Pole saw

Abstract

An outdoor tool includes a powerhead, a tool unit powered by the powerhead, and a shaft assembly extending between the powerhead and the tool unit. The tool unit includes a transmission housing, a support plate, a guide bar adjustably supported by the support plate, a drive gear, and a chain circumscribing a portion of the drive gear and a portion of the guide bar, the drive gear operatively coupled to the powerhead. The tool unit further includes a tension adjustment mechanism for adjusting a position of the guide bar relative to the drive gear to increase and decrease a tension in the chain. The tension adjustment mechanism includes an adjustment screw, a threaded adjustment bolt, at least one adjustment gear, and a member coupled to the adjustment bolt and the guide bar. Rotation of the adjustment screw causes translation of the guide bar relative to the drive gear.

Description

FIELD OF THE INVENTION

The invention generally relates to outdoor tools, and, more particularly, to a pole saw.

BACKGROUND OF THE INVENTION

Outdoor tools, such as pole saws, are used to perform outdoor tasks, such as cutting tree branches.

SUMMARY OF THE INVENTION

In one aspect, an outdoor tool generally includes a powerhead, tool unit powered by the powerhead, and an elongated shaft assembly extending along a shaft axis between the powerhead and the tool unit. The tool unit includes a transmission housing fixed to the shaft assembly, a support plate coupled to the transmission housing, a guide bar adjustably supported by the support plate, a drive gear rotatably supported by the transmission housing, and a chain circumscribing a portion of the drive gear and a portion of the guide bar, the drive gear operatively coupled to the powerhead for driving the chain about the guide bar. The tool unit further includes a tension adjustment mechanism for adjusting a position of the guide bar relative to the drive gear in order to increase and decrease a tension in the chain. The tension adjustment mechanism includes an adjustment screw, a threaded adjustment bolt, at least one adjustment gear intermeshed with the adjustment screw and the adjustment bolt, and a member coupled to the adjustment bolt and the guide bar. Rotation of the adjustment screw rotates the adjustment bolt and thereby causes translation of the guide bar relative to the drive gear.

In another aspect, an outdoor tool generally includes a powerhead, a tool unit powered by the powerhead, and an elongated shaft assembly extending along a shaft axis between the powerhead and the tool unit. The tool unit includes a transmission housing fixed to the shaft assembly, a support plate coupled to the transmission housing, a cover coupled to the support plate wherein the support plate and cover define a cavity, a guide bar adjustably supported by the support plate, a drive gear rotatably supported by the transmission housing, and a chain circumscribing a portion of the drive gear and a portion of the guide bar, the drive gear operatively coupled to the powerhead for driving the chain about the guide bar. The drive gear, a portion of the guide bar, and a portion of chain are housed in the cavity. The tool unit also includes a lubrication system operable to lubricate the chain. The lubrication system includes an oil reservoir, a pump drivingly coupled to the drive gear and in fluid communication with the oil reservoir and the cavity, wherein operation of the pump pumps lubricant from the oil reservoir to the cavity. The lubrication system also includes an inlet tube extending from the oil reservoir to the pump, a channel defined in the cavity between the support plate and a surface of the guide bar, and an outlet tube extends from the pump to the cavity.

Other independent aspects of the invention may become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an outdoor tool, such as a pole saw, including a pole saw attachment.

FIG. 2 is a perspective view of the pole saw attachment of FIG. 1.

FIG. 3 is another perspective view of the pole saw attachment of FIG. 1.

FIG. 4 is a side view of the pole saw attachment of FIG. 1.

FIG. 5 is another side view of the pole saw attachment of FIG. 1.

FIG. 6 is a top view of the pole saw attachment of FIG. 1.

FIG. 7 is a bottom view of the pole saw attachment of FIG. 1.

FIG. 8 is an end view of the pole saw attachment of FIG. 1.

FIG. 9 is another end view of the pole saw attachment of FIG. 1.

FIG. 10 is a side view of a saw head of FIG. 2.

FIG. 11 is another side view of the saw head of FIG. 2.

FIG. 12 is a top view of the saw head of FIG. 2.

