Stop attachable to chainsaw bar

Abstract

A stop has an elongate form between a base and a tip, with the base configured to be attachable to a chainsaw bar closer to a free end of the bar then to a housing of the chainsaw to which the bar is mounted. The stop extends below a lower edge of the bar. Bolts or other fasteners pass through holes in the stop and through holes in the bar for attachment. Positioning of the stop separates a tip space from a main space where chain teeth can cut wooden material. Smaller branches can conveniently be cut in the tip space while larger wooden material can be cut in the main space. The stop is configured to include clearance for the chain to pass thereby, such as by including standoffs in the stop adjacent to holes at the base, or by providing a clearance groove or clearance bend.

Claims

1. A chainsaw comprising: an elongate bar extending from a first end to a second free end; a chain with cutting teeth carried over first and second edges of said bar and routed around said second free end of said bar; a housing supporting a motor of the chainsaw, the motor configured to drive said chain over said bar, and with said housing having at least one grip for handling the chainsaw; a stop fixed to said bar at a base of said stop; said stop extending beyond said second edge of said bar to a tip, said tip opposite said base; said stop spaced toward said first end from said second free end of said bar by a tip space; said stop spaced from said housing by a main space greater than said tip space, said main space fully open to allow wooden members having a size of up to a size similar to said main space to access said chain beyond said second edge of said bar and between said stop and said housing; wherein said bar includes a plurality of holes passing therethrough, and wherein said stop has an elongate form extending between terminal ends including said base and said tip, said stop including holes therein which are closer to said base than to said tip, and wherein fasteners secure said stop to said bar by passing of said fasteners through said holes in said stop and said holes in said bar; wherein said stop is spaced laterally from said bar to provide clearance for said chain passing adjacent to said stop by standoffs adjacent to said holes in said stop, which the standoffs space said stop away from a mounting plane at which said standoffs terminate, said mounting plane adjacent to a surface of said bar that is adjacent to said stop; wherein said stop has the elongate form extending between the two terminal ends including the tip at a first end opposite the base at a second end, said stop including three holes passing laterally through said stop at locations on said stop which are each closer to said base than to said tip, said stop having a C-shaped cross-section along a plane perpendicular to a line extending between said two terminal ends, said C-shaped cross-section including a planar web and a pair of flanges extending laterally from edges of said web, said holes of the stop located within said web, said web having an adjacent side closer to said bar than an opposite side of said web, said flanges extending from said opposite side of said web, away from said adjacent side of said web, said holes of the stop each located within the standoffs which the standoffs extend from said adjacent side of said web and toward said bar and cause said adjacent side of said web to be spaced by a clearance amount from said bar while said web remains parallel with said mounting plane and parallel with said bar; and wherein said standoffs include wells pressed into said web and extending into said opposite side of said web and out of said adjacent side of said web, each of said standoffs having a length, longer than a wide of said standoff, extending parallel to a length of said bar.

2. The chainsaw of claim 1 wherein said tip of said stop extends beyond said second edge of said bar by a distance between half and two times said tip space.

3. The chainsaw of claim 1 wherein said tip of said stop extends from said base of said stop in a direction closer to perpendicular to a centerline of said bar than parallel to said centerline of said bar.

4. The chainsaw of claim 3 wherein said tip extends from said base at an angle relative to said centerline of said bar measuring between 90° and 45°.

5. The chainsaw of claim 4 wherein said tip extends from said base at an angle relative to said centerline of said bar of 70°.

6. The chainsaw of claim 1 wherein said main space is greater than two times said tip space.

7. The chainsaw of claim 6 wherein said main space is greater than three times said tip space.

8. The chainsaw of claim 1 wherein said stop has a bend therein, between said base and said tip, with said base and said tip parallel to each other, but with said tip offset relative to said base by a clearance space to keep said chain adjacent to said bar from impacting portions of said stop beyond said bend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side elevation view of a chainsaw with a stop according to one embodiment of this invention attached to a bar thereof, and showing a large wooden member and a smaller wooden member adjacent to the chainsaw to illustrate function of the chainsaw with the stop in place.

(2) FIG. 2 is a perspective view of that which is shown in FIG. 1, illustrating how the stop is attached to the bar of the chainsaw.

(3) FIG. 3 is a left side elevation view of the stop of FIG. 1.

(4) FIG. 4 is a right side elevation view of that which is shown in FIG. 3.

(5) FIG. 5 is a front elevation view of that which is shown in FIG. 3, and with broken lines illustrating an alternative embodiment clearance groove.

(6) FIG. 6 is a rear elevation view of that which is shown in FIG. 3, and with broken lines illustrating an alternative embodiment bent stop.

(7) FIG. 7 is a top plan view of that which is shown in FIG. 4.

