Tracked compact utility loader

• US 6,709,223 B2
• Filed: 09/24/2002
• Issued: 03/23/2004
• Est. Priority Date: 04/27/2000
• Status: Expired due to Term

• Current Assignee: Toro Company (Toro)
• Original Assignee: Toro Company (Toro)
• Inventors: Stalpes, Philip G., Walto, Joseph J., Keagle, Ronald T.
• Primary Examiner(s): Underwood, Donald W.
• Application Number:
  US10/254,047
• Publication Number:
  US 20030108414A1
• Time in Patent Office: 546 Days
• Field of Search: 414/680, 414/685, 414/686, 305/151, 305/152, 305/154, 305/156, 180/19.1, 180/19.3
• US Class Current: 414/685
• CPC Class Codes: B62D 51/04 the driver walking
• CPC Class Codes: B62D 55/00 Endless track vehicles steering aspects B62D11/00; characterised by the driver not being seated B62D51/007
• CPC Class Codes: E02F 3/3414 the arms being pivoted at the rear of the vehicle chassis, e.g. skid steer loader
• CPC Class Codes: E02F 9/02 Travelling-gear, e.g. associated with slewing gears drives therefor E02F9/20; for motor vehicles B60B, B60G; undercarriages for locomotives or railroad cars B61F; track-laying vehicles B62D; for cranes B66C23/18
• CPC Class Codes: E02F 9/0808 Improving mounting or assembling, e.g. frame elements, disposition of all the components on the superstructures for disposition of specific components, E02F9/0858
• CPC Class Codes: E02F 9/2004 Control mechanisms, e.g. control levers control levers per se G05G

Abstract

This invention relates to an outdoor equipment unit such as a walk-behind skid steer loader. The loader has a tracked traction system in which endless tracks are entrained around a rear drive support member and a front support member. The front support member is spring biased forwardly, but can move rearwardly against the spring bias to allow debris that is caught between the front support member to clear itself to help prevent the track from un-tracking. A single control handle having front and rear hand grips located between a fixed grab bar can be rotated and/or twisted to control the traction system. Return to neutral systems ensure that the control handle will return to a centered, neutral position upon release of the control handle by the operator.

Claims

1. A walk-behind loader, which comprises:

(a) a walk-behind frame

(b) a ground grooming or working attachment carried on the frame;

(c) a source of power carried on the frame;

(d) a traction system carried on the frame for propelling the frame in forward and reverse directions, the traction system being powered by the power source;

(e) the traction system comprising left and right endless drive tracks carried on the frame, wherein each drive track is entrained around rotatable front and rear support members, and wherein the front support member of each drive track is yieldably carried on the frame to be able to move towards the rear support member during operation of the traction system by biasing means comprising;

(i) a substantially U-shaped yoke having side walls joined together by a rear wall, the front support member being rotatably journalled between the side walls of the yoke;

(ii) a slide secured to the rear wall of the yoke and extending rearwardly from the yoke, the slide comprising a hollow tube having a front end attached to the rear wall of the yoke and an open rear end to provide access to the interior of the slide through the open rear end of the slide;

(iii) a slideway on the frame with the slideway having an open front end and a rear end, wherein the slide is inserted into the slideway through an open front end of the slideway for movement of the slide in a fore-and-aft direction on the frame;

(iv) a spring carried inside the hollow tube of the slide and an abutment positioned inside the hollow tube of the slide generally proximate to the rear end of the hollow tube, the spring having a rear end in engagement with the abutment and the spring having a front end acting operatively against the rear wall of the yoke such that the spring has a spring bias that pushes the yoke and the front support member forwardly relative to the slideway and relative to the rear support member to tension the drive track;

(v) a shaft rotatable on a rear wall of the slideway with the rear wall of the slideway being generally proximate to the rear end of the slideway, wherein the shaft has a rear end and a forwardly extending elongated shank, the forwardly extending elongated shank of the shaft extending forwardly into the hollow tube of the slide with the shank of the shaft passing through the open rear end of the hollow tube and with the shank of the shaft being connected to the abutment located inside the hollow tube while the rear end of the shaft is located exteriorly of the hollow tube; and

(vi) wherein the rear end of the slideway is configured to permit access to the rear end of the shaft from the rear end of the slideway to permit an operator to selectively apply torque to the shaft to thereby move the abutment inside the hollow tube in a fore-and-aft direction to selectively vary the spring bias provided by the spring.

