Impact tool

Information

  • Patent Grant
  • 6477922
  • Patent Number
    6,477,922
  • Date Filed
    Monday, October 25, 1999
    25 years ago
  • Date Issued
    Tuesday, November 12, 2002
    22 years ago
  • Inventors
  • Examiners
    • Morgan; Eileen P.
    • Danganan; Joni B.
    Agents
    • Harbst; John W.
Abstract
An impact tool having a head structure including first head piece, a second head piece and an elongated handle structure. With a lengthwise section of the handle structure being arranged in operative association with and maintaining the first and second head piece of the head structure in operative combination relative to each other. A woven fiber material is arranged about and epoxied to the lengthwise section of the handle structure arranged in operative association with the first and second heads to enhance the interface therebetween.
Description




FIELD OF THE INVENTION




The present invention relates to hand held manually operated tools and, more particularly, to impacts tools such as hammers and the like having a head structure including two separated members which are joined by an elongated handle structure.




BACKGROUND OF THE INVENTION




Impact tools such as hammers, axes, picks and other hand held manually operated striking tools are well known and have been used for centuries. Each of these tools come in a variety of shapes and sizes. The specific construction of the impact tool varies widely according to the desired specified use.




Such tools are typically provided with a one-piece head structure formed from steel or the like and usually includes two metallic impact or striking surfaces. Carpentry hammers typically have a metal striking head at one end and a claw configuration at an opposite end. Alternatively, the hammer can include heads formed from a softer material such as lead or hardened rubber material to provide nonmarring impact surfaces.




Hammers typically have included a handle extending away from the head structure to provide the hammer with a generally T-shaped configuration. The one-piece head structure is typically created from a forging operation to add strength to the head structure of the impact tool. Typically, a lengthwise portion of the handle fits through a bore or opening provided in the one-piece head structure. A wedge or other suitable fastening device is driven into the free end of the handle to fasten the handle to the head structure.




When a tool such as a hammer is moved to strike a surface of an object, part of the kinetic energy developed through the hammer's swing is utilized in doing the desired work on the object being struck, another part is dissipated as heat, while another part is converted into potential energy in the form of recoil or rebound of the hammer from the surface being struck. The distortion of the striking surface of the hammer has potential energy much the same way as a compressed spring. It is this potential energy that causes the hammer to recoil or bounce back from the surface of the object being struck. Moreover, hammers usually transmit some force of the impact to the user's hand, which will increase efforts and labor of the user, thus reducing the operating efficiency of the tool.




To reduce this problem, there have been developed hammers offering a “dead-blow” characteristic. For example, attention is directed to my U.S. Pat. No. 5,408,902, offering a composite hammer embodying a split head design wherein a non-load bearing internal head assembly is carried by a rigid outer load bearing framework which provides strength and stiffness to the tool. The “dead-blow” characteristic offered by my patented tool is accomplished through a split head tool design that remarkably reduces and substantially eliminates transference of the impact from the striking head to the user's hand.




While the invention disclosed in my U.S. Pat. No. 5,408,902 offers significantly improved results over other impact tool designs, there is and industry mandates a continuing effort to improve product technology. As a result of those continuing efforts, the present invention has been realized.




SUMMARY OF THE INVENTION




In view of the above, and in accordance with a preferred form of the present invention, there is provided an impact tool including a head structure with first and second members extending in opposite directions from each other but which are maintained in interconnected relationship relative to each other by a handle structure extending normally from and secured to the head structure.




In one form of the invention, the members of the head structure are formed from metal. In that embodiment wherein the impact tool is configured as a hammer, at least one of the members of the head structure is a striking head which can include an exposed metal striking surface. The other member of the head structure for the hammer can be configured as a claw or, alternatively, a second striking head with an exposed metal striking surface.




In a preferred form of the invention, each member of the head structure includes a working portion and an attachment portion. The attachment portion of each member of the head structure extends, at least partially, in surrounding relation relative to a lengthwise portion of the handle structure so as to prevent the member from becoming disassociated with the handle. Forming the attachment portion of a claw-like configured head with a clevis-like configuration appears beneficial to distribute forces imparted thereto during operation of the tool.




The handle structure includes an elongated handle formed from any of a myriad of materials selected from the class comprising; wood, plastic, metal, nylon, fiberglass, an elastomer, or suitable rigid material. In a preferred form, the handle structure further includes a wedge-like member driven into the free end of the handle. The wedge-like member serves to maintain the handle structure and head structure in secured engagement relative to each other.




In accordance with one aspect of the present invention, and while remaining interconnected through the handle structure, the members of the head structure are separated from each other in an axial direction. The spacing between the members of the head structure allows for movement of the head structure members in response to one of the head structure members being struck against a surface. That is, when one member or head of the head structure is struck against a surface, the spacing between the heads or members of the head structure allows the unstruck head to move toward and impact against the struck head thereby providing a secondary blow that inhibits the tool's struck head from rebounding from the struck surface and thereby dampening vibration through the handle.




In a preferred form of the invention, the attachment portions of the heads or members of the head structure are configured with confronting impact surfaces. The spacing mentioned above is provided between the impact surfaces on the heads or members of the head structure. The range of spacing between the members of the head structure varies and is dependent upon a number of factors. That is, the spacing between the members of the head assembly varies as a function of the mass distribution or geometry of the head structure members, the material from which the head structure members are formed, the timing of the collision between the head structure members, and the length of time the striking surface of the head structure striking member remains in contact with the struck surface. A spacing between the impact surfaces ranging between about 0.010 inches to about 0.070 inches appears appropriate.




To promote movement of the members or heads of the head structure moving toward each other in response to use, the tool of the present invention can further include elastomeric material disposed between the handle of the tool and the heads or members of the head structure. The elastomeric material has a hardness ranging between about 40 Shore A durometer hardness and about a 95 Shore A durometer hardness. Suffice it to say, the elastomeric material acts as a spring for returning the nonstruck head to a normal or operational position after moving toward and impacting with the struck head or member of the head structure. Accordingly, any suitable material which, during operation of tool, will initially compress and subsequently return the unstruck head to an operational position will suffice.




Another aspect of the present invention relates to configuring at least one of the members of the head structure from laminations. The other member or head of the head structure is captively received between laminations of the other member. After captively arranging the heads or members of the head structure relative to each other, the laminations are fixedly secured to each other. The handle of the tool extends through and is maintained in association with either of the members or heads of the head structure and extends generally perpendicular relative thereto.




With this aspect of the present invention, a striking plate or cap can be arranged in combination with the laminations. The striking plate defines a striking surface for the tool and, thus, inhibits separation of the laminations during use of the tool.




With the present invention, the head structure preferably comprises dual heads or members which are generally axially aligned relative to each other. Because the heads or members of the head assembly of the present invention can be manufactured separately, the manufacturing equipment and processes for forming the heads or members of the head structure are significantly simplified, thus, reducing manufacturing costs and thereby enhancing the selling price of the tool. Configuring one or more of the striking heads with laminations furthermore enhances the manufacturing process.




Arranging elastomeric material between the heads and the handle of the tool furthermore enhances this invention. The elastomeric material effectively isolates the heads from the handle and thereby significantly reduces vibration transfer from the head structure through the handle and to the user's hand.




The concept of splitting the heads of the head structure to allow for axial movement of the heads relative to each other furthermore enhances performance characteristics of the present invention. Thus, when one head or member of the head structure is struck against a surface, the other head or member of the head structure acts as a lagging mass and provides a secondary blow to inhibit the struck head from rebounding from the surface being struck. According, an advantageous “dead-blow” feel is provided to the tool. It has been found that vibrations normally experienced in the handle of the tool are not discernable with the tool designed in accordance with the present invention.




