US3819288A

US3819288A - Adapter for fiberglass tool handles and other fiberglass connections

Info

Publication number: US3819288A
Application number: US00320554A
Authority: US
Inventors: J Carmien
Original assignee: Nupla Corp
Current assignee: Nupla Corp
Priority date: 1972-01-28
Filing date: 1973-01-02
Publication date: 1974-06-25
Anticipated expiration: 1991-06-25

Abstract

An adapter for connecting tool heads to fiberglass tool handles and for making other fiberglass attachments. An adapter which is preferably formed in two sections is mounted around and over the end of the tool handle. Interlocking means or frictional engagement are provided to hold the adapter in place. The upper portions of the exterior walls of the adapter sections are tapered complementarily to the inwardly tapered upper section of a conventional double tapered tool head opening and are adapted to make frictional engagement therewith. The adapter is capable of being cold molded to a limited degree to make a locking engagement with the tool head adjacent to the midportion of the tool head opening. A plurality of spacers are removably mounted in the adapter sections to compensate for variations in the tool head opening. Molded inserts are also provided so that a single adapter can be used on two different standard sizes of tool handles.

Description

Carmien 1.1] 3,819,288 June 25, 1974 ADAPTERFOR FIBERGLASS TOOL HANDLES AND OTHER IBERGLASS CONNECTIONS Inventor: Joseph Allen Cat-mien, Sun Valley,

Calif.

Assignee: Nupla Corporation, Sun Valley,

Calif.

Filed: Jan. 2, 1973 App]. No.: 320,554

Related U.S. Application Data Continuation-impart of Ser. No. 221,615, Jan. 28, 1972, Pat. No. 3,753,602.

U.S. Cl 403/247, 403/263, 403/369 Int. CL; B25g 3/24 8] Field of Search 403/247,.249, 250', 253, 403/254, 256, 257, 261, 26-3, 344, 369, 372,

References Cited UNITED STATES PATENTS 3/1882 Hardie 403/369- 6/1933 Cochrane 403/334-j 4/l950 Slayton, Jr. 403/247 X lZa 1 2,755,112 7/1956 Klancnik 403/263 X 'Primary Examiner-Werner H. Schroeder Attorney, Agent, or Firm-Robert C. Comstock 5 7] ABSTRACT An adapter for connecting tool heads to fiberglass tool handles and for making other fiberglass attachments. An adapter which is preferably formed in two sections is mounted around and over the end of the tool handle. Interlocking means or frictional engagement are provided to hold the adapter in place. The upper portions of the exterior walls of the adapter sections are tapered complementarily to the inwardly tapered upper section of a conventional double tapered tool head opening and are adapted to make frictional engagement therewith. The adapter is capable of being cold molded to a limited degree to make a locking engagement with the tool head adjacent to the midportion of the tool head opening. A plurality of spacers are removably mounted in the adapter sections to compensate for variations in the tool head opening. Molded inserts are also provided so that a single adapter can be used on two different standard sizes of tool handles.

10 Claims, 8 Drawing Figures /3a V A l g ADAPTER FOR FIBERGLASS TOOL HANDLES AND OTHER FIBERGLASS CONNECTIONS REFERENCES TO RELATED APPLICATION BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to an adapter for fiberglass tool handles such as hammers, sledges, axes, etc. which may also be used for other attachments or connections to fiberglass such as guy rods, catenaries, concrete reinforcing bars and any other uses where a connection is made to a fiberglass rod or bar.

2. Description of the Prior Art Until recent years, the only material used for handles in striking, cutting and/or prying tools such as hammers, sledges, peaveys, axes, etc. has been wood. For this reason, the method of attaching the handle to the head, whatever type it might have been, was dictated by the property characteristics of the material, namely wood.

On many tools other than picks and mattocks, the eyehole has a double taper or venturi shape, elliptical and conical, with the smallest cross section disposed at approximately the midpoint of the head. The upper conical section, which received the portion of the head farthest away from the grip, is for the purpose of allowing the wood to be expanded by means of a wedge, so that the wood is larger than the waist of the eyehole and the head cannot come off the wood handle when used.

