US3870091A

US3870091A - Hand tool connection and trim collar therefor

Info

Publication number: US3870091A
Application number: US463403A
Authority: US
Inventors: Oscar Burge Burgeson
Original assignee: Stanley Works
Current assignee: Stanley Works
Priority date: 1974-04-23
Filing date: 1974-04-23
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11
Also published as: JPS5813310B2; AU8048675A; JPS50145980A

Abstract

An aligned connection is provided between a hammer head and a handle without the necessity for fixturing by providing the tool head with a closed handle-receiving eye having a conical interior end wall, a handle loosely received within the eye to provide an annular space extending fully around the handle and a trim collar extending into the annular space. The innermost end of the handle engages the conical end wall to center the end of the handle within the eye and the preformed annular trim collar circumscribes the handle at the entrance end of the eye to assist in alignment of the handle within the hammer head. The trim collar includes an exposed trim portion and a concealed skirt portion, the latter having substantially the same cross-sectional dimensions as the annular space defined by the eye and the hammer handle. Fluid bonding material initially placed within the closed handle-receiving eye is displaced by the innermost end of the handle as it is brought into engagement with the conical end wall and the annular skirt portion of the trim collar is disposed within the annular space by a force fit connection to effectively align the handle within the eye and retain the handle in its aligned condition while the fluid bonding material hardens or sets to a solid impact resistant bonded state. The exterior trim portion of the trim collar provides a neat finished appearance to the handle connection.

Description

United States Patent 11 1 Burgeson 1 Mar. 11, 1975 1 HAND TOOL CONNECTION AND TRIM COLLAR THEREFOR [75] Inventor: Oscar Burge Burgeson, Bristol,

Conn.

[73] Assignee: The Stanley Works, New Britain,

Conn.

22 Filed: Apr. 23, 1974 21 Appl. No.2 463,403

[52] US. Cl 145/29 R, 145/29 B [51] Int. Cl B25d 1/00 [58] Field of Search 145/29 R, 29 A, 29 B, 29 C,

145/29 D, 30 R, 30 A, 30.5, 36

[56] References Cited UNITED STATES PATENTS 2,831,202 4/1958 Lay 145/29 R 2,994,353 8/1961 Yearley 145/29 B 3,355,226 11/1967 Portz 145/29 R 3,602,277 8/1971 Stump 145/29 R 3,792,725 2/1974 Burgeson 145/29 R Primary E.\'aminer-Al Lawrence Smith Assistant ExaminerMarc R. Davidson Attorney, Agent, or FirmPrutzman, Hayes, Kalb & Chilton [57] ABSTRACT An aligned connection is provided between a hammer head and a handle without the necessity for fixturing by providing the tool head with a closed handlereceiving eye having a conical interior end wall, a handle loosely received within the eye to provide an annular space extending fully around the handle and a trim collar extending into the annular space. The innermost end of the handle engages the conical end wall to center the end of the handle within the eye and the pre formed annular trim collar circumscribes the handle at the entrance end ofthe eye to assist in alignment of the handle within the hammer head. The trim collar includes an exposed trim portion and a concealed skirt portion, the latter having substantially the same crosssectional dimensions as the annular space defined by the eye and the hammer handle. Fluid bonding mate rial initially placed within the closed handle-receiving eye is displaced by the innermost end of the handle as it is brought into engagement with the conical end wall and the annular skirt portion of the trim collar is disposed within the annular space by a force fit connection to effectively align the handle within the eye and retain the handle in its aligned condition while the fluid bonding material hardens or sets to a solid impact resistant bonded state. The exterior trim portion of the trim collar provides a neat finished appearance to the handle connection.

5 Claims, 4 Drawing Figures 1 HAND TOOL CONNECTION AND TRIM COLLAR THEREFOR BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates generally to hand tools of the percussive or impact type such as hammers and the like. More particularly, the present invention is concerned with the connection between the head and the handle of such tools and finds particular application in hand tools using handles made from synthetic materials such as fiber reinforced plastics and the like.