(8) FIG. 8 is a bottom plan view of that which is shown in FIG. 4.

(9) FIG. 9 is a top plan section view taken along line 9-9 of FIG. 4.

(10) FIG. 10 is a top plan sectional view taken along line 10-10 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(11) Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral 10 is directed to a stop for a chainsaw C (FIG. 1). This stop 10 is configured to attach to a blade/bar B (FIG. 2) of a chainsaw C so that the chainsaw C can be configured to more effectively cut branches and other small material W, while maintaining the chainsaw's ability to also cut larger diameter material W.

(12) In essence, and with particular reference to FIGS. 1 and 2, basic details of the stop 10 are described, according to one example embodiment. The stop 10 is an elongated rigid structure extending from a base end 20 to a tip 60. Standoffs 30 preferably surround holes 40 in the base end 20 of the stop 10. Fasteners 50 interact with the holes 40 (and holes H) to mount the base end 20 of the stop 10 to the blade/bar B of the chainsaw C. Strategic positioning of the stop 10 relative to the bar B causes a tip space S between the stop 10 and a free end E of the bar B to be smaller than a main space M between the stop 10 and a root R of the bar B opposite of the free end E, and adjacent to a housing of the chainsaw C. The standoffs 30 provide a clearance space for passage of teeth T of the chain I carried by the bar B to avoid striking the stop 10 as the chain I moves along arrow A. Alternatively or in addition, a clearance groove 120 (FIG. 5) can be provided to keep the stop 10 from contacting the teeth T of the chain I, or the stop 10 can be configured with a bend 110 (FIG. 6) to keep the stop 10 from contacting the teeth T of the chain I.

(13) More specifically, and with particular reference to FIGS. 3-10, details of the stop 10 are described according to one example embodiment. This stop 10 is a rigid elongate structure having a greater length than its width or thickness. The stop 10 is formed of rigid material, such as steel or other metal or high strength polymeric hydrocarbon material or similar material. Most preferably, the stop 10 is formed by extrusion and/or bending/pressing of a planar sheet of steel into the finished form desired for the stop 10.

(14) A general form of the stop 10 includes a planar web 14 bounded on forward and rearward edges by two parallel flanges 12. The flanges 12 are preferably oriented perpendicular to the web 14 so that the stop 10 has the general cross-sectional form of C-channel. The flanges 12 extend in a direction away from a mounting plane, which mounting plane defines a surface of the bar B to which the stop 10 attaches. In this way, the flanges 12 add rigidity and strength to the stop 10, without the flanges 12 risking coming into contact with the teeth T of the chain I as the chain I moves (along arrow A of FIG. 1) upon the edges of the bar B. In other embodiments, the flanges 12 could be eliminated or have other configurations.

(15) The base end 20 of the stop 10 define a portion of the stop 10 which attaches to the bar B of the chainsaw C. In this example embodiment, three holes 40 pass through the stop 10 near the base end 20. Other numbers of holes could alternatively be provided. Holes H are also formed in the bar B (FIG. 2) which can be aligned with the holes 40 in the stop 10. Fasteners 50, such as bolts 52, nuts 54 and washers 56 (FIG. 2) can work with the holes 40 and holes H to secure the stop 10 to the bar B.

(16) While three holes 40 are shown in this example embodiment, two holes 40 could alternatively be utilized. It is also conceivable that a single hole could be provided, so long as some structure is provided to prevent rotation of the stop 10 relative to the bar B. Larger number of holes H could also alternatively be provided. The holes 40 are shown with a particular pattern relative to each other. Such an arrangement of holes 40 allows for sufficient space so the holes 40 do not weaken the stop 10 or the corresponding holes H in the bar B do not appreciably weaken the bar B, even if the stop 10 is not attached. The stop 10 could be modified to have different shapes and orientations to allow for various different numbers of holes to be positioned at different locations in the bar B and within such a modified stop.

(17) The holes 40 preferably are located within standoffs 30. These standoffs 30 are in this embodiment formed by pressing elongate wells 32 into a surface of the web 14 between the flanges 12, to cause the standoffs 30 to protrude from a surface of the web 14 adjacent to the mounting plane. The wells 32 preferably are oblong in form with a stepped perimeter 34 defining a depth of the wells 32 and a height of the standoffs 30. The wells 32 have parallel sides 36 opposite each other which sides 36 are generally horizontal, and which space apart ends 38 at a forward and rearward extent of each of the wells 32.

(18) The holes 40 reside within these wells 32 and preferably a space between the sides 36 of the wells 32 is similar to a diameter of the holes 40. In this particular embodiment, the wells 32 are centrally aligned with an elongate central axis of the stop 10, but with the holes 40 having differing positions within each of the wells 32, with a lowermost hole 40 being located most forward, and with an uppermost well 32 having its corresponding hole 40 located most rearward, and with a hole 40 in a central well 32 located at a center point thereof.

