mechanism can abut against the corner of the metal block away from the pair of strip-shaped limit support seats, so the side walls of the metal block in contact with the corresponding strip-shaped limit support seats can all apply pressure to the strip-shaped limit support seats, so that the metal block can fit tightly with the corresponding strip-shaped limit support seats, which not only facilitates the positioning of the metal block, but also improves the positioning accuracy;
[0014] Secondly, because several support columns have been installed in a matrix distribution on the porous base plate, there is no need to increase or decrease the number of support columns when the specifications of the metal block to be processed change, and the clamp unit is installed on two adjacent through holes of the porous base plate, so the clamp unit can adjust the installation position according to the specifications of the metal block. The operation is simple and convenient, so the position can be selected to avoid the support columns and installed on the porous base plate without removing the support columns.
[0015] Other features and advantages of the utility model will be described in detail in the subsequent specific implementation mode; and the parts not involved in the utility model are the same as the prior art or can be implemented by using the prior art. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the accompanying drawings:
[0017] Figure 1 It is a three-dimensional structural schematic diagram of an adjustable mold clamp device provided by the present invention;
[0018] Figure 2 It is a three-dimensional structural schematic diagram of a clamp unit of an adjustable mold clamp device provided by the present invention;
[0019] Figure 3 It is a partial exploded schematic diagram of the installation mechanism of an adjustable mold clamp device provided by the present invention;
[0020] Figure 4 This utility model provides an adjustable mold clamp device Figure 1 The enlarged schematic diagram of point A in the middle;
[0021] Figure 5 It is a partial three-dimensional structural schematic diagram of an adjustable mold clamp device provided by the present invention.
[0022] Description of Reference Numerals
[0023] 1. Perforated bottom plate; 2. Strip-shaped limit support seat; 3. Support column; 4. First strip plate; 5. Mounting sleeve; 6. Turntable; 7. Limiting plate; 8. Connecting plate; 9. Mounting plate; 10. Gear; 11. First strip slide groove; 12. Rack; 13. Finger ring; 14. Positioning hole; 15. Rotary connection; 16. Positioning bolt; 17. First rotating shaft; 18. Second strip plate; 19. Guide sleeve; 20. Connecting sleeve; 21. Adjusting screw; 22. Connecting piece; 23. Clamp; 24. Limiting bolt; 25. Slider; 26. Sliding arm; 27. Pressing arm; 28. Adjusting bolt. DETAILED DESCRIPTION
[0024] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.
[0025] In the present utility model, unless otherwise stated, directional words such as "upper, lower, inside, outside" contained in a term merely represent the orientation of the term in normal use, or are common names understood by those skilled in the art, and should not be regarded as limitations on the term.
[0026] like Figure 1-5 As shown, an adjustable mold fixture device comprises: a horizontal porous bottom plate 1, a pair of horizontal strip-shaped limit support seats 2 both mounted on the porous bottom plate 1 and with their length directions perpendicular to each other, a plurality of support columns 3 distributed in a matrix and mounted on the porous bottom plate 1, and a fixture unit detachably mounted on two adjacent through holes of the porous bottom plate 1 and capable of contacting a metal block away from a corner of the pair of strip-shaped limit support seats 2;
[0027] The clamp unit includes a first strip plate 4 that can be in contact with the upper surface of the porous bottom plate 1, a pair of mounting mechanisms that are symmetrically arranged and respectively installed on the two ends of the first strip plate 4, and a clamp mechanism that can abut against the corner of the metal block. The mounting mechanism includes a vertical mounting sleeve 5 that is installed on the first strip plate 4 and can fit through the through hole on the porous bottom plate 1, a rotating rod 6 that passes through the mounting sleeve 5 with an eccentric axis and can rotate around its own axis, and a limiting plate 7 that is fixedly installed at the lower end of the rotating rod 6 and can fit with the lower surface of the porous bottom plate 1. When the rotating rod 6 is rotated, the limiting plate 7 can be driven to rotate so as to be misaligned or completely overlapped with the mounting sleeve 5.
[0028] The metal block is placed on a pair of strip limit support seats 2 and corresponding support columns 3, so that the two adjacent side walls of the metal block correspond to the strip limit support seats 2 in contact with each other. Because the clamp mechanism can contact the corner of the metal block away from the pair of strip limit support seats 2, the side walls where the metal block contacts the corresponding strip limit support seats 2 can exert pressure on the strip limit support seats 2, so that the metal block can fit tightly with the corresponding strip limit support seats 2, which not only facilitates the positioning of the metal block, but also improves the positioning accuracy.