FIG. 13 is a bottom view of the saw head of FIG. 2.

FIG. 14 is a perspective view of the saw head of FIG. 2.

FIG. 15 is another perspective view of the saw head of FIG. 2.

FIG. 16 is another perspective view of the saw head of FIG. 2, with a cover removed.

FIG. 17 is a side view of the saw head of FIG. 2 with the reservoir removed.

FIG. 18 is a cross-sectional side view of the saw head of FIG. 2, taken generally along line 18-18 of FIG. 12.

FIG. 19 is another cross-sectional view of the saw head of FIG. 2, taken generally along line 19-19 of FIG. 10.

FIG. 20 is another cross-sectional side view of the saw head of FIG. 2, taken along line 20-20 of FIG. 12.

FIG. 21 is another cross-sectional view of the saw head of FIG. 2, taken along line 21-21 of FIG. 10.

FIG. 22 is another cross-sectional view of the saw head of FIG. 2, taken along line 22-22 of FIG. 11.

FIG. 23 is a perspective view of a connecting portion of the pole saw attachment shown in FIG. 2.

FIG. 24 is another perspective view of the connecting portion of FIG. 2.

FIG. 25 is a cross-sectional view of the connecting portion of FIG. 2, taken along line 25-25 of FIG. 23.

FIG. 26 is a perspective end view of a connecting portion of a powerhead of the pole saw shown in FIG. 1.

FIG. 27 is another perspective end view of the connecting portion as shown in FIG. 26.

Before any independent embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other independent embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

Also, the functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not listed.

DETAILED DESCRIPTION

FIG. 1 illustrates an outdoor tool T, such as a pole saw, for use in performing outdoor tasks such as cutting tree branches. The outdoor tool T includes an elongated shaft assembly 10 extending along a shaft axis 14, a tool or saw head 18 at one end of the shaft assembly 10, and a powerhead 22 at an opposite end of the shaft assembly 10. The saw head 18 includes a saw chain 26 for performing cutting. The powerhead 22 generates a motive force to drive the saw chain 26 during operation of the outdoor tool T.

In the illustrated construction, the outdoor tool T includes a powerhead unit 30 and an attachment or tool unit 34, such as a pole saw attachment 34, selectively and removably coupled to the powerhead unit 30 via connecting portions 38, 42 (FIGS. 23-27). The shaft assembly 10 includes first and second shaft segments 44, 46. The powerhead unit 30 includes the powerhead 22, the first shaft segment 44, and the first connecting portion 38, and the attachment unit 34 includes the saw head 18, the second shaft segment 46, and the second connecting portion 42. In other constructions (not shown), the outdoor tool T is a standalone tool, so that the saw head 18 and the powerhead 22 are not separable.

A first driveshaft segment 48 (partially shown in FIGS. 26-27) extends axially within the first shaft segment 44 along the shaft axis 14 and is drivingly coupled to the powerhead 22. A second driveshaft segment 50 (FIG. 18) extends axially within the second shaft segment 46 and is drivingly coupled to the saw head 18. When the attachment unit 34 is attached to the powerhead unit 30, the first driveshaft segment 48 couples to the second driveshaft segment 50 to drivingly transmit rotary power from the powerhead 22 to the saw head 18.

A similar powerhead unit is described and illustrated in U.S. Provisional Patent Application No. 62/675,661, filed May 23, 2018, entitled “POWERHEAD UNIT FOR TOOL”, and in corresponding U.S. patent application Ser. No. 16/417,713, filed May 21, 2019, now U.S. Pat. No. 11,485,003, entitled “POWERHEAD UNIT FOR TOOL”, the entire contents of which is hereby incorporated by reference.

With reference to FIGS. 14-16, the saw head 18 includes a support plate 54 (FIG. 16) and a guide bar 58 adjustably mounted to the support plate 54. The guide bar 58 supports the chain 26 so that the chain 26 circulates about a perimeter of the guide bar 58 during operation. A sprocket 62 (FIG. 16) engages the chain 26 and rotates about a sprocket axis 66 to drive the chain 26 about the guide bar 58. A sprocket cover 70 (FIG. 15) is coupled to the support plate 54 to retain and shield the covered components (e.g., the sprocket 62, the chain 26, etc.) from debris and to inhibit accidental contact with moving components (e.g., the sprocket 62, the chain 26, etc.).

