US3402969A - Impact tool assembly - Google Patents

Description

Sept. 24, 1968 K. H. HOEN 3,4 9

IMPACT TOOL ASSEMBLY Original Filed Feb. 14, 1964 i '2 She t s-Sheet 1 IN VENTOR.

KENNETH H. HOEN U ATTORNEY p 24, 8 K. H. HOEN IMPACT TOOL ASSEMBLY Original Filed Feb. 14, 1964 I 2 Sheets-Sheet z IN VEN TOR. KENNETH H. HOEN ATTORNEY United States Patent 3,402,969 IMPACT TOOL ASSEMBLY Kenneth H. Hoen, 2396 Orchard Lane, Littleton, Colo. 80120 Original application Feb. 14, 1964, Ser. No. 345,006, now Patent No. 3,318,392, dated May 9, 1967. Divided and this application Mar. 28, 1967, Ser. No. 626,529

4 Claims. (Cl. 29993) ABSTRACT OF THE DISCLOSURE The rectangular connecting end of an impact tool is releasably clamped within the slot of an attaching head by one or more wedges disposed in guide slots along one side of the blade-receiving slot, and a locking member is removably positioned behind each wedge and is adjustable to tigthen each wedge against one side of the connecting end of the tool.

This is a divisional application of Ser. No. 345,006, filed Feb. 14, 1964, now Patent No. 3,318,392.

The impact tool is of generally T-shaped configuration including an attaching head and an elongated generally rectangular blade stock having opposite, outwardly divergent side portions of transversely concave configuration which terminate in an elongated cutting face squared to the blade axis. The blade stock can be detachably clamped within .a blade-receiving slot in the attaching head through the combined utilization of wedges inserted in the slot and locking screws to force the wedges into clamping engagement with one end of the blade within the slot.

This invention relates to tool attachments and tools for powered hammers and the like; more particularly this invention relates to novel and improved means for interchangeably mounting different tools on powered hammers depending upon the work to be performed, and additionally to impact tools that are adaptable for use in association with powered hammers for the specific purpose of cutting and breaking concrete, asphalt, rock and other hard surfaces in an efiicient and reliable manner.

The advantages and features of the tool attachment and tool of the present invention can be best appreciated from a consideration of their use in association with powered hammers of the type used for performing a number of different tasks, such as, for breaking and cutting concrete, asphalt and similar materials, as well as for tamping earth fills, digging trenches and other earth working operations. Necessarily, different tools are attached to the lower end of the hammer mechanism according to the character of the work to be performed, and the hammer mechanism and attached tool are reciprocated or otherwise operated to deliver a series of impacts or blows under considerable force to the surface being worked. Accordingly, it will be appreciated that it is highly desirable to afford some rapid, dependable means for rigidly but releasably attaching each different tool in place, and specifically in such a way that the tool will not have a tendency to loosen or in any way shift in delivering a succession of blows to the work surface.

In cutting and breaking relatively hard surfaces such as bedrock, concrete or hard asphalt areas, it is also desirable to utilize a tool which is capable of clean, rapid, straight-line cutting with a minimum of fracturing of the material. In this relation, the cutting tool is so constructed and arranged in association with the tool holder that the assembly can be mounted on hammers of different types, and also the tool can be reversibly mounted to "ice compensate for the effects of localized wear on the cutting face.

Accordingly, it is a principal and foremost object of the present invention to provide a hammer tool attachment for powered hammers that is characterized by being conformable for use with different types of hammers and of being self-adjusting for clamping and accommodating different types of tools in carrying out cutting, breaking, tamping and similar operations.

It is another object of the present invention to provide for a novel and improved means for removably attaching different tools to a powered hammer mechanism and wherein the tools can be rapidly connected and removed in a safe, efiicient manner by one person; and further, wherein each tool in attached relation is rigidly clamped and wedged against loosening or displacement in use.

It is a furtherobject of the present invention to provide for a hammer tool attachment characterized by providing a relatively broad surface area of connection between the hammer head and tool while at the same time being formed of a minimum number of parts and requiring a minimum number of operations in connecting and removing each tool; and furthermore, wherein the clamping arrangement employed as part of the tool attachment will permit reversible mounting of each different tool to minimize the effects of localized wear on the tool.

It is a still further object of the present invention to provide for a new and useful tool for cutting and breaking hard surfaces such as rock, concrete and asphalt wherein the tool is characterized by having a blade which will accomplish rapid straight-line cutting Without fracturing the material and will avoid the adverse effects of wear under repeated use; moreover, to provide a tool blade removably connected to the attaching head of the tool in such a way as to permit replacement of the blade as required without replacement of the entire tool, and wherein the blade is firmly locked in place so as to effectively form an integral part of the entire tool and attachment with the hammer head.