[0029] When it is necessary to install the clamp unit on the porous bottom plate 1, first rotate the rotating rod 6 in the mounting sleeve 5 so that the limit plate 7 overlaps with the mounting sleeve 5. At this time, the limit plate 7 and the mounting sleeve 5 can be inserted downward into the through hole of the porous bottom plate 1. When the first strip plate 4 is in contact with the upper surface of the porous bottom plate 1, rotate the rotating rod 6 again to make the limit plate 7 and the mounting sleeve 5 misaligned, and the limit plate 7 can contact with the lower surface of the porous bottom plate 1, thereby installing the clamp unit on two adjacent through holes on the porous bottom plate 1.
[0030] Because several support columns 3 have been installed in a matrix distribution on the porous bottom plate 1, there is no need to increase or decrease the number of support columns 3 when the specifications of the metal block to be processed change, and the clamp unit is installed on two adjacent through holes of the porous bottom plate 1, so the clamp unit can adjust the installation position according to the specifications of the metal block. The operation is simple and convenient, so the position can be selected to avoid the support columns 3 and installed on the porous bottom plate 1 without removing the support columns 3.
[0031] The clamping device also includes a connecting plate 8 fixedly mounted on a pair of mounting sleeves 5, and a mounting plate 9 located above the support column 3 is fixedly mounted on the connecting plate 8. Each of the rotating rods 6 is axially connected to the connecting plate 8 through a bearing, and a gear 10 is coaxially connected to the upper end of each of the rotating rods 6. An adjustment mechanism for synchronously driving a pair of gears 10 to rotate in the same direction is installed on the mounting plate 9.
[0032] When the fixture unit needs to be installed, the two gears 10 are driven to rotate synchronously through the adjusting mechanism, thereby driving the corresponding rotating rod 6 to rotate, so that the mounting plate and the corresponding mounting sleeve 5 overlap, and the limit plate 7 and the mounting sleeve 5 can be inserted downward into the through hole on the porous bottom plate 1; when the first strip plate 4 contacts the upper surface of the porous bottom plate 1, the two gears 10 are driven to rotate through the adjusting mechanism, driving the corresponding rotating rod 6 to rotate, and driving the limit plate 7 and the mounting sleeve 5 to be misaligned.
[0033] Because a pair of mounting mechanisms are arranged in a symmetrical state, a pair of limit plates 7 and corresponding rotating rods 6 are also arranged in a symmetrical state. In order to avoid different misalignment or overlapping states of the two limit plates 7, the rotating rod 6 is driven by the gear 10 to rotate 180° each time; when the two limit plates 7 and the corresponding mounting sleeves 5 are in an overlapping state, the adjusting mechanism gear 10 drives the rotating rod 6 to rotate 180°, and the misalignment degree between the limit plates 7 and the mounting sleeve 5 is the largest. Then the adjusting mechanism drives the rotating rod 6 to rotate 180° in the opposite direction, and the limit plates 7 return to a state of complete overlapping with the mounting sleeve 5.
[0034] The mounting plate 9 is recessed with a first strip-shaped slot 11 whose length direction is parallel to that of the first strip-shaped plate 4. The adjustment mechanism comprises a rack 12 which is slidably inserted into the first strip-shaped slot 11 in the same length direction and meshes with the two gears 10, and a finger ring 13 which is fixedly mounted on the end of the rack 12. The rack 12 has two recessed positioning holes 14 which are spaced along its length direction. The mounting plate 9 is protruded with a screw-on portion 15 which can slide in contact with the upper surface of the rack 12. The screw-on portion 15 is threadedly penetrated with a positioning bolt 16 whose end can be inserted into the corresponding positioning hole 14.
[0035] When it is necessary to drive the gear 10 to rotate, first rotate the positioning bolt 16 so that the end of the positioning bolt 16 moves out of the corresponding positioning hole 14, and pull or push the rack 12 to slide on the mounting plate 9 through the finger ring 13, thereby driving the two gears 10 to rotate. After the other positioning hole 14 corresponds to the positioning bolt 16, loosen the positioning bolt 16 so that the end of the positioning bolt 16 is inserted into the corresponding positioning hole 14. At this time, the gear 10 cannot rotate.
