HK40006927B - Demolition shear and demolition shear piercing tip insert and nose configuration - Google Patents

Description

Demolition shears and thorn tip inserts and end accessories for demolition shears

This application is a divisional application of the invention patent application with application number 201380077298.X, application date April 9, 2013, and invention name “Demolition shears and thorn tip plug-in and end head accessories of demolition shears”.

Technical Field

The invention relates to a pair of demolition shears and a thorn tip plug-in unit and an end head accessory of the demolition shears.

Background Art

It is necessary to set the dismantling shears with a thorn tip plug-in and end head accessories to reduce end head wear and resist the retraction force applied to the thorn tip plug-in when the thorn tip plug-in is interfered with or blocked.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a right side perspective view (from an operator's position) of one embodiment of a demolition shears attachment.

FIG. 2 is a left perspective view of the demolition shears attachment shown in FIG. 1 .

3A-3C illustrate the movement of the upper jaw relative to the lower jaw of the demolition shears attachment shown in FIG. 1 during a shearing operation in a typical working state.

FIG. 4 is an exploded perspective view of the jaw pivot of the removal shears attachment shown in FIG. 1 .

FIG5 is an enlarged view of the jaws of the removal shears attachment shown in FIG1 .

Figure 6 is the same as the position shown in Figure 5, but the blade insert and the thorn tip insert have been removed.

FIG. 7 is an enlarged view of the jaws of the removal shears attachment shown in FIG. 2 .

8 is a perspective view of the lower jaw shown in FIG. 1 with the upper jaw removed in this view to better illustrate the blade side shear blade insert and the guide blade insert.

9 is another perspective view of the lower jaw shown in FIG. 1 , with the upper jaw removed in this view to better illustrate the guide side guide blade insert and the cross blade insert.

Figure 10 is the same as the position shown in Figure 7, but the blade insert and the thorn tip insert have been removed.

Figure 11 shows the lower jaw shown in Figure 9 with the blade insert removed.

12 shows views of an embodiment of a shear blade insert from different angles, wherein FIG. 12A is a front perspective view, FIG. 12B is a front view, FIG. 12C is a side view, and FIG. 12D is a rear view.

13 shows views of an embodiment of a guide blade insert at different angles, wherein FIG. 13A is a front perspective view, FIG. 13B is a front view, FIG. 13C is a side view, and FIG. 13D is a rear view.

14 shows views of an embodiment of a cross blade insert at different angles, wherein FIG. 14A is a front perspective view, FIG. 14B is a rear perspective view, FIG. 14C is a side view, FIG. 14D is a front view, and FIG. 14E is a rear view.

Figure 15 shows different angle views of an embodiment of the blade side spike half, wherein Figure 15A is a front stereoscopic view, Figure 15B is a rear stereoscopic view, Figure 15C is a front side view, Figure 15D is an outer side view, and Figure 15E is an inner side view.

Figure 16 shows different angle views of an embodiment of the guide side spike half piece, wherein Figure 16A is a front stereoscopic view, Figure 16B is a rear view, Figure 16C is a front side view, Figure 16D is an inner front view, and Figure 16E is an outer front view.

17 is a perspective view of the upper jaw of the removal shears attachment shown in FIG1 , in which the spike tip insert is shown separated from the end mount of the upper jaw.

18 is an enlarged side view of the upper and lower jaws of the removal shears attachment shown in FIG. 1 , with the upper jaw in a fully open position.

19 is an enlarged side view of the upper and lower jaws of the removal shears attachment shown in FIG. 1 , with the upper jaw in a partially closed position.

20 is an enlarged side view of the upper and lower jaws of the removal shears attachment shown in FIG. 1 , with the upper jaw about to enter the slot of the lower jaw.

21 is an enlarged side view of the upper and lower jaws of the removal shears attachment shown in FIG. 1 , with the upper jaw fully closed and extending into the slot of the lower jaw.

22 is an enlarged side view of the upper and lower jaws illustrating the forces acting on the thorn tip under a disturbed condition.

FIG. 23 is an enlarged side view of the upper and lower jaws illustrating the forces acting on the thorn tip during another interference scenario.

FIG. 24 is an enlarged side view of the upper and lower jaws illustrating the forces acting on the thorn tip due to wear of the parent material of the upper jaw end when the upper end of the thorn tip insert is obstructed.