The taper starting at the bottom, or the side into which the handle is normally inserted, is for the purpose of accommodating variations in the original wood handle size and the eyehole of the head and, more importantly, allowing the user to re-tighten the head when it becomes loose by driving the handle further into the head and then driving the original wedge further in or adding another wedge. v

An ideal tool handle is one which is formed of fiberglass rather than wood. Fiberglass is far stronger and far outlasts wood. Tool heads cannot be attached to fiberglass handles in the same manner in which they are attached to wood handles because, for example, a wedge cannot be driven into the end of a fiberglass handle in order to spread it in the manner conventionally used with a wood handle.

In this connection, it must be realized that most striking, prying and/or cutting tools are not precision made and, therefore, the eyehole has a rather liberal tolerance as to its size and shape.

Inasmuch as this invention contemplates a handle assembled to a head as a new product, and also a handle used as a replacement, the attachment method must accommodate thesevarying conditions.

SUMMARY OF THE INVENTION double tapered tool head opening, regardless of whatever variations may exist in the dimensions, tolerances and surface imperfections of the tool head opening.

Another object of the invention is to provide such an adapter which is capable of being used with two different standard sizes of tool handles and handle receiving openings.

The invention utilizes an adapter which is preferably divided into two sections. The interior of the adapter and the exterior of the handle are provided with mating means such as complementary notches and projections which prevent longitudinally axial movement of the adapter with respect to the tool handle.

Each of the adapter'sections has a closed top or end portion adjacent to which the exterior walls of the adapter sections are tapered outwardly in an amount somewhat greater than the inwardly directed taper of the upper portion of the tool head opening. The portion of the exterior walls of the adapter sections adjacent thereto is tapered complementarily to the tapering of the upper portion of the tool head opening and is adapted to form a frictional engagement therewith.

The head of the tool is first mounted on the handle. The adaptersections are then positioned surrounding the handle and in engagement therewith. The head of the tool is then slid along the handle into a position where its opening surrounds the adapterQThe head is then firmly driven onto the adapter until the upper portion of the adapter is firmly wedged within the upper tapered portion of the tool head opening.

In order to compensate for variations in the dimensions, tolerances and surface inperfections of various tool head openings, each of the adapter sections is preferably furnished to the user with three spacers removably mounted therein. The spacers are removed as required to provide a perfect fit between the adapter and tool head.

Since most tool heads are of two standard sizes which vary only in width, a pair of molded inserts are provided which permit the adapter to be used with either size of handle.

It is accordingly among the objects of the invention to provide an adapter for fiberglass tool handles which is capable of being used with substantially any tool head now in use or manufactured within the last twenty-five years. A more particular object of the invention is to provide such an adapter which utilizes removably mounted spacers which compensate for variations'iri dimensions and irregularities in various tool head openings.

Another object of the invention is to provide such an adapter which is capable of being used with two different standard sizes of tool handles.

A further object of the invention is to provide a tool handle mounting means which not only satisfies but actually far exceeds the'safety pull-off standards specified by the federal government.

It is accordingly among the objects of the invention to provide an adapter having all of the advantages and benefits of the structure set forth and described in further detail hereinafter in this specification.

The invention also comprises such other objects, advantages and capabilities as will later more fully appear and which are inherently possessed by the invention.

While there is shown in the accompanying drawings a preferred embodiment of the invention, it should be understood that the same is susceptible of modification 3 and change without departing from the spirit of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a tool with the adapter in use thereon;

FIG. 2 is a longitudinal sectional view of the adapter portion of the tool shown in FIG. 1, with two spacers in each adapter section;

FIG. 3 is a transverse sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is an enlarged partial sectional view similar to FIG. 2 showing the locking relationship between the adapter and tool head;

FIG. 5 is an exploded isometric view showing the spacer and the interior of an adapter section;

FIG. 6 is an isometric view of the exterior of the handle, showing the notch which receives the projections on the interior of the adapter sections;

FIG. 7 is an isometric view of an insert used for fitting a different size handle;

FIG. 8 is a transverse sectional view of an adapter section with an insert mounted therein and a spacer shown in phantom lines.

DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment which has been selected to illustrate the invention comprises a fiberglass elongated member 10. The elongated member 10 may comprise the handle of a tool or a rod or other member to which a connection or attachment is to be made. The elongated member 10 customarily has flat sides and rounded edges. The end of the elongated member 10 to which the attachment is to be made may be provided with a pair of oppositely disposed indentations 11.

