US20030226929A1

US20030226929A1 - Holding device for spare string trimmer line spools with slotted inner cavities

Info

Publication number: US20030226929A1
Application number: US10/164,440
Authority: US
Inventors: Robert Knizner
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-06-06
Filing date: 2002-06-06
Publication date: 2003-12-11

Abstract

The holding device comprises a clamp body attached to a pair of support arms. Each support arm has a round lug near its upper surface that engages a slot in the inner cavity of the trimmer line spool. The holding device is held on the shaft of a string trimmer by a pair of resilient clamp arms.

Description

FIELD OF THE INVENTION

This invention relates in general to string trimmers used to cut grass and weeds. In particular, the invention relates to a holding device comprising a single member for holding a spare spool of trimmer line on the string trimmer while the string trimmer is in use.

BACKGROUND OF THE INVENTION

Without limiting the scope of the invention, its background is described in connection with holding a spare spool of trimmer line on an operating string trimmer.

String trimmers are the most popular means to cut grass and weeds where larger machines such as lawn mowers cannot go, such as in ditches and along borders. String trimmers use a consumable plastic filament or line to accomplish the cutting action. Since this line is constantly abraded during the operation of the string trimmer, most string trimmers employ a spool that holds a quantity of line and dispenses it to allow continuous operation of the string trimmer.

There are no means to verify the quantity of line present on the spool without partially disassembling the spool assembly. Many operators of string trimmers, particularly commercial landscapers, use string trimmers a significant distance from where spare spools of line are stored. The size of these spare spools is large enough that they will not easily fit in the pockets of pants. The combination of these factors commonly results in wasted time and effort from walking back to where the spare spools of line are kept.

A popular string trimmer line spool design that is used by a number of manufacturers utilizes a slotted inner cavity as a means of holding the spool in the rotating head of the string trimmer.

As such, a need exists for a holding device for spare string trimmer spools with a slotted inner cavity, which provides a means to attach a spare spool of line to a string trimmer while the trimmer is in use.

SUMMARY OF THE INVENTION

The present invention provides for a holding device for spare string trimmer line spools.

Disclosed in one embodiment is a holding device for spare string trimmer line spools. The holding device, shown in FIG. 1, comprises a clamp body attached to a pair of support arms. The clamp body consists of two curved clamp arms that are arranged so that a resulting hole for the trimmer shaft, and clamp opening, forms a spring-action clamp when made of a resilient material.

A spool is shown for reference in FIG. 2. The reference spool is hollow, with a spool inner cavity having a cylindrical shape. A pair of grooves in the spool inner cavity are oriented parallel to the axis of the spool inner cavity and on opposite sides of the spool inner cavity. The spool inner cavity is open at one end, and closed at the other. The interior of the closed end of the spool inner cavity forms an upper surface of the inner spool cavity.

The support arms, project from the upper surface of the clamp body. These support arms have curved surfaces that allow the support arms to fit inside the spool inner cavity. The center area between the support arms is cut away to save material, except for a cross bar that acts to prevent the support arms from deflecting towards each other during use. Each support arm has a round lug located near its top surface. These round lugs project from the curved surface of the support arms a distance slightly less than the depth of the grooves in the spool inner cavity, and have a diameter slightly less than the width of the grooves in the spool inner cavity. During use, these lugs each engage the grooves in the spool inner cavity.

The spool holder is placed on a string trimmer shaft by positioning the clamp opening over the string trimmer shaft as shown in FIG. 4 a, and then forcing the spool holder manually towards the centerline of the string trimmer shaft. The clamp arms will deflect to allow the clamp opening to enlarge sufficiently to slip over the string trimmer shaft as shown in FIG. 4b. Once on the string trimmer shaft, the slightly smaller inside diameter of the hole for trimmer shaft compared to the outside diameter of the trimmer shaft provides an interference fit that securely holds the spool holder in place on the shaft.

Each groove in the spool inner cavity has an offset in the groove in the spool inner cavity located at the end of the groove in the spool inner cavity closest to the upper surface of the inner spool cavity. These offsets in the groove in the spool inner cavity are at a nearly right angle to the inner spool cavity grooves. These offsets in the groove in the spool inner cavity are not parallel to the upper surface of the spool inner cavity, but are inclined slightly with a relief at the end of each offset in the groove in the spool inner cavity.

The spool is placed in the spool holder by first aligning the round lugs with the grooves in the spool inner cavity as shown in FIG. 3. The spool is pushed towards the top surface clamp body until the top surfaces the support arms contact the upper surface of the spool cavity. At this point, the round lugs, are lined up with the offset in the groove in the inner spool cavity. The spool is then twisted counterclockwise so that the round lugs enter the offset in the groove in the spool inner cavity. As the spool is twisted, and the round lugs move to each end of the offset in the groove in the inner spool cavity, the incline in the offset in the groove in the inner spool cavity, cause the ends of the support arms to be forced against the upper surface of the spool inner cavity, until the round lugs enter the relief in the offset in the groove in the inner spool cavity. The relief relieves the interference fit produced by the incline in the offset in the groove in the inner spool cavity, and causes the spool to be positively retained on the spool holder.