With the advent of low cost synthetic materials considerable interest has been generated in the use of fiber glass reinforced handles for hand tools and the like. However the traditional means of interconnecting the handle with the tool head such as a hammer head has involved the use of the usual wedges and these wedges have proven unsatisfactory for synthetic materials due to the tendency of such materials to split and delaminate. Accordingly, efforts have been directed toward the use of suitable bonding adhesives of the impactresistant type. However, in order to provide an effective and long lasting connection it has been necessary to assure positive bonding of the handle along a major axial extent of the eye within the tool head. This, in turn, has necessitated provisions for a gap or space between the head and the handle along a substantial portion of the eye to accommodate the resin and has required the use of aligning devices to accurately hold the two spaced components in an aligned condition during the application and curing of the bonding resin. In order to provide proper positioning of the head relative to the handle, fixturing of these components was found to be necessary and this introduced additional manufacturing operations and costs that detract from the advantages of using. such materials. Additionally, an unsightly gap was visible between the eye of the tool head and the handle at the end of the eye from which the handle protrudes. Although this gap could be covered with a trim collar to provide a finished appearance, the collar was merely a decorative band serving only an aesthetic function.

Accordingly, it is an object of the present invention to provide a new and improved connection between the handle and the head of an impact tool that includes a trim collar construction extending into the eye of the tool head for a short distance to assist in providing proper alignment between the tool head and the handle positioned within the eye of the tool head while sealing the gap therebetween.

Another object of the present invention is to provide a new and improved handle connection of the type described which utilizes a closed handle socket and a trim collar capable of cooperating therewith to provide the necessary alignment between a loose fitting handle and the tool head without fixturing while at the same time imparting improved appearance to the assembly and facilitating the formation of a tight, effective connection having a prolonged and useful life. Included in this object is the provision for a trim collar of non-impacttransmitting character that extends into the eye of the tool head to provide a force fit connection and seal between the eye and the tool handle.

A further object of the present invention is to provide a tool handle connection including a trim collar capable of preventing leakage of the bonding resin while at the same time resisting rotation of the handle relative to the tool head while the'resin is hardening. Included in this object is the provision for a new and improved interconnection between a tool head and a fiberglass handle of a character where the handle is smaller than the eye so that there is an extremely loose fit between the tool head and handle yet the connection provides the aforementioned sealing and aligning capabilities in an attractive tool of high quality.

' Other objects will be in part obvious and in part pointed outin more detail hereinafter.

These and related objects are accomplished in accordance with the present invention by providing a hand tool comprised of a tool head with a closed handlereceiving eye having a tapered interior end wall, a handle having an end portion positioned within the eye a sufficient distance to engage the end wall and being substantially free of direct contact with the tool head except at the end wall to provide an annular space extending fully around the handle portion within the eye, a pre-formed annular trim collar sealably interconnecting the handle and the tool head and a bonding resin providing a tight and durable interconnection therebetween. The annular trim collar is comprised of an exposed trim portion and a concealed skirt portion having substantially the same cross-sectional dimensions as the annular space around the handle and is disposed within the space to effectively seal the open end of the eye. The skirt portion is held in position by a force fit interconnection with the tool head and handle. The bonding resin is disposed within the annular space sealed by the trim collar for bondably joining the head and handle in a tight effective connection.

A better understanding of the objects, advantages, features, properties and relations of the invention will be obtained from the following detailed description and accompanying drawing which set forth certain illustrative embodiments and are indicative of the various ways in which the principles of the invention are employed.

BRIEF DESCRIPTION OF THE DRAWING In the drawing: FIG. 1 is a side view of a hammer incorporating one embodiment of the handle connection of the present DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing in greater detail wherein like reference numerals indicate like parts throughout the several figures, the invention is shown as embodied in a hammer having a forged steel hammer head 10 of the claw type provided on one end with the usual poll and bell 12 including a striking surface 14 and at the other end with bifurcated claws 16. A transversely projecting shank or neck portion 18 is disposed intermediate the ends. A closed handle-receiving eye 20 extends centrally into the head 10 passing axially through the shank 18 from an entrance end 22 at the free end of the shank l8 and terminating within the interior of the head in a conical end wall 24. As best seen in FIGS. 2 and 3 the eye is of uniform size and shape along its entire length and is of circular cross section. However, as will be apparent, the principles of the present invention will apply equally well if the side walls are noncircular throughout their full extent or even taper slightly toward the ends of the eye. Consequently, it is clear the present invention may utilize existing equipment and manufacturing techniques for the tool head construction thereby effecting considerable economies in the manufacturing operation.

