Patent Publication Number: US-2023150107-A1

Title: Vibration damper for hand-operated striking tools

Description:
RELATED APPLICATION DATA 
     This application claims priority to U.S. Provisional Application Ser. No. 63/279,277, filed Nov. 15, 2021, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to handled tools, and particularly handled striking tools. 
     BACKGROUND OF THE INVENTION 
     Various tools are known which are designed to be used to strike an object, such as a workpiece or other object. Such tools include, but are not limited to, hammers, mauls, axes, mattocks and the like. 
     These tools typically have a handle which is connected to the head. When the head strikes an object, substantial energy may be transmitted back through the head to the handle, and then to the operator of the tool. This can fatigue or even injure the user. 
     Various solutions have been proposed for limiting the transfer of energy to the user when using these types of tools. However, many of these solutions are relatively ineffective. Other solutions are very complex and thus greatly increase the cost and complexity of manufacturing the tool. 
     An improved striking tool having vibration damping technology is desired. 
     SUMMARY OF THE INVENTION 
     Aspects of the invention comprise a vibration damper for a striking tool, a striking tool having a vibration damper, and methods of making/assembling a striking tool having a vibration damper. 
     In one embodiment, a striking tool with a vibration damper comprises a handle having a first end and a second end, a vibration damping core having a top end, an opposing bottom end and a passage extending into the bottom end, the vibration damping core located on the first end of the handle so that the first end of the handle is located in the passage through the vibration damping core, and a head having a top end and a bottom end and a passage therethrough from the first end to the second end, the head located on the vibration damping core such that at least a portion of the vibration damping core is located in the passage through the head and wherein at least a portion of the bottom end of the vibration damping core extends downwardly below a bottom of the head. 
     In one embodiment, the vibration damping core has a draft such that an outer dimension of the vibration damping core is greater at the top end than the bottom end, and where a dimension of the passage through the head at the top end thereof is smaller than the outer dimension of the vibration damping core at its top end, preventing the head from passing over the vibration damping core from the bottom towards the top thereof. 
     In another embodiment, the striking tool may further comprise an overstrike protector. The overstrike protector may be located over a portion of the handle below the bottom of the head, including the potion of the vibration damping core that extends below the head. 
     The vibration damping core may be connected to the handle, such as by one or more pins. Likewise, the overstrike protector may be connected to the vibration damping core, such as by one or more pins. 
     The passage through the vibration damping core and the exterior of the vibration damping core may include projections, such as longitudinal ribs, for engaging the handle in the passage of the core and the head at the exterior of the core. 
     Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a striking tool with vibration damping technology in accordance with an embodiment of the invention; 
         FIG.  2    is a front view of the striking tool illustrated in  FIG.  1   ; 
         FIG.  3    is a second side view of the striking tool illustrated in  FIG.  1   ; 
         FIG.  4    is a cross-sectional view of the striking tool illustrated in  FIG.  3   , taken along line  4 - 4  therein; 
         FIG.  5    is an enlarged perspective view of a head portion of the striking tool illustrated in  FIG.  1   ; 
         FIG.  6    is an exploded view of the head portion of the striking tool illustrated in  FIG.  5   ; 
         FIG.  7    is a top view of the head portion of the striking tool illustrated in  FIG.  5   ; 
         FIG.  8    is a cross-sectional view of the head portion of the striking tool illustrated in  FIG.  7   , taken along line  8 - 8  therein; 
         FIG.  9    is a side view of the head portion of the striking tool illustrated in  FIG.  7   ; 
         FIG.  10    is a front view of a damping core in accordance with an embodiment of the invention; 
         FIG.  11    is a side view of the damping core illustrated in  FIG.  10   ; 
         FIG.  12    is a cross-sectional view of the damping core illustrated in  FIG.  11   , taken along line  12 - 12  therein; 
         FIG.  13    is a top view of the damping core illustrated in  FIG.  10   ; 
         FIG.  14    is an enlarged view of the portion of the damping core indicated in  FIG.  13   ; 