The above and other objects, advantages and features of the present invention will become more readily understood and appreciated from a consideration of the following detailed description of alternate forms of the present invention taken together with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a hammer tool attachment consisting of a tool holder and cutting tool in attached relation on the lower end of a hammer head.

FIGURE 2 is a front fragmentary view in elevation illustrating the relationship between parts comprising the preferred form of tool holder in attached relation to the hammer head.

FIGURE 3 is a view in detail of one form of tool adapter plate forming part of the tool holder assembly.

FIGURE 4 is an enlarged elevational view of a preferred form of clamp defining a part of the tool holder shown in FIGURES 1 and 2.

FIGURE 5 is an enlarged end view of the preferred form of clamp.

FIGURE 6 is an enlarged top view of the preferred form of clamp.

FIGURE 7 is an enlarged elevational view of the cutting tool shown in FIGURE 1.

FIGURE 8 is a bottom plan view of the cutting tool illustrated in FIGURE 1.

FIGURE 9 is a front elevation of a tamping device having an attaching head formed for use in association with the preferred form of tool holder assembly, in accordance with the present invention.

FIGURE 10 is a front view of a modified form of cutting tool showing the parts in assembled relation.

FIGURE 11 is a side view of the blade attaching head for the modified form of cutting tool shown in FIG- URE l; and

FIGURE 12 is an enlarged view of the wedge locking device used in association with the blade attaching head shown in FIGURE 10.

Referring in detail to the drawings, a preferred form of hammer tool attachment is designated generally at in FIGURE 1 and which is broadly comprised of a tool holder assembly 11 for attachment of a cutting tool 12 to a hammer head 13. The hammer head illustrated is merely representative of various forms of impact members or weights which in accordance with conventional practice, in a manner not shown, are suitably mounted for reciprocation in a hammer guide frame. For instance, the hammer can be secured to the lower end of a ram extending from a ram cylinder, and the ram is reciprocated to deliver a series of impact blows through the tool against the work surface; and typical examples of powered hammers of this general type or disclosed in Patent No. 2,659,584 to Dorkins and Patent No. 2,335,172 to Cornett.

A principal feature of the present invention resides in the construction and arrangement of the tool holder assembly 11 which, as will be noted from FIGURES 2 and 3, consists of an adapter plate 15 and clamping members 16 adjustably secured in spaced parallel relation to the undersurface of the adapter plate 15. It is emphasized that the adapter plate serves only as a means for conforming the tool attachment for use with hammer heads of different sizes and constructions and accordingly is specifically designed for direct connection of the clamping members and tool attaching head thereto. Thus, the adapter plate 15 is provided with outward bores 18 aligned with threaded apertures 19 in the bottom of the hammer head for threaded insertion of cap screws 20. In connected relation, the adapted plate provides a relatively fiat downwardly facing seating surface 22 with spaced rearwardly disposed positioning lugs 25 projecting downwardly therefrom; threaded bores 25 spaced inwardly of each of the apertures 18 and extend upwardly through the major thickness of the plate for connection of the clamps 16 in a manner now to be described.

Broadly, the clamping members 16 are formed to rigidly but releasably secure different tools against the seat formed either at the bottom of the hammer head or the undersurface of the adapter plate, as the case may be, and in such a way that the clamps will form longitudinal guideways for positioning of the tool in loosely supported relation, after which the clamps are tightened to rigidly hold the tool in place both against loosening or lateral displacement. To this end, and as best seen from FIG- URES 4 to 6, each clamp is defined by a relatively thick elongated body portion having a top angularly relieved surface portion 31 and a shoulder 32 projecting laterally and inwardly from the lower part of the body, the shoulder 32 forming a guideway along the seating surface 22 for insertion of one side of the tool 12. Preferably, each shoulder has top wedging surface portions 40 which incline downwardly and inwardly toward one another from opposite ends and terminate in a shallow recessed area 41. Opposite ends of the body include bores 34 extending vertically therethrough and a shallow spherical recessed area 35 is formed at the entrance to each bore. Spaced intermediately between the bore 34 is an upwardly directed spring-receiving opening 36 for a compression spring 38 as indicated in FIGURES 1 and 5. To adjustably secure the clamps in spaced facing relation along opposite sides of the adapter plate 15, cap screws 42 are passed upwardly through the bores 34 and into the threaded apertures 25 in the adapter plate. Each cap screw 42 is provided with a spherical washer 44 to seat in the recess 35 of each bore 34 and in this way to prevent any lateral shifting of the clamps and afford more uniform distribution of pressure against the screws and clamps when in attached relation. On account of the sloping surfaces 31 it will be noted that the shoulders 32 will be drawn upwardly and somewhat inwardly, upon inward threading of the screws, so as to be self-adjusting according to the thickness of the clamp-engaging portions on the tool.

