RETRACTABLE CHAINSAW GUARD

Abstract

The disclosed technology generally regards a chainsaw guard mountable on a chainsaw having a motor powerhead housing, a drive motor contained in the housing, a saw chain guide bar mounted on the housing, and a saw cutter chain driven by the drive motor and carried on the saw chain guide bar, the chainsaw guard forming a physical barrier that limits access to the saw cutter chain when the chainsaw guard is mounted on the powerhead housing. The chainsaw guard includes a bracket member mountable to a chainsaw motor powerhead housing, and a retractable member movably engaged with the bracket member and designed and configured to sheathe the saw chain guide bar and saw cutter chain of the chainsaw when the chainsaw guard is mounted on a chainsaw. Engaged with the bracket member and the retractable member are compressible springs about one or more guide rods, the springs having a spring force to position the retractable member relative to the bracket member in the extended position until a force greater than the spring force is applied to the distal end of the retractable member, translating the retractable member towards the retracted position; when the force is removed from the distal end of the retractable member, the retractable member by the spring force moves to the extended position.

Claims

1. A chainsaw guard mountable on a chainsaw having a motor powerhead housing, a drive motor contained in the housing, a saw chain guide bar mounted on the housing, and a saw cutter chain driven by the drive motor and carried on the saw chain guide bar, the chainsaw guard forming a physical barrier that limits access to the saw cutter chain when the chainsaw guard is mounted on the powerhead housing, the chainsaw guard comprising: a bracket member mountable to a chainsaw motor powerhead housing, the bracket member having a receiving track extending along its length, and a retractable member movably engaged with the bracket member and designed and configured to sheathe the saw chain guide bar and saw cutter chain of the chainsaw when the chainsaw guard is mounted on a chainsaw, the retractable member having proximal and distal ends and a top, a bottom, and an elongated side forming an open sheath, and being translatable between and among a retracted position and an extended position relative to the bracket member, and one or more compressible springs engaged with one or more guide rods, wherein a first end of each guide rod is slidably received and supported by the bracket member, and a second end of each guide rod is secured to the distal end of the retractable member, the springs having a spring force to position the retractable member relative to the bracket member in the extended position until a force greater than the spring force is applied to the distal end of the retractable member, translating the retractable member towards the retracted position relative to the bracket member; when the force is removed from the distal end of the retractable member, the retractable member by the spring force moves to the extended position relative to the bracket member.

2. The chainsaw guard of claim 1, wherein the bracket member comprises a vacuous area formed within an interior surface of the bracket member, with a collar forming the perimeter of the vacuous area, and a mounting bracket positioned on the interior surface area of the bracket member, in the vacuous area, the mounting bracket having one or more apertures for receiving affixation means to secure the bracket member to a motor powerhead housing of a chainsaw.

3. The chainsaw guard of claim 2, wherein the mounting bracket extends from the interior surface of the bracket member a sufficient distance so that when affixation means are positioned through the mounting bracket and secured to a motor powerhead housing of the chainsaw, the affixation means do not interfere with the sliding engagement of the retractable member with the bracket member.

4. The chainsaw guard of claim 3, wherein the bracket member further comprises a port through the bracket member, aligned with and providing access to the mounting bracket when the retractable member is in the extended position.

5. The chainsaw guard of claim 1, wherein the receiving track comprises an interior channel of the bracket member, sized and configured to receive and allow the retractable member to slide longitudinally within and through the bracket member.

6. The chainsaw guard of claim 5, wherein the receiving track is a narrow, rectilinear channel extending within and through the length of the bracket at its top, bottom and side.

7. The chainsaw guard of claim 6, wherein the receiving track comprises a rail formed in top and bottom segments of the channel, wherein the rail is sized and shaped to receive a corresponding groove positioned along a length of the top and bottom of the retractable member.

