Adjustable clamping tool for die wedge

Abstract

The invention discloses an adjustable clamping tool for a mold wedge, relates to the technical field of tools for wedges, and mainly aims to solve the problems that most of existing clamping tools for standard wedges can only meet the clamping requirements of standard wedges of single specifications and are poor in universality. According to the main structure, the device comprises a base plate, a sliding rail is arranged on the base plate, a sliding block is arranged on the sliding rail, a supporting block capable of horizontally moving is arranged at the top of the sliding block, the moving direction of the supporting block is perpendicular to the extending direction of the sliding rail, a supporting plate capable of vertically swinging is hinged to the top of the supporting block, and a stand column is vertically arranged on the side, away from the supporting block, of the supporting plate; the side, close to the supporting plate, of the stand column is detachably provided with a jacking protruding block with the V-shaped cross section, and a pressing plate is arranged at the upper end of the stand column. The invention provides an adjustable clamping tool for a die wedge, which can meet the clamping requirements of standard wedges of various specifications and models and is good in universality.

Description

Technical Field

[0001] The invention relates to the technical field of tooling for angled wedges, and in particular to a clamping tooling for adjustable mold angled wedges. Background Art

[0002] The cam mechanism is a mechanism that converts the vertical movement of the slide on the press into horizontal / inclined movement. The standard cam refers to the cam product that meets the relevant standards and specifications. In the field of mechanical processing, the standard cam is often used for pin hole drilling and screw hole tapping. Due to its large size, the standard cam often needs to be fixed with a clamping tool.

[0003] At present, with the continuous development of technology, standard cams of various sizes have emerged. However, most of the existing clamping tools for standard cams can only meet the clamping requirements of standard cams of a single specification, and cannot meet the clamping requirements of standard cams of different specifications and models, and have poor versatility. This not only affects the quality of hole processing of standard cams, but also increases processing costs and operating difficulties, and prolongs the assembly cycle. Summary of the invention

[0004] The purpose of the present invention is to provide an adjustable clamping tool for a mold wedge, which can meet the clamping requirements of standard wedges of various specifications and models and has good versatility.

[0005] The technical solution of the present invention for solving the above-mentioned technical problems is: a clamping fixture for an adjustable mold wedge, comprising a horizontally arranged base plate, a slide rail being horizontally arranged on the upper surface of the base plate, and a slider being movable along its extension direction being arranged on the slide rail, a support block being movable horizontally and the moving direction being perpendicular to the extension direction of the slide rail being arranged on the top of the slider, a support plate being hinged on the top of the support block and capable of vertical swinging and the plate surface being parallel to the slide rail, a column being vertically arranged on the side of the support plate facing away from the support block and having its lower end fixed on the base plate, a tightening protrusion being detachably mounted on the side of the column close to the support plate and extending vertically and having a V-shaped cross section, and a pressure plate being movable up and down and extending toward one side of the support plate being arranged horizontally on the upper end of the column.

[0006] As a further improvement of the present invention, a bracket mounting groove which can extend along the moving direction of the bracket is provided on the top of the slider, and the bracket is slidably installed above the bracket mounting groove by means of a bracket mounting convex rail arranged on its lower surface; a plurality of limit snap-in slots arranged along the extending direction thereof are provided on the top of the side wall of the bracket mounting groove, a bracket mounting convex rail is vertically provided on the side wall of the bracket, and a bracket is slidably installed on the bracket mounting convex rail, and a protrusion which engages with the limit snap-in is provided on the lower surface of the bracket.

[0007] As a further improvement of the present invention, the support block is provided with a support plate mounting groove which is inclined toward the side away from the column and whose extension direction is perpendicular to the extension direction of the slide rail, and a support plate mounting plate is provided in the support plate mounting groove which extends in the same direction as the support plate and whose upper edge is connected to the lower plate surface of the support plate; a hinge shaft is horizontally penetrated through the plate surface of the support plate mounting plate on the side away from the column, and its two ends are respectively hinged to the side walls of the support plate mounting groove on both sides; a positioning pin is horizontally penetrated through the plate surface of the support plate mounting plate on the side close to the column, and at least two support plate positioning holes for inserting the positioning pins are provided on both side walls of the support plate mounting groove.

