Park brake and control lever interlock for ZTR vehicle

• US 7,451,865 B2
• Filed: 01/10/2006
• Issued: 11/18/2008
• Est. Priority Date: 01/18/2005
• Status: Expired due to Fees

• Current Assignee: Mtd Products Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Commercial Turf Products
• Inventors: Eavenson, Jimmy N. Sr., Buchanan, Peter
• Primary Examiner(s): Lewis; Tisha D
• Application Number:
  US11/328,920
• Publication Number:
  US 20060172857A1
• Time in Patent Office: 1,043 Days
• Field of Search: 192/219, 56/113, 56/167, 180/305, 180/307
• US Class Current: 192/219
• CPC Class Codes: A01D 34/64 mounted on a vehicle, e.g. a tractor, or drawn by an animal or a vehicle A01D34/695 takes precedence
• CPC Class Codes: B60T 11/04 transmitting mechanically
• CPC Class Codes: B60T 7/10 Disposition of hand control
• CPC Class Codes: B62D 11/006 Mechanical control systems

Abstract

A ZTR lawnmower having first and second drive wheels and first and second control levers to control the direction and speed of rotation of the first and second drive wheels. The lawnmower further includes a park brake system operatively interconnected with at least one of the drive wheels, and an interlock mechanism interfacing with the parking system. The park brake interlock mechanism includes a parking brake handle movable between an engaged position and a disengaged position to cause the park brake system to respectively resist and not resist rotation of the at least one drive wheel. The interlock mechanism interfaces with the park brake handle and the control levers such that when the first and second control levers are in the neutral position, the interlock mechanism permits the parking brake handle to be placed in the engaged position, and when the first and/or second control levers are not in the neutral position, the interlock mechanism prevents the parking brake handle from being placed in the engaged position.

Claims

1. A riding lawnmower comprising:

a chassis;

a power source;

first and second drive wheels at least partially supporting said chassis and rotatable via the power source to cause movement of said lawnmower;

first and second control levers associated with and controlling first and second drive systems, respectively, to control the direction and speed of rotation of said first and second drive wheels, respectively, each of said control levers having a neutral position in which the associated drive system does not cause rotation of the associated drive wheel, wherein each of said control levers comprises a plate member having a notch in an edge of said plate member;

a park brake system operatively interconnected with at least one of said drive wheels, said park brake system comprising a parking brake handle movable between an engaged position and a disengaged position to cause said park brake system to respectively resist and not resist rotation of said at least one drive wheel; and

an interlock mechanism providing an interface between the park brake handle and the control levers, wherein the notch in each plate member is located such that when said control lever is in said neutral position, a portion of said interlock mechanism is received within said notch when the park brake handle is placed in said engaged position such that said interlock mechanism permits said parking brake handle to be placed in said engaged position, and when said control lever is not in said neutral position, said interlock mechanism contacts the edge of the plate member and prevents the park brake handle from being placed in said engaged position.

2. The lawnmower of claim 1 wherein said park brake interlock mechanism comprises first and second interlock arms linked to said park brake handle, said interlock arms having respective portions configured to be received within said notches in said control plates.

3. The lawnmower of claim 2, further comprising a parking brake sensor configured to determine when said parking brake handle is in the engaged position, said sensor interfacing with a starting device for starting said power source, wherein said sensor prevents said starting device from starting said power source when said parking brake handle is not in said engaged position.

4. The lawnmower of claim 3, wherein said sensor does not directly determine whether said control levers are in said neutral positions.

5. The lawnmower of claim 3, wherein said parking brake sensor includes a plunger depressed by a finger on said brake handle in response to movement of said parking brake handle into said engaged position.

6. The lawnmower of claim 1, wherein the parking brake interlock mechanism is mounted to the chassis and further comprises a a brake actuating rod affixed to the parking brake handle, and wherein each of the interlock arms has a post extending therefrom.

7. The lawnmower of claim 6, wherein one end of the brake actuating rod is mounted to the park brake handle and a second end of the brake actuating rod is affixed to a bell-crank linkage comprising two offset links with an extension arm that extends transverse across the mower chassis connecting the two links.

8. The lawnmower of claim 7, wherein the interlock arms are linked to the park brake handle so that movement of the park brake handle causes movement of the interlock arms.

9. The lawnmower of claim 8, wherein the edge of the control plate has the notch formed therein, the notch being located in the control plate so that when the control arm and the control plate are in the neutral position, the notch aligns with the post on the interlock arm.

10. The lawnmower of claim 9, wherein when the parking brake handle is rotated to the engaged position, thereby causing the interlock arms to move in a rearward direction, the post is received in the aligned notch and when the parking brake handle is rotated toward the engaged position while the control lever and control plate are not in the neutral position, the notch does not align with the post on the interlock arm and the post contacts the edge of the plate member, thereby preventing the parking brake handle from being positioned in the engaged position.

11. The lawnmower of claim 10, wherein the control plates have substantially identical notches such that the parking brake system can only be engaged when both of the control levers are in the neutral position.