DETAILED DESCRIPTION

Referring to the accompanying drawings, reference numerals indicate like parts and their corresponding parts in the various views. FIG. 1 and FIG. 2 show, respectively, right and left perspective views (from the operator's position) of a demolition shears attachment 10. The demolition shears attachment 10 comprises a body 12 having a front end 14 and a rear end 16. The rear end 16 can be mounted to a boom or rod 18 of an excavator (see FIG. 3A ) by means of a swivel attachment 19 or other suitable mounting attachments known to those skilled in the art. The front end 14 of the body 12 is provided with a movable upper jaw 40 and a fixed lower jaw 42 (described in detail below).

3A-3C illustrate the demolition shear attachment 10 mounted on the boom or rod 18 of an excavator in a typical operating position, showing the closing movement of the upper jaw 40 relative to the lower jaw 42 during shearing of an object 11. The object 11 is optionally a structural member such as an I-beam or channel, steel plate, pipe, or other material such as scrap metal, sheet metal, or any other object or material suitable for handling or processing with the demolition shears.

As shown in Figures 1-4, the main body 12 is generally composed of steel side plates 20, steel side plates 22, a top plate 24 and a bottom plate 26, forming a generally enclosed area. The hydraulic actuator 30 (see Figures 3A-3C) and other hydraulic components of the removal shear attachment 10 are basically enclosed and protected within this area. The hydraulic actuator 30 is hingedly fixed to the rear end of the main body 12 by an actuator pivot pin 32 passing through the steel side plates 20 and steel side plates 22, an inner angle plate (not shown in the figure) and a hydraulic cylinder tie rod fork 34. The front end of the hydraulic actuator 30 is hingedly mounted on the movable upper jaw 40 by a cylinder pin 36 extending into a cylinder fork 38 and a cylinder pin hole 39 (see also Figure 17), wherein the cylinder fork 38 and cylinder pin hole 39 are located on the rear lobe of the upper jaw 40. 3A-3C , the hydraulic actuator 30 extends and retracts, allowing the upper jaw 40 to rotate about the longitudinal axis of a jaw pivot assembly 60 (described in detail below) to open and close the upper jaw 40 relative to the lower jaw 42. An access hole with an inspection cover 25 (see FIG. 2 ) is provided in the top panel to facilitate installation, maintenance, service, and repair of the hydraulic actuator and other components of the hydraulic system within the main body 12.

4, 8 and 9, jaw bosses 44, 46 on each side of front end 14 of body 12 include hub holes 48, 50, respectively. A jaw pivot assembly 60 is disposed within hub holes 48, 50 and pivotally supports upper jaw 40 via pivot hole 54 (see FIG. 17).

Jaw pivot assembly 60 includes flanged bushings 56, 58 mounted in hub bores 48, 50. A spindle 62 is press-fitted into pivot bore 54 and rotates with upper jaw 40. Spindle 62 includes a central bore 64, into which a tie rod 66 having a threaded end 68 is disposed. End caps 70, 72 are secured to flanged bushings 56, 58 via threaded connectors extending into aligned bores in flanged bushings 56, 58 and threadedly seated in aligned internally threaded bores in bosses 44, 46. A tie rod nut 74 is threaded onto the threaded end 68 of tie rod 66. Tie rod nut 74 is secured to end caps 70, 72 via threaded connectors threaded into aligned internally threaded bores in flanged bushings 56, 58. According to the embodiment shown, tie rod 66 and tie rod nut 74 laterally constrain and protect hubs 48, 50 from lateral forces applied to the jaws during shearing operations.

As best shown in Figures 4 and 8, a lateral jaw stabilizing disc assembly 80, such as the invention disclosed in U.S. Patent No. 7,216,575, can be used in conjunction with a matching wear plate or wear surface 82 (see Figure 17) provided on the adjacent side of the upper jaw 40 to prevent lateral movement of the upper jaw 40 during the shearing operation until the upper jaw extends into the narrow slot 96 of the lower jaw 42 (described in detail below).

As shown in Figures 5-11, the lower jaw 42 includes forward-extending, laterally spaced, substantially parallel jaw beams 90, 92 and a crossbar 94 extending transversely between the laterally spaced jaw beams 90, 92. The laterally spaced jaw beams 90, 92, together with the crossbar 94, define a slot 96 into which the upper jaw 40 is positioned during the cutting process (see Figures 3C and 4). As described in detail below, the forward-extending jaw beam 90 is used to position and guide the cutting blade insert and is hereinafter referred to as the blade-side jaw beam 90. The other forward-extending jaw beam 92 is used to provide structural rigidity to the lower jaw and to laterally constrain and guide the upper jaw into the slot 96 during the cutting process and is hereinafter referred to as the guide-side jaw beam 92.