(19) As an alternative, or in addition, washers 56 (FIG. 2) could be provided adjacent to the holes 40. Such washers 56 could be lock washers or plain washers, or a combination of both. Washers 56 can help to keep bolt 52 and nut 54 pairs from becoming loosened when encountering vibration. Furthermore, the washers 56 help to increase the spacing from the web 14 to the mounting plane, which clearance space helps to keep the chain teeth T from impacting the stop 10.

(20) The stop 10 is preferably configured so that the tip 60 is truncated along a horizontal line. However, the stop 10 is preferably attached to the bar B (FIGS. 1 and 2) so that it is angled forward from vertical somewhat. In the embodiment depicted, an angle α of 70° is provided between a central axis of the stop 10 and a centerline L of the bar B. This angle α could be between 90° and 45° and still have some effectiveness. An uppermost end of the base end 20 is also preferably cut horizontally so that the overall stop 10 has the form of a parallelogram with opposite corners measuring either 70° or 110°. Other angular measurements could alternatively be provided. In one embodiment, the tip 60 tapers in width between the flanges 12 or other forward and rearward surfaces as it extends down to a lowermost portion thereof.

(21) The stop 10 is positioned strategically so that a tip space S and a main space M are defined (FIG. 1). The tip space S is a portion of the lower edge of the bar B between the stop 10 and the free end E of the bar B. The main space M is a distance between the stop 10 and the root R of the bar B adjacent to the dogs D (if any) on the housing of the chainsaw C. The tip space S is preferably less than half of a size of the main space M. In many embodiments, the tip space S is less than a third of a size of the main space M. Most preferably, if the bar B is of a greater and greater length, the tip space S is held relatively constant at approximately 4 to 5 inches, while the main space S can be allowed to increase to a greater and greater size. Longer bars B can allow for larger and larger material to be cut. Typically material having a diameter of more than 4 inches is not prone to much movement when encountering forces from the chainsaw C acting thereon. Thus, it is generally most preferable to keep the tip space less than 4 or 5 inches to maintain the ability of chainsaws C of all sizes to cut smaller diameter material which is prone to bending and movement during cutting procedures.

(22) The length of the stop 10 defines a height Y between the tip 60 of the stop 10 and the lower edge of the bar B. Most preferably, this height Y is similar to the tip space S, such as about 4 to 5 inches. As an alternative, the tip space S and/or the height Y could be a lesser amount, such as 3 inches or even as little as 2 inches and still maintain at least some limited effectiveness. Generally, the height Y is between half and double the tip space S.

(23) In use and operation, and with particular reference to FIG. 1, details of the use of the chainsaw C with associated stop 10 is described, according to this illustrated embodiment. First, a bar B is selected which has holes H therein, or holes are formed therein as shown (FIG. 2). The stop 10 can then be mounted to the bar B, as illustrated in FIG. 2. As an alternative, a bar B with the stop 10 already attached thereto can be used to replace an existing bar B of a chainsaw C. The chainsaw C will then be configured as shown in FIG. 1.

(24) A user who wishes to rapidly cut both small and large branches starts the chainsaw C and approaches the area to be cut. Using judgment as to which material is best cut first, the user selects a branch, limb or trunk to be cut. If the material W to be cut is smaller than about 4 inches in diameter, the user manipulates at least one grip G on the housing F and orients the chainsaw C relative to the material W to be cut so the material W is engaged by the lower edge of the blade B and the teeth T of the chain forward of the stop 10. Such material W is pinched between a leading portion of the stop 10 and the chain I. The chain I then cuts through the material while the material is supported by the stop 10. The housing F supports a motor N of the chainsaw C that is configured to drive the chain I over the bar B.

(25) If the material W to be cut is larger than about 4 inches, the chainsaw C is oriented so that the material W to be cut engages the chain teeth T between the stop 10 and the housing of the chainsaw C. Typically, the dogs D will be allowed to engage the material W being cut, so that additional leverage can be exerted by the user and the larger material W is allowed to be cut by the chain teeth T. This process is then repeated for new material to be cut. The user can move rapidly through large quantities of material W of a wide variety of sizes, which can be useful when cutting paths rapidly through dense brush, such as when cutting firebreak when fighting wildfire or taking preventative measures in advance of wildfire.

(26) This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this invention disclosure. When embodiments are referred to as “exemplary” or “preferred” this term is meant to indicate one example of the invention, and does not exclude other possible embodiments. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together or coupled together through intervening structures. Such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment, unless specifically restricted.