Patent Application
20060261195
The present invention relates generally to a controlled feed device having an associated safety device and, more specifically, to a waste reducing device, such as a wood chipper, having an infeed chute safety device.
Wood chippers are used to reduce branches, trees, brush, and other bulk wood products into small wood chips. A wood chipper typically includes an infeed chute, a feed system for controlling the feed rate of wood products into the chipper, a wood chipping mechanism, a drive system for powering the feed system and the chipping mechanism, and a discharge chute. The infeed chute is typically a funnel-shaped conduit with a wide opening which tapers towards the feed system, converging the wood products towards the chipping mechanism. Through the operation of the feed system, wood products are brought into contact with the chipping mechanism, which grinds, flails, or cuts the wood products into small pieces. These wood chips are propelled into the discharge chute and expelled from the wood chipper. Wood chippers, if operated incorrectly, are potentially dangerous devices. The chipping mechanism typically rotates at high speeds, producing the high torque necessary to chip wood products. The feed system, located at the narrowest point of the infeed chute, is a dangerous area which may catch an operator's clothing or, more importantly, an operator's limb if he or she improperly reaches into the infeed chute during operation of the wood chipper.
Existing wood chippers incorporate a number of safety devices designed to prevent such accidents and interrupt or reverse chipper motive operation should they occur. Such devices include, for example, warning labels, a safety bar which an operator may push, in the feed direction of the wood chipper, if he or she becomes caught by the feed system or cutting mechanism, and various cords/handles which hang inside the infeed chute. Although marginally effective, these safety devices suffer from the fact that their effectiveness is limited by the inattentiveness of an operator and that they are difficult to operate in an emergency situation.
The present invention overcomes the aforementioned shortcomings and provides a wood chipper safety device that is effective and easy to operate in an emergency situation, thus preventing or minimizing operator injury. In one embodiment, a wood chipper safety device includes an elongated structure positioned outside of and adjacent to the infeed chute of a wood chipper. The elongated structure can be movable vertically downward between a plurality of positions. An actuator can be operably connected to the elongated structure and have a plurality of operable positions corresponding to the plurality of positions of the elongated structure. In various ones of the operable positions, the actuator can permit or stop motive operation of the powered feed and cutting systems of the wood chipper. The wood chipper includes a feed system control bar for controlling operation of the feed system. The safety device can operate independently of the feed system control bar.
In another embodiment, a waste reducing device, such as a wood chipper, having an infeed chute, a powered feed system, a powered cutting system, and a discharge chute includes an elongated structure positioned outside of and adjacent to the infeed chute of the waste reducing device. The elongated structure can be movable vertically downward between a plurality of positions. An actuator can be operably connected to the elongated structure and have a plurality of operable positions corresponding to the plurality of positions of the elongated structure. In various ones of the operable positions, the actuator can permit or stop motive operation of the powered feed and cutting systems of the waste reducing device. The waste reducing device includes a feed system control bar for controlling operation of the feed system. The safety device can operate independently of the feed system control bar.
As will be realized by those of skill in the art, many different embodiments of a wood chipper having an infeed chute safety device according to the present invention are possible. Additional uses, objects, advantages, and novel features of the invention are set forth in the detailed description that follows and will become more apparent to those skilled in the art upon examination of the following or by practice of the invention.
Referring to
The internal combustion engine is generally operated such that the rotary cutting blade 26 rotates at a high velocity, while the feed wheels 32 rotate relatively slowly. In operation, branches, trees, brush, and other bulk wood products are fed into the infeed chute 20, in the feed direction 48, and captured between the opposed, rotating feed wheels 32. The wood products are thus advanced until they encounter the rotary cutting blade 26. The cutting blade 26 reduces the bulk wood products into chips which are expelled from the chipper 10 in a high-velocity air stream such that centrifugal force is imparted to the wood chips, driving them into the discharge chute 22. The wood chips enter the discharge chute 22 with sufficient linear velocity to be propelled an adequate distance from the wood chipper 10. Optionally, the swivel bracket 28 at the base of the discharge chute 22 and the deflector 30 at the exit of the discharge chute 22 may be adjusted to direct the exiting wood chip stream to a predetermined location away from the wood chipper 10.