The spool is removed from the spool holder by twisting the spool clockwise and lifting it off of the spool holder.

An advantage of the present invention includes the ease with which a spool can be placed into or be removed from the holder, and the positive way that the spool is held. Other advantages of the present invention include its relatively small size, and the ease of manufacturing and the low costs associated therewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the preferred embodiment of the spare spool holder. [0016]
FIG. 2 is a perspective view of a string trimmer spool for reference. [0017]
FIG. 3 is a perspective view of a string trimmer spool being installed on the spare spool holder. [0018]
FIGS. 4[0019] a and 4 b are perspective views of the spare spool holder being installed on the string trimmer shaft.
FIG. 5 is a perspective view of an alternate embodiment of the spare spool holder with an alternate clamping arrangement. [0020]

FIG. 6 is a perspective view of an alternate embodiment of the spare spool holder with clips to hold the trimmer line ends in place.



Refereoce Numerals Used In The Drawings

18	Spool Holder, Preferred Embodiment
20a, 20b	Round Lug
21	Top Surface of Clamp Body
22a, 22b	Support Arm
23a, 23b	Curved Surfaces of Support Arms
24	Cross Bar
25	Clamp Body
26a, 26b	Clamp Arm
27a, 27b	Top Surfaces of Support Arms
28	Clamp Opening
30	Hole For Trimmer Shaft
32	Spool (Prior Art, For Reference Only)
33a, 33b	Relief
34	Spool Inner Cavity
36a, 36b	Groove in the Spool Inner Cavity
38	Upper Surface of the Inner Spool Cavity
40a, 40b	Offset in the Groove in the Spool Inner Cavity
42	String Trimmer Shaft (Prior Art, For Reference Only)
44	Spool Holder, Alternate Embodiment, clamping arrangement
46	Fastener Hole, Alternate Embodiment
48	Split Collar, Alternate Embodiment
50	Spool Holder, Alternate Embodiment, Line end holder clips
52a, 52b	Clip, line end holder
54a, 54b	Gap, line end holder clip