For purposes of illustration and in accordance with the preferred embodiment, a tool handle 28 formed of fiber-reinforced material such as resin impregnated fiberglass is shown as an elongated, straight, rodlike member of substantially uniform cross section throughout its entire length. The handle mounts a contoured hand grip 30 over its free end while an opposite end portion 32 is disposed within the eye 20 of the tool head. The rodlike handle 28 is of generally circular cross section, at least along the portion 32 positioned within the eye, and of substantially smaller diameter than eye 20 so that an annular spacing 34 is provided between the handle and the tool head.

The preferred handle material for use in the assembly of the present invention is molded glass fiber reinforced polyester. Such material is substantially less susceptible to dimensional variation under differing ambient humidity conditions and exhibits higher tensile strength and greater resistance to compressive forces than the conventionally employed wooden handles. Extruded fiberglass filaments extend continuously along the handle in a substantially straight manner and constitute at least sixty percent by weight and preferably seventy to seventy-five percent by weight of the handle. These continuous filaments or strands are embedded within and encompassed by the resin to provide a smooth, aesthetically pleasing exterior appearance for the handle. If desired, the handle portion 32 positioned within the eye 20 may be provided with a side notch (not shown) to enable the bonding resin of the connection to freely flow therein during assembly and form a mechanical interlock with the handle.

Since the handle 28 exhibits cross-sectional dimensions that are substantially smaller than the crosssectional dimensions of the eye 20 there is no direct contact between the handle 28 and the side walls of the eye when the handle is centrally located within the eye. However, the circular peripheral edge 38 at the innermost end of the handle rests against the conical interior end wall 24 of the eye and, due to the walls conical configuration, slides therealong until it is centered within the eye.

As mentioned, the tool head connection of the present invention is directed to those tools having no direct contact between the handle and the tool head except at the end wall, i.e., the parts are sized to provide the annular space or clearance gap 34 between the side walls of the eye and the handle portion 32 positioned within the eye. In such an assembly it is of utmost importance to maintain proper alignment between the striking face 14 of the tool and the longitudinal axis of the handle in order to provide for proper operation of the tool as well as appropriate balance, feel and heft. This can be achieved by both the engagement of the handle periphery 38 with the conical end wall 24 and the use of an alignment skirt at the entrance end 22 of the eye.

In accordance with the present invention a new and improved trim collar is utilized to assist in this alignment operation. Referring particularly to FIGS. 1-3, the trim collar 40 illustrated therein is a preformed annular ringlike member of generally circular configuration and constructed of suitable plastic material. For example, good results have been obtained using a vinyl plastic such as polyvinyl chloride plastic sold by B. F. Goodrich Chemical Co. under the trademark Geon 8814GP" and having a durameter value of A-85A. The collar 40 is comprised of a concealed skirt portion 42 and an exposed trim portion 44 that not only assures a neat external appearance at the entrance end 22 of the eye but also firmly abuts the neck 18 of the tool head at the entrance periphery of the eye to assure a positive seal for retaining the bonding resin within the eye and prevent leakage thereof as the resin hardens. The concealed skirt portion 42 of the collar exhibits substantially the same cross-sectional dimension as the annular space defined by the walls of the eye and the handle portion 32 mounted therein. In fact, in practice the thickness of the concealed skirt portion 42 is slightly greater than the annular space within which it must fit in order to provide the desired force-fit or interference-fit connection between the trim collar and both the handle and the tool head.

The ringlike trim collar 40 defines a central, axially extending aperture 46 having substantially the identical shape as the periphery of the tool handle 28. The aperture 46 is substantially uniform in size throughout the skirt portion 42 but is provided with a slight diverging taper as it extends from the skirt portion through the trim portion 44 to the outer end thereof. In the preferred embodiment, the tapered portion of the aperture 46 is sufficiently divergent so that the size of the aperture at the bottom of the trim collar is slightly larger than the periphery of the tool handle and permits smooth initial insertion of the handle 28 into the aperture during the assembly operation.

The exterior of the concealed skirt portion 42 is of circular configuration and is substantially identical in size and shape to the entrance end 22 of the eye. However, the external periphery of the concealed skirt portion 42 is slightly larger than the peripheral opening of the eye 20 at its entrance end 22 so that upon insertion of the trim collar 40 into the eye, a firm interference or force fit is effected between the collar and the walls of the eye.