Still another aspect of the present invention involves arranging a skin of resin impregnated fiber material, preferably an arimid fiber material, along and about the lengthwise portion of the handle structure extending into operative association with the head structure of the impact tool. Preferably, an epoxy is used in combination with the fiber material or skin. Moreover, the fiber skin or material plus the epoxy defines a more cumbersome path for impact vibrations to traverse between the striking head of the head structure and the handle structure thereby significantly reducing vibration transference during use of the tool. Additionally, a cosmetic cover is preferably arranged beneath the head structure and extends about the handle of the handle structure to aesthetically cover any free ends of the fiber material extending from the head structure of the tool. As will be appreciated from an understanding of this aspect of the present invention, the presence of an epoxy material about that portion of the handle structure extending into operative combination with the head structure will enhance securement of the head structure and handle structure to each other while advantageously dampening vibrations whether the head structure is of a unitary design or of the two piece design as disclosed above.




These and other objects, aims, and advantages of the present invention will become more readily apparent from the following detailed description of the invention, the appended claims, and the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a top plan view of an impact tool embodying features of the present invention;





FIG. 2

is a sectional view taken along line


2





2


of

FIG. 1

;





FIG. 3

is a sectional view taken along line


3





3


of

FIG. 1

;





FIG. 4

is an exploded perspective view of the members forming a head structure of the impact tool illustrated in

FIG. 1

;





FIG. 5

is a top plan view of the alternative embodiment of the present invention;





FIG. 6

is a sectional view taken along line


6





6


of

FIG. 5

;





FIG. 7

is a longitudinal sectional view of another alternative form of the present invention;





FIG. 8

is a top plan view of another alternative embodiment of the invention;





FIG. 9

is a sectional view taken along line


9





9


of

FIG. 8

;





FIG. 10

is a top plan view of yet another alternative form of the present invention;





FIG. 11

is a sectional view taken along line


11





11


of

FIG. 10

;





FIG. 12

is a top plan view of another alterative form of the present invention;





FIG. 13

is a sectional view taken along line


13





13


of

FIG. 12

;





FIG. 14

illustrates a top plan view of still another alternative form of the present invention;





FIG. 15

is a sectional view taken along line


15





15


of

FIG. 14

;





FIG. 16

is a top plan view of still another form of the present invention; and





FIG. 17

is a sectional view taken along line


17





17


of

FIG. 16

;





FIG. 18

is a partial longitudinal section of still, another embodiment of the present invention; and





FIG. 19

is a sectional view taken along line


19





19


of FIG.


18


.











DETAILED DESCRIPTION OF THE PRESENT INVENTION




While the present invention is susceptible of embodiment in multiple forms, there are shown in the drawings and will hereinafter be described various preferred embodiments of the present invention with the understanding the present disclosure is to be considered as setting forth exemplifications of the invention which are not intended to limit the invention to the specific embodiments illustrated and described.




Referring now to the drawings, wherein like reference numerals indicate like parts throughout the views, there is shown in

FIGS. 1 through 3

an impact tool


10


constructed in accordance with the present invention. The tool illustrated in

FIGS. 1 through 3

for purposes of illustration is in the form of a hammer having exposed striking heads. It should be appreciated, however, the teachings of the present invention are equally applicable to other forms of impact tools such as axes, picks and the like tools.




In the example of the invention shown in

FIGS. 1 through 3

, and as is typical, hammer


10


has a generally T-shaped configuration and includes a head structure


12


with a handle structure


14


extending therefrom and in a generally perpendicular relationship therewith.




The head structure


12


includes first and second independent or separate heads or members


20


and


30


which, in the illustrated form of the invention, are generally axially aligned in a first direction relative to each other. The heads or members


20


,


30


extend toward first and second sides, respectively, of the tool


10


. In one form of the invention, the heads or members


20


,


30


of the head structure


12


are fabricated from a suitable metal or metal alloy. The head or member


20


of head structure


12


defines an exposed striking surface


22


while head or member


30


of head structure


12


defines an exposed striking surface


32


. As will be appreciated, the heads


20


,


30


and the striking surfaces


22


,


32


respectively, could be encased to limit marring of the surface struck or impacted with the tool without detracting or departing from the spirit and scope of the present invention. Moreover, the configurations of the heads or member


20


,


30


of head structure


12


can be other than that shown without departing or detracting from the spirit and scope of the present invention.




The handle structure interconnects the heads


20


,


30


of the head structure


12


to each other and extends in a second direction away from the head structure


12


to provide a generally T-shaped formation or configuration to the tool


10


. The handle structure


14


includes an elongated handle


40


, a lengthwise portion of which extends through and interconnects the heads or members


20


,


30


of the head structure


12


to each other. The handle


40


of handle structure


14


is formed from a class of materials including: wood such as hickory, plastic, metal, nylon, fiberglass, elastomeric, or composite materials. In the illustrated form of the invention, the handle


40


of handle structure


14


is preferably of one-piece construction between opposite ends


42


and


44


thereof to reduce the opportunity of vibrations passing therethrough.




As shown in

FIG. 2

, the head piece or member


20


of the head structure


12


includes a working portion


24


and an attachment portion


26


. Similarly, the head piece or member


30


of the head structure


12


includes a working portion


34


and an attachment portion


36


. Notably, a lengthwise portion of the handle


40


extends through and interconnects the attachment portions


26


,


36


of the heads or members


20


,


30


of the head structure


12


.




The head pieces or members


20


,


30


of the head structure


12


are configured to interconnect relative to each other to prevent their inadvertent separation from each other and from the handle structure


14


during use of the impact tool. To prevent the head pieces or members


20


,


30


from moving beyond a predetermined axial distance or becoming disassociated with the handle structure


14


during use the tool


10


, the attachment sections or portions


26


,


36


are each configured to surround more than a 180′ circumferential segment of the lengthwise portion of the handle


40


extending therethrough. In the illustrated form of the invention, shown in

FIG. 4

, each head piece or member


20


,


30


defines a bore


21


,


31


, respectively, extending therethrough for accommodating endwise reception and holding of a lengthwise portion of the handle


40


.




As shown in

FIGS. 2 and 3

, handle structure


14


furthermore preferably includes a wedge-like insert


16


is driven into the free upper end


42


of the handle


40


passing through the attachment portions


26


,


36


of the heads or members


20


,


30


, respectively, thereby facilitating securement of the head structure


12


to the handle structure


14


. Of course, adhesive or other forms of attachment devices can be used to secure the head structure


12


to the


40


handle structure


14


in addition to the use of a wedge-like member


16


without detracting or departing from the spirit and scope of the present invention.




The head pieces or members


20


,


30


of the head structure


12


are furthermore configured to prevent their axial displacement along the length of the handle


30


. As mentioned, the attachment sections or portions


26


,


36


of the head pieces


20


,


30


, respectively, are each secured to a lengthwise portion of the handle structure


14


extending therethrough. Moreover, the attachment sections


26


,


36


of the heads or members


20


,


30


of the head structure


12


are vertically arranged relative to each other to prevent their inadvertent displacement along the axial length of the handle


40


during operation of the tool


10


.