[0008] As a further improvement of the present invention, one end of the positioning pin extends through the positioning hole of the support plate to the outside of the support block, and an anti-dropout groove is provided on the outer wall of the positioning pin located outside the support block, and an anti-dropout strap is provided on the outer wall of the support block, one end of which is overlapped in the anti-dropout groove and the other end is hinged to the support block through a strap mounting screw.

[0009] As a further improvement of the present invention, a tightening protrusion installation groove penetrating the entire column is vertically provided on the side wall of the column, and a T-shaped block slidably installed in the tightening protrusion installation groove is provided on the side wall of the tightening protrusion facing the column.

[0010] As a further improvement of the present invention, the lower surface of the tightening protrusion abuts against the upper end surface of the tightening protrusion limiting step arranged on the outer side wall of the column.

[0011] As a further improvement of the present invention, a locking block is arranged above the pressure plate, and a screw is vertically arranged on the lower surface of the locking block, which penetrates downward through the pressure plate and is threadedly connected to the upper end face of the column; a screw opening for the screw to pass through is provided on the pressure plate, and the screw opening is a strip-shaped opening extending in the same direction as the pressure plate.

[0012] As a further improvement of the present invention, the locking block is also horizontally provided with a handle bar that runs through the entire locking block.

[0013] As a further improvement of the present invention, a plurality of lifting rods are vertically provided at the edge of the upper surface of the substrate. The upper portion of the lifting rods is bent and the lower portion is threadedly connected to the substrate. The outer portion of the lifting rods is also threadedly connected to a nut located above the substrate.

[0014] As a further improvement of the present invention, a tightening bump placement assembly for placing spare tightening bumps is fixedly provided on the upper surface of the base plate on both sides of the column, and the tightening bump placement assembly includes two parallel channel steels with grooves facing upward, and the upper edges of the side plates on the opposite sides of the two channel steels are provided with V-shaped bayonet sockets.

[0015] Beneficial Effects

[0016] Compared with the prior art, the advantages of the clamping tool for an adjustable mold wedge of the present invention are:

[0017] 1. The tooling uses a support plate to support the guide surface below the mold wedge, and cooperates with the tightening protrusion that is in tight contact with the V-shaped guide surface on the side wall of the mold wedge, and the pressure plate that can press down the upper end surface of the mold wedge, so that the mold wedge can be positioned from the top, bottom and back of the mold wedge at the same time, thereby realizing the stable clamping of the mold wedge by the tooling. Among them, the left and right position of the support plate can be adjusted by the sliding fit between the slide rail and the slider; the spacing between the support plate and the tightening protrusion can be adjusted by the sliding fit between the support block and the slider; the inclination angle of the support plate itself can be adjusted by the hinged fit between the support plate and the support block; the tightening protrusion is detachably connected to the column, and tightening protrusions of different specifications can be replaced as needed; the pressure plate can move up and down.

[0018] Therefore, the tooling can flexibly adjust the left and right position of the support plate, the distance between the support plate and the tightening protrusion, the inclination angle of the support plate, the specifications of the tightening protrusion and the horizontal height of the pressure plate according to the specifications and models of the mold wedge, so that the tooling can adapt to the clamping requirements of standard wedges of various specifications and models and has good versatility.

[0019] 2. The tooling can use the support plate and the tightening convex block to position and support the lower surface and side surface of the mold wedge at the same time, keeping the mold wedge in a horizontal state, thereby ensuring that the processed surface of the mold wedge is perpendicular to the drilling direction of the drill bit, so that the drilling and tapping have good verticality. In addition, the cooperation of the support plate, the tightening convex block and the pressure plate makes the clamping tooling easy to use, and can quickly clamp the mold wedge, thereby improving the processing efficiency. The device has a clever structure and is easy to operate. It is more efficient in making holes and tapping the mold wedge. At the same time, the verticality of the screw hole or pin hole of the mold wedge can also be guaranteed, improving the product quality.

