Impact cushioning tool handle

Information

  • Patent Grant
  • 6370986
  • Patent Number
    6,370,986
  • Date Filed
    Thursday, March 23, 2000
    25 years ago
  • Date Issued
    Tuesday, April 16, 2002
    23 years ago
Abstract
A manually operable impact tool that includes an elongated rigid interior handle structure extending longitudinally with respect to the tool, an impact head disposed at one longitudinal end portion of the handle structure and an exterior impact cushioning gripping structure affixed to a second longitudinal end portion of the elongated interior handle structure in surrounding relation thereto. The exterior impact cushioning gripping structure is formed of inner and outer layers of molded material. The inner layer is a foamed material that is selected from a group consisting of polyvinyl chloride, polypropylene, and thermoplastic elastomer and is molded in surrounding relation to the elongated interior handle structure. The outer layer is constructed of a solid nonfoamed material that is chemically compatible with the inner layer and is molded in surrounding abutting relation to the inner layer. The chemically compatible material used to form the outer layer is chosen from the same group of materials that is used to form the inner layer, viz., polyvinyl chloride, polypropylene, and thermoplastic elastomer. The outer layer is constructed and arranged to provide an inner surface on the outer layer that chemically compatibly bonds to an outside surface of the inner layer and to provide an exterior surface on the outer layer configured to accommodate a manually gripping hand. The arrangement of the gripping structure is such that when it is gripped by a user and the tool is manually operated to impact the tool head on a work piece, the inner layer of foamed material cushions the impact to the gripping hand of the user.
Description




FIELD OF THE INVENTION




The present invention relates to handles for hand tools and more particularly relates to an impact cushioning, molded plastic handle grip that reduces the impact transferred to the hand of a user when the hand tool impacts a work piece.




BACKGROUND OF THE INVENTION




Many tool handles, such as hammer handles, are constructed of a metal, a synthetic or a composite material. Steel and fiberglass, for example, are often used for tool handle construction. These materials offer reduced materials cost, uniformity of structure and the ability to securely and permanently affix the hammer head or other tool head to the handle. Metal, synthetic and composite handles are relatively durable as compared to wooden handles. Metal, synthetic and composite handles have some disadvantages, however. These handles tend to transfer an undesirable degree of kinetic energy to a user's hand when a work piece is impacted. Many hammers with metal or synthetic handles are provided with rubber or rubber-like sleeves at the free end opposite the hammer head to provide a degree of impact protection for the hand of the user. Most of these sleeves are constructed of a relatively hard, non-cushioned single material, however, and provide insufficient protection. A need exists for an impact tool grip that can be used on metal, composite and synthetic handles that provides a high degree of cushioning to protect the hand from the kinetic energy transferred thereto during impact and that can be applied to these handles easily during the manufacturing process.




SUMMARY OF THE INVENTION




It is an object of the present invention to meet the need expressed above by providing a manually operable impact tool that includes an elongated rigid interior handle structure extending longitudinally with respect to the tool, an impact head disposed at one longitudinal end portion of the handle structure and an exterior impact cushioning gripping structure affixed to a second longitudinal end portion of the elongated interior handle structure in surrounding relation thereto. The exterior impact cushioning gripping structure is formed of inner and outer layers of molded material. The inner layer is a foamed material that is selected from a group consisting of polyvinyl chloride, polypropylene, and thermoplastic elastomer and is molded in surrounding relation to the elongated interior handle structure. The outer layer is constructed of a solid nonfoamed material that is chemically compatible with the inner layer and is molded in surrounding abutting relation to the inner layer. The chemically compatible material used to form the outer layer is chosen from the same group of materials that is used to form the inner layer, viz., polyvinyl chloride, polypropylene, and thermoplastic elastomer. The outer layer is constructed and arranged to provide an inner surface on the outer layer that chemically compatibly bonds to an outside surface of the inner layer and to provide an exterior surface on the outer layer configured to accommodate a manually gripping hand. The arrangement of the gripping structure is such that when it is gripped by a user and the tool is manually operated to impact the tool head on a work piece, the inner layer of foamed material cushions the impact to the gripping hand of the user.




