WO1998008372A1

WO1998008372A1 - An adapter kit for a rotary trimmer attachment

Info

Publication number: WO1998008372A1
Application number: PCT/US1997/015191
Authority: WO
Inventors: Jeffrey B. Mounce; Bruce V. Diamond
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-08-28
Filing date: 1997-08-28
Publication date: 1998-03-05
Anticipated expiration: 1999-02-28

Abstract

An adapter kit (10) comprising a conversion member (30), an attachment member (40), a means (37, 39) for positioning the attachment member (40) so that the attachment member (40) is radially and longitudinally fixed relative to the conversion member (30), and a means (28A/28B) for detachably securing the attachment member (40) to the mounting member (26) of the rotary trimmer (15). When the adapter kit (10) of the present invention connects the mounting member (26) to the trimming head (20), rotation of the rotary trimmer (15) causes the trimming head (20) to rotate, which thus allows the attached cutting members (22) to cut vegetation. The adapter kit (10) allows different models, brands, and sizes of rotary trimmers to be individually connected to a single trimming head (20) by providing an attachment member (40) designed to connect to the mounting member (26) of the rotary trimmer (15).

Description

An Adapter Kit for a Rotary Trimmer Attachment

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention is directed to rotary trimmers for trimming vegetation and, more specifically, to an adapter kit that allows one trimming head to be used with different models, sizes, and designs of rotary trimmers that are manufactured by various companies.

Background Art

Hand-held rotary cutters, or trimmers, are well known in the art. Rotary trimmers usually have a motor at the top end of an elongated support member and a trimming head at the lower end. The trimming head has cutting members disposed on it.

A drive shaft is disposed within the support member and connects the motor, which can be electric or a two-cycle combustion engine, to the trimming head. A mounting member disposed at the lower end of the drive shaft connects the trimming head to the drive shaft. Thus, the motor drives the trimming head in a rotating pattern so that the spinning cutting members cut vegetation.

The user moves the rotating trimming head substantially parallel to the ground surface so that it cuts vegetation. Since the trimming head is relatively small, it can be easily manipulated in small areas and around obstacles. This ease of movement is not possible with larger vegetation trimming devices, such as a lawn mower.

Many different types of cutting members can be disposed on the trimming head. The most common attachment has mono-filament nylon lines that rotate with a sufficient angular velocity to cut grass and similar vegetation. The line is usually disposed at two places on opposite sides of the trimming head and fed from a self-contained reel. Another example of cutting members is flexible flat-link chains that are used to cut heavier vegetation but that still retain flexibility to prevent damage from occurring during incidental contact against fixed objects. Such a design is disclosed in U.S. Patent No. 4,631,828, issued to Burnett, which is hereby incorporated by reference. Still another example of cutting members are pivotally mounted nylon blades. This embodiment is shown in U.S. Patent No. 4,270,271, issued to Feldman et al. Thus, there are numerous types of trimming heads.

A problem exists, however, in the prior art because manufacturers of rotary trimmers do not use a universally accepted mounting member to connect the trimming head to the rotary trimmer. For example, a trimming head that is adapted to be used with a Weedeater^® brand rotary trimmer may not fit on a Toro^® brand rotary trimmer and vice versa. There are at least thirty-four manufactures of rotary trimmers that use numerous different mounting members, including the following brands: Echo^®, Homelite^®, John Deere^®, and McCulloch^®. Accordingly, a manufacture of trimming heads must make numerous models to fit the various rotary trimmers on the market. Therefore, a need exists in the art for an apparatus that allows a single trimming head to be used with rotary trimmers manufactured by different companies.