As shown in

FIGS. 2 and 4

, the attachment portion


26


,


36


of each head piece or member


20


,


30


is configured with an axially extending recess


23


,


33


shaped to complement an axial projection


25


,


35


defined on the heads or members


20


,


30


of the head structure


12


. As will be appreciated, and as shown in

FIG. 2

, when the head pieces or members


20


,


30


of the head structure


12


are assembled relative to each other, the axial projection


25


on the head or member


20


is accommodated within the complementary shaped axially extending recess


33


defined on the head piece or member


30


of head structure


12


. Similarly, and after the head pieces or members


20


,


30


of the head structure


12


are assembled relative to each other, the axial projection


35


on the head or member


30


is accommodated within the complementary shaped axially extending recess


23


defined on the head piece or member


20


of head structure


12


. Since the head pieces


20


,


30


are each secured to a lengthwise portion of the handle structure


14


extending therethrough, the relationship of the projections


25


,


35


coact with the recesses


23


,


33


to prevent displacement of the head pieces or members


20


,


30


relative to each other and along the length of the handle structure


14


even if the securement between the one of the head pieces or members


20


,


30


fails.




According to one salient feature of the present invention, the head pieces or members


20


,


30


of the head structure


12


are axially separated from each other by a predetermined axial distance. As shown in the drawings, the head pieces


20




30


of the head structure


12


are separated from each other in an axial or first direction extending generally perpendicular to the axis of the handle


40


a distance ranging between about 0.010 inches and about 0.070 inches. The distance separating the heads or members


20


,


30


of head structure


12


being substantially exaggerated in the drawings for purposes of explanation.




As shown in

FIGS. 2 and 4

, the head pieces or members


20


,


30


of head structure


12


are provided with complementary and confronting impact surfaces that are axially separated from each other by the predetermined distance mentioned above. In the illustrated form of the invention, an impact surface


27


is provided within the recess


23


on the head piece or member


20


of head structure


12


in spaced and confronting relationship relative to an impact surface


38


on the axial projection


35


of head piece or member


30


of the head structure


12


. Similarly, an impact surface


37


is provided within the recess


33


on the head piece or member


30


of head structure


12


in spaced and confronting relationship relative to impact surface


28


on the axial projection


25


head piece or member


20


of the head structure


12


.




In this, as well as the other illustrated forms of the invention disclosed herein, only one set or pair of complementary confronting impact surfaces necessarily needs to be spaced apart the preferable range of about 0.010 inches to about 0.070 inches. Other confronting impact surfaces defined on the head pieces or members


20


,


30


of the head structure


12


can be spaced a further distance apart from each other without detracting or departing from the spirit and scope of the present invention. As will be appreciated, and as shown, more than one impact surface can be defined on the head pieces or member


20


,


30


of head structure


12


without detracting or departing from the spirit and scope of the present invention as long as the axial spacing between the confronting surfaces is the same.




Another salient feature which distinguishes the present invention from heretofore known tools relates to isolating the two-piece head structure


12


from the handle structure


14


to significantly reduce vibrations transmitted to and through the handle


40


to the user. As shown in

FIGS. 1 through 3

, elastomeric material


50


is provided between the handle structure


14


and the head pieces or members


20


,


30


of the head structure


12


along the lengthwise portion of the handle


40


extending through the head structure


12


. Notably, the elastomeric material


50


, disposed between the head pieces


20


,


30


of the head structure


12


and the handle structure


14


, promotes axial movement of the unstruck head piece toward the head piece that is struck against a surface.




In the illustrated form of the invention, a sleeve


52


formed from an elastomeric material is disposed about and along the lengthwise portion of the handle


40


passing through the head structure


12


. The elastomeric sleeve


52


is secured to that lengthwise portion of the handle structure


14


passing through the head structure


12


and to each of the head pieces or members


20


,


30


of the head structure


12


as by adhesive or the like. As will be appreciated, and in addition to the wedge-like member


16


driven into the free end


42


of the handle


40


, the adhesiveness of the sleeve


52


to the heads or members


20


,


30


and to the handle portion


40


furthermore facilitates maintaining the head structure


12


in operable association with the handle structure


14


.




As will be appreciated by those skilled in the art, the elastomeric material can take a myriad of forms. In the preferred embodiment, an elastomeric composition having a Shore A durometer hardness ranging between about 40 and 95 appears to be best suited for this application.




Another embodiment of a tool embodying features of the present invention is schematically illustrated in

FIGS. 5 and 6

. This alternative form of impact tool is designated generally by reference numeral


110


. The elements of this alternative form of impact tool that are identical to or functionally analogous to those components discussed above regarding impact tool


10


are designated by reference numerals identical to those used above with the exception that this embodiment uses reference numerals in the


100


series.




In this embodiment of the invention, the head structure


112


and handle structure


114


are substantially similar to that discussed above. As mentioned above, the head structure


112


includes a pair of axially separated striking heads


120


,


130


. Moreover, the handle structure


114


includes an elongated handle


140


having opposite ends


142


,


144


.




The head piece or member


130


of the head structure


112


defines a bore


131


extending therethrough and through which a lengthwise portion of the handle structure


114


extends. The head piece or member


120


of the head structure


112


, however, defines a counterbore


121


which accommodates a lengthwise portion of the handle


140


of handle structure


114


. In the embodiment of the invention schematically illustrated in

FIG. 16

, the handle structure


114


furthermore preferably includes a wedge-like insert


116


. As shown, the head piece or member


120


of head completely therethrough. Notably, the counterbore


121


of head piece or member


120


can be structure


112


is provided with an aperture or opening


129


for permitting endwise passage of the wedge-like member therethrough and into the free end of the handle


140


thereby enhancing securement of the head structure


112


and handle structure


114


in operative combination relative to each other.




Notably, the counterbore


121


of the head piece or member


120


and the bore


131


of head piece or member


130


are each configured to accommodate elastomeric material


150


disposed, at least, on opposite sides of the handle structure


114


. As will be appreciated, and as discussed in detail above, the handle structure


114


and/or the elastomeric material


150


can be suitable secured to the head structure as through adhesive or the like.




Another embodiment of a tool embodying features of the present invention is schematically illustrated in FIG.


7


. This alternative form of impact tool is designated generally by reference numeral


210


. The elements of this alternative form of impact tool that are identical to or functionally analogous to those components discussed above regarding impact tool


10


are designated by reference numerals identical to those used above with the exception that this embodiment uses reference numerals in the


200


series.




In this embodiment of the invention, the head structure


212


is substantially similar to that discussed above. As mentioned above, the head structure


212


includes a pair of axially separated striking heads


220


,


230


. The head pieces or members


220


,


230


of the head structure


212


defines bores


221


,


231


, respectively, extending therethrough and through which a lengthwise portion of a handle structure


214


extends to hold the attachment portions


226


,


236


of the head pieces or members


220


,


230


, respectively, together in interconnected relationship relative to each other. Of course, with a simple change the bore


221


of head piece


220


could be configured with a counterbore like head piece


120


discussed above without detracting or departing from the spirit and scope of the present invention.




The handle structure


214


in this embodiment of the invention extends through and holds the head pieces


220


,


230


of the head structure


220


in axially separated relation relative to each other. In this embodiment, the handle structure


214


includes an elongated handle


240


with an enlarged head piece


241


toward that end that passes endwise through the attachment portions


226


,


236


of the head pieces or members


220


,


230


, respectively, of the head structure


212


. In this embodiment of the invention, at least the enlarged head piece


241


of handle structure


214


is formed from an elastomeric composition having a Shore A durometer hardness ranging between about 40 and 95.




The enlarged head piece


241


of handle


240


is sized to snugly fit within bores


221


,


231


defined in the head pieces or members


220


,


230


of the head structure


212


and be secured thereto as with adhesive. The handle structure


214


can further include a wedge-like member (not shown) driven onto the free end thereof, or any other suitable affixation device or method. As discussed above, attachment portions


226


,


236


of the head pieces or members


220


,


230


, respectively, extend at least partially in surrounding circumferential relation relative to a lengthwise portion of the enlarged head piece


242


thereby preventing complete separation of the head pieces or members


220


,


230


from the handle


240


. Although the attachment portions


226


,


236


of the head pieces or members


220


,


230


, respectively, of the head structure


212


appear different than the attachment portions


26


,


36


discussed above regarding head pieces


20


,


30


, they are intended to serve the identical function to that discussed above and are maintained in normally separated relation relative to each other.




