US20030025344A1

US20030025344A1 - Snow removal tool having an insert-molded wearstrip and method of forming same

Info

Publication number: US20030025344A1
Application number: US09/919,615
Authority: US
Inventors: Jan Schultice; Thomas Parker
Original assignee: UnionTools Inc
Current assignee: UnionTools Inc
Priority date: 2001-08-01
Filing date: 2001-08-01
Publication date: 2003-02-06
Also published as: CA2390929A1

Abstract

An snow removal tool having an insert-molded wearstrip is disclosed. According to one embodiment of the present invention, the tool includes: a plastic blade portion and a wearstrip attached to each other by insert molding. Insert molding is performed by placing the wearstrip, which has one or more openings therethrough, in a recess of a mold cavity. Plastic is injected into the mold cavity and flows through the openings in the wearstrip. Upon solidification of the plastic, the final molded product has a cutting edge of the wearstrip protruding from a front edge of said snowtool. Preferably the wearstrip is made from galvanized steel and has a fold or ridge across it to increase stiffness of said snowtool in bending.

Description

FIELD OF THE INVENTION

The invention relates to snow tools; in particular, it relates to a snow removal tool having an insert-molded wearstrip.

DESCRIPTION OF THE RELATED ART

Many snow tools, such as snow shovels and snow pushers, on the market today are made of molded plastic. Some of these tools feature a metal wearstrip attached to the front edge of the tool. The function of this metal wearstrip is to reduce the wear on the front edge of the tool as it is used on abrasive surfaces such as asphalt and concrete. In addition, the metal wearstrip can provide a sharper cutting edge which allows snow and ice to be removed more cleanly and completely.

In general, these metal wearstrips are attached using metal rivets. Riveting requires that holes be formed in the plastic snowtool by drilling or molding, and carefully aligning the wearstrip and snowtool while rivets are inserted and clinched. A disadvantage of riveting is that riveting equipment is expensive and the act of riveting is costly and labor intensive.

SUMMARY OF THE INVENTION

Therefore, a need has arisen for a snow removal tool having an insert molded wearstrip that overcomes these and other shortcomings of the related art.

It is an object of the present invention to provide a snow tool having a wearstrip attached without using rivets or any secondary operation performed after molding, e.g., crimping.

According to one embodiment of the present invention, a snow tool comprises a blade portion and a wearstrip attached to each other by insert molding. Insert molding is performed by placing the wearstrip, which has one or more openings therethrough, in a recess of a mold cavity. A polymer material is injected into the mold cavity and flows through the openings in the wearstrip. Upon solidification of the polymer, the final molded product has a cutting edge of the wearstrip protruding from a front edge of said snowtool. Preferably, the wearstrip is galvanized steel and has a fold or ridge across it to increase stiffness of the snowtool in bending.

It is a technical advantage of the present invention that rivets are not required, thereby eliminating the costly and labor intensive process of riveting. Moreover, the present invention does not require any secondary attachment operation performed after molding, e.g., crimping.

The foregoing, and other features and advantages of the invention, will be apparent from the following, more particular description of the preferred embodiments of the invention, the accompanying drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, the objects and advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawings in which: [0009]
FIG. 1 depicts a snow tool comprising an insert molded metal wearstrip according to an embodiment of the invention; [0010]
FIGS. [0011] 2(a), 2(b), and 2(c) depict, respectively, a top view, a cross-sectional view, and an expanded cross-sectional view of the snow tool shown in FIG. 1;
FIG. 3 illustrates a metal wearstrip according to an embodiment of the invention; and [0012]
FIG. 4 depicts a method for forming a tool having a metal wearstrip according to one embodiment of the present invention.[0013]