8. The chainsaw guard of claim 1, wherein the bracket member further comprises a first guide rod support structure extending from an outer surface of the member, and having one or more apertures to receive and allow sliding engagement of the guide rods, wherein the apertures of the first guide rod support structure are sized to allow the guide rod(s) to traverse the apertures, but maintaining the spring(s) associated with each guide rod on one side of the aperture; and the retractable member comprises a second guide rod support structure at the distal end of the retractable member, the second guide rod support structure having one or more apertures aligned with the aperture(s) of the first guide rod support structure when the retractable member is slidably engaged with the bracket member, to receive and affix a second end of the guide rod(s).

9. The chainsaw guard of claim 8, wherein the retractable member further comprises a third guide rod support structure 13 at the proximal end of the retractable member, the third guide rod support structure having one or more apertures aligned with the aperture(s) of the first and second guide rod support structures to receive and affix a first end of one or more guide rods.

10. The chainsaw guard of claim 1, wherein the bracket member further comprises a woodchips exhaust extending from an end thereof, facilitating and controlling expulsion of woodchips and other foreign materials from the chainsaw, and wherein the woodchips exhaust is sized, shaped and positioned on the bracket member so that the retractable member slides over a side of the woodchips exhaust as it assumes its retracted position relative to the bracket member.

11. The chainsaw guard of claim 10, wherein the woodchips exhaust comprises a bottom surface, parallel with but positioned above a bottom surface of the bracket member, and is closed along an arced upper surface.

12. The chainsaw guard of claim 11, wherein the bottom surface of the woodchips exhaust comprises one or more apertures sized and configured to allow woodchips and other foreign material to exit through the apertures.

13. The chainsaw guard of claim 10, wherein the woodchips exhaust comprises a handle indention.

14. The chainsaw guard of claim 1, wherein a length of the top and bottom of the retractable member are designed to extend longitudinally beyond the saw chain guide bar and saw cutter chain when the retractable member is in its extended position, and a width of the top and bottom of the retractable member cover and extend laterally beyond the saw chain guide bar and saw cutter chain.

15. The chainsaw guard of claim 1, wherein the retractable member comprises a bumper at its distal end, the bumper protruding from the bottom, top and side of the retractable member.

16. The chainsaw guard of claim 1, wherein the retractable member further comprises a cutting bar bumper, positioned on an interior and near the distal end of the side of the retractable member, centrally located so that when the retractable member is in the extended position, the bumper does not come in contact with the saw chain.

Description

DESCRIPTION OF THE DRAWINGS

[0016] The nature and characteristic features of the disclosed technology will be more readily understood from the following description taken about the accompanying drawings:

[0017] FIG. 1 is a perspective view of an embodiment of the chainsaw guard of the disclosed technology.

[0018] FIG. 2 is an exterior side view of the chainsaw guard of the embodiment of FIG. 1.

[0019] FIG. 3 is an interior side view of the chainsaw guard of the embodiment of FIG. 1.

[0020] FIG. 4 is a bottom view of the chainsaw guard of the embodiment of FIG. 1.

[0021] FIG. 5 is a top view of the chainsaw guard of the embodiment of FIG. 1.

[0022] FIG. 6 is another exterior side view of the chainsaw guard of the embodiment of FIG. 1, wherein the guard is in a position between the extended and retracted positions.

[0023] FIG. 7 is another interior side view of the chainsaw guard of the embodiment of FIG. 1, wherein the guard is in the fully retracted position.

[0024] FIG. 8 is a posterior view of the chainsaw guard of the embodiment of FIG. 1.

[0025] FIG. 9 is an anterior view of the chainsaw guard of the embodiment of FIG. 1.

[0026] FIG. 10 is an anterior view of an embodiment of the bracket member of the disclosed technology.

[0027] FIG. 11 is an interior view of the embodiment of the bracket member of FIG. 10.

[0028] FIG. 12 is a posterior view of the embodiment of the bracket member of FIG. 10.