The saw head 18 also includes a transmission housing 74 affixed to the support plate 54 and coupled to the second shaft segment 46 whereby the second shaft segment 46 is received therein. In the illustrated construction, the saw head 18 is fixed relative to the shaft assembly 10. In other constructions (not shown), the saw head 18 may be supported for pivoting movement relative to the shaft assembly 10 about an axis generally perpendicular to the shaft axis 14 (e.g., about the sprocket axis 66). A similar pivoting mechanism is described and illustrated in U.S. Provisional Patent Application No. 62/675,662, filed May 23, 2018, entitled “HEDGE TRIMMER”, and in corresponding U.S. patent application Ser. No. 16/417,715, filed May 21, 2019, now U.S. Pat. No. 11,284,568, entitled “HEDGE TRIMMER”, the entire contents of which is hereby incorporated by reference.

The second driveshaft segment 50 of the saw head 18 terminates within the gear housing 74. A transmission or gear assembly 78 (FIG. 19) transmits the rotary motion of the second driveshaft segment 50 to the sprocket 62 to circulate the chain 26 about the guide bar 58.

The gear assembly 78 includes an input gear 82 and an output gear 86. The input gear 82 is coupled to the second driveshaft segment 50 within the gear housing 74 for rotation about the shaft axis 14. The output gear 86 is supported within the gear housing 74 by an output shaft 90 for rotation about the sprocket axis 66. The input gear 82 engages and drives the output gear 86 when the second driveshaft segment 50 is rotated by the powerhead 22. A portion of the output shaft 90 extends through the support plate 54 and is drivingly coupled to the sprocket 62.

The saw head 18 also includes an oil reservoir 94 (FIG. 14) and a lubrication system 98 (FIG. 17) operable to supply lubricant (e.g., oil, etc.) from the oil reservoir 94 to the guide bar 58 and to the chain 26. Specifically, FIG. 17 illustrates the saw head 18 with the oil reservoir 94 removed and depicts an oil pump 102 housed within the gear housing 74. The oil pump 102 includes a pinion 106 (FIG. 19) that engages a worm gear 110 formed on the output shaft 90 (FIG. 19). The worm gear 110 rotates during operation of the outdoor tool T to drive the pinion 106 and operate the oil pump 102.

The oil pump 102 pumps lubricant through a fluid flow path 114 extending from the oil reservoir 94, through the oil pump 102, to a flow path outlet 118 (FIG. 22) to lubricate the guide bar 58 and the chain 26. The flow path 114 includes an inlet tube 122 (FIG. 17) extending from the reservoir 94 to a pump inlet 126 of the oil pump 102. An outlet tube 130 extends from a pump outlet 134 of the oil pump 102, passes behind an adjustment bracket 138 (FIG. 17), and fluidly couples to a hollow tube member 142 (FIG. 22) fastened to the support plate 54.

The tube member 142 extends through a flow path aperture 146 (FIG. 22) in the support plate 54 and terminates within a channel 150 defined between a flow path recess 154 in the support plate 54 and a surface of the guide bar 58. The channel 150 is fluidly connected to the flow path outlet 118. During operation of the outdoor tool T, oil flows through the flow path 114 from the reservoir 94 through the inlet tube 122, the oil pump 102, the outlet tube 130, the tube member 142, and the channel 150 to the flow path outlet 118 to lubricate the guide bar 58 and the chain 26.

With reference to FIGS. 16 and 20, the saw head 18 includes a tension adjustment mechanism 158 operable to adjust a tension force of the chain 26 by adjusting the distance between the sprocket 62 and an end 160 of the guide bar 58. The tension adjustment mechanism 158 includes an adjustment screw 162 that extends through an axial slot 166 in the guide bar 58. The adjustment screw 162 also extends through a screw aperture 170 (FIG. 19) in the support plate 54.