As best shown in FIG10 , the inner side of the blade side jaw beam 90 includes a shear blade seat 100 for receiving a set of hardened steel shear blade inserts 110 (see FIG7 and FIG8 ). An embodiment of the shear blade insert 110 is shown in FIG12 . Each shear blade insert 110 has substantially planar vertical wear surfaces 114, 116 and planar horizontal wear surfaces 118, 120. The vertical wear surfaces intersect with the planar horizontal wear surfaces to form four cutting edges 122. The shear blade insert 110 has parallel, beveled end surfaces 124, 126 forming a parallelogram configuration such that when the shear blade insert 110 is positioned and oriented within the shear blade seat 100, the adjacent end surfaces rest against each other at their downwardly directed tips (see FIG7 and FIG8 ). According to the embodiment shown, because the shear blade inserts 110 are parallelepiped-shaped, the shear blade inserts 110 can be rotated and oriented relative to each other within the shear blade holder 100 so that all four cutting edges 122 can be used as cutting edges during use. The planar vertical wear surfaces 114, 116 include countersunk holes 130 for receiving threaded connectors 132 (preferably hexagon socket head screws) in the countersunk holes 130 to removably mount the shear blade inserts 110 within the shear blade holder 100. The head of the threaded connector 132 can be positioned in the countersunk holes 130. The threaded end of the threaded connector 132 extends through the countersunk holes 130 and the alignment hole 134 (see FIG. 10 ) in the shear blade holder 100 and is secured by a nut 136 (see FIG. 5 and FIG. 9 ), wherein the nut 136 is positioned in a countersunk hole 138 on the outside of the blade-side jaw beam 90.

As best shown in FIG10 , the inner side of the blade-side jaw beam 90 also includes a guide blade seat 200 for receiving a hardened steel guide blade insert 210 (best viewed in FIG8 ). An embodiment of the guide blade insert 210 is shown in FIG13 . Each guide blade insert 210 has substantially planar vertical wear surfaces 214, 216 and planar horizontal wear surfaces 218, 220. The vertical wear surfaces intersect with the planar horizontal wear surfaces to form four cutting edges 222. The guide blade insert 210 has parallel, oblique end surfaces 224, 226 forming a parallelogram configuration. The beveled end surfaces 224, 226 of the guide blade insert 210 complement the beveled end surfaces 124, 126 of the shear blade insert 110. Therefore, when the guide blade insert 210 is positioned and oriented within the guide blade holder 200, one of the end surfaces 224, 226 will abut one of the end surfaces 124, 126 of the adjacent shear blade insert 110 (best shown in FIG8 ). According to the embodiment shown, because the guide blade inserts 210 are parallelepiped-shaped, they can be rotated and oriented within the guide blade holder 200 (or alternatively, the guide side guide blade holder 300 described below), allowing all four cutting edges 222 to function as cutting edges during use. The vertical wear surfaces 214, 216 include internally tapped threaded holes 230 into which threaded connectors 232 (e.g., bolts) are positioned to removably mount the guide blade insert 210 within the guide blade holder 200. The threaded end of the nipple 232 extends through an aligned countersunk hole 234 ( FIGS. 5 and 9 ) on the outside of the blade side jaw beam 90 and threads into the internally tapped threaded hole 230 of the guide blade insert 210 .

9 and 11 , the guide-side jaw beam 92 further includes a guide blade holder 300 (see FIG. 11 ) for receiving the same guide blade insert 210 used in the blade-side guide blade holder 200, such that the guide blade insert 210 is interchangeable between the guide-side guide blade holder 300 and the blade-side guide blade holder 200. Thus, the guide blade insert 210 is retained in place on the guide-side guide blade holder 300 in substantially the same manner as the blade-side guide blade holder 200 by the same threaded connector 232 (e.g., a bolt) threadedly extending through aligned countersunk holes 334 ( FIG. 7 , FIG. 8 , and FIG. 10 ) on the outside of the guide-side beam 92 and threadedly engaging the threaded hole 230 of the guide blade insert 210.

