GB2355172A

GB2355172A - Impact producing tool for pruning

Info

Publication number: GB2355172A
Application number: GB9924369A
Authority: GB
Inventors: Aime Adam
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-15
Filing date: 1999-10-15
Publication date: 2001-04-18
Also published as: GB9924369D0

Abstract

An impact producing cutting tool for pruning shrubs at ground level having an elongated bar with a reciprocating slide hammer between two hammer stops transmitting the striking force to a frusto-conical blade holder with a seventy degree angled, single bevel cutting blade.

Description

2355172 IMPACT PRODUCING TOOL FOR PRUNING This invention relates to impact

cutting tools. More particularly, the invention relates to hand-operated reciprocating impact producing cutting tool for the selective pruning of shrubs at ground level.

Shrubs, which are defined as woody perennials of a relatively low height having several stems arising from the base, and lacking a single trunk; require regular pruning of old, dying or unwanted stock (stems) to continually improve the health and shape of the maturing plant. Removal of the older center stock at ground level eliminates overgrowth, and prevents the shrub from drying up and choking itself. Selective pruning of unwanted stems allows an acceptable shape of the shrub to form.

Some examples of shrubs requiring regular pruning include: Dogwoods (cornus), Ninebark (physocarpus opalifolius), Lilacs (syringa), Honeysuckle (lonicera), Snowball (vibarnum), Wolf Willow (elaeagnus commatata), Purple Leaf Sandberry (Prunus x cistena), Elder (sambacus), Chokeberry (aronia melanocarpa), Potentillas (potentilla fruitcosa), Hardy Shrub Roses, Explorer Roses, and Junipers Ouniper-us).

A tool for pruning shrubs should able to reach through or around good stock, preferrably used at a distance from the shrub. This minimizes shrub damage caused by the tool user, and likewise avoids cuts, scratches to the tool user from plant parts (i.e. thorns, branch ends).

The tool should be able to be manipulated easily, allowing placement of selective, precise, and clean cuts of the unwanted stem(s) at ground level or as near to the ground as possible, while avoiding damage to adjacent good stock from either the cutting edge or tool body.

Presently several different types of cutting tools are used to prune shrubs. These include close quarter precise cutting tools such as knifes and pruning shears; and long range rough cutting tools like: shovels, lawn edge choppers, axes, and the chisel end of a crowbar.

2 Pruning shears and knifes while providing precise clean cuts, require the user to work in close, proximity to the shrub. This makes it difficult to avoid cuts, scratches from the plant, especially when pruning thorny shrubs, In shrubbery with heavy overgrowth, pruning shears are difficult to operate, because the stems of the shrub interfere with the opening or closing of either the jaws or handle of the shears.

Selective pruning with rough cutting tools is difficult. In addition to the wide blunt cutting blade, a certain level of operator skill and strength is required to direct the tool at unwanted stems, while simultaneously avoiding any damage to adjacent good stock.

Reciprocating slide hammer tools of various configurations are well known. Some examples include log/firewood splitters, wood chisels, ice choppers, lawn edgers, hoof trimmers, roof shingle removers, and tree branch trimmers.

This invention relates to a reciprocating impact producing cutting tool for the selective pruning of shrubs at ground level.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which:

FIGURE I is a perspective view of the impact producing tool for pruning according to the preferred form of the invention.

FIGURE 2 is an exploded perspective view of the impact producing tool for pruning referred to in FIGURE 1.

FIGURE 3 is a pictorial side view of the impact producing tool for pruning as referred to in FIGURES I and 2, demonstrating its use on a shrub.

Referring now to the drawings in greater detail, and more particularly to FIGS. I and 2 thereof at this time, the reference number 10 represents a impact producing tool for pruning according to the present invention. Tool 10 comprises a solid cylindrical elongated rod I I 3 with externally threaded upper and lower ends I I a, I I b. Lower end I I b having a longer thread. A lower stopper 12 with a flattened semi- spherical upper face 12a is rigidly fixed as by welding or the like to an intermediate point on rod 10.