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides for a holding device for spare string trimmer line spools. [0022]
Disclosed in one embodiment is a holding device for spare string trimmer line spools. The holding device, shown in FIG. 1, comprises a [0023] clamp body 25 attached to a pair of support arms, 22 a and 22 b. The clamp body 25 consists of two curved clamp arms 26 a and 26 b that are arranged so that a resulting hole for the trimmer shaft 3, and clamp opening 28, forms a spring-action clamp when made of a resilient material.
A [0024] spool 32 is shown for reference in FIG. 2. The reference spool 32 is hollow, with a spool inner cavity 34 having a cylindrical shape. A pair of grooves in the spool inner cavity 36 a, 36 b are oriented parallel to the axis of the spool inner cavity 34 and on opposite sides of the spool inner cavity 34. The spool inner cavity 34 is open at one end, and closed at the other. The interior of the closed end of the spool inner cavity 34 forms an upper surface of the inner spool cavity 38.
The support arms, [0025] 22 a and 22 b project from the upper surface 21 of the clamp body 25. These support arms 22 a and 22 b have curved surfaces 23 a and 23 b that allow the support arms 22 a and 22 b to fit inside the spool inner cavity 34. The center area between the support arms 22 a and 22 b is cut away to save material, except for a cross bar 24 that acts to prevent the support arms 22 a and 22 b from deflecting towards each other during use. Each support arm 22 a and 22 b has a round lug 20 a and 20 b located near its top surface 27 a and 27 b. These round lugs 20 a and 20 b project from the curved surface of the support arms 23 a and 23 b a distance slightly less than the depth of the grooves in the spool inner cavity 36 a and 36 b, and have a diameter slightly less than the width of the grooves in the spool inner cavity 36 a and 36 b. During use, these lugs 20 a and 20 b each engage the grooves in the spool inner cavity 36 a and 36 b.
The [0026] spool holder 18 is placed on a string trimmer shaft 42 by positioning the clamp opening 28 over the string trimmer shaft 42 as shown in FIG. 4a, and then forcing the spool holder 18 manually towards the centerline of the string trimmer shaft 42. The clamp arms 26 a and 26 b will deflect to allow the clamp opening 28 to enlarge sufficiently to slip over the string trimmer shaft 42 as shown in FIG. 4b. Once on the string trimmer shaft 42, the slightly smaller inside diameter of the hole for trimmer shaft 30 compared to the outside diameter of the trimmer shaft 42 provides an interference fit that securely holds the spool holder 18 in place on the shaft 42.
Each groove in the spool [0027] inner cavity 36 a and 36 b has an offset in the groove in the spool inner cavity 40 a, 40 b located at the end of the groove in the spool inner cavity 36 a and 36 b closest to the upper surface of the inner spool cavity 38. These offsets in the groove in the spool inner cavity 40 a, 40 b are at a nearly right angle to the inner spool cavity grooves 36 a and 36 b. These offsets in the groove in the spool inner cavity 40 a, 40 b are not parallel to the upper surface of the spool inner cavity 38, but are inclined slightly with a relief 33 a, 33 b at the end of each offset in the groove in the spool inner cavity 40 a, 40 b.
The [0028] spool 32 is placed in the spool holder 18 by first aligning the round lugs 20 a and 20 b with the grooves in the spool inner cavity 36 a and 36 b as shown in FIG. 3. The spool 32 is pushed towards the top surface clamp body 21 until the top surfaces the support arms 27 a and 27 b contact the upper surface of the spool cavity 38. At this point, the round lugs, 20 a and 20 b are lined up with the offset in the groove in the inner spool cavity 40 a and 40 b. The spool 32 is then twisted counterclockwise so that the round lugs 20 a and 20 b enter the offset in the groove in the spool inner cavity 40 a and 40 b. As the spool 32 is twisted, and the round lugs 20 a and 20 b move to each end of the offset in the groove in the inner spool cavity 40 a and 40 b, the incline in the offset in the groove in the inner spool cavity 40 a and 40 b, cause the ends of the support arms 27 a and 27 b to be forced against the upper surface of the spool inner cavity 38, until the round lugs 20 a and 20 b enter the relief 33 a, 33 b in the offset in the groove in the inner spool cavity 40 a and 40 b. The relief 33 a, 33 b relieves the interference fit produced by the incline in the offset in the groove in the inner spool cavity 40 a and 40 b, and causes the spool 32 to be positively retained on the spool holder 18.
The [0029] spool 32 is removed from the spool holder 18 by twisting the spool 32 clockwise and lifting it off of the spool holder 18.
An advantage of the present invention includes the ease with which a spool can be placed into or be removed from the holder, and the positive way that the spool is held. Other advantages of the present invention include its relatively small size, and the ease of manufacturing and the low costs associated therewith. [0030]

DETAILED DESCRIPTION OF ALTERNATE EMBODIMENTS

One alternate embodiment provides for the [0031] clamp arms 26 a and 26 b described in the preferred embodiment to be replaced with a clamping arrangement utilizing a split collar 48 and a fastener hole 46 to accommodate a threaded fastener as shown in FIG. 5. This embodiment provides a more positive clamping action at the expense of higher manufacturing cost and reduced ease of installation.
Another alternate embodiment provides for trimmer line end clips [0032] 52 a and 52 b as shown in FIG. 6. These trimmer line end clips 52 a and 52 b provide a means of securing the loose ends of trimmer line that extend downward from the spool 32 when it is filled with trimmer line. The trimmer line is pushed into a gap 54 a and 54 b between the trimmer line end clips 52 a and 52 b and the clamp body 25. The trimmer line end clips 52 a and 52 b are arranged so that the trimmer line is pulled out of the gaps 54 a and 54 b as the spool 32 is twisted clockwise to remove it from the spool holder 50. This embodiment prevents the loose ends of trimmer line from unwinding off of the spool 32 while the trimmer is in use.

Claims

I claim:

1. A device for holding a spare string trimmer spool on a string trimmer, comprising:

(a) a clamping means to hold the device on the string trimmer's shaft, and

(b) a pair of support arms that utilize round lugs to engage the grooves in the spare spool of trimmer line's inner cavity as a means of holding the spare spool of trimmer line in place

whereby the spare spool of trimmer line is securely held on the string trimmer during use of the string trimmer and can be conveniently removed from the spare spool holder and put into use on the string trimmer when required.

2. The holder of claim 1 wherein the clamping means comprises a pair of clamp arms that grip the string trimmer's shaft after the shaft is pushed between the clamp arms.

3. The holder of claim 1 wherein the clamping means comprises a split collar and threaded fastener.

4. The holder of claim 1 wherein the support arms each have an outer surface that is substantially curved to fit inside the spare spool of trimmer line's inner cavity.

5. The holder of claim 1 wherein a cross bar spans the gap between the support arms to prevent deflection of the support arms

6. The holder of claim 1 wherein the loose ends of trimmer line are pushed into gaps between clips and the clamp body as a means of keeping the loose ends of trimmer line from unwinding from the spool while the trimmer is in use.