A pair of identially formed hemispherical

crosssection adapter sections

12 and 13 are provided with vertically straight rounded interior surfaces which conform generally to and are complementary with the exterior of the rounded edges of the elongated member 10. Each of the

adapter sections

12 and 13 is provided on its interior with a pair of oppositely disposed projections 14 and 15 respectively which conform generally to and are complementary with the configuration of the indentations 11 in the end of the elongated member 10.

The outer walls of the

adapter sections

12 and 13 are tapered outwardly along a

short portion

12b and 13b respectively at their upper ends somewhat in excessof 4, which is the normal taper of a tool head opening. A short circumferential ridge 18 protrudes outwardly from the outer wall of each of the adapter sections in approximate alignment with the bottom of the

top walls

12a and 13a.

Beneath the ridge 18, slightly less tapered

portions

120 and 13c extend at approximately a 4 angle to adjacent the bottom of the projections 14 and 15. The remaining

lower portions

12d and 13d of the outer walls are substantially straight.

If the elongated member 10 comprises the handle of a tool, it is preferable for the ends of the adapter sections to extend longitudinally along the sides of the handle. In this way, any striking or prying force resulting from the use of the tool will not be directed in such a manner that it will tend to separate the adapter sections. In such case, which is illustrated in the drawings herein, each of the projections 14 and 15 extends approximately half way across each of the indentations l l.

The tool or the like to which attachment is to be made comprises a head 16 having extending therethrough a double tapered opening 17 comprising an inwardly directed tapered portion 17a at the top, an outwardly directed tapered portion 17b at the bottom and a straight midportion 17c therebetween.

A double tapered tool head opening should in theory comprise a pair of conical tapered portions directed inwardly from the top and bottom of the tool head and meeting at a point in the center. In actual practice, the cutting tools which form these openings do not quite reach the center. This leaves a wafer at the center which is punched out, leaving a straight side wall portion 170, between the inner ends of the two tapered side wall portions 17a and 17b. As the cutting tools become progressively worn, the thickness of the wafer and the center straight portion 17c increases. In the average tool head opening, there is accordingly a straight side wall portion 17c of varying length disposed at the center between the two tapered side wall portions 17a and 17b.

The

adapter sections

12 and 13 are preferably formed of material which is capable of being cold molded to a limited degree under pressure so that they will make a secure locking engagement with the tool head 16 in the manner described hereinafter and will also compensate for minor surface irregularities and tolerance variations in the head 16 and/or handle 10. The adapter material should also preferably have a high coefficient of friction, so that it forms a relatively high degree of frictional engagement with both the tool handle and head. At the present time, glass filled nylon has been found to be the most satisfactory material for use in forming the adapter. It has the properties set forth above, plus the strength and other properties required for the adapter. Polyurethane, polycarbonate, acrylonitrile butadiene styrene and similar moldable thermoplastic materials may also be used.

Removably mounted within each of the

adapter sections

12 and 13 as furnished to the user are three overlying spacers 20. The spacers 20 are preferably approximately ten thousandths of an inch thick. The spacers 20 may be formed of any suitable material, but fiber has been found particularly satisfactory in use. Other materials such as vinyl, fiberglass or phenolic sheet, insulating type fish paper or other comparable material may also be used.

The spacers 20 are formed from sheet material which is normally flat. When they are curved to fit within the interior of the

adapter sections

12 and 13, they try to return to a flat configuration and their side edges are accordingly resiliently urged into frictional engagement with the inner side walls of the adapter sections. The spacers 20 are also provided with notches 21 in their side edges which are formed complementarily to and are fitted around the projections 14 and 15. The upper ends of the spacers 20 are accordingly quite securely held between the

end walls

12a and 13a and the projections 14 and 15 in addition to the side edge frictional engagement described above.

The spacers 20 are preferably of progressively increasing length so that their lower ends are shingled with the longest on top, to permit them to be manually engaged one at a time for the purpose of removing the spacers from the adapter sections.

The spacers 20 are used tocontrolthe longitudinal positioning of the

adapter sections

12 and 13 within the tool head 16. It has been found that the manufacturers of forged tool heads have not consistently maintained high standards of accuracy with regard to dimensions and tolerances of the tool head openings 17. As a result, the present invention cannot be utilized in a universal manner with all tool heads unless some means is provided which will compensate for the variations which exist and which cannot be changed. The

adapter sections

12 and 13 are accordingly furnished to the user with three spacers 20 mounted within each adapter section. v

In order to mount the head 16, it is first slid over the end of the elongated member which carried the indentationsll. The two

adapter sections

12 and 13 are then mounted on the end of the elongated member 10 in such a position that their projections 14 and 15 fit into and engage the indentations 11. The head 16 is then moved back along the elongated member until the inwardly tapered portion 17a of the opening 17 makes substantial frictional engagement with the outer walls of the

adapter sections

12 and 13.

