Shaft locking system and snowthrower chute control system incorporating same

Abstract

A shaft locking system is provided that includes a shaft, a wrap spring wrapped about the shaft, and an optional actuator configured to deflect the wrap spring. The actuator may be connected to a handle or joystick. An exemplary system may be configured as a joystick control system for a snowthrower discharge chute deflector. When the wrap spring is in a neutral position, it provides a high friction force to restrict relative rotation between the shaft and the wrap spring in one rotational direction and allow rotation in the opposite rotational direction. The actuator can act upon the wrap spring to reduce the friction force, allowing relative rotation between the shaft and the wrap spring in both directions.

Description

PATENTDocket No. 0206.000353W001SHAFT LOCKING SYSTEM AND SNOWTHROWER CHUTE CONTROL SYSTEM INCORPORATING SAME

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 718,796, filed on 11 November 2024, which is incorporated herein by reference in its entirety.

[0002] Embodiments described herein are directed generally to systems for locking rotation of a shaft, and for example, to snowthrower chute and other power equipment control systems incorporating the same.SUMMARY

[0003] In one or more embodiments of the present disclosure, a snowthrower is provided that includes: a housing containing an auger therein; a chute connected to the housing and configured to direct snow discharged from the housing by the auger; a movable chute deflector attached to a distal end of the chute; and a control system configured to change an ejection angle of the deflector. The control system includes: a shaft defining an axis; and a wrap spring comprising a helical coil wrapped about the shaft. The coil is configured to engage the shaft with a first friction force when the wrap spring is in a neutral position, the first friction force configured to: restrict relative rotation between the shaft and the wrap spring in a first direction; and permit relative rotation between the shaft and the wrap spring in a second direction. An actuator is also provided and configured to deflect the wrap spring to a deflected position wherein the coil engages the shaft with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting relative rotation between the shaft and the wrap spring in the first direction.

[0004] In another embodiment, a snowthrower is provided that includes: a housing containing an auger therein; a chute connected to the housing and configured to rotate about a chute axis to control a direction of discharged snow from the housing; a movable chute deflector attached to a distal end of the chute; and a control system adapted to change an ejection angle of the deflector. The control system includes: a joystick; a shaftdefining an axis about which the joystick rotates; and a wrap spring comprising a helical coil wrapped about the shaft, the coil configured to engage the shaft with a first friction force when the wrap spring is in a neutral position. The first friction force is configured to: restrict relative rotation between the shaft and the wrap spring in a first direction; and permit relative rotation between the shaft and the wrap spring in a second direction. The snowthrower further includes a Bowden cable having a first end operatively connected to a first leg of the wrap spring and a second end operatively connected to the deflector.

[0005] In yet another embodiment, a shaft locking system is provided that includes: a shaft defining an axis; and a wrap spring comprising a helical coil wrapped about the shaft, the coil configured to engage the shaft with a first friction force when the wrap spring is in a neutral position. The first friction force is configured to: restrict relative rotation between the shaft and the wrap spring in a first direction; and permit relative rotation between the shaft and the wrap spring in a second direction. The system also includes an actuator configured to deflect the wrap spring to a deflected position wherein the coil engages the shaft with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting relative rotation between the shaft and the wrap spring in the first direction.

[0006] In still another embodiment, a snowthrower is provided that includes: a housing containing an auger therein; a chute connected to the housing and configured to direct snow ejected from the housing; a movable chute deflector attached to a distal end of the chute; and a control system comprising a deflector ejection angle mechanism configured to change at least an ejection angle of the chute deflector. The control system includes: a shaft defining an axis; and a wrap spring including a helical coil wrapped about the shaft. The coil is configured to engage the shaft with a first friction force when the wrap spring is in a neutral position, the first friction force configured to: restrict relative rotation between the shaft and the wrap spring in a first direction; and permit relative rotation between the shaft and the wrap spring in a second direction. An actuator is also provided and configured to deflect the wrap spring to a deflected position wherein the coil engages the shaft with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting relative rotation between the shaft and the wrap spring in the first direction.

[0007] In yet another embodiment, a shaft locking system is provided that includes: first and second shafts aligned along a shaft axis; and a first wrap spring having a helical coil wrapped about the first and second shafts, the coil configured to engage outer surfaces of both the first and second shafts with a first friction force when the first wrap spring is in a neutral position. The first friction force is configured to: restrict rotation of the first shaft relative to the second shaft in a first direction about the shaft axis; and permit rotation of the first shaft relative to the second shaft in a second direction opposite the first direction about the shaft axis. An actuator is also provided and is configured to deflect the first wrap spring to a deflected position wherein the coil engages the outer surfaces of the first and second shafts with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting rotation of the first shaft relative to the second shaft in the first direction about the shaft axis.

[0008] The above summary is not intended to describe each embodiment or every implementation. Rather, a more complete understanding of illustrative embodiments will become apparent and appreciated by reference to the following Detailed Description of Illustrative Embodiments and claims in view of the accompanying figures of the drawing.BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING

[0009] Exemplary embodiments will be further described with reference to the figures of the drawing, wherein:

[0010] FIG. l is a perspective view of a snowthrower incorporating a snowthrower chute control system in accordance with embodiments of the present disclosure, the control system incorporating one or more exemplary shaft locking systems;

[0011] FIG. 2 is a diagrammatic top plan view of the chute control system of FIG. 1;

[0012] FIG. 3 is a diagrammatic side elevation view of an adjustable deflector of the chute control system of FIG. 1;

[0013] FIG. 4 is an isolated perspective view of an exemplary snowthrower chute control system for use with a snowthrower such as that illustrated in FIG. 1, the chute control system including both a chute rotation mechanism and a deflector ejection angle mechanism;

[0014] FIG. 5 is an exploded perspective view of the snowthrower chute control system of FIG. 4;

[0015] FIG. 6 is an enlarged exploded perspective view of the chute rotation mechanism of the exemplary chute control system of FIG. 4;

[0016] FIG. 7 is another enlarged exploded perspective view of the chute rotation mechanism of FIG. 4;

[0017] FIG. 8 is a section view taken along line 8-8 of FIG. 4 with various structure removed;

[0018] FIG. 9 is an enlarged exploded perspective view of the deflector ejection angle mechanism of the exemplary chute control system of FIG. 4;

[0019] FIG. 10 is an enlarged perspective view of the deflector ejection angle mechanism of FIG. 9 as assembled;

[0020] FIG. 11 is a section view taken along line 11-11 of FIG. 4;

[0021] FIG. 12 is a partial perspective view of the chute rotation mechanism of FIG.4;

[0022] FIG. 13 is another exploded perspective view of a portion of the chute rotation mechanism of FIG. 4;

[0023] FIG. 14 is a front elevation view of a portion of the chute rotation mechanism of FIG. 4;

[0024] FIG. 15 is a section view taken along line 15-15 of FIG. 4;

[0025] FIG. 16 is an isolated perspective view of another exemplary snowthrower chute control system for use with a snowthrower such as that illustrated in FIG. 1, the chute control system again including both a chute rotation mechanism and a deflector ejection angle mechanism that incorporate exemplary shaft locking systems;

[0026] FIG. 17 is an exploded perspective view of the snowthrower chute control system of FIG. 16;

[0027] FIG. 18 is a partial exploded perspective view of the chute rotation mechanism of the exemplary chute control system of FIG. 16;

[0028] FIG. 19 is another perspective view of the chute control system of FIG. 16;

[0029] FIG. 20 is a section view taken along line 20-20 of FIG. 16;

[0030] FIG. 21 is a perspective view of yet another exemplary snowthrower chute control system for use with a snowthrower such as that illustrated in FIG. 1, the chute control system again including both a chute rotation mechanism and a deflector ejection angle mechanism that incorporate exemplary shaft locking systems;

[0031] FIG. 22 is an isolated section view of the chute control system of FIG. 21;

[0032] FIG. 23 is an exploded perspective view of the chute control system of FIG.21; and

[0033] FIG. 24 is a perspective view of yet another exemplary snowthrower chute control system for use with a snowthrower such as that illustrated in FIG. 1, the chute control system incorporating one or more exemplary shaft locking systems;

[0034] FIG. 25 is a perspective view of still yet another exemplary snowthrower chute control system for use with a snowthrower such as that illustrated in FIG. 1, the chute control system incorporating one or more exemplary shaft locking systems;

[0035] FIG. 26 is another perspective view of the chute control system of FIG. 25;

[0036] FIG. 27 is an exploded perspective view of the chute control system of FIG.25;

[0037] FIG. 28 is a perspective view of a wrap spring shaft locking system in accordance with another embodiment of the present disclosure, the system configured to attach a lawn mower blade to a mower drive or spindle shaft;

[0038] FIG. 29 is an exploded view of the system of FIG. 28;

[0039] FIG. 30 is a section view taken along line 30-30 of FIG. 28;

[0040] FIG. 31 is a perspective view of yet another exemplary snowthrower chute control system for use with a snowthrower such as that illustrated in FIG. 1, the chute control system again including both a chute rotation mechanism (illustrated in more detail in FIGS. 37-43) and a deflector ejection angle mechanism that both incorporate exemplary shaft locking systems;

[0041] FIG. 32 is an exploded perspective view of portions of the snowthrower chute control system of FIG. 31;

[0042] FIG. 33 is a section view taken along line 33-33 of FIG. 31;

[0043] FIG. 34 is a section view taken along line 34-34 of FIG. 31;

[0044] FIG. 35 is an enlarged side elevation view of a portion of the chute control system of FIG. 31;

[0045] FIG. 36 is a rear elevation view of the deflector ejection angle mechanism of the chute control system of FIG. 31;

[0046] FIG. 37 is a perspective view of a chute rotation mechanism in accordance with embodiments of the present disclosure, the chute rotation mechanism forming part of the chute control system of FIG. 31;

[0047] FIG. 38 is a top plan view of the chute rotation mechanism of FIG. 37;

[0048] FIG. 39 is an enlarged perspective view of the chute rotation mechanism of FIG. 37;

[0049] FIG. 40 is another enlarged perspective view of the chute rotation mechanism of FIG. 37 with various structure removed;

[0050] FIG. 41 is yet another enlarged perspective view of the chute rotation mechanism of FIG. 37;

[0051] FIG. 42 is an exploded perspective view of the chute rotation mechanism of FIG. 37;

[0052] FIG. 43 is a section view taken along line 43-43 of FIG. 37 with some structure removed;

[0053] FIG. 44 is an enlarged perspective view of a pulley of the chute rotation mechanism of FIG. 37;

[0054] FIG. 45 is a diagrammatic view of an outdoor power equipment unit, e.g., lawn mower, incorporating a shaft locking system in accordance with embodiments of the present disclosure, the shaft locking system configured to lock a handle of the mower at a pivotal position relative to a chassis or frame of the mower;

[0055] FIG. 46 is a perspective view of the shaft locking system shown in FIG. 45; and

[0056] FIG. 47 is a section view of the shaft locking system shown in FIG. 46.

[0057] The figures are rendered primarily for clarity and, as a result, are not necessarily drawn to scale. Moreover, various structure / components, including but not limited to fasteners, electrical components (wiring, cables, etc.), and the like, may be shown diagrammatically or removed from some or all of the views to better illustrate aspects of the depicted embodiments, or where inclusion of such structure / components is not necessary to an understanding of the various exemplary embodiments described. The lack of illustration / description of such structure / components in a particular figure is, however, not to be interpreted as limiting the various embodiments in any way.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0058] In the following detailed description of illustrative embodiments, reference is made to the accompanying figures of the drawing which form a part hereof. It is to be understood that other embodiments, which may not be described and / or illustrated herein, are certainly contemplated. Unless otherwise indicated, all numbers expressing quantities, and all terms expressing direction / orientation (e.g., vertical, horizontal, parallel, perpendicular, etc.) in the specification and claims are to be understood as being modified in all instances by the term “about.” The term “and / or” (if used) means one or all of the listed elements or a combination of any two or more of the listed elements. “I.e ” is usedas an abbreviation for the Latin phrase id est and means “that is.” “E.g.” is used as an abbreviation for the Latin phrase exempli gratia and means “for example.”

[0059] With reference to the figures of the drawing, wherein like reference numerals designate like parts and assemblies throughout the several views, FIG. 1 illustrates a dedicated self-propelled, two-stage snowthrower 100. While so described and illustrated, such a construction is not limiting as aspects of the depicted / described embodiments may find application to other types of snowthrowers (e.g., those that attach as implements to general purpose or other vehicles, single-stage snowthrowers, etc.) as well as to other types of power equipment that require relative locking between a shaft and an associated rotatably engaged component (such systems being referred to broadly herein as “shaft locking systems” or “wrap spring locking systems”).