The exposed trim portion 44 of the collar 40 is provided with a shoulder 48 extending outwardly from the concealed skirt portion 42 at substantially a right angle thereto. When the collar is mounted on the tool head, the shoulder rests against the end of shank 18 and positively seals and conceals the entrance end 22 of the eye. A tapered, exterior trim surface 50 extends from the shoulder 48 toward the end of the collar to provide a neat, finished appearance to the connection between the tool head and the handle.

As will be appreciated, the trim collar centers the handle 28 and provides a secure seal at the entrance end of the eye to prevent leakage of the bonding resin 52 after assembly of the tool. The liquid resin placed within the eye prior to assembly is displaced by the end of the handle as it is inserted into the eye and as the edge 38 comes to rest against the conical end wall 24.

The annular gap 34 is sufficient in radial dimension to enable the resin to flow-freely between the confronting walls of the handle and the eye around the entire periphery of the handle so that peripheral gaps in bond between the handle and the head are avoided. As mentioned, the end wall centers the end of the handle. Simultaneously, the collar and particularly the skirt portion 42 also centers the handle at the entrance end 22 of the eye. The two centering locations hold the handle 28 in place while the resin, now displaced into the annular space 34, hardens or cures to a solid impactresistant condition and forms a firm connection between the handle and the tool head. No fillers or wedges are required since the clearance gap is preferably narrow.

Referring now to FIG. 4 of the drawing, there is illustrated an alternative embodiment of the handle connection of the present invention. A tool head 70 of a ball peen hammer or the like is provided with a handlereceiving, cylindrical, closed-eye socket 72 having a conical interior end wall 74 and a counterbore 76 at its entrance end. The counterbore 76 extends into the eye 72 for only a short distance. In this embodiment a handle portion 32 of handle 28 is positioned within socket 72 so that edge 38 contacts the conical end wall 74. A generally cylindrical trim ring 80 is provided with a skirt portion 82 of greater thickness than the corresponding skirt portion 42 illustrated in FIG. 2 and is received within the annular gap at the counterbore 76. As shown, the trim collar may also be provided with a trim portion 84 that is essentially of cylindrical external configuration. As will be appreciated, the skirt 82 will perform the same centering and scaling function in this embodiment as skirt 42 and will cooperate with the handle to appropriately maintain the handle within its desired centered location as the impact-resistant resin hardens within the annular space between the handle and the side walls of the eye.

As can be seen by persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.

I claim:

1. A hand tool for percussive use comprising a toolhead having a closed handle-receiving eye with a generally concave interior end wall, a handle having an end portion positioned within the eye a sufficient distance to engage said end wall, said handle portion being substantially free of direct contact with the tool head except at the end wall to provide an annular space extending fully around the handle portion within the eye. a preformed, annular trim collar sealably interconnecting the handle and the tool head comprised of an exposed trim portion and a concealed skirt portion having substantially the same cross-sectional dimension as the annular space and being disposed within the space, said skirt portion being held in position by a force fit interconnecting and cooperating with the tapered end wall to maintain the handle in a stabilized axial position within the eye; and an impact resistant resin disposed within said annular space for bondably joining said tool head and said handle.

2. The hand tool of claim 1 wherein said eye and said handle end portion are substantially cylindrical with the handle being of sufficiently smaller diameter to provide said annular space along the entire length of the eye.

3. The hand tool of claim 1 wherein said interior end wall is of conical configuration, and the handle portion has an edge on the end thereof engaging the conical wall to center the end of the handle within the eye.

4. The hand tool of claim 1 wherein said eye is counterbored at its exterior end, and the skirt portion of the trim collar firmly seats within the counterbore.

5. The hand tool of claim 1 wherein the handle is a reinforced glass fiber member of uniform circular cross-section, said end wall is conical and the engagement between the handle and the conical wall centers the handle within the eye.

Claims

1. A hand tool for percussive use comprising a tool head having a closed handle-receiving eye with a generally concave interior end wall, a handle having an end portion positioned within the eye a sufficient distance to engage said end wall, said handle portion being substantially free of direct contact with the tool head except at the end wall to provide an annular space extending fully around the handle portion within the eye, a preformed, annular trim collar sealably interconnecting the handle and the tool head comprised of an exposed trim portion and a concealed skirt portion having substantially the same cross-sectional dimension as the annular space and being disposed within the space, said skirt portion being held in position by a force fit interconnecting and cooperating with the tapered end wall to maintain the handle in a stabilized axial position within the eye; and an impact resistant resin disposed within said annular space for bondably joining said tool head and said handle.