Preferably, the inner layer is molded to provide a plurality of longitudinally extending, circumferentially spaced grooves on the outside surface thereof and the outer layer is molded to provide a plurality of integral inwardly extending ribs on the inner surface thereof that extend within the grooves and that are compatibly chemically bonded therein. The ribs are constructed and arranged so that when a hand grips the exterior impact cushioning gripping structure, the ribs lend rigidity to the gripping load and provide a measure of control of the compression of the foamed inner layer against the handle structure.




The exterior impact cushioning gripping structure can be used on the handles of a wide range of manually operable impact tools including carpenter's hammers, axes, sledge hammers, pick axes, hatchets and ball peen hammers. The exterior impact cushioning gripping structure can be used, for example, on a hammer that includes an interior handle structure configured to dampen the vibrations that occur in the handle structure when the impact head impacts a work piece. More specifically, the second end portion of the handle structure may include a pair of vibration receiving elements extending longitudinally away from the one longitudinal first end portion and terminating in spaced relation to one another. The vibration receiving elements define a space therebetween and the inner layer of foamed material is formed around the second end portion so that a portion of the inner layer is received within the space and surrounds the vibration receiving elements. Vibrations resulting when the impacting head impacts a work piece are received by the vibration receiving elements and are damped by cooperation between the elements and the inner layer of material to thereby reduce the vibrations that are transmitted to the hand of the user when the impact tool impacts a work piece.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a cross-sectional view of an impact tool;





FIG. 2

is a cross-sectional view of the impact tool taken through the line


2





2


in

FIG. 1

;





FIG. 3

is a cross-sectional view of a second embodiment of the impact tool;





FIG. 4

is a cross-sectional view of the impact tool of

FIG. 3

taken through the line


4





4


of

FIG. 3

;





FIG. 5

is a cross-sectional view of a third embodiment of the impact tool; and





FIG. 6

is a cross-sectional view of the impact tool of

FIG. 5

taken through the line


6





6


of FIG.


5


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE OF THE INVENTION





FIG. 1

is a cross-sectional view of a manually operable impact tool, generally designated


10


, constructed according to the principles of the present invention. The impact tool shown is a carpenter's or “claw” hammer, but this is exemplary only and not intended to be limiting. It is within the scope of the invention to apply the principles of the invention to any type of hand tool used to manually impact a work piece.




The manually operable impact tool


10


includes an impact head


12


(which is not cross sectioned in

FIG. 1

to more clearly illustrate the invention), an elongated rigid interior handle structure


14


extending longitudinally with respect to the manually operable impact tool


10


and an exterior impact-cushioning gripping structure


16


affixed to a second end portion


17


of the interior handle structure


14


in surrounding relation thereto.




The impact head


12


for the hammer shown is of conventional construction and is preferably made of steel or other appropriate metal. The impact head


12


includes a striking surface


18


and a pair of nail removing claws


20


.




The interior handle structure


14


is a rigid structural member that supports the impact head


12


. The preferred interior handle structure


14


shown in

FIG. 1

is an I-beam structure having a vibration reducing “tuning fork” portion toward the handle end thereof as disclosed fully in U.S. Provisional Patent Application, Ser. No. 60/096,688, filed Aug. 14 1998, which is hereby incorporated by reference in its entirety. While it has been found that the anti-vibration characteristics of the impact-cushioning gripping structure are particularly effective when used with the aforementioned preferred interior handle structure


14


, the cushioning gripping structure of the present invention is beneficial to other types of handle structures as well. Thus, the present invention contemplates that virtually any known interior handle structure may be used.




The interior handle structure


14


shown in

FIGS. 1-2

is preferably made of steel, but any interior handle constructed of a metal, composite or synthetic material can be used in the hammer construction. The impact head


12


can be affixed to the interior handle structure


14


in any conventional manner. The details of the structure of the impact head


12


and the structure of the interior handle structure


14


and the manner in which the impact head


12


is rigidly mounted on the first end portion of the interior handle structure


14


are fully disclosed in U.S. Provisional Patent Application Ser. No. 60/096,688 filed Aug. 14, 1998 as aforesaid.