[0060] It is noted that the terms “comprises” and variations thereof do not have a limiting meaning and are used in their open-ended sense to generally mean “including but not limited to” where these terms appear in the accompanying description and claims. Further, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably herein. Moreover, relative terms such as “left,” “right,” “front,” “fore,” “forward,” “rear,” “aft,” “rearward,” “top,” “bottom,” “side,” “upper,” “lower,” “above,” “below,” “horizontal,” “vertical,” and the like may be used herein and, if so, are from the perspective of one operating the snowthrower 100 while the snowthrower is in an operating configuration, e.g., while the snowthrower 100 is positioned such that traction wheels 106 and skids 118 rest upon a generally horizontal ground surface 103 as shown in FIG. 1. These terms are used only to simplify the description, however, and not to limit the interpretation of any described embodiment. In a similar manner, terms such as “first” and “second” may be used herein to describe various elements. However, such terms are provided merely to simplify identification of the element(s). Accordingly, if an element is described as “first,” there may or may not be subsequent elements - that is, a “second” element is not necessarily present. It is further understood that the description of any particular element as being operatively attached to, connected to, coupled to, and / or otherwise in communication with another element may indicate that the elements are either directly attached to, connected to, coupled to, and / or in communication with oneanother, or are indirectly attached to, coupled to, connected to, and / or in communication with one another via intervening elements.

[0061] Still further, the suffixes “a” and “b” may be used throughout this description to denote various left- and right- side parts / features, respectively. However, in most pertinent respects, the parts / features denoted with “a” and “b” suffixes are substantially identical to, or mirror images of, one another. It is understood that, unless otherwise noted, the description of an individual part / feature (e.g., part / feature identified with an “a” suffix) also applies to the opposing part / feature (e.g., part / feature identified with a “b” suffix). Similarly, the description of a part / feature identified with no suffix may apply, unless noted otherwise, to both the corresponding left and right part / feature. That is to say, parts identified with “a” and “b” suffixes may be referred to separately or collectively without any suffix, and the figures may refer to the part / feature with or without using the suffix.

[0062] As illustrated in FIG. 1, the snowthrower 100 may include a chassis or frame 102 (having first and second lateral sides and defining a centerline longitudinal axis 101). One or more, e.g., first and second, drive members such as traction wheels 106 (first or left wheel 106a and second or right wheel 106b) may be coupled to - one on or near each of the first (e.g., left) and a second (e.g., right) side of - the frame. The traction wheels 106 may each rotate about a traction axis 107 (transverse to the longitudinal axis, and which may be the same or a different axis for each wheel) and may form a portion of a traction assembly 105 supporting the frame relative to the ground surface 103. In some embodiments, one or more electric motors 190 may be operatively coupled to the traction wheels 106 and configured to rotate the traction wheels about the traction axis 107 to propel the snowthrower over / relative to the ground surface. While shown as remote from the traction wheels 106, motor(s) 190 could be located at or near the traction axis 107.

[0063] One or more battery packs (e.g., battery back 171) may be carried by the frame 102. The battery pack(s) 171 may be configured to supply electrical power to the snowthrower 100, e.g., to the various snowthrower components. The battery pack(s) 171 may be of a lithium-based chemistry (e.g., lithium ion, lithium polymer). However, batteries of other chemistries (e.g., nickel-metal hydride, nickel-cadmium, etc.) are also possible, as are other types of electrical energy sources. While described and illustrated asusing an on-board battery pack, most any electrical power supply configuration, e.g., externally-provided AC power, external battery system, fuel cell, or the like may also be utilized. While described and illustrated in FIG. 1 as utilizing a battery-powered electric motor(s), such a configuration is exemplary only as other power sources (e.g., petroleumbased (gasoline, diesel), natural gas, liquid propane, etc.) are also possible within the scope of this disclosure.

[0064] As stated above, the traction wheels 106 may be selectively powered by the motor 190 to propel the snowthrower 100 relative to or over the ground surface 103 generally in a direction parallel to the longitudinal axis 101 (when travelling in a straight line). The snowthrower 100 may change directions (turn) by differential rotation of the traction wheels 106a, 106b. For example, each wheel may be selectively de-clutched from the traction motor 190 while the opposite wheel remains powered to affect a turn. Alternatively, differential rotation of the traction wheels may be provided by an independent transmission (or motor) unit dedicated to each traction wheel.

[0065] As used herein, the term “wheel” is understood to include at least a support portion (e.g., rim) and a ground contacting portion (e.g., tire). The tire may be of most any configuration (e.g., pneumatic, non-pneumatic, solid) and be made of most any materials (e.g., rubber, plastic, metal, etc.). While described and illustrated as wheels, most any drive member configuration, e.g., tracks, rollers, or the like, may also be utilized.

[0066] The exemplary snowthrower 100 may further include a snowthrower housing 110 attached to the frame 102. The housing 110 may include a pair of spaced-apart sidewalls 112 connected to one another by a rear wall 114 and an upper wall 115 such that the housing 110 forms a generally front-facing collection opening 111 forward of, and in fluid communication with, a partially enclosed chamber containing therein a horizontal auger 160 (i.e., the auger 160 may be positioned between the collection opening 111 and the rear wall 114). Lowermost portions of the housing 110 (e.g., the skids 118; only left skid being visible in FIG. 1), together with the traction wheels 106, may form ground contact portions of the snowthrower 100.-lo

[0067] In one or more embodiments, the housing 110 includes both an auger housing 130 containing the auger 160 and an impeller housing 140 in fluid communication with the auger housing and containing an impeller therein. The impeller housing 140 may define a discharge opening or outlet 116 connected to a discharge chute (“chute”) 120. The discharge chute 120 may be defined by sidewalls 122 such that a passageway formed by the sidewalls is operatively coupled to the housing 110. The discharge chute 120 thus fluidly communicates with the discharge outlet 116 so that snow within the housing 110 may be ejected or discharged through the discharge outlet 116 and directed in a specific direction by the discharge chute 120 (e.g., the chute 120 is configured to direct snow discharged from the housing by the auger / impeller).

[0068] The auger 160 may be selectively powered to rotate about a transverse auger axis 161. As used herein, “longitudinal axis” or “longitudinal direction” refers to a long axis of the snowthrower 100, e.g., the centerline longitudinal axis 101 extending in the travel or fore-and-aft direction as shown in FIG. 1. “Transverse” or “transverse axis” refers to a direction or axis extending side-to-side, e.g., a horizontal axis that is orthogonal to a vertical plane containing the longitudinal axis 101 of the snowthrower 100. During operation, the auger 160 rotates such that snow entering the collection opening 111 (e.g., due to forward propulsion of the snowthrower 100) is collected by the auger 160 and moved towards the center of the auger housing 130. Specifically, the auger 160 may rotate such that snow captured between the sidewalls 112 is directed towards the center of the collection opening 111, where it then enters the impeller housing 140. To permit such rotation, the auger 160 may be coupled to an auger shaft rotatably supported by the sidewalls 112 and extending along the auger axis 161. The auger shaft may then be connected to a powered gearbox 162. The high-speed impeller may receive snow transported by the auger 160 and eject the snow outwardly through the discharge outlet 116 via the chute 120.

[0069] The discharge chute 120 may be configured to rotate about a chute axis 121 and may include a movable (e.g., adjustable) chute deflector (“deflector”) 124 attached to a distal end of the chute. The deflector 124 may assist with directing snow exiting the discharge chute 120. For example, the chute 120 may be rotated from a left discharge position to a right discharge position, e.g., able to discharge snow over a chute rotationangle 125 (when viewed in a plan view; e.g., from the top of the snowthrower as indicated in FIG. 2) of 240 degrees or less (e.g., 220 degrees or less, 200 degrees or less, 180 degrees or less, or most any other desired rotation range). In a similar manner, the angular direction of the deflector 124 may be adjusted to alter an ejection angle 126 of the discharged snow (when viewed from a horizontal elevation view as shown in FIG. 3) between a generally horizontal ejection angle (e.g., ejection angle of 0 degrees (or less)) and a generally vertical ejection angle (e.g., ejection angle of 90 degrees). For example, in some embodiments the ejection angle 126 may be set at any angular position between 0 degrees and 80 degrees. As described herein below, the discharge chute 120 and deflector 124 may be controlled to respectively rotate the discharge chute 120 about the chute axis 121 and / or to adjust the ejection angle 126 of the deflector 124.

[0070] In one or more embodiments, the snowthrower 100 includes operator controls 300 mounted to handle structure 119 supported by handle tubes 117 of the snowthrower. The controls 300 may control various functions and / or components of the snowthrower 100. For example, the controls may include handles 311 for gripping by an operator walking behind the snowthrower 100, as well as engagement levers 319a, 319b (lever 319a shown in an engaged position in FIG. 1, while lever 319b is shown disengaged). The levers 319a and 319b may be used to selectively clutch and de-clutch respective traction wheels 106a and 106b from powered rotation during snowthrower operation (e.g., to assist with turning / directional control). A traction speed control 313 may also be provided to permit the operator to control the forward and reverse speeds of the tractions wheels 106. Other controls, e.g., motor / engine speed, auger engagement, lights, hand warmers, etc.) may also be included.

[0071] In embodiments of the present disclosure, the operator controls 300 may further include an actuator- which may include, or be operatively connected to, a handle or joystick 301 - that forms part of a chute control system, embodiments of which are further described below. The exemplary joystick may be used to control one or both of chute 120 rotation angle 125 (chute rotation mechanism; see FIG. 2) and deflector 124 ejection angle 126 (deflector ejection angle mechanism; see FIGS. 2-3). For convenient access, the joystick 301 may be attached to handle structure 119 as shown in FIGS. 1-2. While not limited to a specific mode of operation, the joystick 301 may, in someembodiments, be displaced forwardly (direction 351) to decrease the ejection angle 126 of the deflector 124 (move it toward a generally horizontal or 0 degree ejection angle) or pulled rearwardly (direction 353) to increase the ejection angle 126 (move it toward a generally vertical or 90 degree discharge angle). Similarly, the joystick 301 may be moved to the left (direction 355) to rotate the chute 120 (through the chute rotation angle shown in FIG. 2) toward a more leftward side ejection, and to the right (direction 357) to rotate the chute toward a more rightward side ejection.

[0072] The Toro Company of Minneapolis, MN, USA has used joystick control of snowthrower chute rotation angle as well as deflector position (see, e.g., U.S. Pat. No. 7,032,333). Such joysticks are mechanical in that they are operatively connected to the chute and / or deflector by mechanical components such as cables or linkages. In order to secure the chute in the desired position, products such as that shown in the ‘333 Patent utilize a joystick locking mechanism that the operator first actively disengages before moving the joystick. For example, the ‘333 Patent illustrates a mechanical release on the joystick that is manipulated by the operator (e.g., by a thumb) to permit joystick movement. Once the chute / deflector is in the desired position, the release may be disengaged, thereby locking the joystick, and thus the chute and deflector positions, in place. While effective, such an independent locking function may require the presence of various mechanical components and secondary actuation assemblies. Embodiments of the present disclosure seek to provide a simplified mechanical system, thereby potentially reducing manufacturing and maintenance complexity.

[0073] Embodiments of the present disclosure may provide a control system configured to change the ejection angle 126 (see FIG. 3) of the deflector 124 and / or the rotation angle 125 (see FIG. 2) of the chute 120 using one or more shaft locking systems that each include one or more wrap springs as described herein. In general, a wrap spring is formed by a spring having a helical coil wrapped or wound about a shaft and configured to engage the shaft with a first friction force or fit (e.g., an interference fit exists between the wrap spring’s inner diameter and an outer diameter of the shaft) when the spring is in a neutral (e.., unactuated) position. When there is attempted relative rotation between the shaft and the wrap spring in the direction of the spring’s helix (e.g., in a first direction), the wrap spring wraps more tightly about the shaft, restricting suchrelative rotation (e.g., effectively locking the shaft relative to the spring). However, when relative rotation is attempted in a second direction (e.g., a direction opposite the first direction and opposite the spring’s helix), the spring may unwrap sufficiently (or at least not wrap more tightly) to permit such relative rotation to occur. That is to say, a wrap spring may functionally provide unidirectional shaft locking by having the first friction force be configured to: restrict relative rotation between the shaft and the wrap spring in a first direction; and permit relative rotation between the shaft and the wrap spring in a second direction. In the illustrated embodiments, the wrap spring may further include a protruding or extending tang or “leg” at one or both of its terminal ends. An actuator (which may be connected to or integral with an associated handle or joystick) may be configured to press against the leg to then move or deflect the wrap spring to a deflected position (e.g., upon pivoting of the handle about the axis of the shaft) wherein the coil engages the shaft with a second friction force of lesser magnitude than the first friction force. As a result, when the wrap spring is actuated or deflected, relative rotation between the shaft and the wrap spring in the first direction may then be permitted.

[0074] FIG. 2 is a diagrammatic top plan view of the chute control system of FIG. 1. As shown in this view, a Bowden cable (chute rotation cable) 127 (left cable 127a, right cable 127b) may extend from each side of the joystick 301. Each cable 127 may include a housing 128 through which a cable wire 129 passes, wherein each wire operatively attaches to the joystick 301 and to an anchor 131 (each wire may attach to the same or different anchor 131). As a result, when a first cable (e.g., left cable 127a) is tensioned while the second cable (e.g., right cable 127b) remains slack (as may occur when the joystick is moved in the direction 355 as further described below), the chute will rotate about the axis 121 in a first (e.g., counterclockwise) direction 132. Similarly, when the second cable 127 (e.g., right cable 127b) is tensioned while the first cable (e.g., left cable 127a) remains slack (as may occur when the joystick is moved in the direction 357), the chute will rotate about the axis 121 in a second (e.g., clockwise) direction 123. This cable configuration may cause each cable 127 to displace the same linear distance (but in opposite directions) during chute rotation so that one cable does not generally “fight” or oppose the force applied by the other cable.