[0029] FIG. 13 is an exterior view of the embodiment of the bracket member of FIG. 10.

[0030] FIG. 14 is an exterior view of an embodiment of the retractable member of the disclosed technology.

[0031] FIG. 15 is a perspective view of the embodiment of the bracket member of FIG. 10 and the retractable member of FIG. 14.

[0032] FIG. 16 is a top view of the embodiment of the retractable member of FIG. 14.

[0033] FIG. 17 is a side view of the chainsaw guard of the disclosed technology, affixed to a chainsaw.

[0034] FIG. 18 is another side view of the chainsaw guard of the disclosed technology, affixed to a chainsaw.

[0035] FIG. 19 is an interior view of a chainsaw sprocket cover of a chainsaw.

[0036] FIG. 20 is a side view of a chainsaw, with the chainsaw sprocket cover removed.

DETAILED DESCRIPTION

[0037] Referring now more particularly to the drawings, embodiments of the chainsaw guard of the disclosed technology are illustrated in FIGS. 1-18. As shown in FIGS. 17-18, the chainsaw guard is intended for mounting on and use with a chainsaw 100 having a motor powerhead housing 101, a drive motor 102 contained in the housing, a saw chain guide bar 103 mounted on the motor powerhead housing, and a saw cutter chain 104 driven by the drive motor and carried on the saw chain guide bar. The saw cutter chain 104 is carried by the chain bar 103, which is detachably secured to the motor powerhead housing by two bolts and nuts with the bolts engaged in a slot in the saw chain guide bar. The chainsaw guard of the disclosed technology replaces the chain sprocket cover (shown in FIG. 19) which traditionally is secured to and covers the motor powerhead housing 101 by means of a plurality of bolts. When mounted on the chainsaw motor powerhead housing, the chainsaw guard of the disclosed technology forms a physical barrier that limits access to the saw cutter chain.

[0038] In the embodiment shown in FIGS. 1-16, the chainsaw guard includes a bracket member 1 mountable to a chainsaw motor powerhead housing, and a retractable member 6 slidably engaged with the bracket member and designed and configured to partially sheathe the saw chain guide bar 103 and saw cutter chain 104 of the chainsaw when the chainsaw guard is mounted on a chainsaw in its extended position (see FIGS. 17 and 18). In this manner, the retractable member 6 covers one side, the top and the bottom of the bar and chain, extending beyond the terminal end of the bar 103 and chain 104; no covering is provided over the other side of the bar and chain, and the terminal end of the chainsaw guard is open, allowing the retractable member 6 to slide relative to the bracket member 1, exposing or covering the bar and chain as it moves between the retracted (FIGS. 6 and 7) and extended (FIGS. 1, 17, 18) positions.

[0039] The chainsaw guard of the disclosed technology further includes means 10, 11 to provide a restorative spring force for positioning the retractable member relative to the bracket member, between and among its retracted and extended positions, as well as positions there-between (shown in FIG. 6). In the retracted position (and positions between the retracted and extended positions), the saw cutter chain is exposed for cutting wood.

[0040] In this embodiment, as shown in FIGS. 1, 10-11, the bracket member 1 comprises a vacuous area 1A formed within the interior surface area 1B of the bracket member 1, with a collar 1C forming the perimeter of the vacuous area, and a mounting bracket 2, the vacuous area being designed and configured to receive a portion of a specific chainsaw motor powerhead housing 101, and allow affixation of the chainsaw guard of the disclosed technology to the housing 101 as hereinafter described. Notably, chainsaw motor powerhead housings vary in configurations among manufacturers, and even among models; therefore, the design and configuration of the vacuous area 1A, the collar 1C, and the mounting bracket 2 (as hereinafter described), may be manufacturer and model specific.

