Button type blade brake clutch control

Button type blade brake controls are disclosed that can be disposed on a handle of a power machine such a lawnmower. A blade brake clutch control can include a housing having a top portion that has a front side and a rear side. A control bail can have a pin extending therefrom that extends into the housing. A pivot arm can be disposed within the housing and connected to a control cable. A rotatable latch can be secured to the pivot arm. The latch can have a latch head that is aligned with the pin extending from the control bail. A rearward button can be disposed on the rear side of the top portion of the housing. The rearward button can have a contact surface positioned above the latch head. The rear button can be configured for pushing downward so that the contact surface contacts the latch head to rotate the latch head into an engaged position about the pin of the control bail so that, as the control bail is pulled downward, the pivot arm also pivots downward to pulled the control cable forward.

TECHNICAL FIELD

The subject matter described herein relates generally to blade brake clutch controls. In particular, the subject matter described herein relates to button blade brake clutch controls for a lawnmower that can reside on a portion of the handle near the location where the operator places his hands to operate the lawnmower.

BACKGROUND

Power machines, particularly walk-behind power machines, often employ an operator control handle or bail to actively control a component of the power machine. In addition to providing a means of controlling the power machine, the bail is often employed to enforce operator presence for safety reasons. For example, it is a requirement for walk-behind power mowing machines to have a “dead man” control or operator presence control, which generally includes a spring-biased bail which can be grasped by the operator during normal operation of the machine to enable the motor of the machine. If the bail is thereafter released, the machine action is rapidly terminated for reasons of safety. In the case of a “dead man” control on a lawnmower, the engine and the rotating blade are both rapidly stopped when the operator releases the bail.

More recently, blade brake clutch control apparatuses have been employed to enforce operator presence while using lawnmowers. A blade brake clutch control allows the rotating cutting blade to be stopped and engine to remain enabled when the operator releases the bail controlling the blade brake clutch. In a blade brake clutch mower equipped with an internal combustion engine, the engine can be started in a generally conventional manner, using either a rope pull or an electric starter. Once the engine is started, the engine remains running during the operation of the lawnmower unless the engine is purposely shut off by the operator. When the bail is moved to the engaged position, the blade brake clutch control activates the clutch whereby the cutting blade is engaged. Once the operator releases the control bail, a clutch between the blade and the output shaft of the engine is released and a blade brake is engaged. Thus, even though the engine continues to run, the blade comes to a stop. This action prevents the blade from freely spinning to a stop, in which an injury could occur to the user while the blade slows from an extremely high velocity of rotation.

The blade brake clutch control action can be contrasted with a dead man control mower in which the blade comes to a stop once the control bail is released since the engine is killed, i.e., engine ignition is disrupted. Nonetheless, the result is the same in both cases, namely the blade comes to a stop when the operator releases the control bail.

It is a safety requirement that bails on walk-behind lawnmowers designed for enforcing operator presence comprise a two-step apparatus such that a user must perform a two-step process before the blade can be engaged for rotation. Thus, a two-step bail apparatus for a lawnmower would provide for operator control of the mowing machine as well as conform to safety regulations. In a blade brake clutch mower, however, the control bail must operate differently than in a dead man control mower due to this need for two separate operator actions to reengage operation of the blade.

The control system used in a blade brake clutch mower to start and stop the rotation of the blade is necessarily more complex than that in a dead man control mower. Generally speaking, such a blade brake clutch control system is not as intuitively obvious to use as that for a dead man control mower. Accordingly, there is a need for a blade brake clutch control system that is simple and relatively easy to understand and use.

SUMMARY

According to the present disclosure, novel button type blade brake clutch controls and methods are provided for controlling a power machine, such as a mowing machine.

It is therefore an object of the present disclosure to provide novel apparatuses and methods for controlling a blade brake clutch of a mowing machine or other power machine via a blade brake clutch control that uses easily recognizable steps that are easy and comfortable for the operator to perform. An object having been stated hereinabove, and which is achieved in whole or in part by the subject matter disclosed herein, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.

DETAILED DESCRIPTION

Reference will now be made in detail to the description of the present subject matter, one or more examples of which are shown in the figures. Each example is provided to explain the subject matter and not as a limitation. In fact, features illustrated or described as part of one embodiment can be used in another embodiment to yield still a further embodiment. It is intended that the present subject matter cover such modifications and variations.

As used herein, “nominal angle” refers to the theoretical angle that most closely aligns with a surface as measured from a base line taking into account whether the surface is curved or of a non-linear shape. For example, for a curved surface, the nominal angle can be from a tangential line that passes through an operation point on the surface and extends to the base line.