Another embodiment of a tool embodying features of the present invention is schematically illustrated in

FIGS. 8 and 9

. This alternative form of impact tool is designated generally by reference numeral


310


. The elements of this alternative form of impact tool that are identical to or functionally analogous to those components discussed above regarding impact tool


10


are designated by reference numerals identical to those used above with the exception that this embodiment uses reference numerals in the


300


series.




In this embodiment of the invention, the tool


310


is configured as a carpentry hammer. The head structure


312


of the hammer


310


includes first and second pieces or members


320


,


330


, respectively, joined to each other by an elongated handle structure


314


extending generally normal to and away from the head structure


312


. The handle structure


314


includes an elongated handle


340


, a lengthwise portion of which extends through and interconnects the heads or members


320


,


330


of the head structure


312


to each other. The handle


340


is preferably formed from a class of materials including: wood such as hickory, plastic, metal, nylon, fiberglass, elastomeric composite materials. The handle


340


is preferably of one-piece construction between opposite ends


342


and


344


thereof. The handle structure


314


furthermore preferably includes a wedge-like structure or insert


316


forced into the upper free end


342


of the one-piece handle


340


of handle structure


314


. The insert


316


of handle structure


314


circumferentially expands that end of handle structure


314


passing, at least partially, through the head structure


312


thereby enhancing the securement of the handle structure


314


to the head structure


312


.




As shown, the first piece


320


of the head structure


212


is configured as a striking head with a striking surface


322


. The other piece or member


330


of the head structure


312


has a claw-like configuration including a pair of laterally spaced tines or members


339


and


339


′ extending away from handle


340


of the handle structure


314


.




To promote axial movement of the heads or members


320


,


330


of the head structure


312


, elastomeric material


350


is inserted between opposed sides of the handle


340


and attachment portions


326


,


336


of the heads or members


320


,


330


, respectively, of the head structure


312


. As will be appreciated, the elastomeric material furthermore isolates the head structure


312


from the handle structure


314


thereby inhibiting vibrations from being transferred along the length of the handle


314


to the user. In the illustrated form of the invention, the elastomeric material


350


is in the form of strips of elastomeric material


352


arranged between opposed lengthwise sides of the handle


340


and the heads


320


,


330


of the head structure


312


.




In this embodiment of the invention, the attachment portions


326


,


336


of the head pieces or members


320


have a clevis-like configuration to enhance distribution of the forces acting on the heads or members


320


,


330


of the head structure


312


. In the embodiment illustrated in

FIG. 9

, the attachment portion


326


of the head piece or member


320


of head structure


312


includes an axially elongated vertically spaced projections


360


. Each axially elongated projection


360


on head piece or member


320


defines an opening or aperture


362


circumferentially extending, at least partially, about a lengthwise section of the handle


340


to hold the striking head


320


to the handle structure


314


. In the illustrated embodiment, the opening


362


defined by the attachment section


326


is sized to fit snugly about the elastomeric material


352


fitted about the handle


340


.




The attachment portion


336


of the head piece or claw-like member


330


of the head structure is configured with a pair of elongated axially extending, vertically spaced projections


370


which, in the illustrated embodiment, are embraced by the projection


360


of head piece or member


320


. The projections


370


of the head piece or claw-like member


330


define a pair of vertically aligned openings or apertures


374


which circumferentially extend, at least partially, about a lengthwise portion of the handle


340


extending endwise therethrough. In the illustrated embodiment, the openings


374


defined by the attachment section


336


of the head piece or claw-like member


330


are sized to fit snugly about the elastomeric material


352


fitted about the handle


353


.




As shown in

FIG. 9

, the striking head


320


of head structure


312


is formed with axially elongated recesses


323


defining vertically aligned impact surfaces


327


for accommodating axial displacement of the attachment portion


336


of the claw-like member


330


there toward. Similarly, the claw-like member or head


330


of the head structure


312


is formed with axially elongated recesses


333


defining impact surfaces


337


.




As shown, each of the axially elongated projections


360


forming part of the attachment portion


326


of the striking head


320


is formed with an impact surface


328


at the distal end thereof Moreover, the axially elongated projections


370


forming part of the attachment portion


336


of the claw-like member


330


of head structure


312


each define vertically aligned impact surfaces


338


at the distal ends of the projections


370


,


372


, respectively.




As shown in

FIG. 9

, when the heads


320


,


330


are assembled relative to each other, the impact surfaces


328


on the head piece or member


320


of the head structure


320


are maintained in a predetermined spaced and confronting relationship relative to the impact surfaces


337


formed on the claw-like member or head


330


. Moreover, when the heads


320


,


330


are assembled relative to each other, the impact surfaces


338


at the distal ends of the projections


370


extending from the claw-like member


330


will be maintained in a predetermined spaced and confronting relationship relative to the impact surfaces


327


formed on the striking head


320


.




Still another embodiment of a tool embodying features of the present invention is illustrated in

FIGS. 10 and 11

. This alternative form of impact tool is designated generally by reference numeral


410


. The elements of this alternative form of impact tool that are identical to or functionally analogous to those components discussed above regarding impact tool


10


are designated by reference numerals identical to those used above with the exception that this embodiment uses reference numerals in the


400


series.




Tool


410


is again configured as a carpentry hammer. The head structure


412


of the hammer


410


includes first and second pieces or members


420


,


430


, respectively. The tool or hammer


410


further includes a handle structure


414


extending from the head structure


412


at a generally perpendicular relationship thereby providing a generally T-shaped configuration to the tool


410


.




As shown, the first piece


420


of the head structure


412


is configured as a striking head with a striking surface


422


. The other member


430


of the head structure


412


is configured with a claw-like design including a pair of laterally spaced tines or members


439


and


439


′.




In this embodiment of the invention, the striking head


420


is preferably of one piece construction and includes a working portion


424


and an attachment portion


426


. The attachment portion


426


of the striking head


420


is specifically configured to be captively received by the claw-like member


430


of the head structure so as to prevent its axial separation therefrom and yet allow a degree of axial movement along a predetermined path relative to the claw-like member or head piece


430


. In the illustrated embodiment, the attachment portion


426


of the striking head


420


is configured with an enlarged end portion


460


to retain the head


420


in captive but axially slidable relationship relative to head piece


430


.




The claw-like member


430


of the head structure


412


has a laminated configuration including first and second halves or pieces


470


,


472


which are the mirror image of each other and, when assembled, provide the entire shape to the claw-like member


430


of the head structure


412


. Each piece


470


,


472


of the claw-like member


430


defines a open sided cavity


473


having a shape corresponding to one half of the attachment portion


426


of the striking head


420


. Moreover, each piece


470


,


472


of the claw-like member


430


defines an open sided channel


474


conforming to one-half of the cross-sectional configuration of the lengthwise portion of the one-piece handle


440


extending endwise therethrough.




In the illustrated form of the invention, and as made possible by the laminated structure of the head piece


430


, the attachment portion


426


of the head piece


420


is captively received within a recess formed by the abutting cavities


473


defined by the pieces


470


,


472


of the head piece


430


of the head structure


412


while the handle


440


forming handle structure


414


extends only through the head piece or claw member


430


of the head structure


412


. The laminations


470


,


472


forming the claw-like member


430


of the head structure


412


are fixedly held to each other as by a series or plurality of rivets


480


or other suitable securement devices.