SUMMARY OF THE INVENTION

The present invention satisfies the need in the art for an adapter kit that allows one trimming head to be used with different models and sizes of rotary trimmers. The present invention encompasses an adapter kit that allows a single trimming head to attach to mounting members having different dimensions

The adapter kit preferably comprises a conversion member, an attachment member, a means for positioning the attachment member so that the attachment member is radially and longitudinally fixed relative to the conversion member, and a means for detachably securing the attachment member to the mounting member of the rotary trimmer. When the adapter kit of the present invention connects the mounting member to the trimming head, rotation of the rotary trimmer causes the trimming head to rotate, which thus allows the attached cutting members to cut vegetation. The adapter kit of the present invention allows different models, brands, and sizes of rotary trimmers to be individually connected to a single trimming head by providing an attachment member designed to connect to the mounting member of the rotary trimmer. The present invention thus alleviates the necessity for a consumer owning two different rotary trimmers to purchase one trimming head for one rotary trimmer and another trimming head for the other rotary trimmer. This invention also allows a single replacement head to be sold packaged with a plurality of attachment members so that one package may be sold to be used with many models of rotary trimmers.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an exploded front view of one embodiment of the present invention.

Fig. 2 is an exploded front view of a second embodiment of the present invention.

Fig. 3 A is a side view of a conversion member of the present invention.

Fig. 3B is a bottom end view of the conversion member of Fig. 3A.

Fig. 4 A is a side view of a stud-type attachment member of the present invention.

Fig. 4B is a top end view of the attachment member of Fig. 4A.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, "a" can mean one or more, depending upon the context in which it is used.

Referring now to Figs. 1 and 2, the present invention encompasses an adapter kit 10 for connecting a trimming head 20 to a selected rotary trimmer 15. The trimming head 20 uses cutting members 22, such as mono-filament lines (not shown), chains 22A, or blades 22B to cut vegetation. The rotary trimmer 15 has a motor (not shown) and a drive shaft (not shown) connected to the motor. The drive shaft, which is disposed within a hollow, elongated support member 25, mechanically links a mounting member 26 disposed at its lower end to the motor disposed at the opposite, upper end of the support member 25. For safety, a debris guard 29 is often placed adjacent the lower end of the support member 25.

The trimming head 20 has a center cavity 24 disposed through it to which the mounting member 26 connects. When the adapter kit 10 of the present invention connects the mounting member 26 to the trimming head 20, rotation of the rotary trimmer 15 causes the trimming head 20 to rotate, which thus allows the attached cutting members 22 to cut vegetation.

The adapter kit 10 preferably comprises a conversion member 30, an attachment member 40, a means for positioning the attachment member 40 so that the attachment member 40 is radially and longitudinally fixed relative to the conversion member 30, and a means for detachably securing the attachment member 40 to the mounting member 26 of the rotary trimmer 15. An important aspect of the adapter kit 10 of the present invention is that it allows different models, brands, designs, and sizes of rotary trimmers to be individually connected to a single trimming head 20. Prior to the present invention, a user would have had to purchase one trimming head 20 designed to be used with a specific rotary trimmer and another trimming head 20 for a different rotary trimmer. The present invention advantageously allows a single trimming head 20 to be used with many different rotary trimmers. Now referring to Figs. 3A and 3B, the conversion member 30 has an upper end 32 disposed adjacent the rotary trimmer 15, an opposite lower end 34, and an outer surface 36. The conversion member 30 also defines a longitudinally-extending bore 37 therethrough. The bore 37 forms an inner surface 38 within the conversion member 30. The outer surface 36 of the conversion member 30 is of a size to be complementarily received in and secured to the center cavity 24 of the trimming head 20.

It is desired that the outer surface 36 of the conversion member 30 and the surface of the center cavity 24 further comprise an interlocking means. The interlocking means comprises the surfaces of the center cavity 24 and the conversion member 30 engaging each other so that the two surfaces interlock. Preferably, the two surfaces have a plurality of complementary, longitudinally-extending ribs 39, wherein the ribs 39 are radially locked with each other. This interlocking means is advantageous to prevent radial slippage as the mounting member 26 rotates the trimming head 20. Other interlocking means can include complementary threaded connections and other complementarily shaped surfaces that prevent radial slippage.