FIG. 1illustrates a perspective view of a walk-behind power machine in the form of a lawnmower LM. Lawnmower LM can be a push mower or a self-propelled mower which is propelled in forward or reverse by one or more wheels such as wheels W that can be driven. Lawnmower LM includes an engine E that can reside atop a mower deck MD of lawnmower LM or can be in any other suitable position such as off-set from mower deck MD. Engine E drives a blade B under mower deck MD to cut the grass or lawn over which lawnmower LM is pushed. Engine E rotates mower blade B at a high speed in order to effectively cut the grass in which the blade B encounters. Due to safety concerns, blade B has a blade brake clutch BBC attached thereto that can engage a clutch to rotate blade B or apply a brake to blade B to stop it from rotating. Blade brake clutch BBC can release the clutch and brake blade B for such times as when the operator has walked away from the lawnmower so that the unattended lawnmower's engine can still run. However, blade B will stop turning to prevent any unnecessary safety hazards associated with a rotating blade B.

Lawnmower LM further includes a handle generally designated H which can include side arms SA that can extend upward from the mower deck MD of lawnmower LM. Handle H can further include a cross bar CB that can connect the side arms SA to form a generally U-shaped handle H. As shown in the figures, handle H can be ergonomically designed to better fit the operator's normal ergonomic position of the hands during use of lawnmower LM.

An operator presence control, in the form of a blade brake clutch control generally designated10, can include an operator presence control bail OPC. Control bail OPC can be secured to handle H near cross bar CB so that the operator can engage control bail OPC when operating lawnmower LM. Such operator presence controls are mandatory under federal regulations to increase the safety of walk-behind power lawnmowers. In the embodiment shown inFIG. 1, control bail OPC can be pulled from its upright position toward cross bar CB of handle H to facilitate the engagement of blade brake clutch BBC to engage the clutch and release the brake to allow rotation of blade B.

To further increase safety during operation of lawnmower LM, blade brake clutch control10can include a second step that can be required to engage the clutch and release the brake of blade brake clutch BBC to permit rotation of blade B during operation of lawnmower LM. For example, blade brake clutch control10can include a brake clutch control apparatus generally designated11that can work in tandem with control bail OPC to require a two-step process before engaging the clutch and releasing the brake of blade brake clutch BBC to permit rotation of blade B. Brake clutch control apparatus11can include a housing12, and a clutch control line CCL can extend from blade brake clutch BBC that engages blade B into housing12. Brake clutch control apparatus11can include a rearward button14(shown in the figures other thanFIG. 1) disposed in housing12that must be activated before control bail OPC can pull clutch control line CCL forward to engage the clutch and release the brake of blade brake clutch BBC to permit rotation of blade B of lawnmower LM. Operation of the blade brake clutch control10will be explained in further detail with reference toFIGS. 2 and 3.

Once an operator has started engine E of lawnmower LM, for example by using a crank pulley CR as shown inFIG. 1, the operator can then use blade brake clutch control10to activate blade brake clutch BBC as shown inFIGS. 2 and 3. Once the engine has started, the operator, while standing in position to operate lawnmower LM, can push rearward button14in housing12and then pull control bail OPC downward, rotating it toward cross bar CB of handle H in direction of arrow A ofFIG. 3.

Brake clutch control apparatus11as mentioned above can include housing12and rearward button14. Housing12can be secured to side arm SA of handle H in any conventional manner, for example, by a nut and bolt combination16. Housing12can include a top portion18which can have a peak19. Top portion18can have a front side20and a rear side22. Rear side22can be closest to the cross bar of handle H and can be sloped downward from peak19of top portion18toward cross bar CB of handle H. The slope of rear side22can extend in a direction opposite to the direction at which handle H (side arms SA) is angled downward to mower deck MD (seeFIG. 1). The slope of rear side22can be curved in a convex or a concave manner or can be in a straight slope. The nominal angle of the slope can vary. For example, the slope can have a nominal angle of between about 15° and about 85° as measured from the side arm SA of handle H.

Rearward button14can be positioned on rear side22of housing12. Since rear side22can be sloped downward toward handle H, rearward button14can be positioned at an angle to handle H. Rearward button14can be angled in a direction opposite to the direction at which handle H (side arms SA) is angled downward to mower deck MD (seeFIG. 1). The angled rearward button14provides easy accessibility from cross bar CB of handle H for operator O. For example, as shown inFIG. 2, operator O can push downward with thumb T in a direction D against rearward button14which extends outward from housing12from a position proximal to the normal placement of operator O's hand on crossbar CB during operation of lawnmower LM. At this point, operator O can pull control bail OPC in direction A ofFIG. 3. Since the rearward button14has been pushed, the cable within clutch control line CCL is engaged with control bail OPC. In this manner, as control bail OPC is pulled downward by the operator O in a direction A, the cable within jacket J of clutch control line CCL moves forward in a direction F. Thereby, blade brake clutch control10activates blade brake clutch BBC causing it to engage the clutch and release the brake to permit blade B of lawnmower LM to rotate.