Further movement of the head 16 toovercome such frictional resistance may be achieved either by suitable mechanical means or by moving-the elongated member vertically and striking the outer ends 12a and 13a of the adapter sections upon the ground or upon any firm surface so that the weight of the head 16 acts to drive it downwardly into tighter frictional engagement with the outer walls of the

adapter sections

12 and 13. If there is a perfect fit, this action is continued until substantially the entire length of the 4 taper outer wall portions 12c and 130 of the adapter sections are in frictional engagement with the complementary 4 inwardly tapering portions 17a of the opening 17 in the tool head 16. When this occurs, the upper end'of the tool head 16 should be in substantial alignment with the ridges 18 on the outer walls of the

adapter sections

12 and 13. It is important to note that as the tool head 16 is driven into engagement with the

adapter sections

12 and 13, the outer walls of the adapter sections adjacent to the lower ends of the tapered portions 12c and 130 are severly compressed inwardly as they are driven through the straight midportion 17c of the opening 17.

Once they pass through the straight midportion 170,

they move radially outwardly by their own resilience to engage the upper part of the bottom inwardly tapered portion 17b of opening 17.

The outer walls of the

adapter sections

12 and 13 accordingly take-on to a limited degree an hourglass or double tapered configuration comparable to that of the opening 17. This is best shown in FIGS. 2 and 4 of the drawings, in which it will be seen that the portions of the walls and which are directly beneath or inwardly from the midportion of the tool head opening 17 are slightly wider than the midportion 17c and they form a locking engagement which, along with the frictional engagement above it, resists removal of the tool head 16. I

This compression and expansion of the

adapter sections

12 and 13 may be compared to cold molding in that the material forming the adapter sections is caused to cold flow and become molded into a locking configuration.

If the tool head 16 cannot be driven to the point where its upper edge is aligned with the ridges 18, the tool head is removed and one or more of the spacers 20 removed from either or both of the

adapter sections

12 and 13. Each spacer 20 which is removed will provide approximately 6 inch additional longitudinal movement of the tool head 16 with respect to the

adapter sections

12 and 13. It is accordingly possible to obtain precisely the proper positioning of the tool head 16 on the handle 10 regardless of the particular dimensions of the opening 17 through removal of the proper number of spacers 20.

The spacers 20 accordingly make the adapter truly universal so that it can be used in almost any tool head opening regardless of the amount of inperfections and variations in dimensions and tolerances.

Most of the tool handles (and tool head openings for receiving them) which are presently in use are 1 inch wide in their smaller transverse dimension, but may be either 1% inches or 1% inches in their longer transverse dimension. In order that the adapter of the present invention may be used with both sizes of handles, a pair of removable inserts 40 is provided. The insert 40 is shown in FIG. 7 of the drawings and is also shown in use within an adapter section in FIG. 8.

The inserts 40 are preferably molded from the same material as the

adapter sections

12 and 13, such as glass filled nylon or other moldable thermoplastic material. The insert 40 is substantially rigid and only slightly resilient, as opposed to the easy flexibility of the spacers 20. The insert 40 is formed in an arcuate configuration and has a crescent-shaped cross section, as best shown in FIG. 8. Its curvature is complementary to that of the inside of the adapter section and it is so constructed as to be easily but securely snap fit therein.

The midportion of the insert 40 has a thickness of approximately 62/ 1000 inch, so that an insert 40 mounted in each of the

adapter sections

12 and 13 effectively reduces the combined inner dimensions of the adapter sections by approximately A; inch. The inserts 40 accordingly permit use of the same adapter on a 1% inches handles with the inserts 40 and a 1% inches handle without the inserts.

The inserts 40 may be used along with the spacers 20, which are preferably mounted above the inserts 40.

The extreme flared

portions

12b and 13b at the upper end of the

adapter sections

12 and 13 act as an added safety feature to prevent the tool head 16 from accidentally coming off the end of the adapter.