The focus of the present invention is the structure of the exterior gripping structure


16


and the manner in which it is formed on the interior handle structure


14


.

FIGS. 1-2

show in sectional view the exterior gripping structure


16


affixed to an outer end portion


17


of the interior handle structure


14


. The exterior gripping structure


16


is comprised of an inner layer


22


of foamed material molded in surrounding relation to the outer end portion


17


of the interior handle structure


14


and an outer layer


24


of solid, non-foamed material molded in surrounding abutting relation to the inner layer


22


. The foamed material of the inner layer is selected from a group consisting essentially of polyvinyl chloride (PVC), thermoplastic elastomer (TPE), and polypropylene. The outer layer


24


is relatively harder in comparison with the inner layer


22


yet may still be flexible or resilient. The outer layer


24


is also selected from the group consisting essentially of PVC, TPE, and polypropylene. These materials for the inner and outer layers


22


,


24


are chosen to be chemically compatible to facilitate bonding of the two layers during the molding process and prevent delamination between layers of the final product. For example, in the most preferred embodiment, the inner layer comprises a foamed PVC material, while the outer layer comprises a non-foamed solid PVC material. Because the inner layer is foamed and the outer layer is not foamed, the inner layer is softer relative to the outer layer. In another preferred embodiment, the inner layer comprises a foamed TPE material, and the outer layer comprises a non-foamed, solid polypropylene material. In yet another preferred embodiment, the inner layer comprises a foamed TPE material, and the outer layer


24


comprises a non-foamed, solid TPE material.




Preferably, the exterior impact-cushioning gripping structure


16


is formed on the outer end portion


17


of the interior handle structure


14


through a two part molding process (sometimes also referred to as “two shot” or “double shot” molding). During tool construction, the impact head


12


and a rigid material


26


are secured to the interior handle structure


14


as described in the above incorporated provisional patent application reference. The rigid material


26


is preferably a thermoplastic polyurethane. The exterior impact-cushioning gripping structure


16


is then molded onto the impact tool


10


to complete the construction of the tool.




In the first part of the two part molding process, the outer end portion


17


of the interior handle structure


14


is placed in a first mold cavity and a foamed or gas-filled polyvinyl chloride is injected into the cavity to completely fill the mold. Foamed polyvinyl chloride is widely commercially available and is sometimes referred to as a “blown”, “self-blown” or “self-skinning” polyvinyl chloride. The foamed polyvinyl chloride forms a honeycomb-like cushioning structure that constitutes the inner layer


22


around the interior handle structure


14


.




Preferably the polyvinyl chloride or other material of the inner layer


22


is relatively soft compared to the harder outer layer of material and has a Shore A Durometer of from about 45 to about 65, the preferred Durometer being


55


. Because the first mold cavity is completely filled with the foamed material, the size of the cavity determines the size and shape of the inner layer


22


. Preferably one or more holes


27


are provided in the outer end portion


17


of the interior handle structure


14


through which the foamed material can flow as the mold is being filled during the molding process to help secure the inner layer


22


to the interior handle structure


14


.




The tool


10


is removed from the first mold and placed in a second mold in which the second part of the molding process occurs. The tool


10


can be transferred from the first mold to the second mold manually by a machine operator or automatically by an appropriate device on the molding machine. A relatively harder polyvinyl chloride (relative to the inner layer


22


) having a Shore A Durometer of from about 66 to about 76, with the preferred Durometer being


71


, is injected into the second mold and completely fills the cavity of the second mold. The outer layer is molded to form an inner surface


28


on the outer layer


24


that chemically compatibly bonds to an outside surface


30


of the inner layer


22


. The outer layer


24


is also molded to provide an exterior surface


32


on the outer layer that is configured to accommodate a manually gripping hand of a tool user.