2. The walk-behind loader of claim 1, wherein the ground grooming or working attachment is releasably coupled to the frame.

12. The walk-behind loader of claim 1, wherein the shank of the shaft is threaded and the abutment is a threaded nut received on the shank of the shaft, the threaded nut moving back and forth in the fore and aft direction on the threaded shank of the shaft when the shaft is rotated in one direction or the other.

13. The walk-behind loader of claim 12, wherein the nut has a non-circular cross-sectional shape that mates inside a non-circular cross-sectional shape of the hollow tube to move the nut back and forth on the threaded shank of the shaft and to prevent the nut from rotating within the tube as the shaft is rotated.

14. The walk-behind loader of claim 1, wherein the rear end of the shaft has an enlarged head configured to be rotated by a tool.

3. A walk-behind loader, which comprises:

(a) a frame having a front and a rear and a pair of laterally spaced uprights at the rear of the frame;

(b) an internal combustion engine carried on the frame enclosed beneath a hood or shroud;

(c) left and right endless drive tracks carried on the frame for propelling the frame in forward and reverse directions, the drive tracks being powered by the internal combustion engine;

(d) left and right loader arms pivotally connected to upper ends of the left and right uprights, respectively, wherein the loader arms extend forwardly and downwardly from the pivotal connections of the loader arms to the uprights to terminate in front ends that extend over the front of the frame, the loader arms having a lowermost position in which the front ends of the loader arms are generally adjacent the ground with the loader arms capable of being raised into elevated positions in which the front ends of the loader arms are spaced further above the ground than in the lowermost position of the loader arms, and wherein the loader arms are configured with an open space between the loader arms which open space is large enough to permit the loader arms to fit down around and receive therebetween at least an upper portion of the hood or shroud of the internal combustion engine when the loader arms are in their lowermost position, the open space between the loader arms providing substantially unobstructed viewing towards the front in elevated positions of the loader arms when the open space is raised in front of an operator'"'"'s face;

(e) a ground grooming or working attachment pivotally connected to the front ends of the loader arms;

(f) at least one actuator extending between the loader arms and the frame for pivoting the loader arms upwardly and downwardly relative to the frame about the pivotal connection of the loader arms to the frame;

(g) at least one actuator extending between the loader arms and the attachment for pivoting the attachment relative to the loader arms; and

(h) a control system positioned at the rear of the frame and comprising a control handle configured to be gripped and manipulated by a standing operator walking behind the frame during operation of the loader, wherein the control system is located sufficiently close to the rear of the frame and the rear of the frame is configured to permit the standing operator walking behind the frame to comfortably reach and operate the control system with the operator'"'"'s arms being bent at the elbow.

4. The walk-behind loader of claim 3, wherein each drive track is powered by its own separate drive motor.

5. The walk-behind loader of claim 3, wherein the ground grooming or working attachment is releasably coupled to the frame.

6. The walk-behind loader of claim 3, wherein the upper portion of the hood or shroud of the internal combustion engine has a profile that is higher towards the rear of the frame and is lower towards the front of the frame to help prevent obstructing the view of the standing operator towards the front of the frame.

7. The walk-behind loader of claim 3, wherein the at least one actuator extending between the loader arms and the frame is pivotally connected at one end to one of the uprights and at an opposite end to one of the loader arms.

8. The walk-behind loader of claim 7, wherein the at least one actuator extends substantially horizontally between the loader arm and the upright when the loader arms are in the lowermost position.

9. The walk-behind loader of claim 7, wherein a pair of left and right substantially horizontal actuators are provided extending between the loader arms and the frame, wherein the left actuator is pivotally connected at one end to the left upright and at an opposite end to the left loader arm and the right actuator is pivotally connected at one end to the right upright and at an opposite end to the right loader arm.

10. The walk-behind loader of claim 9, wherein the left and right actuators are substantially horizontal when the loader arms are in the lowermost position.

11. The walk-behind loader of claim 9, wherein the left and right actuators comprise hydraulic cylinders with extensible piston rods.