[0075] The joystick 301 may also be connected to the deflector 124 by a deflector cable 133 (again configured as a Bowden cable having a housing 134 and a cable wire 135 passing therethrough). Unlike chute rotation, the deflector 124 may be biased, e.g., via a spring such as a torsion spring or other biasing member 136, in a first direction toward its highest ejection angle 126 (see FIG. 3). When the joystick is pushed forward (e.g., in the direction 351), the deflector may move toward its lowest ejection angle by overcoming the biasing force of the spring 136. When the joystick 301 is pulled rearwardly (e.g., in the direction 353), the deflector may move toward its highest ejection angle 126 assisted by the biasing force of the spring 136. An example configuration of biased deflector motion is described in the ‘333 Patent. As one can appreciate, the joystick 301 thus provides an intuitive, one-handed system for controlling the discharge direction and deflector elevation angle of snow ejected from the snowthrower 100.

[0076] FIGS. 4-15 illustrate a snowthrower chute control system 400 in accordance with exemplary embodiments of the present disclosure. As an initial matter, any one of the snowthrower chute control systems described and / or illustrated herein (e.g., systems 400, 500, 600, 700, 800, and 1000) may be utilized with the snowthrower 100 shown in FIG. 1. That is to say, reference numeral 301 in FIGS. 1 and 2 may represent the respective handle or joystick of any of the exemplary chute control systems described herein even though such associated joysticks may be identified with a different reference number.

[0077] FIG. 4 is a perspective view of the snowthrower chute control system 400 and a portion of corresponding mounting structure 119 (see also FIG. 1) of the snowthrower 100, while FIG. 5 is an exploded view of the system 400. As shown in these views, the control system 400 may be understood to include one or both of a chute rotation mechanism 402 (configured to change a rotation angle 125 of the chute about the chute axis 121); and a deflector ejection angle mechanism 404 (configured to change an ejection angle 126 of the chute deflector 124). For context with FIG. 2, the cables 127 and 133 are illustrated in FIGS. 4 and 5. As a result, it is understood that the first and second chute rotation cables 127 both interconnect the chute rotation mechanism with the chute, while the deflector cable interconnects the deflector ejection angle mechanism with the deflector.

[0078] As shown in FIG. 5, the system 400 may include a longitudinal shaft 406 that may be secured to handle structure 119 by fasteners 405 and nuts 403 such that the shaft remains fixed during operation. The handle structure 119 may further provide anchor points to secure the ends of the housings 128 of the cables 127 as shown. The shaft 406 may rotatably support the chute rotation mechanism 402 (as well as the mechanism 404 (e.g., the wrap spring 452, housing 426 (actuator(s)), shaft 450, etc.) for rotation about a shaft axis 412 (which is orthogonal to an axis 455 of the shaft 450), the mechanism including first and second cams 408, 409, wherein the first cam 408 may engage a terminal end 407 of the one chute rotation cable 127 (e.g., the right cable 127b in FIG. 5) while the second cam 409 may engage the terminal end 407 of the opposite cable 127 (e.g., left cable 127a). As a result of this construction, rotation of the cams 408, 409 may pull on one of the cables 127 while simultaneously slackening the opposite cable 127. As shown in FIG. 2, such cable action allows a force to be applied to the chute 120 to cause it to rotate in either the clockwise direction 123 or the counterclockwise direction 132 about the chute axis 121 (depending on the direction of cam rotation about the shaft 406). To longitudinally restrain the cams 408, 409, relative to the shaft 406, the shaft may include a flange 410 that is configured to abut the cam 408 when assembled.

[0079] FIGS. 6 and 7 are enlarged perspective views of the cams 408, 409, while FIG. 8 is a section view taken along line 8-8 of FIG. 4 (with the cam 409 and other structure removed). As shown in these views, a wrap spring 414 may be positioned between the cams 408, 409. The wrap spring 414 may include a protruding first leg 416 and a protruding second leg 418. The wrap spring is configured such that its undeflected inner coil diameter is less than an external diameter of the shaft 406. As a result, when the wrap spring 414 is deflected, slid onto the shaft 406, and released (e.g., placed into a “neutral” position on the shaft), it engages the shaft with an interference fit.

[0080] The cams 408, 409 may form opposing inner faces that each includes a tab 420. The tabs 420 of the cams 408, 409 are configured to engage the legs 416, 418, respectively, of the wrap spring when assembled as best shown in FIG. 8. Each tab 420 may be used to “unwrap” the wrap spring by applying an unwinding or opening force to the associated leg of the wrap spring. For example, as shown in FIG. 8, when the cam 408 is rotated in the clockwise direction 422 (e.g., to pull the cable 127b and thus cause thechute 120 (see FIG. 2) to rotate about the chute axis 121 toward the right side of the snowthrower 100), the tab 420 of the cam 408 will push against the leg 416. As the force of the tab 420 against the leg 416 “unwinds” the wrap spring 414, the frictional engagement of the wrap spring with the shaft 406 is reduced, permitting the spring 414 (and cam 408) to rotate in the clockwise direction 422. The cam 409 (see FIGS. 6 and 7) may then follow due to its engagement with the other leg 418 of the wrap spring. As a result, the chute may be rotated by tension applied to one of the cables 127 (e.g., the cable 127b attached to the cam 408), while the other cam (cam 409) and its associated cable (cable 127a) passively follow this motion. As one can appreciate, intentional movement of the other cam 409 (e.g., by applying a joystick force that causes the cam 409 to rotate in the counterclockwise direction 424 (see FIG. 6) will have a similar effect as its tab 420 (see FIG. 7) will interact with the leg 418 in a similar manner, allowing the cam 409, spring 414, and cam 408 to rotate about the shaft 406 in the opposite (counterclockwise when viewed in FIG. 8) direction 424.

[0081] With reference again to FIG. 5, the shaft 406 may extend rearwardly through the cams 408, 409 and wrap spring 414 and extend into a housing 426 and be rotatably secured thereto by a snap ring 428 that engages a groove 430 (see also FIG. 6) formed in the shaft. The spacing of the flange 410 and the snap ring 428 / housing 426 may be configured to maintain the axial position of the cams 408, 409 and spring 414 relative to the shaft 406 throughout operation of the system 400. That is to say, the cams, 408, 409 may axially trap the spring 414 therebetween, while both cams are axially restrained relative to one another by the flange 410 and housing 426.

[0082] In addition to forming part of the chute rotation mechanism 402, the housing 426 may also form part of the deflector ejection angle mechanism 404. Exemplary embodiments of this mechanism are now described with reference to FIGS. 5 and 9-11, where FIG. 9 is an exploded perspective view of the mechanism 404, FIG. 10 is an assembled perspective view, and FIG. 11 is a section view taken along line 11-11 of FIG. 4. As shown in these views, the housing 426 may support a shaft 450 defining or otherwise having an axis 455 about which a wrap spring 452 is engaged (again, with an interference fit when mounted to the shaft in its neutral position). As with the shaft 406, the shaft 450 may be fixed relative to its associated structure, e.g., relative to the housing426. For example, the shaft 450 (with the wrap spring 452 installed) may slide into clevis slots 456 formed in the housing. Hairpins 458 may then be attached to ends of the shaft via flats 454 formed on the shaft 450 such that the shaft is axially restrained, relative to the housing 426 by the hairpins. The housing 426 may include features, e.g., protruding buttons 460, that may be engaged by the hairpins 458 as shown in FIG. 10 to rotationally hold the hairpins relative to the housing.

[0083] In addition to the wrap spring 452, the ejection angle mechanism 404 may also include an arm 462 rotationally supported by the shaft 450. As further described below, the arm 462 may be configured to interact with a first leg 451 of the spring 452, while a handle bracket 464 may interact with a second leg 453 as described below. The bracket may be rigidly connected to a handle or joystick 401 (see FIG. 5) by fasteners 466 passing through apertures 467 and threadably engaging holes 468 in the joystick. As shown in FIGS. 4 and 5, the joystick 401 may include apertures 457 (only one visible in FIGS. 4 and 5, but opposite side of joystick includes a similar aperture) that are configured to seat upon ends of the shaft 450. As a result, the joystick may be restricted (at least in the fore-and-aft direction) to rotation about the axis 455 of the shaft 450. The joystick is furthermore fixed axially relative to the shaft 450 by the engagement of the shaft with these apertures 457.

[0084] The handle bracket 464 (which includes the spring engaging surface 477 described below) which again may be rigidly connected to or integral with the joystick) may, along with the joystick, form an actuator capable of deflecting the wrap spring as described below. In the illustrated embodiments, the bracket 464 may include a slot 470 adapted to receive therein the second leg 453 of the wrap spring 452 as shown in FIG 10. In order to impart a force to the second leg 453 capable of deflecting the wrap spring slightly (to “unwrap” the spring), an adjustable stop 471 is provided. The stop is attached to the handle bracket 464 with a fastener 472, which passes through an elongate slot 473 formed in the stop and threadably engages a hole 474 in the handle bracket 464. The stop 471 may include a sloped surface 475 that may abut and ride along a tab 476 formed on the handle bracket 464. As a result, a spring engaging surface 477 of the stop 471 may be adjusted along the length of the slot 470 to adjust the default position of the leg 453 of the wrap spring 452. While shown as using the adjustable stop 471, other embodiments mayconfigure the wrap spring 452 such that adjustability provided by the stop is unnecessary (e.g., the leg 453 could engage a fixed element on the handle bracket 464).

[0085] While an adjustable stop may be provided for the second leg 453, the first leg 451 of the wrap spring 452 may interact with one or more fixed tabs 478, 479 of the arm 462. Moreover, the arm may include a receiving surface 480 adapted to interact with a contact surface 482 of the handle bracket 464 as further described below.

[0086] With reference again to FIG. 10, the housing 426 may further define a cable housing anchor 483 configured to secure the end of the cable housing 134 of the cable 133. The cable wire 135 of the cable 133 may then be connected to a receiver 484 of the arm 462 (stated more broadly, the cable may be operatively connected to the leg 451 of the wrap spring). As indicated above, the cable (e.g., cable wire 135), in some embodiments, may be under constant tension (e.g., pulling in the direction 481 in FIG. 10) due to the presence of the spring 136 (see FIG. 2). As a result, there is a biasing force applied to the arm 462, and thus the first leg 451 of the spring 452, in the counterclockwise direction 486 shown in FIG. 10. As the wrap spring is configured as a left-hand spring, this biasing force is in the same direction as the helix (i.e., the biasing force further tightens the wrap spring 452 against the shaft 450). As a result, in a default or neutral state of the wrap spring 452, the arm 462, and thus the chute deflector 124, are locked in place as the wrap spring is effectively locked relative to the shaft 450.

[0087] When the operator applies a force rearwardly to the joystick 401, e.g., in the direction 353 (see FIG. 11) to increase the ejection angle 126, the joystick pivots about the shaft 450 / shaft axis 455. As this pivoting occurs, the handle bracket 464 is also rotated about the shaft 450 / shaft axis 455 in the corresponding counterclockwise direction 486 due to the direct attachment (via fasteners 466) of the joystick with the handle bracket 464. As this joystick force is applied to the handle bracket 464, the spring engaging surface 477 of the adjustable stop 471 presses or bears against the protruding second leg 453 of the wrap spring. As the direction of this force tends to unwrap the wrap spring 452 from the shaft 450, movement of the joystick about the axis 455 causes the wrap spring 452 to move from its neutral position to a deflected position wherein a second friction force (less than the first friction force applied in the neutral position) is then applied by the coil to the shaft. That is to say, application of a sufficient force to thejoystick in the direction 353 will reduce the frictional engagement between the wrap spring and the shaft, ultimately permitting relative rotation therebetween. The arm 462 may follow due to the engagement of the first leg 451 and the tab 478. As the cable wire 135 is attached to the arm, the biasing force of the spring 136 (see FIG. 2) will extend the deflector 124 to the extent permitted by the joystick position. That is to say, the biasing force of the spring 136 will cause the deflector 124 to move toward a higher ejection angle as dictated by the position of the joystick. When the desired ejection angle is achieved, the operator can remove the rearward force on the joystick, causing the stop 471 to reduce the force applied to the second leg 453 of the wrap spring 452, thereby causing the spring to again wrap with sufficient friction against the shaft 450, locking the spring (and thus the arm 462) relative to the shaft.

[0088] Conversely, when it is desired to reduce the ejection angle 126 (see FIG. 2), the operator may again grasp the joystick 401 and push it forwardly (e.g., in the direction 351 of FIG. 11). As this force is applied, it is again transferred to the handle bracket 464 applying a force thereto in the clockwise (in FIG. 11) direction 488. Due to the engagement of the contact surface 482 (see FIG. 9) of the handle bracket 464 with the receiving surface 480 of the arm 462, a corresponding force is also applied to the arm and, more particularly, to the tab 478 of the arm. As the tab 478 is in contact with the first leg 451 of the wrap spring 452, the force acts to open or unwrap the spring from the shaft 450 until the frictional engagement therebetween is reduced sufficiently to permit relative rotation of the wrap spring, and thus the arm, about the shaft. Accordingly the arm 462 and the wrap spring 452 may rotate about the shaft 450 in the clockwise direction 488. Sufficient force may be required to not only deflect the wrap spring 452, but also to overcome the biasing force of the spring 136 (see FIG. 2) before the arm 462 may move. Once the deflector 124 is in the desired position, the operator may remove the force applied to the joystick 401, at which point the wrap spring 452 may again tighten about the shaft sufficiently to prevent further relative rotation.