One skilled in the art will appreciate that the exterior impact-cushioning gripping structure


16


can be formed on the interior handle structure


14


using well known, conventional molding processes on a conventional two part or “two shot” molding machine. Two part molding is advantageous in forming the two layers


22


,


24


of the exterior impact-cushioning gripping structure


16


because this process allows the dimensions of the inner layer and the thickness of the walls of the outer layer


24


to be precisely controlled during manufacturing. It is desirable to have different wall thicknesses at different parts of the gripping structure


16


because the butt end


34


of the gripping structure


16


is frequently subjected to repeated impacts and so it is preferred to make the bottom wall


36


of the gripping structure


16


thicker than the side walls


38


. It is preferable to make the side walls


38


relatively thin to improve the feel of the gripping structure and to provide improved impact cushioning.




The relatively soft foamed inner layer


22


provides most of the impact cushioning when a work piece is struck. It is preferable to provide a plurality of rib or fin-like structures


40


around the gripping structure


16


as shown in

FIG. 2

to increase the firmness of and to rigidify of the gripping structure


16


. As shown in

FIG. 2

, when the ribs


40


are provided, the inner layer


22


is preferably molded to provide a plurality of longitudinally and radially inwardly extending and circumferentially spaced grooves


44


on the outside surface


30


thereof during the first part of the molding process. When the tool


10


is transferred to the second mold, the material that will form the outer layer


24


flows into the grooves


44


as the second mold cavity is filled to provide the plurality of integral, inwardly extending ribs


40


on the inner surface


28


of the outer layer


24


that extend longitudinally the length of the gripped area of the gripping structure when the material of the outer layer


24


solidifies. The ribs


40


therefore extend within the grooves


44


and are compatibly chemically bonded therein during the molding process so that when a hand grips the exterior impact cushioning gripping structure, the ribs


40


lend rigidity to the gripping load and provide a measure of control over the compression of the foamed inner layer


22


against the interior handle structure


14


.




When a user strikes a work piece with the tool


10


, the user grips the gripping structure


16


and manually swings the tool


10


to impact the striking surface


18


on the work piece. When the impact head


12


hits the work piece, a portion of the kinetic energy of the impact is transferred through the interior handle structure


14


back to the user's hand. Metal, synthetic and composite impact tool handles tend to transfer a high degree of impact force to a user's hand when the tool impacts an object such as a nail or a chisel. Repeated exposure to the kinetic energy associated with tool impact frequently causes discomfort and pain in the user's hand. The foamed inner layer


22


of the exterior impact-cushioning gripping structure


16


cushions the impact and increases user comfort. The foamed layer


22


also dampens the vibrations that occur in the interior handle structure


14


following the impact of the impact head


12


on the work piece.




In the embodiment of the hammer shown in

FIGS. 1-2

, the exterior impact-cushioning gripping structure


16


is mounted on an interior handle structure


14


that includes a pair of vibration receiving elements


50


that extend longitudinally away from the end portion of the interior handle structure


14


to which the impact head


12


is secured and terminate in spaced relation to one another. The vibration receiving elements


50


define a space


52


therebetween and the inner layer


22


of foamed material is formed around the outer end portion


17


of the interior handle structure


14


so that a portion of the inner layer


22


is received within the space


52


and surrounds the vibration receiving elements


50


. The vibrations resulting when the impacting head


12


impacts a work piece are received by the vibration receiving elements and are damped by cooperation between the elements


50


and the inner layer


22


of material to thereby reduce the vibrations that are transmitted to the hand of the user when said impact tool


10


impacts a work piece.




The details of the structure and operation of the interior handle structure


14


are described in the incorporated patent application reference and will not be repeated herein. Applying an exterior impact-cushioning gripping structure


16


constructed according to the principles of the present invention improves the vibration dampening performance of the plurality of embodiments of the interior handle structure disclosed in the incorporated application and it is within the scope of the present invention provide any of the handle structures in the referenced application with a gripping structure constructed in accordance with the teachings of the present application.