In order to cooperate with the tool holder to establish rigid clamping engagement between the tool and the hammer head as shown in FIGURES 7 and 8, the tool 12 is of generally T-shaped con-figuration with an attaching head 59 forming a top relatively flat seating surface 51, a central recessed area 52, and shoulder portions 54 projecting laterally in opposite directions from the upper end of the tool. The shoulders 54 are formed with clamp-engaging undersurfaces 55 complementary to the inclined shoulder surfaces on the clamps so as to be wedgingly engaged by the shoulders 32 when the shoulder portions 54 are inserted in the guideways and the clamps are drawn upwardly by the screws 42. Preferably, the attaching head is further characterized by being square-sided so that opposite sides 56 will similarly define clamp-engaging shoulders dimensioned for insertion in the guideways in the event it is desired to turn the tool 90 from its disposition shown in FIGURE 1. By forming the head in this manner, the hammer operator can preset the clamps to provide the required spacing between the shoulders 32 and seat 22 according to the thickness of the shoulders 54, and the springs 38 assist in this by urging the clamps downwardly against the spherical washers so that the clamps need not be held or positioned when the attaching head is inserted through the guideways. Thus, the operator can by grasping the tool align the shoulders 54 with the guideways and advance the shoulders along the guideways until the back surface of the attaching head abuts against the positioning lugs 24, whereupon the inclined surfaces are properly aligned with the surfaces 40 on the clamps. By tightening the cap screws the shoulders 32 are urged upwardly and inwardly to clamp the tool head 50 rigidly against the seating surface 22. The central recessed area 52 merely assures even contact between the abutting surface portions on the adapter plate and tool head and prevents possible misalignment between the abutting surfaces due to uneveness or non-uniformities in the center area.

In the cutting tool 12 shown in FIGURES 7 and 8, a blade shank 60 is formed as an integral part of the tool and is particularly adapted for use in cutting or breaking concrete, bedrock, asphalt and other relatively hard, thick surfaces. For this purpose, the blade shank 60 first tapers outwardly from a relatively broad reinforcing portion 62 then diverges downwardly therefrom and terminates in an elongated, relatively narrow cutting face 64 which is normal or squared to the blade axis. The cutting face 64 gradually increases in width from the center to opposite ends 65 since in use the major wear will take place at opposite ends of the tool, and accordingly the increased width given to the cutting face will compensate for any tendency of the ends to become somewhat tapered relative to the center and which in penetrating different rock surfaces would otherwise have a tendency to stick and develop fractures in the surfaces away from the point of impact. In order to maintain a uniform cross-sectional area for the cutting face after continued wear and sharpening, the sides 66 are given a concave shape in a plane transverse to the blade axis and, along with opposite end surfaces 65, are downwardly divergent away from the reinforcing portion 62 so as to form sharp cutting edges or corners 68 along the periphery of the cutting face.

Generally, the tool will be positioned as illustrated in FIGURE 1 with the cutting face 64 having its major axis aligned with the direction of advancement of the hammer vehicle, although as hereinbefore mentioned the tool may be turned at right angles with the cutting face transverse to the line of travel. Under repeated blows, if the cutting face begins to wear unevenly the tool may be reversed. In any event the principal wear will take place toward the end of the cutting face, but as previously noted this is compensated for by the widened cutting surface toward the ends together with the divergent sides and ends.

A tamping device 70 is illustrated in FIGURE 9 having a tool attaching head 50 which in every respect is identical to the attaching head 50 shown in FIGURES 7 and 8, and this being shown merely to illustrate the adaptation of the tool head for different types of tools. Broadly, in the tamping device illustrated, downwardly divergent walls 72 terminate in a relatively broad tamping head 73 which may be conventionally used in compacting or leveling ground surfaces. Again, the tamping device may be reversed or merely turned 90 since the head is square-sided to form two sets of shoulders 54.

A modified form of cutting tool is illustrated in FIG- URES to 12 in which a blade stock 80 is detachably connected to an attaching head 82 by means of wedges 83 and adjustable wedge-locking members 84. Again, the attaching head '82 is provided with shoulders 54 and clamp-engaging surfaces 55 identical to those formed on the attaching head 50 shown in FIGURES 6 and 7; and the blade stock 80 assumes the same form as the blade shank 60; however, the upper end '86 of the stock is proportioned to fit into a longitudinal, downwardly directed slot 87 opening outwardly from the head 82. Extending along one side of the slot 87 are wedge-shaped guide slots 88 each for insertion of a wedge 83, shown in FIG- URE 12. A pair of adjustable locking members 84 are shown each in the form of a lock nut 90 which is removably inserted in a recess behind and in communication with each guide slot 88 and locked against rotation by the sides of the recess, and a socket head screw 91 extending downwardly through each lock nut 90 against the top surface of the wedge. The screws 91 are accessible from the top seating surface of the head 82 for downward adjustment in order to force the wedges downwardly and inwardly against the side of the blade element. Thus, the wedges 83 and wedge-locking members 84 may first be inserted within the slots 88 followed by insertion of the upper end of the blade stock, and by downward threading of the locking members 84 against the wedges will hold the blade securely in place. Once the blade is connected to the clamp head 82, the assembled tool can then be clamped in place to the lower end of the hammer by the tool holder assembly.