[0020] The present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, which are used to illustrate embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A perspective view of the present invention;

[0023] Figure 2 is a three-dimensional diagram of a substrate of the present invention;

[0024] Figure 3A three-dimensional diagram of the slider, the support block and the support plate of the present invention;

[0025] Figure 4 for Figure 3 A vertical cross-sectional view of

[0026] Figure 5 A three-dimensional diagram of a column of the present invention;

[0027] Figure 6 for Figure 5 A vertical cross-sectional view of

[0028] Figure 7 A state diagram is used for the present invention.

[0029] Wherein: 1-base plate; 11-tightening protrusion placement component; 12-slide rail mounting groove; 13-column mounting groove; 14-lifting rod; 2-slide rail; 21-slide rail fixing screw; 3-slider; 31-slider mounting groove; 32-support block mounting groove; 33-limiting bayonet; 4-support block; 41-support plate mounting groove; 42-support plate positioning hole; 43-block mounting convex rail; 44-block; 45-support block mounting convex rail; 5-support plate; 51-hinge shaft; 52-positioning pin; 53-anti-dropping strap; 54-slap mounting screw; 6-column; 61-V-shaped mounting groove; 62-tightening protrusion limiting step; 7-tightening protrusion; 71-T-block; 8-pressure plate; 81-screw mouth; 9-locking block; 91-screw; 92-handle rod. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; of course, it can also be a mechanical connection or an electrical connection; in addition, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0033] Example

[0034] The specific embodiments of the present invention are as follows Figure 1-7 As shown, a clamping fixture for an adjustable mold wedge includes a horizontally arranged base plate 1, and two slide rails 2 are horizontally arranged on the upper surface of the base plate 1, and the two slide rails 2 are arranged parallel to each other. In order to install the slide rail 2, a slide rail mounting groove 12 corresponding to the slide rail 2 is provided on the upper surface of the base plate 1, and the slide rail 2 is fixedly installed in the slide rail mounting groove 12 by a slide rail fixing screw 21 vertically penetrating the slide rail 2. A slider 3 that can move along the extension direction of the slide rail 2 is provided on the slide rail 2. There are two sliders 3, and the two sliders 2 are arranged in sequence along the extension direction of the slide rail 2. In this embodiment, a slider mounting groove 31 corresponding to the two slide rails 2 is provided on the lower surface of the slider 3. Through the slider mounting groove 31, the slider 3 can be slidably installed on the slide rail 2, so as to realize the adjustment of the position of the slider 3.

[0035] Among them, a support block 4 which can move horizontally and whose moving direction is perpendicular to the extending direction of the slide rail 2 is provided on the top of the slider 3, and a support plate 5 which can swing vertically and whose plate surface is parallel to the slide rail 2 is hinged on the top of the support block 4. A column 6 whose lower end is fixed on the base plate 1 is vertically provided on the side of the support plate 4 away from the support block 4. In order to position and install the column 6, a column mounting groove 13 is provided on the upper surface of the base plate 1, and the column 6 is fixedly installed in the column mounting groove 13 by a column mounting screw which penetrates the base plate 1 from the lower net. At the same time, a vertically extending top tightening protrusion 7 with a V-shaped cross section is detachably installed on the side of the column 6 close to the support plate 4, and a pressure plate 8 which can move up and down and extends toward one side of the support plate 4 is horizontally provided on the upper end of the column 6.

[0036] Before using the tooling to clamp the mold wedge, it is necessary to flexibly adjust the left and right position of the support plate 5, the distance between the two support plates 5, the distance between the support plate 5 and the top tightening protrusion 7, the tilt angle of the support plate 5, the specifications of the top tightening protrusion 7 and the horizontal height of the pressure plate 8 according to the specifications and models of the mold wedge. Specifically: the left and right position of the support plate 5 and the distance between the two support plates 5 can be adjusted by the sliding fit between the slide rail 2 and the slider 3; the distance between the support plate 5 and the top tightening protrusion 7 can be adjusted by the sliding fit between the support block 4 and the slider 3; the tilt angle of the support plate 5 itself can be adjusted by the hinged fit between the support plate 5 and the support block 4; the top tightening protrusion 7 is detachably connected to the column 6, and the top tightening protrusion 7 of different specifications can be replaced as needed; the pressure plate 8 can move up and down.