The interior handle structure


14


of the manually operable impact tool


10


is essentially straight from one longitudinal end to the opposite end. It is also within the scope of the present invention to provide an impact-cushioning gripping structure on an interior handle structure that is curved or shaped to conform to the contours of a gripping hand. Two representative interior handle structures that each include a pair of vibration receiving elements and that are shaped to conform to a gripping hand are shown in

FIGS. 3 and 5

.





FIG. 3

shows a cross-sectional view of a second embodiment of the manually operable impact tool, generally designated


110


. Structures on the manually operable impact tool


110


that are identical to structures on the manually operable impact tool


10


are designated by identical reference numerals and are not further described. The rigid material


126


and the impact head


12


are rigidly secured to an interior handle structure


114


in the same manner in which the rigid material


26


and impact head


12


are secured to the interior handle structure


14


of the manually operable impact tool


10


.




An arcuate central portion


115


of the outer end portion


117


curves rearwardly (relative to the striking surface


18


which is considered to be facing in the forward direction of the manually operable impact tool) to fit comfortably within the palm of a gripping hand of a tool user using the tool to impact a work piece. The outer end portion


117


includes a tuning fork structure that functions and that is constructed according to the principles taught in the 60/096,688 provisional application reference. More specifically, pair of vibration receiving elements


150


extend longitudinally away from the longitudinal end portion of the interior handle structure


114


to which the impact head


12


is secured defining a space


152


therebetween. The vibration receiving elements


150


are essentially straight and parallel and function to damped vibration in the same manner as the vibration receiving elements


50


of the manually operable impact tool


10


. A series of cylindrical apertures


127


are provided in the lower end portion


117


of the interior handle structure


114


.




An exterior impact-cushioning gripping structure


116


is provided in surrounding relation to the end portion


117


of the interior handle structure


114


and is of similar construction to the exterior impact-cushioning gripping structure


16


of the manually operable impact tool


10


. The exterior impact-cushioning gripping structure


116


can be constructed of any of the materials used to construct the exterior impact-cushioning gripping structure


16


and is formed by an identical two part molding process. The relatively soft foamed inner layer


122


of the exterior impact-cushioning gripping structure


116


is formed around the end portion


117


of the interior handle structure


114


and extends through the space


152


to surround both elements


150


and through the apertures


127


.




A plurality of ribs


140


integrally formed with the outer layer


124


of relatively hard material are formed within transversely extending grooves


144


formed in the inner layer


122


during the first molding step. The structure of a rib


140


is shown in the cross-sectional view of the manually operable impact tool


110


shown in FIG.


4


. The ribs


140


of the manually operable impact tool


110


serve a function similar to the ribs


40


of the manually operable impact tool


10


.




The bottom wall


136


of the outer layer


124


at the butt end


134


of the manually operable impact tool


110


is preferably molded to be thicker than the side walls


138


thereof for the same reason the wall


36


is made thicker than walls


38


of the manually operable impact tool


10


, i.e., the butt end


134


may be subjected to repeated impacts. A series of exterior grooves


147


(best seen in the cross-sectional view of

FIG. 4

) are provided on the exterior surface


132


of the exterior impact-cushioning gripping structure


116


to facilitate the gripping engagement of the same with the hand of a tool user.




The preferred embodiment and best mode of the manually operable impact tool, generally designated


210


, is shown in

FIGS. 5-6

that includes a single piece forged vibration damping tool member


211


and an exterior impact-cushioning gripping structure


216


molded about a lower portion thereof. The tool member


211


is an integral structure made of a forged (or alternatively of a die cast) piece of metal, the preferred metal being a high strength steel. The tool member


211


includes an impact head portion


212


, a upper shaft portion


226


and a lower vibration damping shaft portion


217


. The upper and lower shaft portions


226


,


217


comprise an interior handle structure


214


of the manually operable impact tool


210


.