         FIG.  15    is a front view of an overstrike sleeve in accordance with an embodiment of the invention; 
         FIG.  16    is a side view of the overstrike sleeve illustrated in  FIG.  15   ; 
         FIG.  17    is a cross-sectional view of the overstrike sleeve illustrated in  FIG.  16   , taken along line  17 - 17  therein; 
         FIG.  18    is a top view of the overstrike sleeve illustrated in  FIG.  15   ; and 
         FIGS.  19    illustrates a head portion of a striking tool with vibration damping technology in accordance with another embodiment of the invention; 
         FIG.  20    is an exploded view of the head portion of the striking tool illustrated in  FIG.  19   ; 
         FIG.  21    is a top view of the head portion of the striking tool illustrated in  FIG.  19   ; 
         FIG.  22    is a cross-sectional view of the head portion of the striking tool illustrated in  FIG.  21   , taken along line  22 - 22  therein; 
         FIG.  23    is a side view of the head portion of the striking tool illustrated in  FIG.  21   ; 
         FIG.  24    is a top view of a damping core in accordance with another embodiment of the invention; 
         FIG.  25    is a front view of the damping core illustrated in  FIG.  24   ; 
         FIG.  26    a side view of the damping core illustrated in  FIG.  25   ; and 
         FIG.  27    is a cross-sectional view of the damping core illustrated in  FIG.  26   , taken along line  27 - 27  therein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following description, numerous specific details are set forth in order to provide a more thorough description of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known features have not been described in detail so as not to obscure the invention. 
     One embodiment of the invention is vibration damping technology. Other embodiments of the invention comprise a tool, such as a striking tool, with vibration damping technology. In one embodiment, the vibration damping technology comprise a vibration damper. The vibration damper may comprise a vibration damping core that is located between a handle and head of a striking tool. The vibration damper may further comprise an overstrike assembly, such as comprising an overstrike sleeve and a spacer. Additional aspects of the invention comprise methods of assembling/manufacturing a tool with vibration damping technology. 
       FIGS.  1 - 4    illustrate a tool  20  in accordance with the invention, wherein the tool includes vibration damping technology in accordance with the invention. The tool  20  may comprise a striking tool, and preferably a striking tool which is intended or designed to be manually operated. In one embodiment, the tool  20  comprises a head  22  for selective engagement with an object (e.g. such as to be used to strike an object) and a handle  24  which is connected to the head  22 , the handle  24  designed or intended to be used by a user to manipulate the head  22 . 
     The head  22  may have various configurations, including shapes and sizes, such as depending upon the desired or intended use. For example, the head  22  might comprise a hammer or sledge-type head which defines one or more generally planar striking faces, such as at one or both ends of the head. The head  22  might comprise an axe or hatchet head, such as having at least one tapered cutting face. The head  22  might comprise a splitter head, such as having one or more tapered or wedge shaped faces or ends. The head  22  might comprise a mattock, such as having one or more elongate pick elements. Of course the head  22  might have other configurations. 
     In various embodiments, the head  22  may be constructed from metal, such as by being cast, etc. The size and weight of the head  22  may vary, such as depending upon the desired use. 
     In one embodiment, the head  22  has a top  26  and a bottom  28 . A passage  30  (best seen in  FIG.  6   ) extends into the bottom  28  and may extend through the head  22  to the top  26 . 
     The handle  24  preferably has a top end  32  (see  FIG.  4   ) and a generally opposing bottom end  34 . The shape of the handle  24 , including its length, may vary depending upon the desired usage of the tool  20 . In one embodiment, the handle  24  may be generally oval-shaped in cross-section in one or more portions, such as a gripping portion towards the bottom end  34  thereof, where that portion has a height in a direction H (see  FIG.  2   ) which is greater than a width in a direction W (see  FIG.  3   ), where the width direction is generally perpendicular to the height direction H and where the directions H and W are perpendicular to a longitudinal axis through the handle from end to end. The handle  24  may be constructed from various materials, such as wood, fiberglass or the like. In one embodiment, other portions of the handle  24  may have other shapes. For example, as illustrated, a top portion of the tool towards the top end  32  thereof may be generally circular in shape. 