As shown, the handle


440


has a changing cross-sectional configuration along that lengthwise portion extending through the claw-like member


430


of the head structure. The changing cross-sectional configuration of the handle


440


is specifically configured to secure the claw-like member


430


along the length of the handle structure


414


. In the illustrated embodiment of the invention, a generally centralized lengthwise section of the handle


440


has a reduced outer configuration from those lengthwise sections of the handle


440


arranged adjacent upper and lower sides of the claw-like member


430


. Accordingly, the handle


440


is prevented from axially moving along its length relative to the claw-like member. Of course, configurations other than that exemplified may equally suffice without detracting or departing from the scope of the present invention. Notably, however, the laminated or lengthwise split configuration of the member


430


allows such a design to capture the handle structure


414


relative to the head structure


412


. Moreover, in the illustrated form of the invention, the handle


440


has a cross-sectional configuration which inhibits the handle


440


from rotating or turning relative to the head piece


430


. Furthermore, and to inhibit vibrations from transferring along the length of the handle structure, the handle


440


is preferably configured as a one-piece member.




To further reduce vibrations from being transmitted along the length of the handle structure, elastomeric material


450


is inserted between the lengthwise portion of the handle


440


and the that portion of head piece


430


arranged in surrounding relationship thereto. As will be appreciated, the elastomeric material


450


only needs to be positioned on opposite sides of the handle


440


to promote axial movements of the head pieces


420


,


430


toward each other. In the illustrated form of the invention, however, a sleeve


452


of elastomeric material is positioned along and about the lengthwise portion of the handle


440


extending through the head piece


430


of the head structure


412


. The elastomeric material has a hardness ranging between about a Shore A durometer hardness and about a 95 Shore A durometer hardness.




As shown in

FIGS. 10 and 11

, the attachment portion


426


of the head piece or striking head


420


of the head structure


412


is configured with an elongated shank-like projection axially extending from the striking head


420


with an impact surface


428


at a distal end thereof Moreover, the claw-like member


430


is configured with a recess


433


shaped to accommodate the shank-like projection


426


on the head piece or member


420


. Notably, an impact surface


427


is defined by the recess


473


. As will be appreciated, when the heads


420


,


430


are assembled relative to each other, the impact surface


428


on the striking head


420


and the impact surface


437


on the claw-like member


430


are in confronting but axially spaced relation relative to each other. The axial spacing having a predetermined distance therebetween. In the illustrated embodiment, an elastomeric material


481


is positioned between the impact surface


428


on the head or member


420


and the impact surface


437


on the claw-like member


430


to act as a spring for maintaining the axially spaced relationship between the confronting impact surfaces defined by the head or members


420


,


430


of the head structure


412


.





FIGS. 12 and 13

illustrate an alternative embodiment of the invention substantially similar to that illustrated in

FIGS. 10 and 11

. This embodiment of the invention includes substantially the same structure as discussed above regarding tool


410


with the exception of the manner by which the striking head


420


is secured to the claw-like member


430


. In this embodiment of the invention, the attachment portion


426


on the striking head


420


is configured as an axially elongated shank-like projection axially extending away from the striking head


420


and is slidably received for axial movement within a cavity


433


defined by the head piece or claw-like member


430


. That is, and with this embodiment of the hammer


410


, the axially extended projection


426


is arranged for endwise or axial sliding movement within the recess


433


in the claw-like member


430


defined by the two abutting laminations


470


,


472


.




As mentioned above, in this embodiment of the invention, a series of rivets or other suitable fasteners


480


serve to fixedly hold the laminations


470


,


472


to each other. In the illustrated form of the invention, the rivets or fasteners


480


are shown as extending through the laminations


470


,


472


and holding them in fixed relation relative to each other it will be appreciated by those skilled in the art, however, the fasteners do not necessary need to extend completely through both laminations


470


,


472


. Other alternative means of securing the laminations


470


,


472


to each other would equally suffice without detracting or departing from the novel spirit and scope of the present invention. In the illustrated form of the invention shown in

FIGS. 12 and 13

, at least one elongated fastener


480


axially extends through the shank-like axial projection on head piece


420


. The axially elongated projection


426


is provided with a throughbore


482


having a diameter greater than the diameter of the rivet or fastener


480


used to hold the laminations


470


,


472


in assembled relation relative to each other. As shown in the drawings, a bearing sleeve of elastomeric material


484


fills the void around the rivet or fastener


480


and the internal diameter of the bore


482


. The elastomeric material will have generally the same characteristics as mentioned above and will serve to maintain the impact surfaces


437


and


428


on the head members or pieces


420


and


430


of the head structure in predetermined axially spaced relation relative to each other while also allowing for the impact surfaces to collide with each other when the striking head


420


is stricken against a surface or object.




A further embodiment of a tool embodying features of the present invention are schematically illustrated in

FIGS. 14 and 15

. This alternative form of impact tool is designated generally by reference numeral


510


. The elements of this alternative form of impact tool that are identical to or functionally analogous to those components discussed above regarding impact tool


10


are designated by reference numerals identical to those used above with the exception that this embodiment uses reference numerals in the


500


series.




Tool


510


is similar in configuration to the tool


10


discussed above and shown in

FIGS. 1 through 3

. In this embodiment of the invention, the tool


510


includes a head structure


512


including first and second pieces or members


520


and


530


, respectively, which are axially aligned in a first direction. The tool or hammer


510


further includes a handle structure


514


extending from the head structure


512


in a second direction and generally perpendicular to the head structure


512


thereby providing a generally T-shaped configuration to the tool


510


.




The head pieces or members


520


and


530


of the head structure


512


are each formed from a series of laminations


529


and


539


, respectively, fixedly held to each other by a series of suitable rivets or fasteners


580


. Each plate or lamination


529


forming the head piece or member


520


is configured with a cutout


522


which, after the plates


529


are assembled relative to each other, define a recess


523


including at least one impact surface


527


. Moreover, each lamination or plate


529


of the head member or piece


520


has an extension


526


having an impact surface


528


at a distal end thereof. Each plate or lamination


539


forming the head piece or member


520


is configured with a cutout


532


which, after the plates


539


are assembled relative to each other, define a recess


533


including at least one impact surface


537


. Moreover, each lamination or plate


539


of the head member or piece


530


has an extension


536


having an impact surface


538


at a distal end thereof. Notably, when the laminated head pieces


520


,


530


are assembled relative to each other, the impact surfaces


527


,


538


and


537


,


528


, respectively, are arranged in confronting but predetermined spaced relationship relative to each other in substantially the same manner as discussed above.




In this embodiment of the invention, one each of the laminated plates


529


,


539


forming the laminated head pieces


520


,


530


of the head structure


512


is formed like the other except that one each of the plated


529


,


539


is sufficiently sized to permit a bore


521


,


531


to be provided therein for allowing a lengthwise portion of the handle structure


514


to extend endwise therethrough. As described above, the handle structure


514


furthermore preferably includes a suitably shaped member, such as a wedge-like member


516


, which is driven into or operative extends from the free end


542


of the handle


540


of handle structure


514


to facilitate securement of the head structure


512


to the handle structure


514


.




Such that either end of the head structure


512


can be used for striking purposes, a cap structure


570


fits about the ends of the laminations


529


,


539


of the heads or members


520


,


530


of the head structure


512


. As will be appreciated, the cap structure


570


defines a striking surface


525


,


535


for each head or member


520


,


530


of the head structure


512


. In the illustrated form of the invention, each cap structure


570


defines a peripheral wall or skirt


527


arranged in capturing and surrounding relation relative to the laminations


529


,


539


of the head or members


520


,


530


thereby inhibiting the laminations


529


,


539


from “separating” relative to each other as the tool


510


is used to strike a surface. The cap structure


570


is secured as through any suitable means to the ends of the laminations


529


,


539


forming the heads or members


520


,


530


of the head structure


512


. It is also within the scope of the present invention to configure the head structure of the impact tool


510


such that alternating laminations can be formed from an elastomeric material.