As best shown in Figures 9 and 11, the crossbeam 94 includes a cross blade seat 400 (see Figure 11) for receiving a hardened steel cross blade insert 410 (see Figure 9). Figure 14 illustrates one embodiment of the cross blade insert 410. The cross blade insert 410 has a generally planar front wear surface 414, a generally planar top surface 418 and bottom surface 420, generally planar end surfaces 424 and 426, and a back surface 428. The back surface 428 includes four evenly radially spaced internal threaded holes 430. The back surface 428 also has a protrusion 432 embedded therein for mounting within a recess 435 (see Figure 11) in the cross blade seat 400. The front vertical wear surface 414 intersects with the top wear surface 418, the bottom wear surface 420, and the end surfaces 424 and 426 to form four cutting edges 422. Preferably, the cross blade insert 410 is disposed at right angles to the four radially spaced internal threaded holes 430. This allows the cross blade insert 410 to be rotated four times through 90° on the cross blade holder 400, so that all four cutting edges 422 can function as cutting edges during use. The cross blade insert 410 is secured to the cross blade holder 400 by a threaded connector 434 (e.g., a bolt) extending through a countersunk hole in the cross beam 94 (see Figures 5 and 7). The threaded end of the threaded connector 434 is disposed within the aligned internal threaded holes 430 in the back side 428 of the cross blade insert 410.

The upper jaw 40 has a blade side and a guide side, corresponding to the blade-side jaw beam 90 and guide-side jaw beam 92 adjacent to the lower jaw 42, respectively. The blade side of the upper jaw 40 includes a shear blade holder 500 (see FIG. 6 ), which receives a shear blade insert 110 (see FIG. 5 ) similar to that used in the shear blade holder 100 of the lower jaw 42. This allows the shear blade insert 110 to be interchangeable between the upper and lower jaws, thereby reducing the number of different blades required for the shear attachment 10. However, the shear blade 110 in the upper jaw has an upward pointed end facing the lower jaw (compare FIG. 5 to FIG. 7 ), as opposed to a downward pointed end. The shear blade insert 110 is secured to the upper jaw in substantially the same manner as the lower jaw. The threaded end of the threaded connector 132 extends through the countersunk hole 130 and alignment hole 534 in the upper shear blade holder 500 and is secured by a nut 136 provided in a countersunk hole 538 (see FIG. 7 ) in the guide surface of the upper jaw 40.

As shown in Figures 6, 10, and 17, the front end or tip 601 of the upper jaw 40 includes a tip seat 600, which is used to accommodate a hardened steel spike insert 610 (see Figures 5, 7, and 17) to prevent wear of the base material of the upper jaw nose during use. The tip seat 600 includes a blade-side tip seat 602 (see Figures 6 and 17), a guide-side tip seat 604 (see Figure 10), and a front-end tip seat 606 (see Figures 6, 10, and 17), forming a narrow tip portion 608. The front-end tip 609 of the tip seat 600 is preferably rounded to reduce stress concentration on the tip portion 608 during manufacturing and use. The spike insert 610 includes two spike halves 620 and 622, which are generally mirror images of each other, except for the connector holes on each halves (described later). One of the spike half pieces extending to the blade side of the end portion will be referred to as the blade side spike half piece 620 hereinafter, and the other spike half piece extending to the guide side of the end portion will be referred to as the guide side spike half piece 622 hereinafter.

FIG15 illustrates various angled views of one embodiment of a blade-side spike half 620. FIG16 illustrates the same angled views of one embodiment of a guide-side spike half 622. Spike halves 620 and 622 each include an outer wall 630 having a substantially vertical wear surface 632 and a substantially vertical inner support surface 634. Spike halves 620 and 622 also each include a laterally inwardly projecting front wall 636 having an outwardly curved wear surface 638 and an inner support surface 640. Spike halves 620 and 622 also include laterally inwardly projecting bottom legs 642 having a bottom wear surface 644 and an upper leg support surface 646. Spike halves 620 and 622 also include end support surfaces 648 and lugs 650 having upper and lower lug support surfaces 651 and 653. The outer edge of the lug 650 is rounded to reduce stress concentration. A lower lug support surface 653 extends rearward from the end support surface 648. Its purpose will be described in detail later in conjunction with Figures 22 and 23. The planar vertical wear surface 632 intersects with the bottom wear surface 644 to form a shearing edge 652. The curved wear surface 638 of the front wall 636 intersects with the bottom wear surface 644 to form a front stabbing edge 654 (this front stabbing edge may be chamfered).

