Wheelchair Leafblower

Designers: Anirudh Subramanian, Jeffery Gamble, Avtar Varma, Hudson Duan, Matt Davis

Supervising Professor: Larry Bohs

httpv://www.youtube.com/watch?v=NlUEbOVo4yI

INTRODUCTION

Our client, a woman who uses a manual wheelchair, wanted to remove leaves that fall in her hard. A previous student design used a battery powered blower, which did not provide adequate power or duration.  The Wheelchair Leafblower includes a commercial gas-powered leaf blower that attaches behind the wheelchair seat.  A flexible hose mounts to the wheelchair air port, and a throttle switch at the end of the hose allows her to easily vary the blower power. The hose end rests securely in a holster while she is traveling.  The hose is long enough so that she can blow leaves with either her left or right hand, with a good range of motion.  A custom starting station allows her to pull the cord to start the blower.  With the Wheelchair Leafblower, our client can now clear her yard of leaves independently.

SUMMARY OF IMPACT

The Wheelchair Leafblower restores independence in a part of life that our client enjoys: yardwork. According to our client, she is very happy with the device and intends to use it regularly. She said, “This [device] is my favorite piece of adaptive equipment ever. I really love being outdoors, and this is going to make everything better.”

TECHNICAL DESCRIPTION

The Wheelchair Leafblower (Figure 1) comprises a Stihl 86 CE hand-held leafblower, an HDPE mount, a flexible hose, a throttle extension switch, a holster assembly, and a starting station.  The Stihl 86CE leafblower was selected for its blend of power, light weight, and ease of use. It has a 190 mph air speed rating, while weighing only 9.7 lbs.  The leafblower mounts to a 11”x16”, ½” thick piece of high-density polyethylene (HDPE) using short sections of 1/16” insulated cable attached to eye screws in the HDPE and looped over three sections of the blower: one around the nozzle, one around the handle, and one around the base.  Hooks fashioned from aluminum sheet attach the HDPE mount to the wheelchair rear frame member.  A conduit clamp attaches the lower portion of the mount to the tip-stopper on the bottom of the wheelchair, making the leafblower system stable when starting and traveling.

A 3’ long, 3”diameter flexible plastic duct hose attaches to the blower output port, and terminates in a fan-shaped piece of rigid plastic at the blowing end.  Between the flexible hose and the rigid end is a commercial throttle extension switch, which provides a handle and an easy way for the user to vary the blower power from idle to maximum output.  The switch includes a locking mechanism so the user can keep the blower at maximum without continuously squeezing the trigger.  An extended cable, made using bicycle derailleur cable and  housing, connects the trigger switch to the throttle lever on the leafblower using a custom bracket on the HDPE mount.  Zip ties tether the cable to the blower hose so they move in tandem as the user flexes the hose while blowing.

A custom holster assembly holds the leafblower hose end while traveling.  The holster includes a 1” L-bracket that attaches the assembly to a slot previously mounted below the wheelchair seat.  The holster arm, constructed using parts modified from a microphone stand and camera tripod, terminates in an 8” long piece of schedule 40 black PVC, cut lengthwise to create a U-shaped channel in which the hose end fits snugly.  A Velcro strap keeps the hose end from vibrating out of the channel.  The holster assembly keeps the hose end at a slightly downward and outward angle, so that the user can lock the throttle switch at maximum power while wheeling her chair with both hands, thereby blowing leaves while traveling.

The starting station includes a 3’ long arm made from pressure treated wood, attached to an oak tree in the client’s back yard.

A polypropylene rope loops over a 3” diameter plastic pulley at the top outer end of the arm, and terminates on the tree side in a 3” wide, two-pronged hook created from aluminum sheet.  Three pieces of 2×4” pressure treated wood, staked to the ground, locate the optimal parking area for starting. To start the blower, the user backs into the parking area, and then reaches behind the chair to attach the rope hook to the pull-cord handle of the leafblower.  She then grasps knots in the rope, shown in Figure 2, and pulls quickly to start the blower. After unhooking the pulley rope, she is ready to begin blowing leaves. Testing revealed that the user can generate more force using knots in the rope than with a handle on the rope end, since she can then pull with both arms in a more fluid motion. The cost of the components for the device is approximately $520.

Comments are closed.