[0041] The mounting bracket 2 of the bracket member 1 has one or more apertures 3 extending therethrough for receiving affixation bolts, screws or similar means to secure the bracket member to the motor powerhead housing of the chainsaw. As shown in FIGS. 1. 10, 11, the mounting bracket 2 is secured to the interior surface 1B of the bracket member, and seated in the vacuous area 1A thereof, extending from the surface 1B a sufficient distance so that when bolts are positioned through the mounting bracket and secured to the motor powerhead housing, the bolts do not interfere with the sliding engagement of the retractable member with the bracket member, as hereinafter described. The walls forming the mounting bracket should be sized and configured to sit within the aperture of the cutting blade, and allow the saw cutter chain to rotate about the mounting bracket at 16. The mounting bracket 2 is configured so that the surface of the mounting bracket abuts the motor powerhead housing when the bracket member is secured thereto; in most configurations (based upon manufacturer and model of chainsaw) this will require that the depth of the mounting bracket 2 extending from the interior surface 1B of the vacuous area 1A be less than the full depth of the vacuous area 1A. Further, when mounted on the motor powerhead housing the collar 1C of the bracket member (about the vacuous area) is designed and configured to abut the external walls or other structure of the motor powerhead housing. An aperture or port 1D through the bracket member 1 allows full access to the mounting bracket 2 from the exterior thereof, when the retractable member is in the extended position. The aperture or port 1D extends through and beyond the receiving track 19 (hereinafter described), without interfering with the slidable engagement of the retractable member 6 with the bracket member 1. By this access the bracket member may be easily removed or secured to the motor powerhead housing.

[0042] As hereinabove discussed, motor powerhead housings have varying surface shapes, aperture/bolt configurations and related structural designs for securing the chain sprocket cover to the saw, about the drive motor, saw chain guide bar and saw cutter chain. Therefore, the shape of the bracket member 1, vacuous area 1A, interior surface 1B, collar 1C, mounting bracket 2, port 1D and apertures 3 are designed and configured by model and manufacturer to secure the bracket to the motor powerhead housing in this same configuration. By replicating this chainsaw model/manufacturer specific configuration for affixation of the chain sprocket cover, the bracket member 1 may be affixed to, and abut securely against, the chainsaw housing and the motor powerhead housing by bolts (or other securing means).

[0043] The bracket member 1 further includes a receiving track 19 extending along its length to receive the retractable member 6 in sliding engagement with the bracket member. As shown in FIGS. 8 and 10, the receiving track 19 may be an interior channel of the member, sized and configured to receive and allow the retractable member to slide longitudinally within and through the member, while inhibiting material lateral movement of the retractable member. In the embodiment shown, the receiving track is a narrow, rectilinear channel extending within and through the length of the bracket at its top, bottom and side opposing the vacuous area 1A, to receive the top, bottom and side of the retractable member 6. To inhibit lateral or rotational movement of the retractable member and secure the retractable member in sliding engagement with the bracket member, a rail 18 may be provided in the top or bottom segments of the channel 19, or in both the top and bottom segments of the channel 19. In this configuration, the rail 18 may be sized and shaped to receive a corresponding groove 6B positioned along the length of the top and bottom of the retractable member 6 (as shown in FIG. 5). Alternative configurations for supporting and allowing sliding engagement of the retractable member relative to the bracket member between and among an extended position and a retracted position, and for inhibiting the lateral and rotational movement of the retractable member, may also be suitable.

[0044] The bracket member 1 further includes a first guide rod support structure 4 extending from the outer surface of the member, and having one or more apertures to receive and allow sliding engagement of one or more guide rods 10, as hereinafter described. Notably, the apertures of the first guide rod support structure 4 are sized to allow the guide rod(s) 10 to traverse the apertures, but maintaining the spring(s) 11 associated with each guide rod on one side of the aperture, thereby providing the restorative spring force for positioning the retractable member relative to the bracket member, between and among a retracted position and an extended position, as well as positions there-between.