As best shown in Figures 6, 10, and 17, the tip holders 602, 604, and 606 define a peripheral support edge surface 656 that is complementary to the periphery of the spike halves 620 and 622. According to the present embodiment, the width of the inner surface 640 of the laterally inwardly projecting front wall 636 and the upper surface 646 of the laterally inwardly projecting bottom leg 642 of each spike half 620 and 622 is approximately half the width of the narrow end portion 608. This allows the inner support surface 634 of the side wall 630 and the upper leg support surface 646 of the bottom leg 642 of each spike half 620 and 622 to rest against the support surfaces of the blade-side tip holder 602, the guide-side tip holder 604, and the front end holder 606, respectively, when the tip halves 620 and 622 are mounted on the tip holder 600. Furthermore, the upper and lower lug support surfaces 651 and 653 of the spike halves 620 and 622 abut against the peripheral support edge surface 656 of the endpiece 600. On the blade side of the endpiece 601, either angled end 124 or 126 (depending on orientation) of the upper shear blade insert 110 abuts against the back support surface 648 of the blade-side spike half 620. Similarly, the blade-side spike half 620 is rotationally restrained from outward rotation (as described below) by the blade insert 110 and the peripheral support edge surface 656, which couples to the upper and lower lug support surfaces 651 and 653 of the blade-side endpiece. The guide-side spike half 622 is rotationally restrained from movement by the peripheral support edge surface 656, which couples to the upper and lower lug support surfaces 651 and 653 of the guide-side endpiece 604.

According to this embodiment, when the spike halves 620, 622 are mounted on the tip mount 600, the narrow tip portion 608 is completely surrounded by the hardened steel spike insert 610, thereby preventing the base material of the tip portion 601 from being worn during use.

In addition to being rotationally restrained by the peripheral support edge surface 656, the two spike halves 620 and 622 are secured to the narrow end portion 608 by a threaded connector 670. In one embodiment, the threaded connector is preferably a hexagon socket head cap screw. The two spike halves 620 and 622 include alignment holes 660 extending through their respective outer walls 632. Corresponding alignment holes 664 extend through the narrow end portion 608. Coaxial countersunk holes 668 are located in the alignment holes 660 on the outer wall 632 of the blade-side spike half 620. The alignment holes 660 on the outer wall 632 of the guide-side spike half 622 are internally threaded. The head of the threaded connector 670 is positioned in the countersunk holes 668. The threaded end of the threaded connector 670 extends into the alignment holes 660 of the blade-side spike half 620, passes through the alignment holes 664 of the narrow end portion 608, and is threaded into the internally threaded alignment holes 660 of the guide-side spike half 622. Obviously, the countersunk holes 668 and internal thread alignment holes 660 of the two spike halves 620, 622 can be reversed as needed. Alternatively, the countersunk holes 668 can be located on the outer walls 632 of the two spike halves 620, 622, rather than the alignment holes 660 of one spike half, to accommodate the head of the threaded connector 670 and a nut (not shown) on the other opposing spike half. Referring to Figures 18 and 22 , the alignment holes 660, 664 are aligned along an arc coaxial with the leading edge of the spike 610 (i.e., the outer curved wear surface 638), ensuring that the threaded connector 670 receives relatively uniform loading.

According to the embodiment shown, when the shear blade insert 110 is installed in the upper jaw 40, the planar vertical wear surfaces 114, 116 of the shear blade insert 110 (depending on the installation orientation) are substantially coplanar with the vertical wear surface 632 of the blade-side thorn tip half 620, and the cutting edge 122 of the shear blade insert 110 is substantially aligned with the cutting edge 652 of the thorn tip insert 610. Similarly, when the shear blade insert 110 is installed in the lower jaw 42, the planar vertical wear surfaces 114, 116 of the shear blade insert 110 (depending on the installation orientation) are substantially coplanar with the vertical wear surface 214 of the blade-side guide blade insert 210, and the respective cutting edges 122 and 222 are substantially aligned. According to the embodiment shown, the substantially coplanar vertical wear surfaces 114, 116, 632 and cutting edges 122, 652 of the upper shear blade insert and the thorn tip insert 610 are slightly offset laterally inward from the cutting edges 122, 222 of the lower jaw shear blade insert 110 and the blade-side guide blade insert 210 (preferably in the range of 0.01 to 0.05 inches) to prevent the upper cutting edge from being blocked by the lower jaw cutting edge when the upper jaw extends beyond its range of motion into the slot 96 of the lower jaw 42. Similarly, the cutting edge 652 of the guide-side thorn tip half 622 is laterally inwardly offset from the cutting edge 222 of the guide-side guide blade insert 210 (preferably in the range of 0.01 to 0.05 inches). Accordingly, the width of the spike insert 610 is smaller than the width between the opposing cutting edges 222 of the blade-side and guide-side guide blades 210 (preferably a difference of about 0.02-0.1 inches) so that the spike insert 610 can pass between the two lower guide blades 210 when the upper jaw is closed and extends into the slot 96 of the lower jaw 42. A shim can be inserted between each insert 110, 210, 610 and its respective insert seat 100, 200, 300, 500, 600 to maintain close tolerances on the cutting edges.