In use, one attachment member 40 is selected from a plurality of attachment members 40, in which each of the attachment members 40 can be attached to a rotary trimmer 15 of a different size or design. That is, although there are preferably a plurality of attachment members 40 in the adapter kit 10 of the present invention, one attachment member 40 is used at a time. The attachment member 40 used is for a predetermined rotary trimmer 15 and the other attachment members 40 are for other brands, models, configurations, or sizes of rotary trimmers.

Each of the attachment members 40 has a first end 42, an opposed second end 44, and an exterior surface 46. At least a portion of the exterior surface 46 of each attachment member 40 is of a size to be complementarily received within the bore 37 of the conversion member 30. The design of the attachment member 40 is important of the positioning means, which preferably radially and longitudinally fixes the attachment member 40 relative to the conversion member 30. Preferably, the portion of the exterior surface 46 of the attachment member 40 that is received within the bore 37 of the conversion member 30 has at least three substantially flat faces 48. As shown in Figs. 1, 2, 4A, and 4B, each face 48 has opposed edges 49 so that each of the edges 49 is juxtaposed with one edge 49 of another face 48. The faces 48 circumscribe the exterior surface 46 of the attachment member 40. In the preferred embodiment, which is shown best in Fig. 4B, the attachment member 40 has six substantially flat faces 48 circumscribing the exterior surface 46 of the attachment member 40 so that the exterior surface 46 of the attachment member 40 forms a hexagon in cross section. This portion of the exterior surface 46 of the attachment member 40 is thus similar to a conventional "hex" nut

The detachably securing means attaches the attachment member 40 to the mounting member 26 of the rotary trimmer 15 There are two common mounting member 26 designs, one that has a male connector 26A extending therefrom and another that includes a female connector 26B. For the rotary trimmer 15 having the male connector 26A, which is shown in Fig. 2, the attachment member 40 defines a longitudinally-extending opening 50 through at least a portion thereof in which the opening 50 has an end 52 disposed adjacent the first end 42 of the attachment member 40 The opening 50 forms an interior surface 54 within the attachment member 40 The opening 50 is of a size to complementarily receive at least a portion of the male connector 26 A of the mounting member 26 of one predetermined rotary trimmer 15 Preferably, the detachably securing means comprises the interior surface 54 of the opening 50 and at least a portion of the male connector 26A of the mounting member 26 of the rotary trimmer 15 having complementary threaded surfaces that engage each other. This embodiment is a "nut-type" attachment member.

For the mounting member 26 that has a female connector 26B, the attachment member 40 has a stud portion 56 extending therefrom, instead of having an opening 50. As shown in Figs. 1 and 4 A, the stud portion 56 protrudes from the first end 42 of the attachment member 40. The stud portion 56 is of a size to be complementarily received within the female connector 26B of the mounting member 26 of one predetermined rotary trimmer 15. A shaft sleeve 29 is also used with this embodiment for establishing and maintaining the spacing and alignment of the trimming head 20 relative to the rotary trimmer 15. The detachably securing means, similar to the nut-type attachment member 40, preferably comprises the female connector of the mounting member 26 and at least a portion of the stud portion 56 having complementary threaded surfaces that engage each other in this embodiment. This embodiment is a "stud-type" attachment member.

In the preferred adapter kit 10, there are nine attachment members 40 ~ five nut- type and four stud-type attachment members. Each of the nut-type attachment members has a different inside thread diameter and each of the stud-type attachment members has a different outside thread diameter so that the adapter kit 10 can be used with the mounting members 26 of all types of rotary trimmers. Examples of the different rotary trimmers include brands such as Weedeater^®, Echo^®, Homelite^®, John Deere^®, McCulloch^®, and the like.