     In one embodiment, the tool  20  includes vibration damping technology, such as a vibration damper, in accordance with the present invention. As best illustrated in  FIGS.  5 - 9   , the vibration damper may comprise a vibration damping core  100 . The vibration damping technology may further comprise an overstrike assembly, such as comprising an overstrike sleeve  102  and a spacer  104 . 
     One embodiment of a vibration damping core  100  is illustrated in  FIGS.  10 - 14   . As illustrated, the core  100  has a top end and a bottom end. A passage  106  extends into the core  100  from at least the bottom end, and preferably therethrough from end to end as illustrated. The passage  106  is designed to accept therein the top end  32  of the handle  24 . 
     In one embodiment, as best illustrated in  FIGS.  12 - 14   , one or more protrusions  108  may be defined in the passage  106 . The protrusions  108  might be defined, for example, by elongate slots or channels formed in the core  100  in the passage  106 . The protrusions  108  define areas of contact with the exterior of the handle  24 , thus limiting the surface area contact therebetween (as compared, for example, to if the interior of the core  100  at the passage  106  were smooth). In one embodiment, the protrusions  108  might have the form of elongate ribs or the like which extend generally parallel to a line extending through the core  100  from end to end. In other embodiments, however, the protrusions  108  might have other shapes, such as comprising nubs, etc. In a preferred embodiment, the size or diameter of the passage  106  is generally constant from the top to the bottom of the core  100  (even though, as described below, in a preferred embodiment, the exterior of the core is not of a constant size). 
     In one embodiment, as best illustrated in  FIGS.  11  and  12   , at least one aperture  110  may be defined through the core  100 , preferably in the “H” direction (corresponding to the handle  24 ), such as along a centerline of the core  100 . The aperture  110  is preferably aligned with a corresponding aperture in the handle  24 . A pin  111  (see  FIG.  6   ) is preferably passed through the aperture  110  in the core  100  and through the handle  24 , thus locking the core  100  to the handle  24 . While a single aperture and pin may be utilized, in other embodiments, additional pins might be utilized. In a preferred embodiment, the length of the pin is such that it is inset into the core  100  and otherwise does not contact the head  22 , thus reducing the transmission of force from the head to the core. 
     At least a portion of the core  100  is configured to be located in the passage  30  in the head  22  of the tool  20 . The core  100  has an exterior dimension which is sized to fit into the passage  30 . At the same time, as illustrated in  FIGS.  10  and  11   , the exterior dimension of the core  100  is greater at the top end than the bottom end (e.g. it tapers or has a draft, such as of 3 to 5 degrees), thus ensuring that the head  22  is captured by the core  100  and can&#39;t be removed from the core  100  at its top end (e.g. when the core  100  is placed on the handle  24 , the head  22  will slide upwardly towards the top end of the core  100 , but won&#39;t pass over the top of the core  100  so as to be removed from the handle  24 ). Preferably, the shape of the exterior of the core  100  is generally the same (as illustrated, generally oval and having a major axis which is longer than its minor axis) from top to bottom, but where, due to the draft, the overall dimensions reduce proportionally from top to bottom (e.g. at the bottom, the major and minor axes may be 0.95 of the major and minor axes at the top). 
     As best illustrated in  FIGS.  10 ,  13  and  14   , the exterior of at least a portion of the core  100 , such as at the top end, preferably defines one or more protrusions  112 . These protrusions  112  contact the head  22  in a manner which limits the surface area contact therebetween (as compared to if the exterior of the core  100  were smooth). 
     In one embodiment, the core  100  is constructed from at least one (and may be constructed from more than one, such as two or three) materials which are resilient. For example, the core  100  might be constructed from rubber or silicone having a Shore A hardness. The core  100  might be constructed in a molding process. Features of the core  100  might be created during the molding process or via alternation thereafter, such as via machining. 
     In one embodiment, the core  100  is sized, relative to the head  22 , so that a bottom end of the core  100  is located exterior to (e.g. protrudes below) the bottom  28  of the head  22 , as best illustrated in  FIG.  8   . This extended portion of the core  100  serves to protect the handle  24  at its interface with the bottom of the head  22 , such as to aid in dissipating energy which may cause the handle  24  to break in that location. 