Figures 18-22 are enlarged side views of jaws 40 and 42 to better illustrate the relationship between blade inserts 110, 210 and spike insert 610 and cross blade insert 410 as the upper jaw moves from a fully open position (see Figure 18) to a fully closed position (see Figure 21) where the upper jaw reaches its maximum depth within slot 96 of lower jaw 42. Figure 19 shows the upper jaw partially closed, with the front spike blade 654 of spike insert 610 perpendicular to the ground. Figure 20 shows the upper jaw at the intersection of front spike blade 654 and lower jaw 42.

A tip wear plate 700 is secured (e.g., by welding) to the tip section 601 of the upper jaw 40 above the spike insert 610 to protect the upper jaw base material from wear during use. When the tip wear plate 700 becomes worn, it can be removed and replaced with another one. The wear plate 700 can be made of the same material as the base material or can be made of hardened steel. As shown in FIG20 , the tip wear plate preferably extends sufficiently along the tip section to ensure that the base material of the tip section is protected at least to the maximum depth reached by the upper jaw 40 extending into the lower jaw 42. In another embodiment, the spike insert 610 can extend along the tip section 601 to the maximum depth reached by the upper jaw extending into the lower jaw. In this embodiment, the tip base 600 can also be extended, with an additional hole 660 used to adequately confine a longer spike insert 610 within the narrow tip section 608.

According to this embodiment, the base material of the end portion 601 above the spike insert 610 is more susceptible to wear than the hardened steel spike insert 610. Therefore, without the wear plate 700, the end portion 601 would wear until the upper edge of the spike insert 610 protruded beyond the end portion. If the upper edge of the spike insert 610 protruded from the end portion 601, the protruding portion could obstruct the material clamped within the jaws when the jaws reopened or the upper jaw retracted from the lower jaw. If the retraction force applied to the upper jaw was sufficient, the spike insert could be pulled away from the end portion by the obstructed material, shearing the threaded connection or breaking the spike insert in the process. Therefore, as described below, the end portion 601 of the upper jaw is designed to reduce the risk of obstruction, even when the wear plate 700 is not attached to the end portion 601, or if the wear plate itself wears out, causing the base material of the end portion to no longer be protected by the wear plate.

Figures 18 and 21 illustrate a preferred configuration of the tip section 601 to avoid or minimize the occurrence of obstruction. The double-dashed line denoted by reference numeral 800 illustrates the arc formed by the frontmost thorn blade 654 of the spike tip insert 610 as the upper jaw moves within its range of motion. The radius from arc 800 to the center axis of the jaw pivot 60 is R1. The outermost periphery of the tip section 601 extends from the front thorn blade 654 of the spike tip 610 to the end of the tip section wear plate 700, or to the tip tip at the maximum penetration depth of the corresponding tip section 601 into the lower jaw. The outermost periphery of the tip section 601 is designed as a generally smooth tip section arc 802, with a gradually increasing distance from the front thorn blade arc 800. The radius R2 of tip section arc 802 is smaller than the radius R1, so the radial distance from the center axis of the jaw pivot 60 to the tip along the tip section 601 or tip section arc 802 gradually decreases relative to the thorn blade arc 800. Alternatively, the distance between the thorn blade arc 800 and the tip portion arc 802 gradually decreases along the tip portion 601 or tip portion arc 802 from the front thorn blade arc 654. This structure allows the tip portion 601 to only make contact at the front thorn blade 654, thereby preventing or reducing the possibility of the tip portion 601 being scratched by an object penetrating the spike tip 610 and minimizing tip portion wear. Furthermore, because the distance between the tip portion and the thorn blade arc 800 gradually increases, even if the tip portion base material is worn, causing the leading edge of the spike tip insert 610 to protrude outward from the worn base material, the likelihood of material being clamped by the jaws being obstructed is reduced.