[0036] The positioning bolt 16 cooperates with the positioning hole 14, allowing the installer to quickly find the complete overlapping state of the limit plate 7 and the installation sleeve 5, and can also fix the overlapping and misaligned state of the limit plate 7 to prevent looseness between the clamp unit and the porous bottom plate 1 during the cutting process of the metal block.
[0037] The clamp mechanism includes a vertical first rotating shaft 17 axially connected to the connecting plate 8, a second strip plate 18 fixedly connected to the first rotating shaft 17 and located above the support column 3, a guide sleeve 19 fixedly installed at the end of the first strip plate 4 away from the first rotating shaft 17, an axle seat fixedly installed at the end of the second strip plate 18 away from the guide sleeve 19, a connecting sleeve 20 arranged in the same length direction as the second strip plate 18 and sliding through the guide sleeve 19 along its own length direction, an adjusting screw 21 coaxially arranged with the connecting sleeve 20 and threadedly connected to the inner wall of the connecting sleeve 20, a connecting piece 22 fixedly installed at the end of the connecting sleeve 20 away from the adjusting screw 21, and an L-shaped clamp 23 hinged to the connecting piece 22 through a vertical hinge axis, and the hinge axis is located at the bending part of the clamp 23.
[0038] After a pair of mounting mechanisms are installed on two adjacent through holes on the porous bottom plate 1, first rotate the adjusting screw 21 to drive the connecting sleeve 20 to slide on the guide sleeve 19 close to the metal block, and drive the clamp 23 to slide close to the metal block. When the clamp 23 approaches the metal block, rotate the second strip plate 18 to drive the connecting sleeve 20 to rotate so that the clamp 23 is facing the corner of the metal block. Continue to rotate so that the two ends of the clamp 23 are respectively in contact with the two side walls of the metal block, and then rotate the adjusting screw 21 so that the clamp 23 is completely in contact with the corner of the metal block.
[0039] When the axis of the adjusting screw 21 intersects the diagonal of the metal block, after the clamp 23 contacts the metal block, the clamp 23 will rotate around the hinge axis, so that the two ends of the clamp 23 automatically fit on the two side walls of the metal block corner, thereby improving the applicability of the clamp unit.
[0040] The rack 12 is fixedly mounted with two limit bolts 24 which are spaced apart along the length direction of the rack 12 and are respectively located on both sides of the screw connection portion 15 .
[0041] Because the screw-on portion 15 is located between the two limit bolts 24 , it can prevent the rack 12 from falling off. At the same time, the two limit bolts 24 also have a positioning function. When the rack 12 slides, the corresponding limit bolt 24 contacts the screw-on portion 15 , and the positioning bolt 16 corresponds to one of the positioning holes 14 .
[0042] The strip-shaped limit support seat 2 is formed with a stepped portion for placing the metal block, and a second strip-shaped slide groove with the same length direction is recessed on one side of the strip-shaped limit support seat 2 away from the support column 3, and at least one safety mechanism that can press on the metal block is slidably arranged in the second strip-shaped slide groove.
[0043] The metal block is placed on the step portion. After the clamp unit cooperates with a pair of strip-shaped limit support seats 2 to clamp the metal block, the metal block is pressed by the installation mechanism to prevent the metal block from bouncing upward, thereby improving safety.
[0044] The mounting mechanism includes a slider 25 slidably mounted in the second strip-shaped slide groove, a slide arm 26 vertically slidably connected to the slider 25, a pressure arm 27 fixedly connected to the top of the slide arm 26 and capable of pressing on the metal block, and a vertical adjustment bolt 28 threadedly passing through the pressure arm 27 and having its lower end axially connected to the slider 25.
[0045] When placing the metal block, push the slider 25 to slide to avoid the pre-placement area of the metal block. After the metal block is clamped, push the slider 25 again to move the pressure arm 27 to the top of the metal block, and turn the adjusting bolt 28 to drive the sliding arm 26 to slide downward on the slider 25, so that the pressure arm 27 is pressed on the metal block.
[0046] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention.
[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present utility model will not further describe various possible combinations.
[0048] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.