I claim:

1. An adapter for connecting a tool head to a fiberglass tool handle and for making other attachments to fiberglass members in which a tool head or other member being attached has a double tapered opening with conical side walls tapering inwardly from the top and bottom thereof joined at the center by a short portion having substantially straight side walls, said adapter comprising a plurality of sections having a combined outwardly tapered exterior formed substantially complementarily to the upper tapered portion of said tool head opening and adapted to fit therein, said adapter being mounted on the end of said handle so that the end of said handle is substantially completely surrounded circumferentially by said adapter, engagement means between said adapter and tool handle for preventing substantial longitudinal movement of said adapter with respect to said handle, said tool head adapted to be brought into tighter engagement with said adapter by the application of force to the end of said tool handle, said adapter being formed of material which is solid but somewhat malleable, so as to becapable of being cold molded in response to pressure exerted thereon in mounting said tool handle on said adapter so that the exterior of said adapter is compressed inwardly as it is driven through the straight portion of said opening and then moves radially outwardly by its own resilience to engage the lower edge of the straight portion of said opening and form a locking engagement therewith which prevents undesirable longitudinal movement of said tool head with respect to said adapter, the exterior of said adapter also extending into surface irregularities and dimensional variations in the upper and midportion of said opening.

2. The structure described in claim 1, and at least one spacer removably mounted in each of said adapter sections, whereby said adapter can be used in tool head openings of various dimensions.

3. The structure described in claim 2, said spacers being held within said adapter sections by snap fit engagement resulting from bending flat sheet material to an arcuate configuration 4. The structure described in claim 3, there being a pair of said adapter sections having three of said spacers removably mounted in overlying relationship to each other within each of said sections.

5. The structure described in claim 4, each of said spacers having a thickness of approximately 10/1000 of an inch, whereby said spacers provide variability between two difierent standard sizes of tool head openmgs.

6. The structure described in claim 5, the lower ends of said spacers being shingled to facilitate manual removal of said spacers from said adapter sections.

7. The structure described in claim 1, there being a pair of said adapter sections, and a molded substantially rigid arcuate insert removably mounted within each of said adapter sections, said inserts being of sufficient thickness to permit the use of said adapter on handles of two different standard widths.

8. The structure described in claim 7, said inserts being held within said adapter sections by frictional engagement of their side edges with the interior of said adapter sections.

9. The structure described in claim 7, and at least one spacer mounted within each of said adapter sections in overlying relationship to said inserts.

10. The structure described in claim 9, there being three of said spacers mounted within each of said adapter sections in overlying relationship to said inserts, said spacers being held in place by snap fit engagement resulting from bending flat sheet material to an arcuate configuration.

Claims

1. An adapter for connecting a tool head to a fiberglass tool handle and for making other attachments to fiberglass members in which a tool head or other member being attached has a double tapered opening with conical side walls tapering inwardly from the top and bottom thereof joined at the center by a short portion having substantially straight side walls, said adapter comprising a plurality of sections having a combined outwardly tapered exterior formed substantially complementarily to the upper tapered portion of said tool head opening and adapted to fit therein, said adapter being mounted on the end of said handle so that the end of said handle is substantially completely surrounded circumferentially by said adapter, engagement means between said adapter and tool handle for preventing substantial longitudinal movement of said adapter with respect to said handle, said tool head adapted to be brought into tighter engagement with said adapter by the application of force to the end of said tool handle, said adapter being formed of material which is solid but somewhat malleable, so as to be capable of being cold molded in response to pressure exerted thereon in mounting said tool handle on said adapter so that the exterior of said adapter is compressed inwardly as it is driven through the straight portion of said opening and then moves radially outwardly by its own resilience to engage the lower edge of the straight portion of said opening and form a locking engagement therewith which prevents undesirable longitudinal movement of said tool head with respect to said adapter, the exterior of said adapter also extending into surface irregularities and dimensional variations in the upper and midportion of said opening.

3. The structure described in claim 2, said spacers being held within said adapter sections by snap fit engagement resulting from bending flat sheet material to an arcuate configuration.

4. The structure described in claim 3, there being a pair of said adapter sections having three of said spacers removably mounted in overlying relationship to each other within each of said sections.

5. The structure described in claim 4, each of said spacers having a thickness of approximately 10/1000 of an inch, whereby said spacers provide variability between two different standard sizes of tool head openings.