[0089] As one can appreciate, control systems in accordance with embodiments of the present disclosure may thus provide, at a minimum, a shaft relative locking system or function, wherein the system includes a shaft defining an axis, and a wrap spring associated with a shaft. The wrap spring includes a helical coil wrapped about the shaft toengage the shaft with a first friction force when the wrap spring is in a neutral position. In the neutral position, rotation of the shaft relative to the spring in a first direction is restricted while relative rotation in a second direction is permitted. An actuator (which may be part of a handle or joystick) may optionally be provided and configured to move the wrap spring to a deflected position, wherein the coil engages the shaft with a second friction force that is less than the first friction force, thereby selectively permitting relative rotation between the shaft and the spring in the first direction.

[0090] With reference to FIGS. 12-15, additional aspects of the system 400 are now described, particularly those features that permit the housing 426 to interact with the chute rotation mechanism 402 already described above. FIG. 12 illustrates a perspective front side of the housing 426 with the wrap spring 414 and the shaft 406 shown installed, but with other structure (e.g., cams 408, 409) removed for clarity. As shown in this view, the housing may include a spring engaging member or finger 436 protruding from the front side of the housing. The spring engaging member 436 may extend forwardly through windows 434 (see FIG. 5) formed in the cams 408, 409. The windows 434 may be sufficiently sized to accommodate the spring engaging member 436 as the housing 426 is rotated about the shaft 406 during operation. An adjustment tab 438 may also be provided to control initial wrap spring deflection / engagement characteristics.

[0091] As shown in FIG. 13, the adjustment tab 438 may be attached to the housing 426 with a fastener 439. The adjustment tab 438 may include an angled surface 440 adapted to abut and slide against a corresponding angled surface 441 formed on the housing 426. As the fastener 439 engages the adjustment tab via a slot 442, the tab may be slid relative to the surface 441 to position an ear 443 of the tab as desired before tightening the fastener 439 in a threaded opening 444 of the housing 426.

[0092] FIG. 14 is a front elevation view looking along an axis of the shaft 406. Various structure, including the cams 408, 409 are removed in this view for clarity. When the chute control system is assembled, the finger 436 may be configured to abut (or nearly abut) the leg 416 of the wrap spring 414 as shown. The adjustment tab 438 may then be positioned (e.g., by sliding along the fastener 439 / angled surface 441 (see FIG. 13) such that the ear 443 abuts or nearly abuts the leg 418 as shown. During operation, the finger 436 may thus abut and push against the leg 416 to unwrap the wrap spring 414 when thehandle 401 / housing 426 is rotated (about the shaft 406) in the direction 422, while the ear 443 of the adjustment tab 438 may abut and push against the leg 418 to unwrap the spring when the handle / body is rotated in the direction 424. FIG. 15 is a section view taken along line 15-15 of FIG. 4, illustrating the interaction of the finger 436 with the leg 416.

[0093] The chute control system 400 described herein thus provides a simplified configuration for allowing locking of the joystick in a desired position without the need for more conventional lock and actuation components. While described with some degree of specificity, the system 400 is exemplary only as other chute control systems are certainly possible within the scope of this disclosure. For example, FIGS. 16-20 illustrate a chute control system 500 in accordance with other embodiments of this disclosure. The chute control system 500 may be similar in many respects to the system 400 already described and illustrated herein. As a result, the description below focuses on the differences between these two systems while deferring to the description above for similar / common components. For simplicity of description, similar components between the system 400 and the system 500 (as well as the systems 600, 700, 800, and 1000 described below) may, where appropriate, utilize corresponding reference numerals. For instance, the reference numeral 5xx (e.g., joystick 501) may be used to refer the corresponding component of the system 500 as the reference numeral 4xx (e.g., joystick 401) is used in the system 400.

[0094] FIG. 16 illustrates the exemplary chute control system 500 attached to snowthrower structure 119. Like the system 400, the system includes a chute rotation mechanism 502 configured to rotate the chute 120 about the chute axis 121 (see FIG. 2) via cables 127 (127a, 127b), and a deflector ejection angle mechanism 504 configured to adjust the ejection angle 126 (see FIG. 3) of the chute deflector 124 via the cable 133.

[0095] The system 500 may again utilize a longitudinal shaft 506 secured to structure 119 (not shown) with fasteners 505 and nuts 503 as shown in FIGS. 16 and 17. The shaft 506 may rotatably support first and second cams 508, 509. Instead of a flange 410, the shaft 506 may include a circumferential groove that receives a snap ring 510, and a second circumferential groove 530 that receives a snap ring 528 once the shaft is received within a housing 526. Accordingly, the cams 508, 508 may be axially retained betweenthe snap ring 510 and the housing 526 in a manner similar to that of the cams 408, 409 described above.

[0096] As with the cams 408, 409, the cams 508, 509 may also sit on opposite sides of a wrap spring 514 that is also mounted to the shaft 506. However, instead of the tabs 420 used to interact with the legs of the spring, the cams 508, 509 may define slots 520 to accommodate their respective spring legs 516, 518 as best shown in the partial perspective view of FIG. 18.

[0097] To deflect the spring legs 516, 518 the system 500 may also include the housing 526 (which may, in this embodiment, be a bent sheet metal component) having a forwardly protruding spring engaging member or finger 536. The finger 536 may contact the spring legs as the joystick 501 is moved to the left (e.g., in the direction 355 in FIG. 16) and to the right (e.g., in the direction 357) as already described herein. During operation, the wrap spring 514 may, upon application of a force in the direction 355 or 357, be selectively unlocked from the fixed shaft 506 such that it, and thus the cams 508, 509, may rotate about the shaft to affect chute rotation as described with reference to the cams 408, 409. Once the joystick force is removed, the wrap spring 514 may return to its neutral position, where it is again effectively locked to the shaft 506 (effectively locking the cams 508, 509 in place).

[0098] With reference now to FIGS. 16, 17, 19, and 20, the exemplary deflector ejection angle mechanism 504 is now described. Similar to the system 400, the housing 526 may form an element of both the chute rotation mechanism 502 and the deflector ejection angle mechanism 504. The housing 526 may be configured to receive a shaft 550 having a wrap spring 552 mounted thereto in an interference fit. The shaft may include a rectangular end that is received within a corresponding opening 556 and a round end received within a corresponding opening 555 of the housing 526. The shaft may then be secured to the housing using snap rings 559 engaged with corresponding circumferential grooves 561 on the shaft.

[0099] As with the joystick 401, the joystick 501 may be secured to or integral with a handle bracket 564 (in this case, via a threaded stud 566 as shown). The handle bracket may include an aperture 563 to permit sliding of the handle bracket onto the shaft 550(see FIG. 16) such that the joystick may move in the directions 351 and 353 by rotating about the shaft 550 (e.g., movement in the direction 355 and 357 (see FIG. 19) is accommodated by rotation of the joystick and housing 526 about the shaft 506). The spacing of the circumferential grooves 561 permits the snap rings 559 to engage the shaft such that both the handle bracket 564 and the ear of the housing 526 (e.g., the portion defining the opening 555) are positioned therebetween, securing the components to one another.

[0100] As perhaps best visible in FIGS. 19 and 20, the handle bracket 564 may define an actuator or spring engaging surface 578 configured to engage the first leg 551, and a second spring engaging surface 577 configured to engage the second leg 553. The surfaces may be formed as slots (see surface 578), or as part of a side of the bracket 564 (see surface 577). The cable wire of the cable 133 (see FIG. 16) may connect to the handle bracket 564 or directly to the leg 551 of the spring 552.

[0101] When the operator applies a force rearwardly to the joystick 501, e.g., in the direction 353 (see FIG. 16) to increase the ejection angle 126 (see FIG. 3), the joystick rotates about the shaft 550. As this pivoting occurs, handle bracket 564 (forming part of an actuator) is also rotated about the shaft 550 in the corresponding counterclockwise direction 586 due to the direct attachment of the joystick to the handle bracket 564. As this joystick force is applied to the handle bracket 564, the spring engaging surface 577 bears against the second leg 553 (see FIG. 19). As the direction of this force tends to unwrap the wrap spring 552 from the shaft 550, a sufficient force will reduce the frictional engagement between the wrap spring and the shaft, ultimately permitting relative rotation therebetween. As the cable wire (not shown) is attached to the leg 551, the biasing force of the spring 136 (see FIG. 2) will assist in rotating the joystick in the direction 353 (and the spring in the direction 586) and extend the deflector 124 to the extent permitted by the joystick position. That is to say, the biasing force of the spring 136 will cause the deflector 124 to move toward a higher ejection angle as dictated by the position of the joystick. When the desired ejection angle is achieved, the operator can remove the rearward force on the joystick, causing the surface 577 to reduce the force applied to the second leg 553 of the wrap spring 552, thereby causing the spring to again wrap with sufficient friction against the shaft 550, locking the spring relative to the shaft.

[0102] Conversely, when it is desired to reduce the ejection angle 126 (see FIG. 2), the operator may again grasp the joystick 501 and push it forwardly (e.g., in the direction 351 of FIG. 16). As this force is applied, it is again transferred to the handle bracket 564 applying a force thereto in the clockwise direction 588. Due to the engagement of the contact surface 578 of the handle bracket 564 with the first leg 551 of the wrap spring 552, the force acts to open or unwrap the spring from the shaft 550 until the frictional engagement therebetween is reduced sufficiently to permit relative rotation of the wrap spring about the shaft. Accordingly, the wrap spring 552 and the handle bracket 564 (and the joystick) rotate about the shaft 550 in the clockwise direction 588. Sufficient force may be required to not only deflect the wrap spring 552, but also to overcome the biasing force of the spring 136 (see FIG. 2) before the handle bracket 564 may move. Once the deflector 124 is in the desired position, the operator may remove the force applied to the joystick 501, at which point the wrap spring 552 may again tighten about the shaft sufficiently to prevent further relative rotation.

[0103] FIGS. 21-23 illustrate yet another chute control system 600 in accordance with embodiments of the present disclosure. Where FIG. 21 is a perspective view of the system, FIG. 22 is a partial perspective view thereof, and FIG. 23 is an exploded view thereof. As with the systems 400 and 500, the system 600 includes both a chute rotation mechanism 602 and a deflector ejection angle mechanism 604. The system is connected to snowthrower structure 119, and includes a joystick 601 (note, only joystick frame is illustrated in these figures).

[0104] The chute rotation mechanism 602 may again include a fore-and-aft or longitudinal shaft 606. However, unlike the systems 400 and 500 wherein the wrap springs may rotate relative to their respective shafts, the shaft 606 is not fixed and is instead configured to rotate relative to the associated wrap spring(s) as the joystick is moved (rotated) side to side. Moreover, the system 600 may use one or more, e.g., two or more, wrap springs associated with the shaft 606. In some embodiments, the system may include at least one left hand wrap spring 614 and one right hand (opposite hand) wrap spring 615. While not illustrated herein, the cables 127 and / or 133 may also be included with the system 600 to permit one or both of chute rotation and ejector angle adjustment as already described herein.

[0105] As shown in FIG. 23, the shaft 606 may include a central hub 607 with stub shafts extending from each side (fore-and-aft). A transverse shaft 650 (which forms part of the deflector ejection angle mechanism 604) may pass through the hub 607 and be held rigidly in place as shown in FIGS. 22 and 23 using a fastener 611 passing through the hub and engaging the shaft 606 via a threaded aperture 613. As with the systems 400 and 500, the system 600 may also include a handle bracket 664 that may interact with legs 651, 653 of a wrap spring 652 associated with the shaft 650 to provide the desired deflector angle adjustment in a manner already described herein. As such, further description of the deflector ejection angle mechanism 604 and its operation are not provided.

[0106] The chute rotation mechanism 602 differs from the mechanisms 402 and 502 in that the system 600 may require positive joystick actuation before movement to the left or right (e.g., in the directions 355 and 357 shown in FIG. 21) is permitted. In the illustrated embodiment, the actuation occurs when a downward force 358 (see FIG. 21) is applied to the joystick, e.g., by the operator’s hand. In some embodiments, the force 358 is light, and results merely from the operator resting his or her hand on the joystick. In other embodiments, the operator may be required to apply a slight downward pressure to the joystick to provide the necessary force 358.

[0107] When an adequate downward force 358 is applied to the joystick 601, the forces pushes the mechanisms 602, 604 (e.g., the shafts 606, 650) downwardly. As shown in FIG. 21, a clearance 180 is provided between the bottom of the shaft 606 and the structure 119 that allows the shaft to move vertically downward in response to the force 358. That is to say, the shaft 606 is suspended within a channel 181 defined by the snowthrower structure by engagement of protruding legs 616, 618 of the springs 614, 615 with ledges of the structure 119 formed above the channel 181. Stated yet another way, in their default or neutral positions, the springs 614, 615 support the shaft 606 within the channel 181. In the default positions, the springs 614, 615 engage the shaft 606 with interference such that relative rotation between the shaft 606 and the springs is restricted. Because at least one left hand and one right hand wrap spring are provided, restriction in both rotational directions is provided. In some embodiments, a shaft collar 690 may be provided to assist with supporting the shaft 606 relative to the structure 119.