A still further embodiment of a tool embodying features of the present invention are schematically illustrated in

FIGS. 16 and 17

. This alternative form of impact tool is designated generally by reference numeral


610


. The elements of this alternative form of impact tool that are identical to or functionally analogous to those components discussed above regarding impact tool


10


are designated by reference numerals identical to those used above with the exception that this embodiment uses reference numerals in the


500


series.




The tool


610


is similar in configuration to the laminated tool


510


discussed above and shown in

FIGS. 14 and 15

. In this embodiment of the invention, the tool


610


includes a head structure


612


including first and second pieces or members


620


and


630


, respectively, which are axially aligned in a first direction. The tool or hammer


610


further includes a handle structure


614


extending from the head structure


612


in a second direction and generally perpendicular to the head structure


612


thereby providing a generally T-shaped configuration to the tool


610


.




The head pieces or members


620


and


630


of the head structure


612


are each formed from laminations


621


and


631


, respectively, fixedly held to each other by a series of suitable rivets or fasteners


680


. To reduce vibration transmission through the handle structure


614


and to allow the head pieces


620


,


630


of the head structure


612


to collide relative to each other, at least one other lamination


625


formed from an elastomeric material is sandwiched or inserted between the laminations


621


and


631


forming the head pieces or member


620


,


630


and is secured to each by the fasteners


680


.




The laminations


621


,


631


each define an impact surface


627


,


638


and


628


,


637


, respectively, arranged thereon. The impact surfaces


627


,


638


and


637


,


628


, respectively, on the laminations


621


,


631


forming the head pieces or members


620


,


630


of head structure


612


are arranged in confronting axially spaced relation relative to each other.




As shown, the handle structure


614


includes a one-piece handle


640


have a changing cross-sectional configuration along that lengthwise portion extending endwise through the elastomeric lamination


625


of the head structure


612


. The changing cross-sectional configuration of the handle


640


is specifically configured to secure the elastomeric lamination


625


along the length of the handle structure


614


. As shown, the lengthwise section of the handle


640


arranged in operative association with the head structure


612


preferably has an hourglass configuration. Accordingly, the handle


640


is prevented from axially moving along its length relative to the laminations


625


and, thus, relative to head structure


612


. Of course, configurations other than that exemplified may equally suffice without detracting or departing from the scope of the present invention. Notably, however, the laminated or lengthwise split configuration of the head structure


612


allows such a design to capture the handle structure


614


relative to the head structure


612


.





FIGS. 18 and 19

schematically illustrate still another embodiment of an impact tool embodying salient features of the present invention. This alternative form of impact tool is designated generally by reference numeral


710


. The elements of this alternative form of impact tool that are identical to or functionally analogous to those components discussed above regarding impact tool


10


are designated by reference numerals identical to those used above with the exception that this embodiment uses reference numerals in the


700


series.




Tool


710


is again configured as a carpentry hammer. The hammer


710


includes a head structure


712


and an elongated handle structure


714


extending generally normal to the head structure


712


. One of the salient features involving this embodiment of the invention concerns the composite structure of the hammer


710


. That is, in this embodiment of the invention, a skin or sock


702


extends about and along at least that lengthwise portion of the handle structure


714


extending into operative cooperation with the head structure.




In a preferred form of the invention, the skin


702


is fabricated from an arimid fiber material such as KEVLAR® marketed and sold by the DuPont Corporation. The arimid fiber material used in combination with the present invention has a unique combination of high strength, high modulus and toughness. The arimid fiber material or skin


702


is encapsulated or impregnated into an epoxy such as that sold and marketed by Ad-Tech as CER-


112


. This aspect of the present invention takes advantage of the natural tendency of the free ends of woven or braided fiber to fray and expand. As will be appreciated, and after the epoxy solidifies and hardens about the woven fabric or skin


702


, the epoxy impregnated into the fiber sleeve maintains the frayed ends of the sleeve


702


in a radially expanded configuration, as schematically illustrated in

FIG. 18

, and thereby enhances the interface between the head structure


712


and the handle structure


714


while furthermore preventing the handle structure


714


from pulling out or separating from the head structure


712


.




In one form, a cover


704


is disposed along and about a lengthwise portion of the handle structure


714


disposed beneath and in combination with the head structure


712


. The purpose of the cover


704


is to extend about a lengthwise portion of the epoxied and impregnated fiber material extending beyond the head structure


712


of the tool


710


. To maintain the distinctive character of the tool


710


, however, at least a lengthwise portion of the cover


704


is transparent or otherwise visually permeable to permit visual access to the material skin


702


while inhibiting inadvertent unwrapping or unraveling of the impregnated fiber skin


702


.




In that form illustrated in

FIGS. 18 and 19

, head structure


712


includes first and second pieces or members


720


and


730


, respectively. The members or pieces


720


,


730


of head structure


712


are joined by the elongated handle structure


714


extending, at least partially, therethrough.




As shown, the first member or piece


720


of head structure


712


is configured as a striking head with a striling surface


722


. In the illustrated embodiment of the invention, the other piece or member


730


of the head structure


712


has a claw-like configuration including a pair of laterally spaced tines or members


739


and


739


′.




In the illustrated form of the invention, and as made possible by the two-piece split head design, the head piece


720


includes an attachment portion


726


projecting away from and generally normal to the striking surface


722


. The head piece


730


likewise includes an attachment portion


736


defining an elongated opening


773


for endwise receiving the attachment portion


726


of head piece or member


720


. Notably, the opening


773


allows for radial expansion of the frayed free ends of the sock


702


in the manner described above. In the illustrated embodiment, the attachment portion


726


of head piece or member


720


has a generally semi-circular configuration extending axially away from the distal end of member


720


arranged opposite from the striking surface


722


to provide further space for expansion of the free ends of the braided sock


702


. Moreover, the distal end of the attachment portion


726


of head piece or member


720


defines an impact surface


728


arranged in confronting but spaced relationship to an impact surface


738


defined by an end wall of the elongated recess or opening


773


defined by head member or piece


730


. The confronting impact surfaces


728


,


738


on the heads


720


,


730


, respectively, are spaced from reach other in the same relationship described above to advantageously yield a dead-blow characteristic to the hammer


710


.




As shown in

FIGS. 18 and 19

, the attachment portion


726


of head piece or member


720


further defines an open ended recess or opening


727


extending therethrough. Similarly, the attachment portion


736


of the head piece


730


defines a throughbore or opening


737


for accommodating the handle structure


714


and which opens to an upper surface of the head piece or member


730


of head structure


712


. Notably, when the split head pieces or members


720


and


730


of head structure


712


are arranged in operative relationship relative to each other, as shown in

FIGS. 18 and 19

, the openings or recesses


727


and


737


defined by the attachment portions


726


and


736


of the head members


720


and


730


, respectively, of head structure


712


are in general registry with one another.




A lengthwise portion of handle structure


714


of tool


710


extends through the head pieces or members


620


,


730


of head structure


712


thereby joining them in operative combination relative to each other. In the embodiment of the invention schematically illustrated in

FIGS. 187 and 19

, handle structure


714


includes an elongated handle


740


, a member


716


extending endwise from that end of the handle


740


extending into the head structure


712


, and an elastomeric link


750


which operatively acts as a lengthwise extension of that portion of the handle


740


inserted into the head structure


712


.