When the selected attachment member 40 is disposed within the bore 37 of the conversion member 30, the positioning means ensures that the attachment member 40 is radially fixed relative to the conversion member 30. The positioning means preferably comprises the bore 37 of the conversion member 30 being of a size to complementarily receive and securably engage the attachment member 40 therein so that the attachment member 40 is radially fixed relative to the conversion member 30. In the preferred embodiment, the conversion member 30 and the attachment member 40 are both hex- shaped, similar to a socket wrench and a correspondingly sized nut. The complementary shapes of the conversion member 30 and the attachment member 40 are shown in Figs. 3B and 4B, respectively. Tests show that a 1/2, 9/16th and 5/8th inch hex-shaped attachment members 40 are all desirable. Other positioning means are also contemplated, such as the design discussed above for the interlocking means used with the conversion member 30 and the trimming head 20. Thus, the mounting member 26 of the rotary trimmer 15 is connected to the attachment member 40, which is disposed within and radially fixed relative to the conversion member 30 The conversion member 30 is secured to the center cavity 24 of the trimming head Accordingly, rotation of the mounting member 26 by the motor causes the attachment member 40 to rotate and the conversion member 30 to rotate so that the trimming head correspondingly rotates. Rotation of the trimming head 20 allows the user to cut vegetation safely

The positioning means preferably further comprises a means for locating the first end 42 of the attachment member 40 at a desired longitudinal position within the bore 37 of the conversion member 30 A circular bore has a diameter and, if the bore is not circular, then it has an effective diameter, in which

D_eff=(2)x((A_bore)/(π))⁰⁵, wherein D_eff is the effective diameter and A_t,^. is the cross-sectional area of the bore 37 The preferred locating means encompasses the effective diameter of the upper end 32 of the bore 37 of the conversion member 30, shown as D,, being smaller than the effective diameter of the lower end 34 of the bore 37, shown as D₂

The first end 42 of the attachment member 40 is slidably received into the lower end 34 of the bore 37 The first end 42 of the attachment member 40 longitudinally traverses at least a portion of the bore 37 until the first end 42 contacts the portion of the bore 37 adjacent its upper end 32 where the effective diameter decreases Accordingly, the attachment member 40 is positioned at a desired longitudinal position within the bore 37

In the preferred embodiment, the upper end 32 of the bore 37, which has the smaller diameter D₂, is disposed between the first end 42 of the attachment member 40 and the rotary trimmer 15 and is held there by the detachably securing means. The locating means fixes the attachment member 40 at the desired longitudinal position and the detachably securing means holds the attachment member 40 at this desired longitudinal position by the respective male or female connector 26A, 26B connecting to the attachment member 40.

It is further contemplated that a selected one of the plurality of attachment members 40 can be directly disposed within the center cavity 24 of the trimming head 20 without the conversion member 30. That is, the conversion member 30 is not used and the positioning means comprises the attachment member 40 being radially fixed relative to the trimming head 20. This alternate embodiment, however, is not preferred because of engineering considerations. For example, it is equally effective to design a smaller conversion member 30 to handle the stresses of operating the rotary trimmer 15 cutting vegetation as opposed to a larger trimming head 20 to handle these same stresses.

In the preferred embodiment, the conversion member 30 is made of a material, such as ceramic filled nylon or a hardened plastic, to handle the operating stresses and the trimming head 20 is made from a more ductile plastic. In the alternate embodiment that does not use a conversion member 30, the entire trimming head 20 would have to be harder, and therefore more brittle, for the stress loading requirements. In addition, the preferred attachment member 40 is made of steel or similar material.