The lower shaft portion


217


includes a tuning fork structure constructed according to the principles taught in the 60/096,688 provisional application reference. A pair of arcuate vibration receiving elements


250


extend longitudinally away from the end portion of the interior handle structure


214


at which the impact head


212


is integrally formed and define a space


252


therebetween that receives the inner layer


222


of the relatively soft foamed material during the two part molding process that forms the exterior impact-cushioning gripping structure


216


. An elongated aperture


227


is provided in a central portion of the lower shaft portion


217


to facilitate attachment of the molded exterior impact-cushioning gripping structure


216


.




It can be appreciated that the structure of the exterior impact-cushioning gripping structure


216


are similar to that of the exterior impact-cushioning gripping structure


116


shown in

FIGS. 3-4

and includes similarly constructed ribs


240


, a thick bottom wall


236


of outer layer


224


material at the butt end


234


that is thicker than the side walls


238


of the outer layer


224


and exterior, grip enhancing grooves


247


.




It can be appreciated that the inner layer


222


and outer layer


224


of the exterior impact-cushioning gripping structure


216


is of the same general construction as the exterior impact-cushioning gripping structure


16


of the manually operable impact tool


10


and is formed by an identical two part molding process. The same materials can be used to construct the exterior impact-cushioning gripping structure


216


as are used to construct the exterior impact-cushioning gripping structure


16


, the preferred material for the exterior impact-cushioning gripping structure


216


being polyvinyl chloride having a Shore A Durometer of


55


for the inner layer


222


and a Shore A Durometer of


71


for the outer layer


224


. The same ranges of hardness for the layers


222


,


224


recited above for the exterior impact-cushioning gripping structure


216


are applicable for the exterior impact-cushioning gripping structure


16


.




It is understood that it is also within the scope of the present invention to provide two layer exterior impact-cushioning gripping structures on a wide variety of impact tools including all types of hammers, axes, picks, and hatchets. Furthermore it is understood that many molding methods can be used to provide an impact cushioning grip structure without departing from the broad teachings of the invention. These molding methods include transfer molding and monosandwich molding. These and other methods are effective in molding an impact cushioning and vibration dampening grip structure on a wide range of handles on a wide range of impact tools, but are not the preferred methods for molding the exterior impact-cushioning gripping structure


16


on the hammer illustrated and described herein because two part molding allows the tool maker to have greater control over inner layer


22


dimensions and thicknesses and over outer layer


24


dimensions and thicknesses.




The principles, preferred embodiment and modes of manufacturing the present invention have been described in the foregoing specification. However, the invention should not be construed as limited to the particular embodiments or methods which have been described above. Instead, the embodiments and methods described here should be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the present invention as defined by the following claims:



Claims
  • 1. A manually operable impact tool comprising:an elongated rigid interior handle structure extending longitudinally with respect to said impact tool; an impact head disposed at one longitudinal end portion of said handle structure, an exterior impact cushioning gripping structure affixed to a second longitudinal end portion of said elongated interior handle structure in surrounding relation thereto, said exterior impact cushioning gripping structure comprising an inner layer of foamed material selected from a group consisting of polyvinyl chloride, polypropylene, and thermoplastic elastomer and molded in surrounding relation to said elongated interior handle structure, wherein said inner layer is molded to provide a plurality of longitudinal extending circumferentially spaced grooves on the outside surface thereof and wherein the outer layer is molded to provide a plurality of integral radially inwardly extending ribs on the inner surface thereof extending within said grooves and compatibly chemically bonded therein as aforesaid so that when a hand grips the exterior impact cushioning gripping structure, the ribs lend rigidity for the gripping load and provide a measure of control of the compression of the foamed inner layer against the handle structure, and an outer layer of solid nonfoamed material that is chemically compatible with said inner layer, said outer layer selected from said group and molded in surrounding abutting relation to said inner layer, said outer layer being constructed and arranged to provide an inner surface on the outer layer and chemically compatibly bonds to an outside surface of said inner layer and to provide an exterior surface on said outer layer configured to accommodate a manually gripping hand, the arrangement being such that when said exterior impact cushioning gripping structure is gripped by a user and the tool is manually operated to impact the tool head on a work piece, the inner layer of foamed material cushions the impact to the gripping hand of the user.
  • 2. A manually operable impact tool as defined in claim 1 wherein the second end portion of said handle structure comprises a pair of vibration receiving elements extending longitudinally away from said one longitudinal end portion and terminating in spaced relation to one another, said vibration receiving elements defining a space therebetween and wherein said inner layer of foamed material is formed around said opposite end portion so that a portion of said inner layer is received within said space and surrounds said vibration receiving elements such that vibrations resulting when the impacting head impacts a work piece are received by said vibration receiving elements and are damped by cooperation between said elements and said inner layer of material to thereby reduce the vibrations that are transmitted to the hand of the user when said impact tool impacts a work piece.
  • 3. A manually operable impact tool comprising:an elongated rigid interior handle structure extending longitudinally with respect to said impact tool; an impact head disposed at one longitudinal end portion of said handle structure, an exterior impact cushioning gripping structure affixed to a second longitudinal end portion of said elongated interior handle structure in surrounding relation thereto, said exterior impact cushioning gripping structure comprising an inner layer of foamed material selected from a group consisting of polyvinyl chloride, polypropylene, and thermoplastic elastomer and molded in surrounding relation to said elongated interior handle structure, and an outer layer of solid nonfoamed material that is chemically compatible with said inner layer, said outer layer selected from said group and molded in surrounding abutting relation to said inner layer, said outer layer being constructed and arranged to provide an inner surface on the outer layer that chemically compatibly bonds to an outside surface of said inner layer and to provide an exterior surface on said outer layer configured to accommodate a manually gripping hand, the arrangement being such that when said exterior impact cushioning gripping structure is gripped by a user and the tool is manually operated to impact the tool head on a work piece, the inner layer of foamed material cushions the impact to the gripping hand of the user, and said impact head is a hammer head.
  • 4. A manually operable impact tool as described in claim 3, wherein said hammer head has a blunt striking surface and a nail removing claw.
  • 5. A method for making a manually operable impact tool comprising the steps of:providing an elongated rigid interior handle structure having a first end portion and a second end portion opposite the first end, and an impact head disposed at the first end thereof, placing the second end portion of said impact tool in a first mold cavity, filling said first mold cavity with a foamed material selected from a group consisting of polyvinyl chloride, polypropylene and thermoplastic elastomer to form an inner layer of foamed material in surrounding relation to said second end portion of said interior handle structure, said inner layer having an outer surface, placing the second end portion in a second mold cavity such that the outer surface of said inner layer is spaced from an interior surface of said second mold cavity, filling said second mold cavity with a solid, nonfoamed material that is selected from said group and that is chemically compatible with said inner layer to fill the space between said outer surface of said inner foamed layer to form an outer layer of solid, nonfoamed material bonded to the outer surface of said inner layer, said outer layer having an exterior surface that is configured to accommodate gripping by a hand, and the providing an impact head disposed at the first end thereof includes providing an impact head formed as a hammer head.
  • 6. A method as described in claim 5, whereinsaid providing an impact head disposed at the first end thereof includes providing an impact head formed as a hammer head having a blunt striking surface and a nail removing claw.
Parent Case Info

The present application claims priority to U.S. Provisional Application of Scott, filed Mar. 25, 1999, Ser. No. 60/126,256, the entirety of which is hereby incorporated into the present application by reference.

US Referenced Citations (12)
Number Name Date Kind
2754863 Yearley Jul 1956 A
2960133 Shepherd, Jr. Nov 1960 A
2983296 Lay May 1961 A
4166488 Irby Sep 1979 A
4738166 Yamaguchi Apr 1988 A
5280739 Liou Jan 1994 A
5299475 Stroop Apr 1994 A
5443378 Jaroschek et al. Aug 1995 A
5588343 Rust et al. Dec 1996 A
5601003 Amtenbrink et al. Feb 1997 A
5657674 Burnett Aug 1997 A
5704259 Riehle Jan 1998 A
Provisional Applications (1)
Number Date Country
60/126256 Mar 1999 US