The rearward and angled placement of button14in brake clutch control apparatus11provides an ergonomic and easily recognizable step in the two-step operator presence control of blade brake clutch control10. The nominal angle of rearward button14can vary. For example, rearward button14can be positioned at a nominal angle within housing12as measured from the downward extending side arm SA of handle H from about 15° to about 85°. For instance, the nominal angle of rearward button14can be between about 30° and 60°. Of course, the nominal angle of rearward button14can depend on the slope of rear side22of top portion18of housing12. The nominal angle of rearward button14can be substantially equal to the nominal angle of the slope of rear side22. In the alternative, the nominal angle of rearward button14can be different from the nominal angle of the slope of rear side22. For example, the nominal angle of rearward button14can be slightly offset (meaning slightly larger or smaller) than the nominal angle of rear side22. The nominal angles of both rearward button14and sloped rear side22will be explained in more detail below.

Referring now toFIG. 4, an exploded view of blade brake clutch control10is shown. Housing12can be constructed of two housing halves24,26. Housing half24can include a handle recess28that can extend along housing half24. Handle recess28can be shaped so as to conform around and snugly fit onto side arm SA of handle H (seeFIGS. 1-3). Once housing half24and housing half26are secured together, housing12can be placed on side arm SA of handle H. A bolt30and a nut32of a nut and bolt combination can be used to secure housing12to side arm SA of handle H. Bolt30can be placed through side arm SA and align so as to pass through housing12as shown inFIG. 4with a nut32being screwed onto bolt30on the opposite side of housing half26. In this manner, housing12can be secured to handle H. Other securement methods can also be used to secure housing12to handle H of lawnmower LM. For example, adhesives, screws, snap fastening devices, key and keyway devices, and the like can be used. Further, housing half24can be integral to handle H.

Brake clutch control apparatus11can be secured to either or both side arms SA of handle H through simple design modifications. Further, while housing12is described as comprising two halves herein, it should be noted that housing12can comprise multiple component parts.

Housing halves24,26can be secured together through securement elements36after or during assembly of blade brake clutch control10. Again, securement elements36can be any number of securing devices such as screws, bolts and nuts, adhesives, point bonding, or the like. The securing of housing halves24,26of housing12can aid in the securement of the other components of blade brake clutch control10. When housing halves24,26are secured together housing12can form an aperture through which rearward button14protrudes from sloped rear side22.

Housing half24can include a guidance groove38at its rear portion which defines a ridge40on which a platform42resides. Guidance groove38and ridge40can be sloped with platform42being angled. At the rear and to the side of ridge40, housing half24can form a pivot recess44. Similarly, housing half26can also include a pivot recess (not shown) which aligns with pivot recess44. Button14can include a pivot bar46that has ends46A,46B that extend outward from rearward button14, for example, from a shelf48. Ends46A,46B fit into the pivot recesses44of housing halves24,26, respectively. Once housing halves24,26are secured together with rearward button14in place, a rise50of rearward button14protrudes outward from housing12so as to be easily recognizable as a portion for the user or operator to push during operation of blade brake clutch control10.

Rise50of button14can include a recess52therein. A button spring54can be received within recess52and can reside against platform42of ridge40within housing half24. Button spring54can be used to secure alignment of button14so that rise50protrudes outward from housing12once housing halves24,26are secured together. Button spring54provides a resiliency that allows button14to extend outward from housing halves24,26even after depression by the operator during use. Platform42can include a post which extends a limited distance outward around which button spring54in the form of a coil spring can be placed to secure placement of button spring54for proper alignment within recess52of button14. Other spring mechanisms beside the coil spring, such as a leaf spring, a volute spring, a Belleville spring, resilient material, or the like can be used as button spring54. Since the platform42can be angled, the nominal angle of the platform and the nominal angle of rearward button14can correspond to create an appropriate positioning of button spring54.