     In one embodiment, the vibration damping technology may further comprise an overstrike assembly, such as the sleeve  102  and spacer  104 . One embodiment of the sleeve  102  is illustrated in  FIGS.  15 - 18   . As illustrated, the sleeve  102  has a top end and a bottom end. The sleeve  102  has a passage  114  therethrough from end to end, as best illustrated in  FIG.  17   . In one preferred embodiment, the passage  114  is sized so that at the top end, the sleeve  102  can accept therein the portion of the handle  24  with the bottom end of the core  100  thereon (located exterior to the bottom  28  of the head  22 ), and is sized so that at the bottom end, the sleeve  102  can accept therein the handle  24 . When the handle  24  has a non-circular cross-section (such as generally oval), the core  100  has a similar cross-sectional shape, as does the opening  30  in the head  24 . 
     The sleeve  102  is preferably constructed from a durable material and is designed to protect the handle  24  from damage in the region below the head  22 . The sleeve  102  might be constructed, for example of a durable rubber or plastic, such as having a Shore D hardness. 
     In one embodiment, the sleeve  102  is designed to be connected to the tool  20  by connection to the core  100 . In one embodiment, the sleeve  102  includes one or more apertures  116  therethrough, such as at generally opposing sides of the sleeve  102 . The apertures  116  may extend parallel to the width line W of the handle  24  (e.g. generally perpendicular to the aperture  110  through the core  100 ). The apertures  116  may align with slots  118  formed in the exterior of the core  100 , as best illustrated in  FIGS.  10 - 12   . When the sleeve  102  is located on the handle  24  and over the core  100 , pins  119  (see  FIG.  6   ) may be passed through the apertures  116  in the sleeve  102  and the aligned slots  118  in the core  100 , thus effectively locking the sleeve  102  to the core  100 . 
     As illustrated in  FIG.  17   , one or more tabs, a ring-shaped member  120  may define the opening at the bottom of the sleeve  102 , such as by extending upwardly into the passage  114 . As illustrated, the member  120  may have a draft or taper, such as 3-5 degrees inward. The member  120  preferably serves as a centering and/or shock-absorbing element that engages the handle  24 . 
     In one embodiment, as best illustrated in  FIGS.  6  and  8   , the spacer  104  is located between the head  22  and the sleeve  102 . As illustrated in  FIG.  6   , the spacer  104  may be generally ring-shaped, thus defining a central opening or passage  124  for accepting the core  100  therein. The spacer  104  may be generally planar on the top, such as for abutting against the bottom  28  of the head  22 . The spacer  104  may comprise one or more tabs  126  or other downwardly extending element for location in corresponding openings, channels or the like in the top of the sleeve  102 , thus serving to connect and/or locate the spacer  104  relative to the sleeve  102 . In some embodiments, more than one spacer  104 , such as spacers of different thicknesses, might be located between the head  24  and the top end of the sleeve  102 . 
     While in a preferred embodiment, roll pins or the like may be used to connect the core  100  to the handle  24  and the sleeve  102  to the core  100 , other types of fasteners might be used, such as a bolt or the like. Further other numbers of pins might be utilized in the connections. 
     Another embodiment of a striking tool with vibration damping technology is illustrated in  FIGS.  19 - 27   . In the description of this tool, like numbers are used for like elements to those of the embodiment described above. 
     As illustrated in  FIG.  19   , the striking tool may again comprise a head  22 . A damping core  100 A is preferably located between a handle of the tool (shown in dotted line) and the head  22 . As illustrated in  FIGS.  20 - 23   , the tool may also include an overstrike protector  102 A, where the damping core  100 A may again be mounted to the handle via a pin or other connector  111 A and where the overstrike protector  102 A may again be mounted with one or more pins or connectors  119 A. The tool may or may not again include one or more spacers  104 A. 
       FIGS.  24 - 27    illustrate additional details of this embodiment damping core  100 A. In general, the core  100 A may have a similar configuration to the damping core  100  described above, including comprising the same materials. 
     Once again, the damping core  100 A may comprise a generally tubular body that defines a central passage  106 A for accepting the handle of the tool therein. In this embodiment, the interior of the passage  106 A may be generally smooth, but it could have surface features similar to those described above relative to the damping core  100 A of the first embodiment. 