An impactor 13 with raised ends 13 a and a center gripping/cushioning surface 13b is slide down and supported therearound rod 10 above stopper 12. An upper washer/locknut 14 is fully threaded and tightened onto upper end I I a of rod 11. Stopper 12 and washer/locknut 14 provide lower and upper hammer stops for transmitting the pounding force from reciprocating motion of impactor 13 on rod I I. Raised ends 13 a and gripping/cushioning surface 13b of impactor 13 function to prevent a persons hand, holding around impactor 13 from slipping off and getting pinched at either upper or lower hammer stops. Flattened semispherical upper face 12a of stopper 12 also reduces the likelihood of pinching a person's hand at lower hammer stop region.

A lower locknut/washer 14, followed by a cutting blade holder 15 is threaded onto lower end I lb of rod 11, and counter-tightened against each other to secure holder 15 to rod 11. A cutting blade 17 with a heat treated or hardened or the like seventy-degree angled and single bevel cutting edge 17a is placed in slot 15C of holder 15, with allen screws 16 securing blade 17 to holder 15 through aligned holes l7b of blade 17 and corresponding holes 15b of holder 15.

A frusto-conical taper 15d in center portion of holder 15 serves to reduce outside diameter of lower portion of holder 15 to meet width of blade 17. Taper 15d on holder 15 further reduces the likelihood of catching on or damaging good stock while displacing it to maneuver the cutting blade 17 of tool 10 onto unwanted stems of the shrub.

Referring now to FIG. 3, for normal use and operation, a tool operator (person) holds tool 10 with one hand around elongated rod I I at a point below lower stopper 12, with other hand around impactor 13 on gripping/cushioning surface 13b, protected by raised ends 13a. Tool 10 is orientated and maneuvered through or around good stock of the shrub, displacing the good stock if necessary without damage, to place the cutting edge 17a of blade 17 crosswise against a single selected stem of unwanted stock, preferably near ground level.

4 With edge 17a of blade 17 placed against the unwanted stem, impactor 13 is reciprocally slide back and forth along rod I I striking lower stopper 12, transmitting a pounding force to seventy-degree angle, single bevel edge 17b of blade 17, simultaneously cutting and slicing through unwanted stem of shrub, which may be orientated in any direction.

In contrast, a ninety-degree angle, single bevel edge blade, where the cutting action has no angular force component or slicing action allows the easily moveable shrub stem to deflect in the direction of force, providing increased opportunity for blade slippage, and blade edge bounce creating poor cuts.

In the event blade 17 binds in stem or slips off and imbeds itself in ground, impactor 13 is reciprocally slide back and forth along rod I I striking upper hammer stop (upper washer/locknut 14), therefore releasing blade 17.

CLAMS An impact producing hand tool for pruning shrubs including:

a) an elongated bar having externally threaded upper and lower ends; b) a washer and locknut threaded onto upper end of said bar-, C) a stopper fixed to an intermediate point of said bar; d) a slide hammer mounted for reciprocatory movement on said bar between upper washer/locknut and stopper; e) a second washer and locknut threaded onto lower end of said bar-, f) a blade holder threaded onto lower end of said bar-, g) a cutting blade secured to said holder.

2. A tool as claimed in claim 1, where the elongated bar is solid and cylindrical, and the lower threaded portion of said bar is longer than upper threaded portion of said bar.

Claims

3. A tool as claimed in Claim 1, where the stopper is welded to elongated

bar. 4. A tool as claimed in Claim 1, where the stopper has a flattened semi-spherical upper face.

5. A tool as claimed in Claim 1, where the slide hammer has a gripping/cushioning enhancement.

6. A tool as claimed in Claim 1, where the blade holder has a frustoconical taper. 7. A tool as claimed in Claim 1, where the cutting blade has a 70 degree angle and single beveledge.

8. A tool as claimed in Claim 1, where the cutting blade is heat treated or hardened metal.

6 9. A tool as claimed in Claim 1, where the locknuts, washers, slide hammer, blade holder and cutting blade are removable for replacement or repair.

10. An impact producing hand tool for pruning shrubs substantially as herein and illustrated in the accompanying drawings.