The handle


740


of the handle structure


714


is preferably formed from a class of materials including: woods, such as hickory; plastic; metal; nylon; fiberglass; or other suitable rigid material. The handle


740


has opposed ends


742


and


744


. As shown in

FIGS. 18 and 19

, the end


742


of handle


740


is configured for insertion within the head structure


712


of the tool. In this regard, and to enhance its insertion within the head structure


712


, the end


742


of handle


740


preferably has an inwardly tapered configuration.




In the illustrated form of the invention, member


716


of the handle structure


714


has a generally wedge-like configuration but any suitable design would equally suffice without detracting or departing from the spirit and scope of the present invention. For example, a screw threaded into the free end


742


of the handle


740


would equally apply. Notably, member


716


axially extends from and is secured to the free end


742


of handle


740


of handle structure


714


. Moreover, the member


716


projects endwise through the openings


727


and


737


defined by the attachment portions


726


and


736


, respectively, of the heads or pieces


720


,


730


forming the head structure


712


.




To further reduce vibrations from being transmitted along the handle structure


714


during use of the tool


710


, handle structure


714


further includes the elastomeric link


750


for resiliently joining the head pieces or member's


720


,


730


of the head structure


712


to each other and to handle structure


714


. The elastomeric link


750


has a durometer hardness ranging between about 40 Shore A durometer hardness and about a 95 Shore A durometer hardness. As will be appreciated from an understanding of the present invention, the elastomeric link


750


acts as a spring for returning the nonstruck head of the head structure


712


to a normal or operational position after moving toward and impacting with the struck head or member of the head structure


712


. Accordingly, any suitable material which, during use of the tool


710


, will initially compress and subsequently return the unstruck head piece or member to an operational position relative to the struck head after the struck head has impacted with a surface will suffice.




Assembly of the impact tool


710


illustrated in

FIGS. 18 and 19

preferably involves the following steps and processes. The free end


742


of handle


740


, with the arimid sock to sleeve


702


arranged thereabout, is inserted into the head piece


730


of head structure


712


. The attachment portion


726


of head piece


720


is then inserted into the opening


773


and into operative relationship with the head member


730


. The epoxy or adhesive is the introduced through the openings


727


and


737


of the head pieces


720


,


730


, respectively, to impregnate and wet the arimid fiber sleeve


702


thereby enhancing the securement between the head structure


712


and handle structure


714


interface. Thereafter, member


716


of handle structure


714


is inserted into operative association with the free end


742


of handle


740


thereby causing outward radial expansion of the free end


742


of handle


740


and thereby further enhancing the securement between the head structure


712


and handle structure


714


interface. Next, an elastomer, such as polyurethane, is inserted or injected into the openings


727


and


737


of the head pieces


720


and


730


, respectively, to completely fill the voids and surround that portion of member


716


extending axially from the handle


740


. As will be appreciated, and when solidified, the polyurethane acts as the elastomeric link


750


joining the head pieces or members


720


,


730


of head structure to each other and to handle


740


.




The cover


704


can be arranged about the handle


740


of handle structure


714


prior to insertion of the handle


740


into operative association with the head structure


712


. After the head structure


712


and handle structure


714


are fixed to each other, the cover


704


is slidably moved into the position illustrated in

FIGS. 18 and 19

relative to the head structure


712


. Alternatively, and in a manner well known in the art, the cover


704


can be molded about the handle


740


of handle structure


714


after the head structure


712


and handle structure


714


are arranged in operative association relative to each other.




The split head impact tool described above has several advantages over heretofore known impact tools. Unlike other impact tools, the heads or members of the head structure of the present invention are formed separate from each other. As will be appreciated, separately forming the heads or members of the head structure facilitates interchangability and significantly simplifies the manufacturing process. Rather than having to forge an entire head assembly for a impact tool, various manufacturing methods or processes can be used to fabricate the heads or member so the head structure of then present invention in the most economical fashion possible. For example, the separate heads or members of the head structure may be individually forged, cast, or they can be formed as laminated formations depending on which manufacturing process best serves the manufacturers needs.




Unlike heretofore known impact tools, the separate heads of the head structure of the present invention are interconnected to each other by the handle structure of the tool extending therethrough. In a preferred form of the present invention, each head or member of the head structure includes a working end or portion and an attachment portion. The attachments portions or ends of the heads or members of the head structure are interconnected to each other by the handle extending therethrough in a manner heretofore unknown.




The split head design of the present invention advantageously offers a unique “dead blow” characteristic during use of the impact tool. This dead blow characteristic is enhanced when elastomeric material is provided between the heads and opposite sides of the handle structure. The elastomeric material between the heads and the handle structure serves to maintain impact surfaces defined by the heads of the head structure in a predetermined spaced relationship relative to each other. The predetermined spacing between the impact surfaces on the heads or members of the head structure ranges between about 0.010 inches and about 0.070 inches. The spacing between the heads of the head structure is dependent upon a number of factors including: mass distribution or the head configurations; the hardness of the elastomeric material between the heads and the handle structure; the time of the collision between the impact surfaces; the length of time the striking head of the head structure remains in contact with the struck surface; and, whether the struck surface is stationary or movable. These are a few of the considerations for setting the spacing between the heads of the head structure.




The separated head design offered by the present invention allows the unstruck head of the head structure to act as a lagging mass that suppresses the rebound of the struck head. That is, the split heads of the head structure of the present invention are permitted to axially move along a predetermined path relative to each other such that when one head of the head structure is impacted on a surface of an object, the other head of the head structure moves toward and collides with the struck head thereby providing a secondary blow keeping the struck head from rebounding and, thus, deadening the blow of the hammer or impact tool. Moreover, the elastomeric material between the head structure and the handle structure serves to isolate the handle from the heads or members of the head structure, thus, significantly reducing the vibrations transferred along the handle to the user.




The alternative laminated structure for the heads of the head structure furthermore allows one head of the head structure to be captured by the other head of the head structure to further simplify the present invention. End caps define a striking surface for the head structure of the tool and inhibits “splitting” of the laminations during use of the tool.




As will be appreciated by those skilled in the art, the composite structure of such an impact tool design offers several advantages regardless of whether the head structure embodies a split head design or is of unitary construction. First, using the arimid fiber material in combination with an epoxy offers increased strength between the head structure and handle structure interface. Second, such a composite structure isolates the head structure


712


from the handle structure


714


. Moreover, and because the skin


702


and epoxy add layers about that portion of the handle structure


714


passing into operative combination with the head structure


712


of the tool


710


, a more complex and complicated path needs to be traversed by the vibrations when the head structure


712


is struck against a surface. As will be appreciated, the more complicated path for vibrations to travel between the struck head and the handle advantageously yields vibration dampening characteristics during use of the tool


710


. Moreover, should a portion of the material skin or sock


702


extend beyond the head structure


712


and along a portion of the handle structure


714


, its appearance will undoubtedly add distinctiveness to the hammer design.




From the foregoing it will be observed that numerous modifications and variations can be effected without departing or,detracting from the true spirit and scope of the novel concept of the present invention. It will be appreciated that the present disclosure is intended to set forth exemplifications of the invention which are not intended to limit the invention to the specific embodiments illustrated. The disclosure is intended to cover by the appended claims all such modifications as fall within the spirit and scope of the claims.