As stated above, rearward button14can include a shelf48. Shelf48can reside along any side of rearward button14. For example, shelf48can be disposed around the front portion of rearward button14or disposed around a side portion of rearward button14. Alternatively, shelf48can extend along three sides of button14and abut against pivot bar46. Shelf48can reside under ledges56of housing12so as to provide an abutment for the button14to prevent button14from pivoting outward from housing12. Shelf48can include a latch contact portion48A that can provide a contact surface58on the underside of button14. Contact surface58can be used to engage cable CA of control line CCL with control bail OPC when rearward button14is pushed as will be explained in more detail below. Latch contact portion48A can be anywhere on shelf48that allows a contact surface58to engage cable CA of control line CCL with control bail OPC when rearward button14is pushed. Further, latch contact portion48A can be on the underside of rearward button14if no shelf48is provided.

Brake clutch control apparatus11of blade brake clutch control10further can include a pivot arm60to which cable CA of clutch control line CCL can be secured. For example, pivot arm60can include a cable recess62in which a stop S of cable CA can be secured. The connection between cable CA and pivot arm60can be at different locations along pivot arm60. Cable CA can pass through a cable aperture64in housing12with jacket J of clutch control line CCL secured at cable aperture64(as shown inFIGS. 5A-5C) to prevent moisture leakage into housing12therethrough. Pivot arm60can rotate about a pivot66. Pivot66is centered on a pivot axis68around which pivot arm60rotates within housing12. Pivot arm60can be secured at pivot66along pivot axis68in many different ways including through a pin, bolt, screw, or other securing device which allows rotation of pivot arm60.

In the embodiment shown, operator presence control bail OPC can be used to secure pivot arm60through pivot66along pivot axis68. Control bail OPC can extend between the two side arms SA as shown inFIG. 1. Control bail OPC is secured to each side arm at locations on each side arm SA that are aligned with each other to allow easy rotation toward cross bar CB of handle H. On the side on which housing12is secured, control bail OPC can include a pivot base70which can extend through an aperture72in housing half26and further extend through a pivot aperture74in pivot66along pivot axis68. Pivot base70can then extend further through aperture76in housing half24and on through side arm SA of handle H. A carter pin, nut, or the like can be secured around the end of pivot base70to hold it in place while permitting a rotation of both pivot base70and control bail OPC. In this manner, control bail OPC and pivot arm60can share a pivot axis68so that they both rotate around the same pivot axis68during operation.

Control bail OPC can further include a pin78which extends through a bail groove80in housing half26. Bail groove80can be an arcuate slot which extends along a rear portion26B of housing half26. Pin78can rotate along bail groove80as control bail OPC rotates around pivot axis68with pivot base70.

Pivot arm60can have a latch82secured thereto. Latch82can have a latch head84that aligns with pin78of control bail OPC so that latch head84can hook around pin78. In this manner, both latch82and pivot arm60are secured to control bail OPC when latch head84is hooked on pin78. Thereby, when control bail OPC is pulled downward, pin78pulls latch82along with pivot arm60in the same direction as control bail OPC. As pivot arm60travels with control bail OPC, cable CA is pulled forward as pivot arm60rotates downward. This action of cable CA engages blade brake clutch BBC to activate the clutch and release the brake to permit blade B of lawnmower LM shown inFIG. 1to rotate.

A pivot pin86extends through latch82and latch pivot aperture88in pivot arm60so as to extend into guidance groove38in housing half24. Pivot pin86can be held in place in latch82and pivot arm60in any conventional manner that allows latch82to pivot about pivot pin86. For example, a coffer pin, or beta pin, can be placed through an aperture in the pivot pin86with the coffer pin, or beta pin, riding on a surface of a washer through which pivot pin86passes on the other side of pivot arm60opposite latch82. Guidance groove38can have an arcuate shape that can match the arcuate movement of bail OPC. In this manner, pivot arm60has an upper guidance with pivot pin86extending into guidance groove38, which secures its movement and creates a sturdier brake clutch control apparatus11.

A latch spring90can be used to bias latch82toward a disengaged position away from pin78so that an affirmative action by the operator must occur before latch82secures pivot arm60to control bail OPC before engagement of blade brake clutch BBC to permit the rotation of blade B. For example, latch spring90can be a leaf spring, coil spring, a Belleville spring, or some other resilient material which biases latch82toward a disengaged position. In the embodiment shown, latch spring90can be a coil spring which has an end90A and an end90B. End90A can be secured within a notch92of pivot arm60while end90B can be secured under a ledge94formed on latch82. In this manner, latch spring90biases latch82to an upper position away from pin78of control bail OPC.

Contact surface58of button14aligns with a portion of latch82distal from pivot pin86so that, as button14is depressed, contact surface58contacts latch82and pushes latch head84into engagement around pin78. Control bail OPC can then be pulled at this point thereby causing pivot arm60to rotate with control bail OPC. As pivot arm60rotates downward, cable CA is pulled forward to engage blade brake clutch BBC to permit rotation of blade B by engaging the clutch and releasing the brake of blade brake clutch BBC. This operation is explained in more detail inFIGS. 5A-5C.

