THROTTLE ASSIST MECHANISM FOR MOTORCYCLE

• US 3,752,006 A
• Filed: 07/24/1972
• Issued: 08/14/1973
• Est. Priority Date: 07/24/1972
• Status: Expired due to Term

• Current Assignee: Charles M. Bartlett
• Original Assignee: Charles M. Bartlett
• Inventors: Bartlett, Charles M.
• Primary Examiner(s): Herrmann, Allan D.
• Application Number:
  US05/274,417
• Time in Patent Office: 386 Days
• Field of Search: 74/488,489
• US Class Current: 74/489
• CPC Class Codes: B62K 23/04 Twist grips
• CPC Class Codes: B62M 25/00 Actuators for gearing speed-change mechanisms specially adapted for cycles rider operated controls for cycles in general B62K23/00; gearing speed change mechanisms F16H
• CPC Class Codes: Y10T 74/20287 Flexible control element
• CPC Class Codes: Y10T 74/20828 Handholds and grips

Abstract

In order to alleviate the torsional tension ordinarily required to be maintained constantly to hold a given motorcycle throttle opening, means are provided to apply a partially compensating torque in the opposite direction. The end of the motorcycle twist grip which the operator utilizes to control the throttle. A slightly expansible tubular member, dimensioned to fit within the handlebar, is provided with a tapered expander member for firmly securing the tubular member within the handlebar. A torsion spring within the tubular member is fixed thereto at a first end and is connected to a threaded shaft at its opposite end. The threaded shaft extends through and is fixed to the end of the twist grip, and means are provided for adjustably setting up the torque exerted by the torsion spring, which torque opposes that developed in the twist grip by the usual throttle return spring acting through the conventional cable to which the twist grip is operatively connected in the well known manner.

Claims

1. Apparatus for partially counteracting the torque exerted on the throttle twistgrip of a motorcycle by the conventional throttle return means comprising:

a. torsion spring means disposed within a handlebar of said motorcycle proximate a handlebar end about which the throttle twistgrip rotates;

b. means for securing a first end of said torsion spring means against rotation with respect to said handlebar;

c. shaft means fixed to a second end of said torsion spring, said shaft means extending outwardly, generally coaxial with said handlebar end and terminating beyond said handlebar end;

d. means fixing said shaft to an outboard end of the throttle twistgrIp, concentric with a longitudinal body portion thereof; and

e. means for biasing said torsion spring whereby a compensating torque is exerted by said shaft on the throttle twistgrip outboard end, said compensating torque being opposite in direction to the torque derived from the motorcycle throttle return means.

2. The apparatus of claim 1 which further includes means for adjusting the bias of said torsion spring such that a predetermined compensating torque is present with the throttle twistgrip in the closed position.

3. The apparatus of claim 2 which includes:

a. a tubular housing dimensioned to fit snugly within said handlebar end; and

b. expansion means for rigidly securing said tubular housing to said handlebar end by frictional engagement with the inner surface thereof; and

means for anchoring said first end of said torsion spring within said tubular housing.

4. The apparatus of claim 3 in which said expansion means includes a tapered expander adapted to threadably engage the interior of the outboard end of said tubular housing whereby said outboard end of said housing expands radially to frictionally engage the inner surface of said handlebar end as said tapered expander is screwed into said tubular housing.

5. The apparatus of claim 4 in which said shaft is threaded along at least an outboard portion of its length, said threaded portion extending through a central aperture in said outboard end of the throttle twistgrip, and said means for fixing said shaft to said outboard end of the throttle twistgrip comprises:

a. an inboard nut threaded onto said shaft;

b. an inboard washer disposed between said inboard nut and an inboard surface of said outboard end of the throttle twistgrip;

c. an outboard nut threaded onto said shaft; and

d. an outboard washer disposed between said outboard nut and an outboard surface of said outboard end of the throttle twistgrip whereby tightening said outboard nut squeezes said washers into frictional engagement with said outboard end of the throttle twistgrip.

6. The apparatus of claim 5 in which said tapered expander includes a plurality of diametrically opposed notches about the inner periphery of its outboard end, and further including a pin extending diametrically through said shaft, said notches being dimensioned to engage said pin, the normal position of said pin just outboard said tapered expander whereby longitudinal pressure against the outboard end of said shaft engages said pin with said notches such that said shaft may be rotated to screw said tapered expander into said outboard end of said tubular housing.

7. The apparatus of claim 6 in which said tubular housing is provided with diametrically opposed longitudinal slots at the outboard end thereof to facilitate radial expansion without longitudinal splitting as said tapered expander is screwed in.