[0037] When using the tooling to clamp the mold wedge, the support plate 4 is used to support the guide sliding surface below the mold wedge, and the clamping protrusion 7 that is in tight contact with the V-shaped guide sliding surface on the side wall of the mold wedge, and the pressure plate 8 that can press down the upper end surface of the mold wedge, can simultaneously locate the mold wedge from the top, bottom and rear side, thereby achieving stable clamping of the mold wedge by the tooling.

[0038] Therefore, the fixture can meet the clamping requirements of standard wedges of various specifications and models, and has good versatility. In addition, the fixture can use the support plate 5 and the tightening protrusion 7 to simultaneously position and support the lower surface and side surface of the mold wedge, keeping the mold wedge in a horizontal state, thereby ensuring that the processed surface of the mold wedge is perpendicular to the drilling direction of the drill bit, so that the drilling and tapping have good verticality. In addition, the support plate 5, the tightening protrusion 7 and the pressure plate 8 cooperate to make the clamping fixture easy to use, and can quickly clamp the mold wedge, thereby improving the processing efficiency. The device has an ingenious structure and is easy to operate. The efficiency of making holes and tapping the mold wedge is higher, and the verticality of the screw hole or pin hole of the mold wedge can also be guaranteed, thereby improving the product quality.

[0039] In this tooling, in order to achieve the sliding fit between the support block 4 and the slider 3, the distance between the support plate 5 and the tightening protrusion 7 can be adjusted. Figure 3 , 4 As shown, a support block installation groove 32 extending along the moving direction of the support block 4 is provided on the top of the slider 3, and the support block 4 is slidably installed above the support block installation groove 32 through a support block installation convex rail 45 provided on its lower surface. At the same time, in order to achieve the fixing of the distance between the support plate 5 and the top tightening protrusion 7 after adjustment, a plurality of limit bayonet holes 33 arranged along the extension direction thereof are provided on the top of the side wall of the support block installation groove 32; and a block installation convex rail 43 is vertically provided on the side wall of the support block 4, and a block 44 is slidably installed on the block installation convex rail 43, and a protrusion engaged with the limit bayonet hole 33 is provided on the lower surface of the block 44. When adjusting the distance between the support plate 5 and the top tightening protrusion 7, the protrusion of the block 44 is located above the limit bayonet hole 33, and the position of the support block 4 can be slidably adjusted at this time. After the adjustment is completed, the block 44 only needs to be moved down along the block installation convex rail 43, and the protrusion on the lower surface of the block 44 is engaged with the limit bayonet hole 33.

[0040] In this tooling, in order to achieve the adjustment and fixation of the tilt angle of the support plate 5. Figure 3 , 4As shown, the support block 4 is provided with a support plate installation groove 41 which is inclined toward the side away from the column 6 and the extension direction is perpendicular to the extension direction of the slide rail 2, and a support plate installation plate is provided in the support plate installation groove 41, which extends in the same direction and the upper edge is connected to the lower plate surface of the support plate 4. A hinge shaft 51 is horizontally penetrated on the plate surface of the support plate installation plate away from the column 6, and the two ends are respectively hinged to the side walls of the support plate installation groove 41. A positioning pin 52 is horizontally penetrated on the plate surface of the support plate installation plate close to the column 6, and at least two support plate positioning holes 42 for the positioning pin 52 to be inserted are provided on both sides of the side walls of the support plate installation groove 41. After adjusting the inclination angle of the support plate 4 by the hinge shaft 51, the inclination angle of the support plate 4 can be fixed by plugging and matching the positioning pin 52 and the support plate positioning hole 42. Among them, the position and number of the support plate positioning holes 42 should be based on the common inclination angle of the support plate 4. In addition, the opening on the support plate installation plate for the positioning pin 52 to pass through should be long strip-shaped.