Prior to the present invention, companies have had to market trimming heads 20 as different devices to correspond to a specific rotary trimmer because of variations in shaft sizes of rotary trimmers 15. The present invention allows these companies now to manufacture and market a single trimming head along with the adapter kit 10. This decreases costs, for the consumer. Another advantage is that the trimming head can be used with rotary trimmers made by different companies if, for example, the consumer owns multiple rotary trimmers (e.g., a landscaping company) or replaces the rotary trimmer with a different model. In contrast, prior to the present invention, a consumer would have had to purchase one trimming head 20 designed to be used with a specific rotary trimmer and another trimming head 20 for a different rotary trimmer. Although the present device has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims

Claims

What is claimed is:

1. An adapter kit comprising: a. an attachment member having two opposed ends and an exterior surface, at least a portion of said exterior surface being of a size to be complementarily received in and secured to a center cavity of a trimming head, wherein the attachment member is selected from a plurality of attachment members, each attachment member being complementary to a mounting member of a rotary trimmer having different sizes; b. means for positioning said attachment member within the center cavity of the trimming head so that said attachment member is radially fixed relative to the center cavity; and c. means for detachably securing said attachment member to the mounting member of the selected rotary trimmer, wherein rotation of the mounting member causes said attachment member to rotate so that the trimming head correspondingly rotates.

2. The adapter kit of Claim 1, wherein at least a portion of the exterior surface of said attachment member has at least three substantially flat faces, each face having opposed edges, each of said edges being juxtaposed with one edge of one of said faces so that said faces circumscribe the exterior surface of said attachment member.

3. The adapter kit of Claim 2, wherein said positioning means comprises the center cavity of the trimming head being of a size to complementarily receive and securably engage said attachment member therein so that said attachment member is radially fixed relative to the trimming head.

4. The adapter kit of Claim 1, wherein said positioning means further comprises means for locating the first end of said attachment member at a desired longitudinal position within the center cavity of the trimming head.

5. The adapter kit of Claim 4, wherein said attachment member has a first end, wherein the center cavity of the trimming head has an effective diameter, and wherein said locating means further comprises the effective diameter of the upper end of the center cavity of the trimming head being smaller than the effective diameter of the lower end of the center cavity, wherein the first end of said attachment member is slidably received into the lower end of the center cavity so that the first end of said attachment member longitudinally traverses at least a portion of the center cavity until said first end contacts the portion of the center cavity adjacent the upper end thereof in which its effective diameter decreases, thereby fixing said attachment member at a desired longitudinal position within the center cavity of the trimming head.

6. The adapter kit of Claim 1, wherein said attachment member defines a longitudinally extending opening through at least a portion thereof and having an end disposed adjacent the first end of said attachment member, said opening forming an interior surface within said attachment member, said opening being of a size to complementarily receive at least a portion of the mounting member of one predetermined rotary trimmer, wherein said detachably securing means comprises the interior surface of said opening and at least a portion of the mounting member of the rotary trimmer having complementary threaded surfaces that engage each other.

7. The adapter kit of Claim 6, wherein the opening in each of said attachment members has a diameter, the diameter of at least two of said attachment members being of a different size so that the adapter kit may accommodate the mounting members of different rotary trimmers.

8. The adapter kit of Claim 1, wherein said attachment member has a stud portion extending outwardly from the first end of said attachment member, at least a portion of said stud portion being of a size to be complementarily received within the mounting member of one predetermined rotary trimmer, wherein said detachably securing means comprises at least a portion of said stud portion and at least a portion of the mounting member of the rotary trimmer having complementary threaded surfaces that engage each other.

9. The adapter kit of Claim 8, wherein the stud portion on each of said attachment members has a diameter, the diameter of at least two of said stud portions being of a different size so that the adapter kit may accommodate the mounting members of different rotary trimmers.

10. An adapter kit comprising: a. a conversion member having a upper end, an opposite lower end, and an outer surface, said conversion member defining a longitudinally extending bore therethrough forming an inner surface within said conversion member, said outer surface being of a size to be complementarily received in and secured to a center cavity of a trimming head; b. one attachment member selected from a plurality of attachment members complementary to a rotary trimmer of a different size, each of said attachment members having two opposed ends and an exterior surface, at least a portion of said exterior surface being of a size to be complementarily received within the bore of said conversion member, c. means for positioning each of said attachment members individually within said bore so that the attachment member disposed within said bore is radially fixed relative to said conversion member; and d. means for detachably securing a selected one of said attachment members to a mounting member of the rotary trimmer when that attachment member is disposed within said bore, wherein rotation of the mounting member causes said attachment member to rotate and said conversion member to rotate so that the trimming head correspondingly rotates.