A first adjustment gear 174 is coupled to an end of the adjustment screw 162 such that the two rotate together. A threaded adjustment bolt 178 is supported by the adjustment bracket 138 within an adjustment recess 182. A second adjustment gear 186 intermeshes with both the first adjustment gear 174 and the adjustment bolt 178. The first adjustment gear 174 engages the second adjustment gear 186 within the adjustment bracket 138, such that rotation of the adjustment screw 162 and the first adjustment gear 174 thereby causes the second adjustment gear 186 and the adjustment bolt 178 to rotate within the adjustment recess 182.

An adjustment stud 190 (FIG. 20) is threadably engaged with the adjustment bolt and fixedly coupled to the guide bar 58. The adjustment stud 190 has a generally cylindrical shape and is oriented perpendicular to the guide bar 58. The adjustment stud 190 includes a threaded bolt aperture 194 (FIG. 21) that threadably engages the adjustment bolt 178 within the adjustment recess 182. The adjustment stud 190 extends from the adjustment recess 182 through a gap 198 formed by the support plate 54 and engages a stud aperture 202 formed in the guide bar 58. Rotation of the adjustment bolt 178 by the adjustment screw 162 causes the adjustment stud 190 to move forward or backward within the adjustment recess 182 (i.e., away from or toward the sprocket 62).

With reference to FIGS. 16 and 19, a threaded guide bar stud 206 is coupled to the support plate 54 and extends through the axial slot 166 of the guide bar 58. When the sprocket cover 70 is mounted to the saw head 18, the guide bar stud 206 also extends through a mounting aperture 210 (FIG. 19) in the sprocket cover 70. A nut 214 fastens to the guide bar stud 206 to secure the sprocket cover 70 to the saw head 18. The nut 214 is tightened to lock the guide bar 58 in position relative to the sprocket 62 and the support plate 54 and is loosened to unlock the guide bar 58 so that the tension of the chain 26 can be adjusted via the tension adjustment mechanism 158.

To adjust the tension, the nut 214 is first loosened (e.g., using a tool such as a wrench, socket and driver, etc.) to unlock the guide bar 58 from the support plate 54. When the nut 214 is loosened, the guide bar stud 206 continues to support the guide bar 58 but permits axial movement of the guide bar 58 relative to the support plate 54. With the nut 214 loosened, the adjustment screw 162 is rotated to adjust the tension in the chain 26. Rotation of the adjustment screw 162 rotates the first adjustment gear 174, which causes the second adjustment gear 186 and the adjustment bolt 178 to rotate. Rotation of the adjustment bolt 178 causes the adjustment stud 190 to translate forward or backward within the adjustment recess 182. Translation of the adjustment stud 190 causes the guide bar 58 to translate with the adjustment stud 190 and relative to the sprocket 62 due to the engagement of the adjustment stud 190 with the stud aperture 202 of the guide bar 58 thereby adjusting the chain tension.

The adjustment screw 162 is rotated in a direction corresponding to the desired tension adjustment. For example, in the illustrated construction and referring to FIG. 16, the adjustment screw 162 is rotated clockwise to translate the guide bar 58 away from the sprocket 62 and thereby increase the tension in the chain 26. To decrease the chain tension, the adjustment screw 162 is rotated counter-clockwise to translate the guide bar 58 toward the sprocket 62. In other constructions (not shown), the opposite may be true—clockwise rotation of the adjustment screw 162 may decrease the tension in the chain 26, and counter-clockwise rotation of the adjustment screw 162 may increase the tension in the chain 26.

With reference to FIGS. 23-27, the attachment unit 34 also includes the second connecting portion 42 that selectively couples to the first connecting portion 38 of the powerhead unit 30. In the illustrated construction, the second driveshaft segment 50 terminates at the second connecting portion 42 in a spline hub 218 (FIG. 25). When the powerhead unit 30 is coupled to the attachment unit 34, a spline 222 (FIGS. 26-27) on the first driveshaft segment 46 selectively engages and rotatably couples to the spline hub 218, to transmit rotary power from the first driveshaft segment 48 and the second driveshaft segment 50 and, therethrough, from the powerhead unit 30 to the saw head 18.