[0108] When the force 358 is applied, however, the legs are relatively displaced such that the springs 614, 615 move to deflected positions in which they unwrap from the lowering shaft 606, thereby permitting rotation of the shaft relative to the springs. As a result, the joystick 601 may rotate in the direction 355 and 357, with the chute correspondingly rotating. Upon reaching the desired chute rotation angle, the downward force 358 may be removed, at which point the shaft will rise in the channel 181 and the wrap springs 614, 615 will return to their default neutral positions, locking the shaft from further rotation relative to the springs / structure 119.

[0109] In the systems described above, joystick movement to produce deflector adjustment may occur based on directional (fore-and-aft (and downward in system 600)) operator inputs. FIG. 24 illustrates a system 700 wherein the operator may first be required to positively unlock the joystick 701 before it may move in the directions 351, 353 to effect deflector angle adjustment. The system 700 may include a lock (e.g., lever 790) that is movable between a first position (solid line rendering), wherein movement of the joystick relative to the axis of the deflector shaft is restricted, and a second position (broken line rendering), wherein movement of the joystick relative to the axis of the deflector shaft is permitted. A second lever 792 may also be provided that, along with the lever 790, forms the joystick 701. The two levers may be squeezed together against a biasing force of a spring 794 to unlock the joystick and permit fore-and aft (deflector) movement. While not shown, the locking features of the system 700 could also apply to joystick movement affecting chute rotation. Such a locking joystick may be beneficial in some embodiments wherein a more active process for deflector angle adjustment (or chute rotation) is desired.

[0110] FIGS. 25-27 illustrate yet another exemplary chute control system 800 in accordance with embodiments of the present disclosure, wherein FIGS. 25 and 26 are partial perspective views, and FIG. 27 is an exploded perspective view. As with the other chute control systems described herein, the system 800 may include a chute rotation mechanism 802 and a deflector ejection angle mechanism 804. However, the following description is directed primarily to the mechanism 804 as the chute rotation mechanism 802 may utilize components other than wrap springs.

[0111] As shown in these figures, the system may include a joystick 801 that may be moved forwardly (in the direction 351) to affect a lowering of the deflector ejection angle and rearwardly (in the direction 353) to affect a raising of the deflector ejection angle. As shown in FIG. 27, the joystick may be integral to a shaft 850 defining an axis 855 about which the joystick may pivot. In the illustrated embodiment, the shaft 850 defines a central hub (to which the joystick is attached) with stub shaft sections extending transversely from each side. The shaft 850 (including the hub) is suspended within a channel 181 defined by the snowthrower structure 119 by legs of a first wrap spring 814 and a second wrap spring 815 having a different hand or helical direction than the first wrap spring. For example, the first wrap spring 814 may be a left hand spring while the second wrap spring may be a right hand spring. Each of the springs includes a protruding first leg 816 and a protruding second leg 818. The springs 814, 815 are mounted to the stub shafts sections in a manner already described herein with respect to other wrap springs (see, e.g., interference fit described with respect to wrap spring 414).

[0112] When the shaft 850 is placed within the channel 181, the legs 816 of each wrap spring may suspend the shaft therein by resting against the structure 119. Retention bracket 809 may then be fastened (e.g., with fasteners 810) to the structure as shown in FIG. 25. Each bracket may include a feature (e.g., slot 808) configured to receive and hold its respective leg 818 in the desired orientation. Accordingly, the two wrap springs 814, 815 may generally restrict rotation of the shaft in the clockwise direction 888 and the counterclockwise direction 886 (as shown in FIG. 25).

[0113] To permit movement of the joystick in the directions 351 and 353 (e.g., rotation of the shaft 850 in the directions 888 and 886, respectively), the operator may first actuate the system by applying a downward force 358 to the joystick in a manner similar to the system 600. The downward force 358 (which may be generated merely by the weight of the operator’s hand) may force the shaft 850 deeper into the channel 181 (as with the system 600, the channel may provide sufficient clearance with the shaft to permit such movement). As the shaft is displaced downwardly, the engagement of the legs 816 of each wrap spring 814, 815 with the associated structure 119 causes the springs to unwrap sufficiently to permit movement of the joystick in both directions 351 and 353. Accordingly, the deflector cable (not shown but see cable 133 in FIG. 2) can change theej ection angle 126 of the deflector 124 as desired. To lock the ejector angle once the desired angle is reached, the operator may remove the downward force 358, in which case the shaft 850 will rise to its initial, neutral position within the channel due to the biasing force of the wrap springs 814, 815 as they return to their respective neutral positions.

[0114] While various embodiments of wrap spring chute control systems are provided above with specificity, those of skill in the art will understand that other embodiments are certainly possible within the scope of this disclosure. Moreover, while described in the context of locking chute rotation angle and / or chute deflector ejection angle, aspects of the present disclosure may find use in other shaft rotation locking applications. For instance, wrap springs may find application to speed control systems (e.g., where a throttle or other speed control lever may be moved to multiple locations and then immobilized in the desired location) as well as operator handle height adjustment (see, e.g., FIGS. 45-47) for outdoor power equipment (e.g., to change the angle that a handle may extend from the body of a walk-behind snowthrower or mower, for example).

[0115] Other applications are certainly possible within the scope of this disclosure. For example, FIGS. 28-30 illustrates a shaft wrap spring locking system 900 for use with lawn mower blade attachment. As shown in these figures, a drive shaft 990 (e.g., motor or spindle shaft) may extend downwardly into a cutting deck (deck not shown). A conventional rotary lawn mower blade 991 may be fastened to a blade hub 992 (with fasteners 996). The blade hub may include an integral shaft 993 of generally the same outer diameter as a diameter of a bushing 994 that may be keyed to the drive shaft 990. The blade 991 / blade hub 992 may then be attached to the drive shaft 990 with a blade bolt 997 and washer 998.

[0116] The system 900 may further include a wrap spring 914 that may engage adjacent end portions of both the bushing 994 and the shaft 993 as shown in FIG. 30. The bushing may include a flange to, along with the blade hub 992, axially restrain the wrap spring. The helical direction (e.g., the hand) of the wrap spring may be selected to automatically tighten when the blade spins in a cutting direction 995 (see FIG. 29), allowing the blade to be driven by the interference between the wrap spring and the bushing 994 and between the wrap spring and the shaft 993.

[0117] One advantage of the wrap spring 914 is that, upon an instance of a blade strike against a ground object, the momentary rotational slowing of the mower blade 991 (and attached hub 992 / stub shaft 993) may tend to unwrap the spring 914 (cause relative rotation in the direction 999) as the drive shaft 990 continues to spin at its selected speed in the direction 995. This unwrapping may permit the blade (and attached hub 992 / shaft 993) to slip relative to the drive shaft 990 (allow one of the shafts to rotate relative to the spring 914), potentially reducing damage to the drive shaft / drive train as a result of the strike. While not shown, the wrap spring may include protruding legs to permit the operator to more easily remove / install the blade.

[0118] FIGS. 31-44 illustrate yet another shaft locking system in accordance with embodiments of the present disclosure. Like the embodiments shown in FIGS. 3-27, the shaft locking systems of FIGS. 31-44 may be embodied as a snowthrower chute control system 1000 having an actuator including joystick 1001 for operator manipulation. The system 1000 may be interchangeable with any of the chute control systems already described herein and may replace any of these systems on the snowthrower 100 shown in FIGS. 1 and 2.

[0119] As with the other chute control systems described herein, the system 1000 may include both a chute deflector ejection angle mechanism 1004 as shown in FIGS. 31- 36 (configured to change the ejection angle 126 of the deflector 124 (see FIG. 2) and a chute rotation mechanism 1002 (configured to change the rotation angle 125 of the chute about the chute axis 121; see FIG. 2) as shown in FIGS. 37-44. However, unlike the other chute control systems described herein, the system 1000 may locate portions of the chute rotation mechanism 1002 proximate the snowthrower chute itself rather than at or near the joystick 1001. However, actuation of both mechanisms may still be accomplished through the use of cables 127 (e.g., cables 127a, 127b having cable wires 129a, 129b, and cable 133 (see FIG. 32) having cable wire 135) extending between the joystick and the chute. That is to say, as with the other chute control systems described herein, it is understood that the first and second chute rotation cables 127 interconnect the joystick with the chute rotation mechanism / chute, while the deflector cable 133 interconnects the joystick with the deflector ejection angle mechanism / deflector 124 (e.g., The cable 133may be a Bowden cable have a first end operatively connected to the joystick (e.g., to the arm 1062) and a second end connected to the chute deflector 124 (see FIG. 2)).

[0120] With this introduction, FIGS. 31 and 32 illustrate portions of the system 1000 in and around the joystick 1001 as assembled and exploded, respectively. As shown in these views, the system 1000 may again include a longitudinal shaft 1006 (extending fore-and-aft and orthogonal to the axis 1055 of a shaft 1050 further described below) that may be supported by the handle structure 119 such that the shaft is axially retained (e.g., by a pin or snap ring (not shown), but free to rotate (about a longitudinal or shaft axis 1012) relative to the structure 119 during operation. The handle structure 119 (or other surrounding structure) may further provide anchor points (not shown) to secure the ends of the housings 128 (e.g., 128a, 128b) of the cables 127.

[0121] The shaft 1006 may extend rearwardly from the structure 119 into an opening 1007 of a housing 1026 such that the housing (e.g., joystick and other portions of the system 1000) is supported for rotation about the longitudinal shaft axis 1012 as shown in FIG. 33 (a section taken along line 33-33 of FIG. 31). A fastener, e.g., bolt 1005 may pass through an opening in the housing 1026 aligned with an opening 1009 formed in the shaft 1006 and secured with a nut 1003. As a result of this construction, the joystick 1001, housing 1026, shaft 1050, and wrap springs 1052a, 1052b may rotate about the axis 1012 during operation.

[0122] The housing 426 may also include a protruding leg having an attachment point (e.g., fastener 1011) adapted to secure paddle fittings of terminal ends 1008 of the cables 127a, 127b. Accordingly, rotation of the housing 1026 may pull on one of the cables 127 while simultaneously slackening the opposite cable 127. As shown in FIG. 2, such cable action allows a force to be applied to the chute 120 to cause it to rotate in either the clockwise direction 123 or the counterclockwise direction 132 about the chute axis 121 (depending on the direction of rotation of the joystick / housing about the axis 1012).

[0123] The housing 1026 may form part of the deflector ejection angle mechanism 1004, exemplary embodiments of which are described now with initial reference to the exploded view of FIG. 32 and the section view of FIG. 34 (section view taken along line 34-34 of FIG. 31). As shown in these views, the housing 1026 may include slots 1027configured to support ends of a first or transverse shaft 1050, the shaft defining an axis 1055 about which the joystick 1001 may rotate. The shaft 1050 forms two outer lands 1051 each adapted to receive at least one of two wrap springs 1052 (e.g., first or left spring 1052a and second or right wrap spring 1052b). As with other embodiments described herein, each wrap spring may include a helical coil that can be received on (wrapped about) its respective shaft land of the shaft 1050 as well as about a fixed shaft 1060 (first or left fixed shaft 1060a and second or right fixed shaft 1060b), wherein the associated helical coil engages the shafts with an interference fit (engages the shafts with a first friction force) when in a neutral position. Moreover, in the illustrated embodiment, the two wrap springs 1052a, 1052b may be of the same hand (e.g., left handed).

[0124] The shaft 1050 may also include a flange 1059 positioned between the two lands 1051. The flange 1059 may have a diameter larger than that of the lands and be configured to be received within an opening of an arm 1062 with a slight clearance fit. The arm may include an upwardly extending finger 1063 that is received within an opening 1085 of the joystick 1001. The finger 1063 may include forwardly and rearwardly extending stub shafts 1087 such that the finger forms a “cross” shape. The stub shafts may assist in retaining one or more (e.g., front and rear) compliant elements or biasing members 1089, which may be formed of one or more compression springs or wave washers as shown in FIG. 35 (biasing members shown diagrammatically in other figures). The biasing members 1089 may be retained by the stub shafts 1087 and by corresponding surfaces formed by a window 1086 formed in the joystick 1001 (see FIG. 35). As described below, the biasing members 1089 may keep the joystick 1001 centered such that spring engaging surfaces 1074, 1075 do no contact, or only lightly contact, the wrap springs 1052 as further described below. This is beneficial as, if the joystick is resting against legs of one of the wrap springs, vibration and / or the weight of the joystick may cause the wrap spring to inadvertently “unlock,” allowing unintended deflector movement. However, while the handle / joy stick is shown as being operatively connected to the actuators (e.g., spring engaging surfaces 1074, 1075) by one more compliant elements, alternative embodiments may rigidly connect these components.

[0125] With continued reference to FIGS. 32 and 34, the deflector angle ejection mechanism 1004 also includes the first and second fixed shafts 1060 (1060a, 1060b) thathave axes coincident with the shaft axis 1055. As shown in FIG. 34, each fixed shaft 1060a, 1060b defines a land 1061 that is slightly smaller than the adjacent land 1051 of the shaft 1050 such that an internal diameter of each wrap spring 1052 can “lock” the shaft 1050 relative to its respective fixed shaft 1060, but allow the spring (when deflected) to rotate with the shaft 1050 and joystick 1001 about the fixed shafts 1060 / shaft axis 1055. The fixed shafts may be axially secured in place with a snap ring 1067 and optional washer 1065. This shaft subassembly may then be placed between clevises 1110 of the housing 1026 such that the protruding ends of the shaft 1050 rest within the slots 1027. As shown in FIG. 32, fasteners 1068 (with optional washers 1069) may then pass through openings 1070 in each side (e.g., clevis 1110) of the housing 1026 and threadably engage the respective fixed shafts to secure the fixed shafts to the housing 1026 and prevent relative rotation therebetween.