Claims
1. An adjustable mold fixture device, characterized in that: The clamp device comprises: a horizontal porous bottom plate (1), a pair of horizontal strip-shaped limit support seats (2) both mounted on the porous bottom plate (1) and with their length directions perpendicular to each other, a plurality of support columns (3) distributed in a matrix and mounted on the porous bottom plate (1), and a clamp unit detachably mounted on two adjacent through holes of the porous bottom plate (1) and capable of contacting a metal block at a corner away from the pair of strip-shaped limit support seats (2); The clamp unit comprises a first strip plate (4) capable of being in contact with the upper surface of the porous bottom plate (1), a pair of mounting mechanisms arranged in a symmetrical state and respectively mounted on the two ends of the first strip plate (4), and a clamp mechanism capable of contacting the corner of the metal block, wherein the mounting mechanism comprises a vertical mounting sleeve (5) mounted on the first strip plate (4) and capable of being in contact with the through hole on the porous bottom plate (1), a rotating rod (6) having an eccentric axis passing through the mounting sleeve (5) and capable of rotating around its own axis, and a limiting plate (7) fixedly mounted on the lower end of the rotating rod (6) and capable of being in contact with the lower surface of the porous bottom plate (1), wherein when the rotating rod (6) is rotated, the limiting plate (7) can be driven to rotate so as to be misaligned with or completely overlapped with the mounting sleeve (5).
2. The adjustable mold fixture device according to claim 1, characterized in that: The clamping device also includes a connecting plate (8) fixedly mounted on a pair of mounting sleeves (5), a mounting plate (9) located above the support column (3) being fixedly mounted on the connecting plate (8), each of the rotating rods (6) being axially connected to the connecting plate (8) via a bearing, a gear (10) being coaxially connected to the upper end of each of the rotating rods (6), and an adjusting mechanism for synchronously driving the pair of gears (10) to rotate in the same direction being mounted on the mounting plate (9).
3. The adjustable mold fixture device according to claim 2, characterized in that: The mounting plate (9) is recessed with a first strip-shaped slide groove (11) whose length direction is parallel to the length direction of the first strip-shaped plate (4); the adjustment mechanism comprises a rack (12) which is slidably inserted into the first strip-shaped slide groove (11) in the same length direction and meshed with the two gears (10) and a finger ring (13) fixedly mounted on the end of the rack (12); the rack (12) is recessed with two positioning holes (14) arranged at intervals along its length direction; the mounting plate (9) is protruded with a screw connection portion (15) which can slide in contact with the upper surface of the rack (12); the screw connection portion (15) is threadedly penetrated with a positioning bolt (16) whose end can be inserted into the corresponding positioning hole (14).
4. The adjustable mold clamp device according to claim 2, characterized in that: The clamp mechanism comprises a vertical first rotating shaft (17) axially connected to the connecting plate (8), a second strip plate (18) fixedly connected to the first rotating shaft (17) and located above the supporting column (3), a guide sleeve (19) fixedly mounted on the end of the first strip plate (4) away from the first rotating shaft (17), an axle seat fixedly mounted on the end of the second strip plate (18) away from the guide sleeve (19), a connecting sleeve (20) arranged in the same length direction as the second strip plate (18) and sliding through the guide sleeve (19) along its own length direction, an adjusting screw (21) arranged coaxially with the connecting sleeve (20) and threadedly connected to the inner wall of the connecting sleeve (20), a connecting piece (22) fixedly mounted on the end of the connecting sleeve (20) away from the adjusting screw (21), and an L-shaped clamp (23) hinged to the connecting piece (22) via a vertical hinge axis, wherein the hinge axis is located at the bending part of the clamp (23).
5. The adjustable mold clamp device according to claim 3, characterized in that: The rack (12) is fixedly mounted with two limit bolts (24) which are arranged at intervals along the length direction of the rack (12) and are respectively located on both sides of the screw connection portion (15).
6. The adjustable mold fixture device according to claim 1, characterized in that: The strip-shaped limit support seat (2) is formed with a stepped portion for placing the metal block, and a second strip-shaped slide groove with the same length direction is recessed on one side of the strip-shaped limit support seat (2) away from the support column (3), and at least one safety mechanism capable of pressing on the metal block is slidably arranged in the second strip-shaped slide groove.
7. The adjustable mold clamp device according to claim 6, characterized in that: The mounting mechanism comprises a slider (25) slidably mounted in the second strip-shaped slide groove, a slide arm (26) vertically slidably connected to the slider (25), a pressure arm (27) fixedly connected to the top of the slide arm (26) and capable of pressing on the metal block, and a vertical adjustment bolt (28) threadedly passing through the pressure arm (27) and having its lower end axially connected to the slider (25).