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention and their advantages may be understood by referring to FIGS. [0014] 1-4, like numerals being used for like corresponding parts in the various drawings.
Although the present invention is described in the context of snow removal tools, the present invention is not so limited. The inventive concept can be employed in any type of tool comprising a wearstrip attached to moldable material. [0015]
In the preferred embodiment of the invention, a snow tool features a wearstrip attached to the digging or pushing end (herein referred to as the blade element) of the snow tool by means of insert molding. Referring to FIG. 1, [0016] snow tool 100 is shown comprising blade 110, wearstrip 120, and connector 130 for connecting blade 110 to a shaft and handle (not shown). Blade 110 is manufactured from a material suitable for molding, such as, but not limited to, plastic, preferably, polypropylene, high density polyethylene (“HDPE”), acrylonitrile butadiene styrene (“ABS”), nylon, reinforced plastic, e.g., graphite-impregnated plastic, and the like. Wearstrip 120 is preferably metal, e.g., galvanized steel, but can also be fashioned from any type of solid material, e.g., ceramic, high strength polymer, or a composite material, that will remain rigid during injection molding and has suitable hardness for snow or ice removal.
FIG. 2([0017] b) depicts a cross-sectional view of snow tool 100 taken along axis A-A, shown in FIG. 2(a). FIG. 2(c) portrays an expanded view of snow tool 100 at a location where wearstrip 120 and blade 110 are joined together. Wearstrip 120 comprises one or more openings, e.g., holes, as shown in FIG. 3, to allow blade material to flow through during molding. Axis A-A dissects one of these openings as shown in FIG. 2(c).
Wearstrip [0018] 120 is attached by the process commonly referred and known in the art as insert molding. FIG. 4 depicts method 400 for forming a tool having a metal wearstrip according to one embodiment of the present invention. Wearstrip 120 is placed (step 410) in a proper recess in an open mold cavity. The mold is closed (step 420) and the blade material, e.g., plastic, is injected (step 430) and allowed to flow (step 440) through the openings in wearstrip 120 and then solidify. Upon solidification of the blade material, the molded tool is removed (step 450) from the cavity. After molding, the cutting edge of wearstrip 120 protrudes from the front edge of the snowtool, while a portion of wearstrip 120 remains within the snowtool at a sufficient depth to provide firm anchoring. After molding, wearstrip 120 may be shaped, if desired.
Whereas the wearstrip illustrated in FIGS. [0019] 1-3 is flat and has openings, in other embodiments, wearstrip 120 may include a fold or ridge in order to increase tool stiffness in bending. In other embodiments, wearstrip 120 may be L-shaped, scalloped, notched along one or more surface ends, serrated, or any combination thereof, with or without perforations, in order to improve anchoring within the snowtool or to assist in snow or ice removal.
Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered exemplary only, with the true scope and spirit of the invention indicated by the following claims. [0020]

Claims

We claim:

1. A tool apparatus comprising:

a blade; and

a wearstrip attached to said blade by insert molding.

2. The apparatus of claim 1, further comprising:

a shaft coupled to said blade; and

a handle coupled to said shaft.

3. The apparatus of claim 1, wherein said wearstrip comprises at lest one perforation.

4. The apparatus of claim 3, wherein said blade comprises a moldable material that fills said one or more openings during insert molding.

5. The apparatus of claim 4, wherein said moldable material is plastic.

6. The apparatus of claim 1, wherein said wearstrip is L-shaped.

7. The apparatus of claim 1, wherein said wearstrip comprises metal.

8. The apparatus of claim 7, wherein said wearstrip comprises galvanized steel.

9. The apparatus of claim 1, wherein the wearstrip is scalloped.

10. The apparatus of claim 1, wherein the apparatus is a snow removal tool.

11. A method for attaching a wearstrip to a tool blade, comprising:

placing a wearstrip comprising one or more openings therethrough in a recess in a mold cavity of the tool blade;

injecting a fluid material into said mold cavity, wherein said fluid material flows through said one or more openings;

solidifying said fluid material to obtain a final molded product; wherein said final molded product has a cutting edge of said wearstrip protruding from a front edge of said snowtool.

12. The method of claim 11, wherein said fluid material is plastic.

13. The method of claim 11, wherein said wearstrip is metal.

14. The method of claim 11, further comprising:

shaping the wearstrip after solidification.

15. A snowtool comprising:

a plastic digging end; and

a wearstrip having a first portion comprising one or more openings therethrough;

wherein said plastic digging end covers said first portion and fills said one or more openings.

16. The snowtool of claim 15, wherein said wearstrip comprises a second portion not in direct contact with said plastic digging end.

17. The snowtool of claim 15, wherein said second portion has a cutting edge.

18. The snowtool of claim 15, wherein said wearstrip is metal.

19. The snowtool of claim 18, wherein said metal is galvanized steel.

20. The snowtool of claim 15, wherein said wearstrip comprises a fold or ridge across it to increase stiffness of said snowtool in bending.