As described in more detail in U.S. Provisional Patent Application No. 62/675,661, filed May 23, 2018, entitled “POWERHEAD UNIT FOR TOOL”, and in corresponding U.S. patent application Ser. No. 16/417,713, filed May 21, 2019, now U.S. Pat. No. 11,485,003, entitled “POWERHEAD UNIT FOR TOOL”, as shown in FIGS. 24 and 27, a retainer assembly (e.g., a quick-release mechanism 226 and a clamping mechanism 230) is provided between the connecting portions 38, 42. The illustrated mechanism 226 includes a spring-biased button 234 with a projection 238 engageable in a recess 242 (FIG. 24) to selectively and releasably retain the connecting portions 38, 42. The connecting portion 38 is formed with clamping flanges 246 engaged by a clamping actuator 250 (e.g., a bolt and nut) to apply a clamping force to the connecting portion 42.

One or more independent features and/or independent advantages of the invention may be set forth in the claims.

Claims

1. An outdoor tool comprising: a powerhead;a tool unit powered by the powerhead; andan elongated shaft assembly extending along a shaft axis between the powerhead and the tool unit, the tool unit including a transmission housing fixed to the shaft assembly,a support plate coupled to the transmission housing,a cover coupled to the support plate, wherein the support plate and the cover define a cavity,a guide bar adjustably supported by the support plate,a drive gear rotatably supported by the transmission housing, anda chain circumscribing a portion of the drive gear and a portion of the guide bar, the drive gear operatively coupled to the powerhead for driving the chain about the guide bar,wherein the drive gear, a portion of the guide bar, and a portion of chain are housed in the cavity; anda lubrication system operable to lubricate the chain, the lubrication system including an oil reservoir,a pump drivingly coupled to the drive gear, an inlet tube extending from the oil reservoir to the pump defining fluid communication between the pump and the oil reservoir, a channel defined in the cavity between the support plate and a surface of the guide bar, an outlet tube extending from the pump to the cavity defining fluid communication between the pump and the cavity, and wherein operation of the pump pumps lubricant from the oil reservoir to the cavity.

2. The outdoor tool of claim 1, wherein the tool unit includes an output shaft coupled to the drive gear.

3. The outdoor tool of claim 2, wherein the pump includes a pinion that is drivingly engaged with the output shaft of the tool unit.

4. The outdoor tool of claim 3, wherein the output shaft includes a worm gear drivingly engaged with the pinion.

5. The outdoor tool of claim 4, wherein the shaft assembly includes a first driveshaft segment drivingly coupled to a second driveshaft segment to transmit rotary power from the powerhead to the tool unit, and wherein the second driveshaft segment is coupled to an input gear that engages and drives an output gear supported by the output shaft.

6. The outdoor tool of claim 1, wherein a fluid flow path extends from the oil reservoir to a flow path outlet formed in the guide bar.

7. The outdoor tool of claim 6, wherein the flow path outlet communicates oil from a first lateral side of the guide bar to a second lateral side of the guide bar opposite the first lateral side.

8. The outdoor tool of claim 7, wherein during operation of the lubrication system, oil flows along the flow path from the oil reservoir through the inlet tube, the pump, and the outlet tube, to the cavity.

9. The outdoor tool of claim 1, wherein the lubrication system further includes a tube member extending from the outlet tube to the channel, the channel being fluidly coupled to the cavity.

10. The outdoor tool of claim 9, wherein the tube member extends through a flow path aperture in the support plate and terminates within the channel.

11. The outdoor tool of claim 10, wherein the outlet tube extends from the pump to the tube member.

12. The outdoor tool of claim 10, wherein the tube member is fastened to the support plate.

13. The outdoor tool of claim 1, wherein the tool unit includes an adjustment bracket coupled to the support plate.

14. The outdoor tool of claim 13, wherein the outlet tube passes between the adjustment bracket and the support plate.

15. The outdoor tool of claim 1, wherein the lubrication system further includes a tube member extending from the outlet tube to the channel that is fluidly coupled to the cavity, and wherein the outlet tube extends from the pump to the tube member, and wherein a flow path outlet is formed in the guide bar and fluidly communicates with the channel.