Furthermore, if the protruding edge of the spike becomes obstructed or the upper jaw becomes clogged with material held by the jaws, the spike holder 600 and spike insert 610 serve to retain the spike. For example, as shown in FIG22 , the hatched area 900 indicates that material is trapped or embedded between the spike insert 610 and the wear-resistant surface of the guide shear blade insert 210, wherein the spike insert 610 and the shear blade insert 210 cause the upper jaw 40 to be trapped within the slot 96 of the lower jaw 42, thereby preventing the upper jaw 40 from retracting or reopening. The retraction force F of the upper jaw 40 (applied by the hydraulic actuator 30 pulling the upper jaw) serves to pull the spike insert 610 in a direction perpendicular to a radial line 806 extending from the center axis of the jaw pivot 60 toward the midpoint of the obstructed material 900. Thus, according to the embodiment shown, any support surface that is less than a 90-degree angle with respect to the radial line 806 is subjected to the retraction force F. The rearwardly protruding lug 650 of the spike insert 610 thus ensures that the support surface can withstand the retraction force F.

As shown in FIG22 , because the lower lug support surface 653 forms an angle less than 90 degrees with the radial line 806, the support surface indicated by arrow R, which is opposite the peripheral support edge surface 656 of the tip base 600, receives the retraction force F. Similarly, the inner support surface 640 of the front wall 636 rests on the tip base 606 indicated by arrow R to receive the retraction force F. Thus, receiving or resisting the force R reduces the shear force applied to the connector 670 by the retraction force F, thereby preventing or minimizing the possibility of the spike tip insert 610 being pulled out of the tip or otherwise causing breakage.

In addition, since the holes 660 on the spike insert 610 are arranged along the nose arc 804, the radius R3 of the end head arc 804 is smaller than the radius R2 of the end head arc 802 but is concentric with the end head arc 802. Therefore, all the joints 670 can withstand a more uniform load, thereby further reducing the shear stress applied to any joint and avoiding stress concentration that may cause shearing of the joint or fracture of the spike insert.

FIG23 illustrates another embodiment, wherein the hatched area 902 indicates that the material is blocked between the spike insert 610 and the cross-blade insert 410. In this embodiment, assuming that a retraction force F is applied to the front spike edge 654, the retraction force F pulls the spike in a direction perpendicular to a radial line 806 extending from the center axis of the jaw pivot 60 toward the midpoint of the blocked material. As indicated by arrow 810, the retraction force F causes the spike insert 610 to roll outward or away from the end portion 601. However, a resisting force R causes the upper ledge support surface 651 and the peripheral support edge surface 656 of the end portion holder 600 to cooperate to prevent the spike insert 610 from rotating outward, thereby reducing shear forces on the connector 670 and preventing or minimizing stress fractures in the spike insert 610.

FIG24 illustrates an example of the retraction force F acting on the upper edge of the spike insert 610 when the tip portion 601 is worn to form a ridge that causes material to obstruct, as described above. Given the structure of the tip portion 601, where the distance between the tip portion arc 802 and the front blade arc 800 gradually increases, such a situation is unlikely to occur. However, if the tip portion is worn to form a ridge that causes material to obstruct, the resistance force R resisting the retraction force F causes the upper lug support surface 651 and the peripheral support edge surface 656 of the tip base 600 to cooperate to prevent the blade from rotating outward, thereby reducing the shear force on the connector 670 and preventing or minimizing stress fracture of the spike insert 610.

Based on the foregoing, a person skilled in the art can make and use the present invention according to the entire contents and requirements of this patent specification. Persons skilled in the art should understand and appreciate any modifications, general principles, and characteristics of the embodiments described herein. Therefore, the present invention is not limited to the embodiments described herein and shown in the accompanying drawings, and all matters that do not depart from the spirit and scope of the present invention are intended to be covered by the appended claims.

Claims (24)