It will be evident that different tools, such as, tamping devices, asphalt cutters, pavement breakers and the like may be appropriately formed with an attaching head 50, or in some instances a clamp head 82, of the type described so as to make each tool conformable for attachment in cooperation with the tool holder assembly to various different powered hammers. Of course, the clamp head and wedge locking device may be used for detachably connecting different types of blade elements so that only one clamp head need be furnished and only the blade stock replaced as it becomes worn, or where substitution is required in performing different operations. Moreover, as stated, the tool holder assembly may be defined merely by the spaced clamps and attaching head without the adapter plate where the hammer head is designed for direct connection of the clamps. It is therefore to be understood that various modifications and changes may be made in the construction and arrangement of parts comprising the forms of invention illustrated and described without departing from the spirit and scope of the present invention as defined by the appended claims.

What is claimed is:

1. In a powered hammer, an impact tool for cutting and breaking hard surfaces, said tool being of generally T-shaped configuration and comprising a head, an elongated, generally rectangular blade stock detachably connected to said head and extending forwardly therefrom, said shank having downwardly divergent sides and ends terminating in an elongated cutting face squared to the stock axis, the cutting face progressively increasing in width toward the divergent ends of said stock, said impact tool including a head provided with a blade-receiving slot opening forwardly from one end of said head with a guide slot tapering forwardly along one side of said bladereceiving slot, said blade stock having a connecting end dimensioned for insertion within said blade-receiving slot, a wedge positioned within the guide slot to wedgingly engage one side of the connecting end of said blade stock, and locking means disposed in an opening behind said guide slot being accessible from the end of said head opposite the blade-receiving slot and being movable to force said wedge forwardly against the side of the connecting end of said blade to hold said blade in clamping engagement within the blade-receiving slot.

2. An impact tool for powered hammers and the like comprising an enlarged head including a generally rectangular blade-receiving slot in one end of said head opening forwardly from the end of said head with a guide slot tapering forwardly along one side of said bladereceiving slot, a wedge positioned in the guide slot, and a blade having a connecting end dimensioned for endwise insertion to fit within the blade-receiving slot with said wedge engaging one side of the connecting end of said blade, and locking means removably disposed in an opening behind said wedge abutting the rearward end surface of said wedge, said locking means being accessible from the end of said head opposite the blade-receiving slot and being movable to force said wedge forwardly against the side of the connecting end of said blade so as to hold said blade in clamping engagement within the bladereceiving slot.

3. An impact tool according to claim 2 in which a pair of spaced guide slots are arranged in side-by-side relation to one another along one side of said blade-receiving slot, a wedge positioned in each guide slot to engage one side of the connecting end of said blade stock, and said locking means being defined by a removable lock nut and adjusting screw disposed behind each of said wedges, each screw being independently adjustable to force each of said wedges forwardly against the side of said connecting end whereby to releasably locking said blade stock in clamping engagement between said wedges and the opposite side of the guide slots.

4. An impact tool comprising an enlarged head including a generally rectangular blade-receiving slot in one end of said head and opening forwardly from the end of said head, and a pair of guide slots arranged in side-by-side relation to one another within the head and along one side of and in communication with said blade-receiving slot, a blade having a generally rectangular connecting end being dimensioned for endwise insertion within the blade-receiving slot, a wedge member positioned in each of the guide slots for engagement with laterally spaced surface portions on one side of the connecting end of said blade, and an adjustable locking member being removably disposed in an opening behind each wedge and being independently adjustable to force each respective wedge member forwardly against the side of the connecting end of said blade so as to hold said blade in clamping engagement within the blade-receiving slot.

References Cited UNITED STATES PATENTS 1,403,847 -1/ 1922 De Armond 27987 1,880,623 10/1932 Williams -4 16 2,659,583 11/1953 Dorkins 9449 X 2,7 89,826 4/ 1957 Procter 27987 3,006,424 10/196'1 Dahlin et al. '175414 X FOREIGN PATENTS 9,643 5/ l880 Germany.

'ERNEST R. PURSER, Primary Examiner.

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