[0041] In this embodiment, in order to prevent the positioning pin 52 from falling out, one end of the positioning pin 52 extends through the support plate positioning hole 42 to the outside of the support block 4, and an anti-falling groove is provided on the outer wall of the positioning pin 52 located outside the support block 4; an anti-falling strap 53 is provided on the outer wall of the support block 4, one end of which is overlapped in the anti-falling groove and the other end is hinged to the support block 4 through a strap mounting screw 54.

[0042] In this tooling, Figure 5 , 6 As shown, in order to replace the tightening protrusion 7, a tightening protrusion installation groove 61 that runs through the entire column 6 is vertically provided on the side wall of the column 6, and a T-block 71 that is slidably installed in the tightening protrusion installation groove 61 is provided on the side wall of the tightening protrusion 7 facing the column 6. Through the sliding cooperation between the T-block 71 and the tightening protrusion installation groove 61, the tightening protrusion 7 can be easily disassembled and assembled on the column 6. In this embodiment, in order to quickly locate the horizontal height of the tightening protrusion 7, the lower surface of the tightening protrusion 7 abuts against the upper end surface of the tightening protrusion limiting step 62 set on the outer side wall of the column 6.

[0043] In this tooling, Figure 5 , 6 As shown, in order to achieve height adjustment of the pressing plate 8 and tightening of the pressing plate 8 after height adjustment, a locking block 9 is provided above the pressing plate 8, and a screw 91 is vertically provided on the lower surface of the locking block 9, which passes through the pressing plate 8 downward and is threadedly connected to the upper end surface of the column 6. At the same time, in order to adjust the position of the pressing plate 8 along its extension direction, a screw opening 81 is provided on the pressing plate 8 for the screw 91 to pass through, and the screw opening 81 is a strip-shaped opening extending in the same direction as the pressing plate 8. In this embodiment, in order to facilitate the rotation of the locking block 9, a handle bar 92 that passes through the entire locking block 9 is also horizontally provided on the locking block 9.

[0044] In addition, in order to facilitate the movement of the tooling, a plurality of lifting rods 14 are vertically arranged at the edge of the upper surface of the substrate 1. The upper portion of the lifting rod 14 is bent, and the lower portion is threadedly connected to the substrate 1. The outer portion of the lifting rod 14 is also threadedly connected to a nut located above the substrate 1.

[0045] It should be noted that:

[0046] In order to facilitate the replacement of the tightening protrusions 7, tightening protrusion placement components 11 for placing spare tightening protrusions 7 are fixed on the upper surfaces of the base plates 1 on both sides of the column 6. The tightening protrusion placement components 11 include two parallel channel steels with notches facing upward, and the upper edges of the side plates on the opposite sides of the two channel steels are provided with V-shaped bayonet holes. In this embodiment, in order to place a tightening protrusion 7 of a smaller size, two L-shaped steels parallel to the channel steels are further provided between the two channel steels of one group of tightening protrusion placement components 11. The two L-shaped steels are arranged opposite to each other, and the upper edges of the side plates are also provided with V-shaped bayonet holes.

[0047] The present invention has been described above in conjunction with the best embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations based on the essence of the present invention.

Claims

1. A clamping tool for an adjustable mold wedge, characterized in that: The invention comprises a horizontally arranged base plate (1), a slide rail (2) being arranged horizontally on the upper surface of the base plate (1), and a slider (3) being arranged on the slide rail (2) and being movable in the direction of extension thereof, a support block (4) being arranged on the top of the slider (3) and being movable horizontally and in a direction perpendicular to the direction of extension of the slide rail (2), a support plate (5) being hingedly connected to the top of the support block (4) and being capable of vertical swinging and having a plate surface parallel to the slide rail (2), a column (6) being arranged vertically on the side of the support plate (4) facing away from the support block (4) and having a lower end fixed on the base plate (1), a tightening protrusion (7) extending vertically and having a V-shaped cross section being detachably mounted on the side of the column (6) close to the support plate (4), and a pressing plate (8) being arranged horizontally on the upper end of the column (6) and being movable up and down and extending toward one side of the support plate (4).