     Again, as illustrated, the exterior of at least a portion of the core  100  preferably defines one or more protrusions  112 A. These protrusions  112 A contact the head  22  in a manner which limits the surface area contact therebetween (as compared to if the exterior of the core  100  were smooth). The protrusions  112 A may thus define points or surface of contact  113 A with the head  22  when the head  22  is mounted thereon (which points or surfaces  113 A are smaller in area than if the exterior were smooth). As illustrated, the protrusions  112 A might comprise ribs or similar elements, such as formed in a molding process of the damping core  100 A. In one embodiment, as illustrated, the protrusions  112 A may be elongate, extending generally parallel to a central axis through the passage  106 A. The protrusions  112 A might themselves be hollow or define a passage therein, such as to permit additional compression thereof (beyond the inherent compressibility of the material thereof). 
     Most preferably, this embodiment damping core  100 A defines one or more compartments  115 A. The compartments  115 A may be located at an exterior of the damping core  100 A. As illustrated, two compartments  115 A are provided at opposing sides thereof, such as near the top thereof. However, other number of compartments  115 A might be provided, and in other locations. In general, the purpose of the compartments  115 A is to accept a mass body  117 A, such as in a passage or opening  121 A therein. In one embodiment, the compartments  115 A may extend downwardly from the top of the damping core  100 A, as may the associated openings  121 A therein. 
     A body  117 A may be placed in the opening  121 A. The body  117 A may comprise, for example, a cylindrical rod, balls or other elements. The body  117 A may have a mass, where the mass may vary, such as to achieve a desired damping effect. 
     In particular, in a preferred embodiment, as best illustrated in  FIG.  21   , the compartment portions  115 A of the damping core  100 A preferably do not contact the head  22 . Instead, the protrusions  112 A contact the head  22  and space the head  22  from the compartment portions  115 A. During use of the tool, this prevents force/energy from being directly transferred from the head  22  to the compartments  115 A and the associated bodies  117 A. This allows energy that is transmitted to the damping core  100 A via the protrusions  112 A to be absorbed by the compartments  115 A, and particularly, by the bodies  117 A therein. In one embodiment, the bodies  117 A may vibrate in response to such energy, where the mass and movement of the bodies  117 A serves to dissipate energy which is transmitted to the damping core  100 A via the head  22 . 
     As indicated, a manufacturer or use might adjust the configuration of the one or more bodies  117 A, such as the shape or mass thereof, such as depending upon the tool—such as the size and shape of the head  22 , etc., in order to “tune” the damping core  22  to maximize vibration damping. 
     In accordance with the invention, a simple vibration damping configuration is provided for a tool, such as a striking tool. The configuration has minimal components and is simple to assemble. 
     In accordance with the invention, a vibration damping core isolates the head from the handle of the tool, reducing the transmission of force from the head to the handle. 
     Preferably, the pin or other fastener which mounts the core on the handle does not make contact with the head, thus eliminating that connection as an avenue for force transmission to the handle. 
     The head of the tool is maintained in position by the taper of the core, such as where the core has a taper or draft of 3 to 5 degrees, thus effectively wedging the head onto the core between the ends of the core (and preventing the head from passing over the top end of the core). 
     In one embodiment, the core does not comprise a solid block of material with smooth/continuous surfaces, but instead defines a plurality of projections, slots, etc. These features both minimize the contact surface area of the core with the head and handle, but also aid in retarding the transmission of energy through the core itself. 
     In one embodiment, the vibration damping technology further includes an overstrike assembly (in some embodiments, the core might be utilized without such an assembly). This assembly may comprise the sleeve and spacer. The sleeve provides additional protection and force dissipation features to that provided by the core. One or more spacers may be provided between the sleeve and the head, such as to take up the space therebetween, such as due to play in the head resulting from factors such as temperature variance, humidity variance, manufacturing tolerances, etc. 
     It will be understood that the above described arrangements of apparatus and the method there from are merely illustrative of applications of the principles of this invention and many other embodiments and modifications may be made without departing from the spirit and scope of the invention as defined in the claims.