[0126] The joystick 1001 may then be attached to the shaft 1050. In the illustrated embodiment, the joystick forms part of a handle bracket 1064 that flares outwardly near its lower end to form two clevises 1066. As shown in FIG. 34, the handle assembly / joy stick may then be attached to the shaft 1050 by passing shoulder bolts 1072 through openings 1073 formed in the clevises 1066 of the joystick / handle bracket and threadably engaging ends of the shaft 1050. The shoulder bolts may permit the assembly to be adequately secured while also allowing some lateral movement of the joystick / handle bracket relative to the rest of the assembly.

[0127] The housing 1026 may also define a cable housing anchor 1083 configured to secure the end of the cable housing 134 of the cable 133. The cable wire 135 of the cable 133 may then be connected to a receiver 1084 of the arm 1062 (see also FIG. 31) in a manner similar to embodiments described above.

[0128] The handle bracket 1064 (which again may be rigidly attached or integral with the joystick 1001) may, along with the joystick and spring engaging surfaces 1074, 1075 (described below), form an actuator capable of moving or deflecting the wrap springs 1052a and 1052b to a deflected position. For instance, in the illustrated embodiments (see also FIG. 36), the bracket 1064 may define both: the first spring engaging surface 1074 on its first or forward side adapted to contact and press against a protruding first leg 1016 of the first wrap spring 1052; and the second spring engaging surface 1075 on its secondor rear side adapted to contact and press against a protruding first leg 1017 of the second wrap spring 1052b. A second leg 1018 and 1019 of the first and second wrap springs, respectively, may be unconstrained (i.e., they may not interact with any other stops or structures). Alternatively, the second legs 1018, 1019 could be restrained as well.

[0129] With reference now to FIGS. 31, 32, 34, and 36, when no force is applied to the joystick 1001, the two wrap springs are in their neutral positions, effectively locking the shaft 1050 to the fixed shafts 1060a, 1060b. That is to say, the first wrap spring 1052a will restrict relative rotation between the corresponding shaft 1050 / shaft land 1051 and the first fixed shaft 1060a (e.g., between the fixed shaft and the associated first wrap spring) in a first direction 488 about the axis 1055 (see FIG. 31), while the second wrap spring 1052b will restrict relative rotation between the shaft 1050 / shaft land 1051 and second fixed shaft 1060b (e.g., between the fixed shaft and the associated second wrap spring) in a second direction 486. Due to the unidirectional nature of the wrap springs, the first wrap spring 1052a will permit (not interfere with) relative rotation between the fixed shaft 1060a and the first wrap spring 1052a in the second direction 486 about the axis 1055, while the second wrap spring 1052b will permit (not interfere with) relative rotation in the first direction 488.

[0130] When the operator applies a force rearwardly to the joystick 1001, e.g., in the direction 353 (see FIG. 31) to increase the ejection angle 126, the joystick (including the handle bracket 1064) pivots about the shaft axis 1055 in the corresponding second direction 486 (see also FIG. 1). As this joystick force is applied to the handle bracket 1064, the second spring engaging surface 1075 contacts and presses against the first leg 1017 of the second wrap spring 1052b. As the direction of this force tends to unwrap the second wrap spring 1052b from the shaft 1050 / right fixed shaft 1060b (see FIG. 34), movement of the joystick about the axis 1055 in this direction causes the second wrap spring 1052b to move from its neutral position to a deflected position wherein a second friction force (of lesser magnitude than the first friction force applied in the neutral position) is then applied by the coil to the shaft 1050 / shaft land 1051 and right fixed shaft 1060b. That is to say, application of a sufficient force to the joystick in the direction 353 will reduce the frictional engagement between the second wrap spring 1052b and the shaft 1050 / right fixed shaft 1060b, ultimately permitting rotation of the shaft and wrapspring relative to the fixed shaft. Again, the first or left wrap spring 1052a will not interfere with rotation in the second direction 486 as such rotation does not cause the spring 1052a to tighten.

[0131] When the desired ejection angle is achieved, the operator can remove the rearward force on the joystick 1001, causing the right wrap spring 1052b to again wrap with sufficient friction against the shaft 1050 / fixed shaft 1060b, locking the spring (and thus the arm 462) relative to the shaft / fixed shaft 1060b. The biasing members 1089 may center the joystick and minimize unintended dynamic forces acting on the springs 1052a, 1052b.

[0132] Conversely, when it is desired to reduce the ejection angle 126 (see FIG. 2), the operator may push the joystick 1001 forwardly (e.g., in the direction 351 of FIG. 31). As this force is applied, it is again transferred to the handle bracket 1064 applying a force thereto in the first direction 488. Due to the engagement of the spring engaging surface 1074 with the first leg 1016 of the first wrap spring 1052a, the force acts to open or unwrap the first wrap spring (e.g., move to its deflected position) from the shaft 1050 / left fixed shaft 1060a until the frictional engagement therebetween is reduced sufficiently to permit relative rotation of the shaft, and thus the arm 1062, about the shaft axis 1055 (and relative to the fixed shaft 1060a, 1060b). Accordingly the handle bracket 1064, arm 1062 and the wrap springs 1052 may rotate about the shaft axis 1055 in the first direction 488. As stated above, sufficient force may be required to not only deflect the wrap spring 1052a, but also to overcome the biasing force of the spring 136 (see FIG. 2) before the arm 1062 may move. Once the deflector 124 is in the desired position, the operator may remove the force applied to the joystick 1001, at which point the wrap spring 1052a may again tighten about the shaft 1050 / fixed shaft 1060a sufficiently to prevent further relative rotation.

[0133] While illustrated and described with two wrap springs 1052, other embodiments of the deflector ejection angle mechanism 1004 may be configured with a single wrap spring 1052 (e.g., second wrap spring 1052b) as the spring 136 (see FIG. 2) may negate the need for both springs as already described herein above.

[0134] As with the other chute control systems described herein, the system 1000 also incorporates a chute rotation mechanism 1002. However, unlike the other systems, the chute control system 1000 may locate its corresponding chute rotation mechanism 1002 at the chute rotation axis rather than at or near the joystick. Locating the chute rotation mechanism 1002 proximate the chute may provide various benefits including, for example, improved mechanical advantage to deflect the chute rotation wrap springs. For example, by placing the wrap spring locking mechanism 1002 near the chute rather than near the joystick, there is little reliance on the tension in the cables 127a, 127b to hold the chute 120 rotationally in place. As a result, cable stretch may be minimized, and tolerances inherent with cables may be more easily accommodated.

[0135] Exemplary embodiments of the chute rotation mechanism 1002 are illustrated in FIGS. 37-44. For example, as shown in FIG. 37, the exemplary chute rotation mechanism 1002 is shown attached to an upwardly extending arm 1120 fixed to the frame 102 (see FIG. 1) of the snowthrower, wherein the arm is positioned proximate the chute. As further described below, the mechanism 1002 may be formed by a shaft 1122 (e.g., chute rotation shaft) that defines an axis coincident with the chute axis 121 itself (and thus is referred to herein with the same reference numeral 121). The chute 120 may be journalled for rotation relative to the chute rotation shaft (about the axis 121).

[0136] In order to effect chute rotation, the cables 127a and 127b (see FIG. 31 and diagrammatic representation in FIGS. 37 and 38) have their distal terminal ends attached to first (e.g., upper) and second (e.g., lower) pulleys 1123 and 1124, respectively, as indicated in FIGS. 37 and 38. To permit anchoring of the cable housings 128a, 128b, the arm 1120 may also include cable anchors 1125 as are known in the art.

[0137] Each pulley 1123, 1124 may include a circumferential guide 1126 (e.g., protruding circumferential lip or ledge) to assist with maintaining desired engagement of its respective cable 127a, 127b during operation. Moreover, each cable 127a, 127b may ultimately pass through a wall of the associated pulley via an aperture 1127 as shown in FIGS. 37 and 39, where the cable may then operatively engage an associated wrap spring as further described below.

[0138] FIGS. 40 and 41 are similar to FIGS. 37 and 39, respectively, except that the pulleys 1123 and 1124 and cables 127a, 127b are removed in these views to illustrate the first (e.g., upper) chute rotation wrap spring 1128 and second (e.g., lower) chute rotation wrap spring 1129 corresponding to the pulleys. As with the other wrap springs described herein, each of the springs 1128, 1129 may include a helical coil wrapped about the chute rotation shaft 1122 In this embodiment, each wrap spring 1128, 1129 may be of the same hand, e.g., left-hand, and each may require only a single protruding tang 1130, 1131, respectively, to permit actuation by its associated cable 127.

[0139] FIG. 42 is an exploded view of the chute rotation mechanism 1002 with some components (e.g., cables 127) removed to better illustrate the mechanism, while FIG. 43 is a section view (taken along line 43-43 of FIG. 37) of the assembled mechanism, again with some structure removed. As shown in these views, the shaft 1122 may be fixed or rigidly attached to the arm 1120. While other configurations are certainly possible, the shaft 1122 may be formed by two shaft halves (e.g., first or upper shaft half 1132 and second or lower shaft half 1134) secured (e.g., threaded) to one another as shown in FIG. 43. The shaft 1122 may further include first (e.g., upper) and second (e.g., lower) sleeves 1136, 1138, which may be secured to their respective shaft halves 1132, 1134 by, for example, dowels or fasteners passing through aligned holes 1139. Once assembled, the shaft 1122 (e.g., the shaft halves 1132, 1134 and sleeves 1136, 1138) may be fixed in relation to one another and to the arm 1120.

[0140] To permit the chute 120 to rotate about the shaft 1122, the chute may incorporate or otherwise have rigidly attached thereto bushings (e.g., first or upper bushing 1140, and second or lower bushing 1142). In the illustrated embodiments, the bushings 1140, 1142 may be fixed (e.g., welded) to the chute, e.g., to tabs 1141, 1143, respectively, that are in turn fixed (e.g., welded) to the chute 120. As a result, the chute 120, including the tabs 1141, 1143 and their associated bushings 1140, 1142 may rotate together about the chute axis 121 (e.g., journalled for rotation relative to the shaft 1122) during chute rotation.

[0141] With reference now to FIG. 43, the chute rotation mechanism 1002 may be assembled by inserting the shaft halves 1132, 1134 through their respective tabs 1141, 1143 and through a corresponding aperture formed in the arm 1120 and then securelytightened. The sleeves 1136, 1138 may then be placed over their respective ends of the shaft halves 1132, 1134 and secured thereto via the aligned holes 1139. The sleeves 1136, 1138 may have an outer diameter that is equivalent to (or slightly larger than) the outer diameter of the associated bushings 1140, 1142 as indicated in FIG. 43. As a result, the wrap springs 1128, 1129 when in their neutral positions (when no force is applied thereto), may effectively lock the chute 120 in relation to the arm 1120. That is to say, each wrap spring 1128, 1129 may lock the shaft 1122 (sleeve 1136, 1138) to its associated bushing 1140, 1142 by frictionally engaging the bushing and the adjacent sleeve 1136, 1138. In this way, the first and second wrap springs 1128, 1129 may prevent rotation of the chute 120 in either direction.

[0142] To rotate the chute in, for example, the counterclockwise direction 132 (see FIG. 38), the operator may apply a force to the joystick 1001 in the direction 355 as shown in FIG. 31. Application of a force in this direction will, ultimately, cause the joystick 1001 (and the housing 1026) to rotate about the shaft axis 1012 defined by the shaft 1006 (see FIG. 32) in the corresponding direction. That is, such movement may result in tensioning of the first chute rotation cable 127a and slackening of the second chute rotation cable 127b, while rotation of the joystick in the opposite direction 357 (see FIG. 31) may result in tensioning of the second chute rotation cable 127b and slackening of the first chute rotation cable 127a.

[0143] Before the chute 120 can rotate, however, actuation of the appropriate wrap spring 1128, 1129 is needed so that the bushings 1140, 1142 (rigidly attached to the chute) may rotate relative to the shaft 1122. In this example (counterclockwise chute rotation), the first cable 127a is tensioned by the force applied to the joystick 1001 in the direction 355 (and the second cable 127b is slackened). More specifically, as the force is applied to the joystick 1001, the cable 127a (which again wraps about the pully 1123 as shown in FIG. 38 and passes through the pulley 1123 via the aperture 1127) applies a corresponding counterclockwise torque to the pulley 1123 to cause rotation. An inside surface of the pulley 1123 may, as shown in FIG. 44, form an actuator or pull surface 1145 against which an end 1146 of the cable 127a may act to force rotation of the pulley 1123 about the chute axis 121. In this manner, tension on the cable 127a (resulting from a force applied to the joystick 1001 in the direction 355) will apply a rotational torque tothe pulley 1123 tending to rotate the pulley in the counterclockwise direction 132 (see FIG. 38).