[0045] As shown in FIGS. 1-5, 7, 8, 11 and 12, the bracket member 1 may further have a hollow woodchips exhaust 5 extending from an end thereof, facilitating and controlling expulsion of woodchips and other foreign materials from the chainsaw. The woodchips exhaust is sized, shaped and positioned on the bracket member so that the retractable member 6 slides over one side of the woodchips exhaust as it assumes its retracted position relative to the bracket member (see FIGS. 6 and 7). The wood chips exhaust comprises a bottom surface 5A, parallel with but positioned above the bottom surface of the bracket member, and is closed along an arced upper surface 5B. In some embodiments, as shown in FIG. 4, the bottom surface 5A has apertures 18 sized and configured to allow woodchips and other foreign material to exit the guard. In some configurations, a handle indention 17 may be provided in the wood chips exhaust structure (as shown in FIGS. 3, 11) to allow the retractable chainsaw guard to properly conform to the motor powerhead housing of said chainsaw.

[0046] The retractable member 6 of the chainsaw guard is slidably engaged with the bracket member by means of the bracket member's receiving track 19, such as the channel shown in FIGS. 8 and 10, and generally has proximal and distal ends, and side, top and bottom planate structures, sized and configured to be received within the bracket member's channel and allow the retractable member to slide longitudinally within and through the bracket member, while inhibiting material lateral movement of the retractable member. In this configuration, the retractable member partially sheathes (on three sides) the saw chain guide bar and saw cutter chain of the chainsaw when the chainsaw guard is mounted on a chainsaw and the retractable member is in the extended position. Furthermore, by these and similar configurations, the retractable member translates between and among a retracted position and an extended position relative to the bracket member.

[0047] In some embodiments (not shown) the retractable member includes a plurality of nested sections, which retract and extend; in other embodiments, the retractable member is a rigid member. The length of the top and bottom planate structures of the retractable member are designed to extend longitudinally beyond the saw chain guide bar and saw cutter chain when the retractable member is in its extended position. To spread the impact in the event of a kickback or cut-through, and thereby to minimize the impact injury on the operator, the width of the top and bottom structures of the retractable member cover and extend laterally beyond the saw chain guide bar and saw cutter chain.

[0048] In some embodiments, a groove 6B may be positioned along the length of the top and/or bottom surfaces of the retractable member 6, sized and shaped to receive one or more rails 18 of the channel 6A of the bracket member (see FIGS. 4, 5, 10 and 11). As hereinabove stated, alternative configurations for supporting and allowing sliding engagement of the retractable member 6 relative to the bracket member 1 between and among an extended position and a retracted position, and for inhibiting the lateral and rotational movement of the retractable member relative to the bracket member, may also be suitable.

[0049] At the distal end of the retractable member 6, bumpers 9 protrude from the bottom, top and side structures thereof, as shown in FIGS. 1-7, 9, and 13-18. The bumpers 9 may protrude a distance of between about 1-1 from the top and bottom surfaces of the retractable member. By this configuration, the bumper provides a surface which may contact wood and facilitate generating the force greater than the spring force to move the retractable member 6 from the extended position towards or to the retracted position, as hereinafter described.

[0050] As shown in FIGS. 3, 7, 9 and 14, on the interior and near the distal end of the side of the retractable member 6 is a cutting bar bumper 14, positioned sufficiently far away from the distal end and centrally located so that when the retractable member is in the extended position, the bumper does not come in contact with the saw chain. When the chainsaw guard is mounted on the chainsaw, the cutting bar bumper 14 is intended to rest upon the cutter bar 103, thereby maintaining the interior side of the retractable member 6 a distance away from the saw cutter chain 104 (and the cutter bar 103) so that the cutter chain 104 does not come in contact with the retractable member 6.