Claims
  • 1. A hammer, comprising:a head assembly including first and second members, each member of said head assembly including a working portion and an integral attachment portion, and wherein the attachment portions of said members extend to opposite sides of a longitudinal axis defined by a handle structure; and with said handle structure extending generally perpendicular to and through the attachment portions of said first and second members thereby operably interconnecting said first and second members of said head assembly to each other; and an elastomer arranged in operable association with said handle structure and the attachment portions of the first and second members of said head assembly such that confronting and spaced impact surfaces defined on said first and second members of said head assembly are maintained in spaced relation relative to each other by a predetermined distance measuring between about 0.010 inches and about 0.070 inches.
  • 2. A hammer, comprising:a head assembly including first and second members, each member of said head assembly including a working portion and an attachment portion, with the attachment portion of each member extending to opposite lateral sides of an elongated axis defined by a handle structure; wherein said handle structure passes through and is secured to the attachment portions of said first and second members of said head assembly thereby limiting movement of the first and second members of said head assembly relative to the longitudinal axis of said handle structure, with said handle structure including an elongated handle extending generally perpendicular from said head assembly; and an elastomeric member arranged in operable association with the handle structure and said attachment portions of said first and second members.
  • 3. The hammer according to claim 2 wherein said members of said head assembly are metal.
  • 4. The hammer according to claim 2 wherein at least one of said members includes an exposed metal striking surface.
  • 5. The hammer according to claim 2 wherein one of said members is configured as a striking head while the other member is configured as a claw.
  • 6. The hammer according to claim 2 wherein said elastomeric member is formed from a urethane material having a durometer hardness ranging between about a 40 and about a 95 Shore A hardness.
  • 7. An impact tool, comprisinga head assembly including first and second members, each member of said head assembly including a working portion and an attachment portion, and wherein each member of said head assembly further includes an impact surface arranged in axially spaced but confronting relation to an impact surface on the other member; handle structure defining an elongated axis, with said handle structure passing through and secured to the attachment portions of the first and second members extending to opposite sides of said axis thereby interconnecting said first and second members to each other; and elastomeric material disposed in operable association with said first and second members of said head assembly for maintaining said impact surfaces in predetermined spaced relation relative to each other, said elastomeric material acting as a dampener such that when one member of said head assembly is struck against a surface the unstruck member moves toward the struck member to provide a force that inhibits the struck member from bouncing from the surface and such that rebound of the impact tool is significantly reduced.
  • 8. The impact tool according to claim 7 wherein at least one of the members of said head assembly has an exposed metal striking surface.
  • 9. The impact tool according to claim 7 wherein one of the members of said head assembly is configured as a striking head while the other member of said head assembly is formed as a claw.
  • 10. The impact tool according to claim 7 wherein the attachment portion of each member of the head assembly is arranged in surrounding relation relative to a lengthwise portion of said handle structure.
  • 11. The impact tool according to claim 7 wherein the axial spacing between the confronting surfaces of the members of said head assembly measures approximately 0.010 inches to about 0.070 inches.
  • 12. The impact tool according to claim 7 wherein both members of said head assembly are metal, and wherein said elastomeric member has a durometer hardness ranging between about 60 and about 95 Shore A hardness.
  • 13. The impact tool according to claim 7 wherein said handle is formed from a class of materials including: wood, plastic, metal, nylon, fiberglass, or elastomers.
  • 14. A generally T-shaped hammer, comprising:a head assembly including first and second heads, with said first head extending in a first direction and defining a striking surface thereon, said first head including an attachment portion extending away from said striking surface and to one side of an elongated axis, and with said second head extending in a second direction opposed to said first direction, said second head including an attachment portion extending to an opposite side of said elongated axis; handle structure extending generally normal to said first and second directions, said handle structure including an elongated handle whose longitudinal centerline defines said elongated axis, with a lengthwise section of said handle structure extending into operative association with the first and second heads and said head assembly thereby maintaining said heads in operable association relative to each other; elastomer material arranged in operative association with said first and second heads for maintaining confronting impact surfaces defined by said heads in a predetermined spaced relationship relative to each other; and a woven fiber material disposed about and epoxied to a lengthwise section of said handle structure extending into operative association with said head assembly to enhance the interface therebetween while adding strength to the hammer.
  • 15. The hammer according to claim 14 wherein said woven fiber comprises an arimid fiber.
  • 16. A shock absorbing claw hammer, comprising:a handle defining an elongated axis; and a head structure arranged in combination with and disposed at one end of said handle, said head structure including a striking head portion and a claw portion extending opposite from said striking head portion and defining a slit therebetween which opens to an exterior of said head structure, and wherein the striking head portion and the claw portion define confronting impact surfaces which are spaced a predetermined distance apart from each other, and wherein the head structure and handle combination is configured such that the impact surfaces are disposed to one side of the elongated axis with the spacing between said confronting impact surfaces collapsing upon a hammer strike thereby substantially eliminating vibrations in the handle resulting from the hammer strike.
  • 17. The claw hammer according to claim 16 wherein said handle comprises part of a handle structure, and wherein said handle structure and said head structure comprise individual pieces.
  • 18. The claw hammer according to claim 16 wherein said striking head portion and said claw portion comprise individual pieces.
  • 19. The claw hammer according to claim 17 wherein said striking head portion and said claw portion of said head structure each include attachment portions, and wherein at least a lengthwise portion of said handle structure extends endwise through the attachment portions of said head portion and said claw portion.
  • 20. The claw hammer according to claim 16 wherein the predetermined spacing maintained between the confronting impact surfaces of said striking head portion and said claw portion of said hammer ranges between about 0.010 inches and about 0.70 inches.
  • 21. A shock absorbing claw hammer, comprising:an elongated handle defining an elongated axis and having opposed sides; and a head structure arranged in combination with one end of said handle, said head structure including a striking head portion and a claw portion extending opposite from said striking head portion, and wherein the striking head portion and the claw portion define confronting impact surfaces, and wherein the head structure and handle combination is configured such that the impact surfaces are outwardly disposed to one side of the elongated axis and outwardly from opposed sides of said handle, and with a predetermined spaced relationship between said impact surfaces being maintained by an elastomer disposed within the head structure and which allows the spacing between the confronting impact surfaces to collapse other upon a hammer strike thereby substantially eliminating vibrations in the handle resulting from the hammer strike.
  • 22. The claw hammer according to claim 21 wherein said handle comprises part of a handle structure, and wherein said handle structure and said head structure comprise individual pieces.
  • 23. The claw hammer according to claim 22 wherein said striking head portion and said claw portion of said head structure each include attachment portions, and wherein at least a lengthwise portion of said handle extends endwise through the attachment portions of said head portion and said claw portion.
  • 24. The claw hammer according to claim 21 wherein said striking head portion and said claw portion comprise individual pieces.
  • 25. The claw hammer according to claim 21 wherein the predetermined spacing maintained between the confronting impact surfaces of said striking head portion and said claw portion of said hammer ranges between about 0.010 inches and about 0.70 inches.
PCT Information
Filing Document Filing Date Country Kind
PCT/US98/07479 WO 00
Publishing Document Publishing Date Country Kind
WO98/48978 11/5/1998 WO A
US Referenced Citations (22)
Number Name Date Kind
1045145 Hubbard Nov 1912 A
1501095 Brock Jul 1924 A
2451217 Heinrich Oct 1948 A
2737216 Kenerson Mar 1956 A
2776689 Falzone Jan 1957 A
2833323 Strickland May 1958 A
3000414 Cordis Sep 1961 A
4039012 Cook Aug 1977 A
4183385 Burkybile Jan 1980 A
4216808 Royce Aug 1980 A
4331193 Tudisco May 1982 A
4373565 Soto Feb 1983 A
4498464 Morgan, Jr. Feb 1985 A
4738166 Yamaguchi Apr 1988 A
4831901 Kinne May 1989 A
5012702 Taylor May 1991 A
5216939 Swenson Jun 1993 A
5249776 Johnson Oct 1993 A
5289742 Vaughan Mar 1994 A
5375487 Zimmerman Dec 1994 A
5408902 Burnett Apr 1995 A
5537896 Halder Jul 1996 A
Foreign Referenced Citations (1)
Number Date Country
412030 Feb 1991 EP