2. The clamping tool for the adjustable mold wedge according to claim 1 is characterized in that: The top of the slide block (3) is provided with a support block mounting groove (32) which can extend along the moving direction of the support block (4); the support block (4) is slidably mounted above the support block mounting groove (32) via a support block mounting protruding rail (45) arranged on its lower surface; the top of the side wall of the support block mounting groove (32) is provided with a plurality of limit snap-in openings (33) arranged along its extension direction; a block mounting protruding rail (43) is vertically arranged on the side wall of the support block (4), and a block (44) is slidably mounted on the block mounting protruding rail (43); and a protruding portion engaged with the limit snap-in opening (33) is provided on the lower surface of the block (44).

3. The clamping tool for the adjustable mold wedge according to claim 1 or 2, characterized in that: The support block (4) is provided with a support plate installation groove (41) which is inclined toward the side away from the column (6) and extends in a direction perpendicular to the extension direction of the slide rail (2), and a support plate installation plate is provided in the support plate installation groove (41) which extends in the same direction as the support plate installation groove and whose upper edge is connected to the lower plate surface of the support plate (4); a hinge shaft (51) is horizontally penetrated on the plate surface of the side away from the column (6), and its two ends are respectively hinged to the side walls of the support plate installation groove (41) on both sides; a positioning pin (52) is horizontally penetrated on the plate surface of the support plate installation plate on the side close to the column (6), and at least two support plate positioning holes (42) are provided on the side walls of the support plate installation groove (41) on both sides for the positioning pin (52) to be inserted.

4. The clamping tool for the adjustable mold wedge according to claim 3 is characterized in that: One end of the positioning pin (52) passes through the support plate positioning hole (42) and extends to the outside of the support block (4), and an anti-dropout slot is provided on the outer wall of the positioning pin (52) located outside the support block (4), and an anti-dropout strap (53) is provided on the outer wall of the support block (4), one end of which is overlapped in the anti-dropout slot and the other end of which is hinged to the support block (4) via a strap mounting screw (54).

5. The clamping tool for the adjustable mold wedge according to claim 1, characterized in that: A tightening protrusion mounting groove (61) penetrating the entire column (6) is vertically provided on the side wall of the column (6), and a T-shaped block (71) slidably mounted in the tightening protrusion mounting groove (61) is provided on the side wall of the tightening protrusion (7) facing the column (6).

6. The clamping tool for the adjustable mold wedge according to claim 5, characterized in that: The lower surface of the tightening protrusion (7) abuts against the upper end surface of the tightening protrusion limiting step (62) arranged on the outer side wall of the column (6).

7. The clamping tool for the adjustable mold wedge according to claim 1, characterized in that: A locking block (9) is arranged above the pressing plate (8), and a screw (91) is vertically arranged on the lower surface of the locking block (9) and penetrates downwardly through the pressing plate (8) and is threadedly connected to the upper end surface of the column (6); a screw opening (81) is arranged on the pressing plate (8) for the screw (91) to pass through, and the screw opening (81) is a strip-shaped opening extending in the same direction as the pressing plate (8).

8. The clamping tool for the adjustable mold wedge according to claim 7, characterized in that: The locking block (9) is also horizontally provided with a handle bar (92) that runs through the entire locking block (9).

9. The clamping tool for the adjustable mold wedge according to claim 1, characterized in that: A plurality of lifting rods (14) are vertically arranged at the edge of the upper surface of the base plate (1); the upper portion of the lifting rods (14) is bent and the lower portion is threadedly connected to the base plate (1); the outer portion of the lifting rods (14) is also threadedly connected to a nut located above the base plate (1).

10. The clamping tool for the adjustable mold wedge according to claim 1, characterized in that: A tightening protrusion placement assembly (11) for placing a spare tightening protrusion (7) is fixedly provided on the upper surface of the base plate (1) on both sides of the column (6), and the tightening protrusion placement assembly (11) comprises two parallel channel steels with grooves facing upwards, and the upper edges of the side plates on the opposite sides of the two channel steels are provided with V-shaped bayonet holes.

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