[0051] Further, at or near the distal end of the retractable member, a second guide rod support structure 8 protrudes from the surface of the side of the retractable member (see FIGS. 1, 2, 4-6, 9, 13, 15, 16, 18). The second guide rod support structure 8 has one or more apertures aligned with the aperture(s) of the first guide rod support structure 4 when the retractable member 6 is slidably engaged with the bracket member 1, to receive and affix a second end of one or more guide rods 10, lateral with the outer surface of the retractable member. The guide rods 10 may be secured through the second guide rod support structure 8 by a nut or similar structure. In some embodiments, as shown in FIGS. 1, 2, 4-6, and 8, a third guide rod support structure 13 is provided at the proximal end of the retractable member, protruding from the surface of the side of the retractable member. The third guide rod support structure also has one or more apertures aligned with the aperture(s) of the first and second guide rod support structures when the retractable member is slidably engaged with the bracket member, to receive and affix (by means of a nut 12 or similar structure) a first end of one or more guide rods 10. In an alternate configuration, as shown in FIGS. 13-16 and 18, the guide rods 10 are unsecured at the first end of the guide rods, with a nut or similar structure provided on the first end to ensure that the rods do not pass through the apertures of the first guide rod support structure.

[0052] Further provided with the chainsaw guard of the disclosed technology is a compressible spring 11 to provide a spring force for positioning the retractable member between and among its retracted position and its extended position relative to the bracket member (see FIGS. 1, 2, 4, 6 and 18). In the embodiment shown, one or more guide rods 10 are slidably engaged within the apertures of the first guide rod support structure of the mounting bracket and affixed to the second guide rod support structure of the retractable member (and the third guide rod support structure of the retractable member, if any). The guide rods provide both rigidity to the guard, and stability for springs providing the spring force. The compressible spring 11 is engaged about each of the guide rods, between the first and second guide rod support structures, the springs having a spring force when compressed to position the retractable member relative to the bracket member in the extended position until a force greater than the spring force is applied to the distal end of the retractable member (at the bumpers 9), translating the retractable member towards the retracted position relative to the bracket member; when the force is removed from the distal end of the retractable member, the retractable member by the spring force moves to the extended position relative to the bracket member. For example, a spring force of 7.3 psi is sufficient to restore the retractable member of an embodiment of the guard to its fully extended position in less than one-half second.

[0053] Furthermore, in some embodiments as shown in FIGS. 2, 6 and 12, a notch 13A is provided on the bracket member 1, at its distal end up to the first guide rod support structure, to receive the third guide rod support structure 13 mounted on the retractable member 6, as the retractable member traverses through the bracket member 1 to the extended position, as herein described.

[0054] The bracket member and retractable member may be plastic, metal, composites or combinations thereof, and the components of each member may be molded into a single unit, or affixed by any suitable and durable affixation means.

[0055] To install the chainsaw guard of the disclosed technology, a user removes the chain sprocket cover of the chainsaw; the bracket member of the chainsaw guard of the disclosed technology is then secured by means of one or more bolts (or similar securing structure) to the motor powerhead housing of the chainsaw such that (a) the mounting bracket sits flush with the chainsaw bar, and the apertures of the bar used to secure the chain sprocket cover align with the apertures 3 of the mounting bracket 2; and (b) the collar 1C sits flush with the chainsaw housing surface. The retractable members may be positioned within the receiving track 19 of the bracket member 1, before or after mounting the bracket member on the chainsaw housing. Likewise, the rods 10 and springs 11 may be secured to the bracket member and the retractable members before or after mounting the bracket member on the chainsaw housing.

[0056] In use, the chainsaw guard of the disclosed technology secured on a chainsaw as hereinabove described begins with the retractable member 6 in its extended position. When the user initiates a cut of wood, he applies a force on the bumper 9 greater than the spring force of the compression springs 11, and the retractable member of the guard moves towards its retracted position (based upon the force applied to the bumper by the user). When the user removes the saw from the wood, the applied force is removed and the springs cause the retractable member to return to its extended state.

[0057] While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.