[0144] As further shown in FIG. 44, inner surfaces of the pulley 1123 (as well as of the second pulley 1124) may define a receiver adapted to receive and retain the protruding leg or tang 1130 of the spring 1128 (or the tang 1131 of the spring 1129 for the second pulley 1124). While the receiver is shown in FIG. 44 as a recess 1148 formed in an inner wall of the pulley 1123, it may be configured as any feature that immobilizes or effectively fixes the tang 1130 relative to the pulley. As a result of this construction, the force applied by the cable 127a acts initially to rotate the pulley in the associated first or second direction and deflect the tang 1130 of the associated wrap spring 1128 (or 1129). As the wrap spring 1128 is deflected, it reduces the frictional force applied to the shaft 1122 (e.g., the sleeve 1136) and the corresponding bushing 1140 (see FIG. 43). As a result, the bushing 1140, and thus the chute 120, are free to rotate in the counterclockwise direction 132 shown in FIG. 38. As already explained in the description above regarding other embodiments, the second or lower wrap spring 1129 does not prevent such counterclockwise chute rotation as such motion tends to loosen or unwrap that spring rather than tighten it.

[0145] Although not separately illustrated, rotation of the shaft in the clockwise direction 123 (as a result of movement of the joystick 1001 in the direction 357 in FIG. 31), will cause the cable 127b to similarly operate on the second or lower pulley 1124 (which engages the tang 1131 of the wrap spring 1129 in the same manner as that described above with respect to the wrap spring 1128 / pulley 1123). That is to say, movement of the joystick 1001 in the direction 357 will cause the cable 127b to rotate the lower pulley 1124 and deflect the lower wrap spring 1128 sufficiently to permit rotation of the lower pulley and produce corresponding rotation of the chute. Again, motion in the clockwise direction is permitted by the upper wrap spring 1128 as such motion does not tend to further wrap the spring 1128 about the shaft / bushing, i.e., the upper wrap spring 1128 will not interfere with chute rotation in the clockwise direction 123.

[0146] Thus, the chute control system 1000 may operate under the same engineering principles as the other chute control systems described herein. Accordingly, aspects ofhow the wrap springs provide the desired mechanical shaft locking are not repeated herein.

[0147] While illustrated and described herein as utilizing two separate pulleys 1123, 1124, a single pulley configuration (e.g., only pulley 1123) is also contemplated. In such a configuration, both cables 127a, 127b could connect to the single pulley to provide their opposing rotational input force. Moreover, the single pulley could contain both of the first and second actuators (pull surfaces 1145; see FIG. 44) to which opposing cables 127a, 127b would be respectively connected. Accordingly, a single pulley could: be operatively connected to both of the first and second chute rotation wrap springs; and include both of the first and second actuators. The first and second actuators, when rotated, may then deflect the first and second chute rotation wrap springs, respectively, as already described herein. The first and second cables 127a, 127b may be attached to the pulley such that: the first cable is operatively connected to the first actuator, wherein the first actuator is configured to deflect the first chute rotation wrap spring (e.g., spring 1128) sufficiently to permit the pulley and the chute to rotate in a first direction about the chute axis; and the second cable is operatively connected to the second actuator, wherein the second actuator is configured to deflect the second chute rotation wrap spring (e.g., 1129) sufficiently to permit the pulley and the chute to rotate in a second (opposite to first) direction about the chute axis. Such a construction may yield a more compact and cost-effective (e.g., less parts) chute rotation mechanism.

[0148] FIGS. 45-47 illustrate yet another application of a shaft locking system in accordance with embodiments of the present disclosure. In these figures, a walk-behind outdoor power equipment unit having an upwardly extending handle is illustrated. While any type of machine is contemplated, (e.g., snowthrower, dethatcher, cultivator, etc.), it may be described herein as a walk-behind lawn mower 1200 of which a diagrammatic top view is shown in FIG. 45. The mower 1200 may include a chassis 1202 supported by wheels 1205 upon the ground surface. A prime mover such as an electric motor or internal combustion engine 1204 may be supported by the chassis 1202. A working tool such as a rotary lawn mower blade 1206 may rotate beneath the mower to define a cutting circle 1207. As the mower is advanced along a longitudinal axis 1209, the blade may cut grass and other vegetation over which the blade passes as is known in the art.

[0149] As shown in FIG. 45, the mower 1200 may further include a handle assembly 1210 that includes two laterally spaced, upwardly extending handle tubes 1212. The tubes may be connected to one another near their upper distal upper ends to form a transverse operator grip 1214. That is to say, the handle assembly 1210 may form a generally U- shaped handle as is known in the art.

[0150] To accommodate operators of differing heights, as well as to perming folding of the handle for mower storage, the handle assembly (e.g., the tubes 1212) may be configured to pivot relative to the chassis 1202 of the mower about a horizontal, transverse pivot axis 1216. To accommodate this motion, a shaft locking mechanism 1240 in accordance with embodiments of the present disclosure is provided and shown in more detail in FIGS. 46-47 (illustrating a perspective view and a perspective section view, respectively.) In these views, only one of the side of the mechanism 1240 and one handle tube 1212 are illustrated, with the opposite side understood to be a mirror image thereof.

[0151] Each handle tube 1212 may be rigidly connected to a transverse shaft 1242 such that the shaft 1242 and the handle tubes move in unison. As is visible in FIG. 47, the shaft 1242 may extend through at least one (e.g., two) bushings 1244 (forming fixed shafts) that are each rigidly mounted to the chassis 1202. Between the bushings 1244 is a flange collar 1246 that is rigidly attached to the shaft 1242 (e.g., by a fastener passing through aligned holes 1247) such that the collar may be considered part of the shaft 1242. In a manner similar to the deflector ejection angle mechanism 1004 (see, e.g., FIG. 32), the bushings 1244 and the collar 1246 may have adjacent lands about which at least one (e.g., two, left and right) wrap springs 1248, 1249 may be wrapped. When assembled and in their neutral positions, the wrap springs 1248, 1249 may immobilize the collar 1246 (which is attached to (or part of) the shaft 1242 (which is, in turn, rigidly attached to the handle assembly / handle tubes) relative to the bushings 1244 (which are fixed to the chassis 1202). Accordingly, the handle assembly 1210 (the handle tubes 1212) is immobilized relative to the chassis 1202 of the mower 1200. As already described herein, such immobilization or locking may be achieved with one wrap spring that restricts shaft 1242 rotation in one direction while the other wrap spring resists shaft rotation in the opposite direction.

[0152] Should the operator wish to change an elevation of the grip 1214 (or store the handle assembly by laying it flat against the chassis 1202), the shaft locking mechanism 1240 may be actuated. Actuation may be achieved, in the illustrated embodiments, by an actuator 1250 as shown in FIG. 46. More specifically, the actuator 1250 may be rotated in a first direction 1252. As the actuator rotates, spring engaging surfaces 1253 may deflect first legs 1254, 1255 of the two wrap springs 1248, 1249, allowing the springs to unwrap sufficiently to allow relative rotation between the collar 1246 and the bushings (note that the second legs 1258 (only one shown in FIG. 46) of the wrap springs may be constrained by the chassis, e.g., by the bracket that supports the bushings 1244). In some embodiments, the actuator 1250 may be rotated by a cable 1260 (shown diagrammatically in FIGS. 46-47) that has its distal end connected to a lever 1215 (see FIG. 45) on the transverse grip 1214.

[0153] With the wrap springs 1248, 1249 deflected, the handle assembly / handle tubes may be pivoted (about the axis 1216) to most any desired angular position relative to the chassis 1202. Once in the desired position, the actuator 1250 may be rotated in the opposite (second) direction 1262 to permit the wrap springs 1248, 1249 to return to their neutral positions, once again effectively immobilizing the handle assembly / handle tubes relative to the chassis 1202. In some embodiments, motion in the direction 1262 is achieved by a biasing member, e.g., extension spring 1264 (shown diagrammatically in FIG. 46 only) extending between the chassis 1202 and an arm of the actuator 1250.

[0154] As one can appreciate, the mechanism 1240 could be described as including first (components 1242, 1246) and second (e.g., left bushing 1244) shafts aligned along a shaft axis 1216, and a first wrap spring (e.g., 1248) having a helical coil wrapped about the first and second shafts, wherein the coil is configured to engage outer surfaces of both the first and second shafts with a first friction force when the first wrap spring is in a neutral position. As with other wrap springs described herein, the first friction force of the first wrap spring may be configured to: restrict rotation of the first shaft relative to the second shaft in a first direction about the shaft axis; and permit rotation of the first shaft relative to the second shaft in a second direction opposite the first direction. The mechanism may also include an actuator configured to deflect the first wrap spring to a deflected position, wherein the coil engages the outer surfaces of the first and secondshafts with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting rotation of the first shaft relative to the second shaft in the first direction about the shaft axis.

[0155] As shown in FIG. 47, the mechanism 1240 could further be described as having a third shaft (e.g., right bushing 1244). Such third shaft may also be aligned along the shaft axis 1216 and positioned on a side of the first shaft opposite the second (e.g., left bushing 1244) shaft. In this case, a second wrap spring 1249 (again comprising a helical coil wrapped about the outer surface of the first shaft and an outer surface of the third shaft) may also be provided, wherein the coil is configured to engage the outer surfaces of the first and third shafts with a first friction force when the second wrap spring is in a neutral position. The first friction force configured to: restrict rotation of the first shaft relative to the third shaft in the second direction about the shaft axis; and permit rotation of the first shaft relative to the third shaft in the first direction about the shaft axis. In this dual wrap spring configuration, the second wrap spring 1249 is configured to deflect to a deflected position wherein the coil engages the outer surfaces of the first and third shafts with a second friction force of less magnitude than the first friction force. Moreover the actuator may be configured to move the first and second wrap springs simultaneously from their neutral positions to their deflected positions.

[0156] As one may appreciate, shaft locking concepts as described herein may thus have wide application to outdoor power equipment. Accordingly, while a variety of applications are described and illustrated herein, such applications are illustrative only. An appreciation of various aspects of the disclosure will be gained through a discussion of the specific illustrative examples provided below. Various modifications and combinations of the illustrative examples, as well as additional aspects of the disclosure, are apparent herein.

[0157] Example 1 relates to a snowthrower including: a housing containing an auger therein; a chute connected to the housing and configured to direct snow ejected from the housing; a movable chute deflector attached to a distal end of the chute; and a control system including a deflector ejection angle mechanism configured to change at least an ejection angle of the chute deflector. The control system includes: a shaft defining an axis; a wrap spring including a helical coil wrapped about the shaft, the coil configured toengage the shaft with a first friction force when the wrap spring is in a neutral position, the first friction force configured to: restrict relative rotation between the shaft and the wrap spring in a first direction; and permit relative rotation between the shaft and the wrap spring in a second direction; and an actuator configured to deflect the wrap spring to a deflected position wherein the coil engages the shaft with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting relative rotation between the shaft and the wrap spring in the first direction.

[0158] Example 2 relates to the snowthrower of Example 1, further including a handle operatively connected to the actuator, wherein the actuator is configured to move the wrap spring to the deflected position upon pivoting of the handle about the axis of the shaft.

[0159] Example 3 relates to the snowthrower of any one of Examples 1-2, wherein the handle is rigidly connected to the actuator or alternatively, connected to the actuator via one or more compliant elements.

[0160] Example 4 relates to the snowthrower of any one of Examples 1-3, wherein the wrap spring is configured to rotate relative to the shaft when the wrap spring is in the deflected position.

[0161] Example 5 relates to the snowthrower of any one of Examples 1-4, wherein the shaft is configured to rotate relative to the wrap spring when the wrap spring is in the deflected position.

[0162] Example 6 relates to the snowthrower of any one of Examples 1-5, wherein the actuator presses against a protruding leg of the wrap spring to move the wrap spring to the deflected position.

[0163] Example 7 relates to the snowthrower of any one of Examples 1-6, wherein the shaft, the wrap spring, and the actuator are rotatably connected to structure for rotating about an axis orthogonal to the axis of the shaft.

[0164] Example 8 relates to the snowthrower of any one of Examples 1-7, further including a second wrap spring also including a helical coil wrapped about the shaft, the coil of the second wrap spring configured to also engage the shaft with a first frictionforce when the second wrap spring is in a neutral position, wherein the first friction force applied by the second wrap spring is configured to: restrict relative rotation between the shaft and the second wrap spring in the second direction; and permit relative rotation between the shaft and the second wrap spring in the first direction.

[0165] Example 9 relates to the snowthrower of any one of Examples 1-8, wherein the chute is rotatable about a chute axis, and wherein the control system further includes a chute rotation mechanism including: a chute rotation shaft having an axis coincident with the chute axis, wherein the chute is journalled for rotation relative to the chute rotation shaft; first and second chute rotation wrap springs each including a helical coil wrapped about the chute rotation shaft; a pulley operatively connected to both of the first and second chute rotation wrap springs, wherein the pulley includes first and second actuators configured to, when rotated, deflect the first and second chute rotation wrap springs, respectively; and first and second cables attached to the pulley. The first cable is operatively connected to the first actuator, wherein the first actuator is configured to deflect the first chute rotation wrap spring sufficiently to permit the pulley and the chute to rotate in a first direction about the chute axis. The second cable is operatively connected to the second actuator, wherein the second actuator is configured to deflect the second chute rotation wrap spring sufficiently to permit the pulley and the chute to rotate in a second direction about the chute axis.