FIGS. 5A-5Cshow the operation of blade brake clutch control10in a semi-cutaway view with the housing half26removed to more clearly show the operation of blade brake clutch control10. In normal operation of lawnmower LM (shown inFIG. 1), control bail OPC resides in and is biased toward an upper position away from cross bar CB of handle H. If the operator starts engine E of lawnmower LM and does not depress rearward button14by pressing against user interface surface96thereon, then the pulling down of the operator presence control bail OPC will not result in the engaging of blade brake clutch BBC to permit the rotation of blade B. For example, if rearward button14is not depressed, latch82does not pivot into position where latch head84engages pin78. Thus, when the operator pulls control bail OPC in the direction of arrow A toward cross bar CB (seeFIG. 3) only the control bail OPC and pin78move downward within housing12. Pivot arm60is not rotated about pivot axis68so that cable CA is pulled forward.

However, once the operator pushes against user interface surface96of rearward button14, button spring54compresses as contact surface58contacts against latch head84so that latch82pivots around pivot point87within pivot pin86.

Latch head84of latch82then engages pin78of bail OPC so that latch head84hooks around pin78as shown inFIG. 5B. When button14is pushed, the button pivots downward about pivot bar46. Upon release of the button14, button spring54biases button14back to its protruding position outside of housing12about pivot bar46. At this point, control bail OPC can be pivoted about pivot axis68from its upper position toward cross bar CB of handle H. As control bail OPC rotates downward, pin78, which is engaged and hooked by latch head84of latch82, pulls latch82along with control bail OPC. Since latch82is secured to pivot arm60, pivot arm60also rotates along pivot axis68as control bail OPC rotates toward cross bar CB. As pivot arm60rotates downward, cable CA within clutch control line CCL is pulled forward as shown inFIG. 5C. In this manner, cable CA causes blade brake clutch BBC to engage blade B so that blade B freely rotates.

As described above, sloped rear side22of top portion18of housing12and rearward button14in brake clutch control apparatus11provide an ergonomic step in the two-step operator presence control of blade brake clutch control10. The angles of sloped rear side22and rearward button14can contribute to easy and comfort of use for the operator. Referring toFIG. 6, housing12with top portion18extending above side arm SA of handle H forms a rear side22that slopes from a peak19downward toward handle H. The slope of rear side22can extend in a direction opposite to the direction at which side arms SA of handle H are angled downward to mower deck MD (see FIG.1). In the embodiment shown, rear side22has a convex slope, however, the slope can be concave or straight. Rearward button14protrudes outward from rear side22. Angled rearward button14can also extend in a direction opposite to the direction at which side arms SA of handle H are angled downward to mower deck MD (seeFIG. 1).

As shown inFIG. 6, a nominal angle a for the slope of rear side22can be measured between a tangential line SL that passes through a central portion of rear side22that serves as an operation point from which rearward button14extends and a base line BL that is aligned with side arm SA of handle H. Similarly, a nominal angle β for rearward button14can be measured between a tangential line AL that passes through an operation point of a central portion of the user interface surface96and base line BL.

As stated above, the nominal angles α and β of the respective rear side22and rearward button14can vary. Nominal angle α for the slope of rear side22can be between about 15° and about 85°. Similarly, nominal angle β for rearward button14can be between about 15° and about 85°. The nominal angle β of rearward button14can depend on nominal angle α of the slope of rear side22of top portion18of housing12. Nominal angle β of rearward button14can be substantially equal to nominal angle α of the slope of rear side22. In the alternative, nominal angle β of rearward button14can be different from nominal angle α of the slope of rear side22. For example, nominal angle β of rearward button14can be larger or smaller than nominal angle α of rear side22.

In the above described manner, a more ergonomically acceptable blade brake clutch control can therefore be provided and used. Placement of the button on a sloped rear portion of the housing so that the button can be angled and provides easy accessibility and comfortable pushing for the operator. Such placement of the rearward button is more comfortable and easier for the operator to use when pulling downward on the operator presence control bail. This placement of the rearward button permits easy use while still providing a cognizant recognition of the operator that two steps are required in order to permit the blade to rotate for operation of the lawnmower.

Embodiments of the present disclosure shown in the drawings and described above are exemplary of numerous embodiments that can be made within the scope of the appending claims. It is contemplated that the configurations described herein can comprise numerous configurations other than those specifically disclosed. The scope of a patent issuing from this disclosure will be defined by these appending claims.