1. A demolition shear, comprising: The upper jaw is rotatable within a range of motion between an open position and a closed position. The foremost part of the upper jaw defines an end head, which has a blade side, a guide side, a bottom side, and a front side. A hardened steel spike insert is installed on the end head, the spike insert comprising: The outer plane of the blade side wall; One guide side outer plane sidewall surface; A bottom surface extends laterally between the bottom side of the outer plane sidewall of the blade side and the bottom side of the outer plane sidewall of the guide side; A curved outer front wall extends laterally between the front side of the outer plane side wall of the blade side and the front side of the outer plane side wall of the guide side, and the curved outer front wall has a front wall arc radius; Thus, the tip insert completely surrounds and protects the end head by means of the outer plane sidewall of the blade side along the blade side of the end head, the outer plane sidewall of the guide side along the guide side of the end head, the bottom surface along the bottom side of the end head, and the curved outer front wall surface along the front side of the end head. 2. The removal shears according to claim 1, wherein the spiked insert comprises a first spiked portion and a second spiked portion. 3. The removal shears according to claim 2, wherein the first spike portion and the second spike portion are composed of spike halves that cooperate with the spike insert. 4. The demolition shears according to claim 1, characterized in that: The outer plane sidewall of the blade intersects with the bottom surface to form a shearing blade, and the curved outer front wall intersects with the bottom surface to form a front piercing blade. 5. The demolition shears according to claim 4, characterized in that: when the upper jaw rotates within the range of motion, the front barb defines a barb arc, the radius of the barb arc being greater than the radius of the front wall arc, so that the curved outer front wall surface gradually moves away from the barb arc. 6. The removal shears according to claim 1, characterized in that: each of the outer plane sidewall of the blade side and the outer plane sidewall of the guide side includes a plurality of connecting holes, each of the connecting holes being used to install a threaded connector so as to detachably fix the spike insert to the end head through the threaded connector, the connecting holes being concentrically arranged along the arc radius of the connecting hole, and the arc radius of the connecting hole being smaller than the arc radius of the front wall. 7. The demolition shears according to claim 5, characterized in that it comprises: The end abrasion plate has an end abrasion plate arc, the end abrasion plate arc has an end abrasion plate radius, the end abrasion plate radius is approximately the same as the front wall arc radius, so that the end abrasion plate arc gradually moves away from the thorn arc. 8. The demolition shears according to claim 1, characterized in that: it further includes at least one shearing blade, installed in the upper jaw. 9. The demolition shears according to claim 8, wherein the lower jaws include at least one shearing blade. 10. The demolition shears according to claim 9, wherein the lower jaw further includes at least one guide blade. 11. The demolition shears according to claim 10, wherein the lower jaw further comprises at least one horizontal blade. 12. A spike insert for removal shears, the removal shears including an upper jaw rotatable relative to a lower jaw within a range of motion between an open position and a closed position, the foremost portion of the upper jaw defining an end head having a blade side, a guide side, a bottom side, and a front side; the spike insert comprising: The outer plane of the blade side wall; One guide side outer plane sidewall surface; A bottom surface extends laterally between the bottom side of the outer plane sidewall of the blade side and the bottom side of the outer plane sidewall of the guide side; A curved outer front wall extends laterally between the front side of the outer plane side wall of the blade side and the front side of the outer plane side wall of the guide side, and the curved outer front wall has a front wall arc radius; Thus, when the spike insert is installed on the end head, the end head is completely surrounded and protected by the spike insert through the outer plane sidewall of the blade side along the blade side of the end head, the outer plane sidewall of the guide side along the guide side of the end head, the bottom surface along the bottom side of the end head, and the curved outer front wall surface along the front side of the end head. 13. The spike insert according to claim 12, wherein the spike insert comprises a first spike portion and a second spike portion. 14. The spike insert according to claim 13, wherein the first spike portion and the second spike portion are formed by the spike half-pieces that cooperate with the spike insert. 15. The spike insert according to claim 12, wherein the outer plane sidewall of the blade intersects with the bottom surface to form a shearing blade, and the curved outer front wall intersects with the bottom surface to form a front spike. 16. The spike insert according to claim 12, characterized in that: each of the outer plane sidewall of the blade side and the outer plane sidewall of the guide side includes a plurality of connecting holes, each of the connecting holes being used to install a threaded connector so as to detachably fix the spike insert to the end head through the threaded connector, the connecting holes being concentrically arranged along the arc radius of the connecting hole, and the arc radius of the connecting hole being smaller than the arc radius of the front wall. 17. A blade assembly comprising a spike insert according to any one of claims 12-16, and further comprising at least one shearing blade adapted to be mounted to the upper jaw of the removal shears. 18. The blade assembly according to claim 17, characterized in that: it further comprises at least one shearing blade adapted to be mounted to the lower jaw of the removal shears. 19. The blade assembly according to claim 17, characterized in that: it further includes at least one guide blade adapted to be mounted to the lower jaw of the removal shears. 20. The blade assembly according to claim 18, characterized in that: it further includes at least one guide blade adapted to be mounted to the lower jaw of the removal shears. 21. The blade assembly according to claim 17, characterized in that: it further includes at least one transverse blade adapted to be mounted to the lower jaw of the removal shears. 22. The blade assembly according to claim 18, characterized in that: it further includes at least one transverse blade adapted to be mounted to the lower jaw of the removal shears. 23. The blade assembly according to claim 19, characterized in that: it further includes at least one transverse blade adapted to be mounted to the lower jaw of the removal shears. 24. The blade assembly according to claim 20, characterized in that: it further includes at least one transverse blade adapted to be mounted to the lower jaw of the removal shears.