[0166] Example 10 relates to a snowthrower including: a housing containing an auger therein; a chute connected to the housing and configured to rotate about a chute axis to control a direction of discharged snow from the housing; a movable chute deflector attached to a distal end of the chute; and a control system. The control system includes a joystick for manipulating at least a deflector ejection angle mechanism adapted to change an ejection angle of the deflector. The deflector ejection angle mechanism includes: a fixed shaft defining an axis about which the joystick rotates; and at least a first wrap spring including a helical coil wrapped about the fixed shaft, the coil configured to engage the fixed shaft with a first friction force when the first wrap spring is in a neutral position. The first friction force is configured to: restrict relative rotation between the fixed shaft and the first wrap spring in a first direction about the axis of the fixed shaft; and permit relative rotation between the fixed shaft and the first wrap spring in a seconddirection about the axis of the fixed shaft. The snowthrower also includes a Bowden cable having a first end operatively connected to the joystick and a second end operatively connected to the chute deflector.

[0167] Example 11 relates to the snowthrower of Example 10, wherein the joystick further includes an actuator configured to deflect the first wrap spring to a deflected position wherein the coil engages the fixed shaft with a second friction force that is of lesser magnitude than the first friction force, the second friction force configured to permit relative rotation between the fixed shaft and the wrap spring in the first direction.

[0168] Example 12 relates to the snowthrower of any one of Examples 10-11, wherein the deflector ejection angle mechanism further includes a second wrap spring also including a helical coil wrapped about the fixed shaft, the coil of the second wrap spring configured to engage the fixed shaft with a first friction force when the second wrap spring is in a neutral position, the first friction force configured to: restrict relative rotation between the fixed shaft and the second wrap spring in the second direction; and permit relative rotation between the fixed shaft and the second wrap spring in the first direction.

[0169] Example 13 relates to the snowthrower of any one of Examples 10-12, wherein the chute is rotatable about a chute axis, and wherein the control system further includes a chute rotation mechanism including: a chute rotation shaft having an axis coincident with the chute axis, wherein the chute is journalled for rotation relative to the chute rotation shaft; first and second chute rotation wrap springs each including a helical coil wrapped about the chute rotation shaft; first and second pulleys associated with the first and second chute rotation wrap springs, respectively, wherein each of the first and second pulleys includes an actuator configured to deflect its associated first or second chute rotation wrap spring when the pulley is rotated in one direction; and first and second chute rotation cables attached to the first and second pulleys, respectively, wherein the first and second chute rotation cables are adapted to rotate the first and second pulleys in first and second directions, respectively, about the chute axis.

[0170] Example 14 relates to the snowthrower of any one of Examples 10-13, wherein the first and second chute rotation cables are each operatively connected to thejoystick, and wherein the joystick is further rotatable about a longitudinal axis orthogonal to the axis of the fixed shaft, wherein rotation of the joystick in a first direction about the longitudinal axis results in tensioning of the first chute rotation cable and slackening of the second chute rotation cable, and rotation of the joystick in a second direction about the longitudinal axis results in tensioning of the second chute rotation cable and slackening of the first chute rotation cable.

[0171] Example 15 relates to a shaft locking system including: first and second shafts aligned along a shaft axis; and a first wrap spring including a helical coil wrapped about the first and second shafts, the coil configured to engage outer surfaces of both the first and second shafts with a first friction force when the first wrap spring is in a neutral position. The first friction force is configured to: restrict rotation of the first shaft relative to the second shaft in a first direction about the shaft axis; and permit rotation of the first shaft relative to the second shaft in a second direction opposite the first direction about the shaft axis. The system further includes an actuator configured to deflect the first wrap spring to a deflected position wherein the coil engages the outer surfaces of the first and second shafts with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting rotation of the first shaft relative to the second shaft in the first direction about the shaft axis.

[0172] Example 16 relates to the shaft locking system of Example 15, further including: a third shaft aligned along the shaft axis, the third shaft positioned on a side of the first shaft opposite the second shaft; and a second wrap spring including a helical coil wrapped about the outer surface of the first shaft and an outer surface of the third shaft. The coil of the second wrap spring is configured to engage the outer surfaces of the first and third shafts with a first friction force when the second wrap spring is in a neutral position, the first friction force configured to: restrict rotation of the first shaft relative to the third shaft in the second direction about the shaft axis; and permit rotation of the first shaft relative to the third shaft in the first direction about the shaft axis.

[0173] Example 17 relates to the shaft locking system of Example 16, wherein the second wrap spring is configured to deflect to a deflected position wherein the coil of the second wrap spring engages the outer surfaces of the first and third shafts with a second friction force of lesser magnitude than the first friction force, and wherein the actuator isconfigured to move the first and second wrap springs simultaneously from their neutral positions to their deflected positions.

[0174] Example 18 relates to a lawn mower blade attachment mechanism including the shaft locking system of Example 15.

[0175] Example 19 relates to a lawn mower handle attachment mechanism including the shaft locking system of Example 16 or Example 17.

[0176] Example 20 relates to a snowthrower chute rotation mechanism including the shaft locking system of Example 16 or Example 17.

[0177] The complete disclosure of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. In the event that any inconsistency exists between the disclosure of the present application and the disclosure(s) of any document incorporated herein by reference, the disclosure of the present application shall govern.

[0178] Illustrative embodiments are described and reference has been made to possible variations of the same. These and other variations, combinations, and modifications will be apparent to those skilled in the art, and it should be understood that the claims are not limited to the illustrative embodiments set forth herein.

Claims

CLAIMS1. A snowthrower comprising: a housing containing an auger therein; a chute connected to the housing and configured to direct snow ejected from the housing; a movable chute deflector attached to a distal end of the chute; and a control system comprising a deflector ejection angle mechanism configured to change at least an ejection angle of the chute deflector, the control system comprising: a shaft defining an axis; a wrap spring comprising a helical coil wrapped about the shaft, the coil configured to engage the shaft with a first friction force when the wrap spring is in a neutral position, the first friction force configured to: restrict relative rotation between the shaft and the wrap spring in a first direction; and permit relative rotation between the shaft and the wrap spring in a second direction; and an actuator configured to deflect the wrap spring to a deflected position wherein the coil engages the shaft with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting relative rotation between the shaft and the wrap spring in the first direction.

2. The snowthrower of claim 1, further comprising a handle operatively connected to the actuator, wherein the actuator is configured to move the wrap spring to the deflected position upon pivoting of the handle about the axis of the shaft.

3. The snowthrower of claim 2, wherein the handle is rigidly connected to the actuator or alternatively, connected to the actuator via one or more compliant elements.

4. The snowthrower of any one of claims 1-3, wherein the wrap spring is configured to rotate relative to the shaft when the wrap spring is in the deflected position.

5. The snowthrower of any one of claims 1-3, wherein the shaft is configured to rotate relative to the wrap spring when the wrap spring is in the deflected position.

6. The snowthrower of any one of claims 1-5, wherein the actuator presses against a protruding leg of the wrap spring to move the wrap spring to the deflected position.

7. The snowthrower of any one of claims 1-6, wherein the shaft, the wrap spring, and the actuator are rotatably connected to structure for rotating about an axis orthogonal to the axis of the shaft.

8. The snowthrower of any one of claims 1-7, further comprising a second wrap spring also comprising a helical coil wrapped about the shaft, the coil of the second wrap spring configured to also engage the shaft with a first friction force when the second wrap spring is in a neutral position, wherein the first friction force applied by the second wrap spring is configured to: restrict relative rotation between the shaft and the second wrap spring in the second direction; and permit relative rotation between the shaft and the second wrap spring in the first direction.

9. The snowthrower of any one of claims 1-8, wherein the chute is rotatable about a chute axis, and wherein the control system further comprises a chute rotation mechanism comprising: a chute rotation shaft having an axis coincident with the chute axis, wherein the chute is journalled for rotation relative to the chute rotation shaft; first and second chute rotation wrap springs each comprising a helical coil wrapped about the chute rotation shaft; a pulley operatively connected to both of the first and second chute rotation wrap springs, wherein the pulley comprises first and second actuators configured to, when rotated, deflect the first and second chute rotation wrap springs, respectively; and first and second cables attached to the pulley, wherein: the first cable is operatively connected to the first actuator, wherein the first actuator is configured to deflect the first chute rotation wrap spring sufficiently to permit the pulley and the chute to rotate in a first direction about the chute axis; and the second cable is operatively connected to the second actuator, wherein the second actuator is configured to deflect the second chute rotation wrap springsufficiently to permit the pulley and the chute to rotate in a second direction about the chute axis.

10. A snowthrower compri sing : a housing containing an auger therein; a chute connected to the housing and configured to rotate about a chute axis to control a direction of discharged snow from the housing; a movable chute deflector attached to a distal end of the chute; a control system comprising a joystick for manipulating at least a deflector ejection angle mechanism adapted to change an ejection angle of the deflector, the deflector ejection angle mechanism comprising: a fixed shaft defining an axis about which the joystick rotates; at least a first wrap spring comprising a helical coil wrapped about the fixed shaft, the coil configured to engage the fixed shaft with a first friction force when the first wrap spring is in a neutral position, the first friction force configured to: restrict relative rotation between the fixed shaft and the first wrap spring in a first direction about the axis of the fixed shaft; and permit relative rotation between the fixed shaft and the first wrap spring in a second direction about the axis of the fixed shaft; and a Bowden cable having a first end operatively connected to the joystick and a second end operatively connected to the chute deflector.

11. The snowthrower of claim 10, wherein the joystick further comprises an actuator configured to deflect the first wrap spring to a deflected position wherein the coil engages the fixed shaft with a second friction force that is of lesser magnitude than the first friction force, the second friction force configured to permit relative rotation between the fixed shaft and the wrap spring in the first direction.

12. The snowthrower of either claim 10 or claim 11, wherein the deflector ejection angle mechanism further comprises a second wrap spring also comprising a helical coil wrapped about the fixed shaft, the coil of the second wrap spring configured to engage the fixed shaft with a first friction force when the second wrap spring is in a neutral position, the first friction force configured to:restrict relative rotation between the fixed shaft and the second wrap spring in the second direction; and permit relative rotation between the fixed shaft and the second wrap spring in the first direction.

13. The snowthrower of any one of claims 10-12, wherein the chute is rotatable about a chute axis, and wherein the control system further comprises a chute rotation mechanism comprising: a chute rotation shaft having an axis coincident with the chute axis, wherein the chute is journalled for rotation relative to the chute rotation shaft; first and second chute rotation wrap springs each comprising a helical coil wrapped about the chute rotation shaft; first and second pulleys associated with the first and second chute rotation wrap springs, respectively, wherein each of the first and second pulleys comprises an actuator configured to deflect its associated first or second chute rotation wrap spring when the pulley is rotated in one direction; and first and second chute rotation cables attached to the first and second pulleys, respectively, wherein the first and second chute rotation cables are adapted to rotate the first and second pulleys in first and second directions, respectively, about the chute axis.

14. The snowthrower of claim 13, wherein the first and second chute rotation cables are each operatively connected to the joystick, and wherein the joystick is further rotatable about a longitudinal axis orthogonal to the axis of the fixed shaft, wherein rotation of the joystick in a first direction about the longitudinal axis results in tensioning of the first chute rotation cable and slackening of the second chute rotation cable, and rotation of the joystick in a second direction about the longitudinal axis results in tensioning of the second chute rotation cable and slackening of the first chute rotation cable.

15. A shaft locking system comprising: first and second shafts aligned along a shaft axis; a first wrap spring comprising a helical coil wrapped about the first and second shafts, the coil configured to engage outer surfaces of both the first and second shafts witha first friction force when the first wrap spring is in a neutral position, the first friction force configured to: restrict rotation of the first shaft relative to the second shaft in a first direction about the shaft axis; and permit rotation of the first shaft relative to the second shaft in a second direction opposite the first direction about the shaft axis; and an actuator configured to deflect the first wrap spring to a deflected position wherein the coil engages the outer surfaces of the first and second shafts with a second friction force of lesser magnitude than the first friction force, thereby selectively permitting rotation of the first shaft relative to the second shaft in the first direction about the shaft axis.

16. The shaft locking system of claim 15, further comprising: a third shaft aligned along the shaft axis, the third shaft positioned on a side of the first shaft opposite the second shaft; and a second wrap spring comprising a helical coil wrapped about the outer surface of the first shaft and an outer surface of the third shaft, the coil of the second wrap spring configured to engage the outer surfaces of the first and third shafts with a first friction force when the second wrap spring is in a neutral position, the first friction force configured to: restrict rotation of the first shaft relative to the third shaft in the second direction about the shaft axis; and permit rotation of the first shaft relative to the third shaft in the first direction about the shaft axis.

17. The shaft locking system of claim 16, wherein the second wrap spring is configured to deflect to a deflected position wherein the coil of the second wrap spring engages the outer surfaces of the first and third shafts with a second friction force of lesser magnitude than the first friction force, and wherein the actuator is configured to move the first and second wrap springs simultaneously from their neutral positions to their deflected positions.

18. A lawn mower blade attachment mechanism comprising the shaft locking system of claim 15.

19. A lawn mower handle attachment mechanism comprising the shaft locking system of either one of claims 16 or claim 17.

20. A snowthrower chute rotation mechanism comprising the shaft locking system of either one of claims 16 or claim 17.

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