11. The adapter kit of Claim 10, wherein at least a portion of the exterior surface of said attachment member has at least three substantially flat faces, each face having opposed edges, each of said edges being juxtaposed with one edge of one of said faces so that said faces circumscribe the exterior surface of said attachment member.

12. The adapter kit of Claim 11, wherein said positioning means comprises the bore of said conversion member being of a size to complementarily receive and securably engage said attachment member therein so that said attachment member is radially fixed relative to said conversion member.

13. The adapter kit of Claim 10, wherein said positioning means further comprises means for locating the first end of said attachment member at a desired longitudinal position within the bore of said conversion member.

14. The adapter kit of Claim 13, wherein said attachment member has a first end, wherein the bore of said conversion member has an effective diameter, and wherein said locating means further comprises the effective diameter of the upper end of the bore of said conversion member being smaller than the effective diameter of the lower end of said bore, wherein the first end of said attachment member is slidably received into the lower end of said bore so that the first end of said attachment member longitudinally traverses at least a portion of said bore until said first end contacts the portion of said bore adjacent the upper end thereof in which its effective diameter decreases, thereby fixing said attachment member at a desired longitudinal position within said bore.

15. The adapter kit of Claim 10, wherein said attachment member defines a longitudinally extending opening through at least a portion thereof and having an end disposed adjacent the first end of said attachment member, said opening forming an interior surface within said attachment member, said opening being of a size to complementarily receive at least a portion of the mounting member of one predetermined rotary trimmer, wherein said detachably securing means comprises the interior surface of said opening and at least a portion of the mounting member of the rotary trimmer having complementary threaded surfaces that engage each other.

16. The adapter kit of Claim 15, wherein the opening in each of said attachment members has a diameter, the diameter of at least two of said attachment members being of a different size so that the adapter kit may accommodate the mounting members of different rotary trimmers.

17. The adapter kit of Claim 10, wherein said attachment member has a stud portion extending outwardly from the first end of said attachment member, at least a portion of said stud portion being of a size to be complementarily received within the mounting member of one predetermined rotary trimmer, wherein said detachably securing means comprises at least a portion of said stud portion and at least a portion of the mounting member of the rotary trimmer having complementary threaded surfaces that engage each other.

18. The adapter kit of Claim 17, wherein the stud portion on each of said attachment members has a diameter, the diameter of at least two of said stud portions being of a different size so that the adapter kit may accommodate the mounting members of different rotary trimmers.

19. In combination: a. a trimming head defining a center cavity therethrough; b. a rotary trimmer having a mounting member being of a size to be disposed within the center cavity of said trimming head; c. a conversion member having a upper end, an opposite lower end, and an outer surface, said conversion member defining a longitudinally extending bore therethrough forming an inner surface within said conversion member, said inner surface having an effective diameter, said outer surface being of a size to be complementarily received in and secured to the center cavity of said trimming head; d one attachment member selected from a plurality of attachment members complementary to a rotary trimmer of a different size, each of said attachment members having two opposed ends and an exterior surface, at least a portion of said exterior surface being of a size to be complementarily received within the bore of said conversion member, e means for positioning each of said attachment members individually within said bore so that the attachment member disposed within said bore is radially fixed relative to said conversion member, and f means for detachably secuπng a selected one of said attachment members to a mounting member of the rotary trimmer when that attachment member is disposed within said bore, wherein rotation of the mounting member causes said attachment member to rotate and said conversion member to rotate so that the tnmming head correspondingly rotates