Referring to
The first elongated structure 36 and the second elongated structure 42 are operably connected to an actuator 56 which controls the powered feed and cutting systems of the wood chipper 10. Typically, these systems are hydraulically operated and controlled, however other operational systems may be utilized. The actuator 56 has a plurality of operable positions corresponding to the plurality of positions of the first elongated structure 36 and the second elongated structure 42. The actuator 56 may have a first operable position corresponding to a first position 57 (
The first elongated structure 36 and the second elongated structure 42 may be operably connected to the actuator 56 via a linkage 58, such as one or more nylon, plastic, or metal bars or braces, which may, optionally, be notched at one or more ends. The linkage 58 is operable for holding the actuator valve 56 open, allowing hydraulic fluid to flow to the powered feed and cutting systems, permitting the motive operation of the wood chipper 10. As the first elongated structure 36 and the second elongated structure 42 are moved, the linkage 58 actuates the actuator 56 such that the flow of hydraulic fluid is interrupted or reversed, respectively interrupting or reversing the motive operation of the feed and cutting systems of the wood chipper 10. Alternatively, rather than utilizing a linkage, other mechanical, electrical, electro-mechanical, optical, magnetic, etc. devices may be utilized to sense the position of the elongated structures 36 and 42 and switch the operable position of the actuator valve 56 or other control associated with the feed and cutting systems of the wood chipper 10.
The first elongated structure 36 and the second elongated structure 42 are advantageously positioned to improve the operational safety of the wood chipper 10. The first elongated structure 36 is positioned relative to the infeed chute 20 such that an operator caught in the feed wheel system 24 and/or the cutting blade 26, especially one falling with a backwards motion, may readily grasp the horizontally-extending portion 40 of the first elongated structure 36 and pull vertically downwards and/or radially inwards towards the opening 38 of the infeed chute 20, stopping the motive operation of the wood chipper 10. The second elongated structure 42 is positioned relative to the infeed chute 20 such that an observer may readily grasp the horizontally-extending portion 44 of the second elongated structure 42 and push or pull opposite the feed direction 48 of the wood chipper 10 and/or radially inwards towards the opening 38 of the infeed chute 20, also stopping the motive operation of the wood chipper 10.
The first elongated structure 36 may be rigidly attached to the second elongated structure 42 along the axis of rotation 52 of the first and second elongated structures 36, 42. The first elongated structure 36 and the second elongated structure 42 may be made of, for example, metal, plastic, or any other suitably rigid material. Alternatively, the first and second elongated structures 36, 42 may include a non-rigid and substantially non-extensible structure, such as a chain, cable, or rope. The first and second elongated structures 36, 42 may be attached to the top 46 of the infeed chute 20 via one or more supports 54 near each side 47 of the infeed chute 20. The supports 54, such as bearings or bushings and brackets, can allow rotation of the first and second elongated structures 36, 42. The bearings, bushings, and brackets 54 may be made of, for example, nylon, plastic, metal, or any other suitable material.
The safety device 34 can be positioned between the chipper operator and the feed wheel system 24. In an embodiment, the safety device 34 spans the width of the infeed chute opening 38, making it easier to access the device 34. The safety device 34 can be positioned so that it is highly visible outside the infeed chute 20, rather than being located within the infeed chute 20 where it may be hidden by brush or feed curtains. Accordingly, the safety device 34 may be activated outside of the infeed chute 20, so as to prevent placement of any part of the body into the infeed chute 20 in order to stop the feed wheel system 24.
The first elongated structure 36 and the second elongated structure 42 are operably connected to an actuator 56 which controls operation of the feed wheel system 24 and the cutting blade 26 of the wood chipper 10. In a preferred embodiment, the feed wheel system 24 and the cutting blade 26 are hydraulically operated and controlled. As shown in the embodiment in
The actuator 56 has a second operable position corresponding to the second positions 65, 66, respectively, of the first elongated structure 36 and the second elongated structure 42. In its second operable position, the actuator 56 can mechanically reposition the pin (not shown) such that the actuator valve is closed and the flow of hydraulic fluid from a hydraulic pump through the hydraulic hose 68 is stopped. Thus, in its second operable position, the actuator 56 can immediately stop motive operation of the feed wheel system 24 and the cutting blade 26. Stopping motive operation of the feed wheel system 24 prevents further advancement of feed material or any other object into the feed wheel system 24 and into the cutting blade 26. Accordingly, the first and second elongated structures 36, 42, respectively, may be rotated from their first positions 57, 59, respectively, which allows motive operation of the feed wheel system 24 and the cutting blade 26, to their second positions 65, 66, respectively, in which motive operation of the feed wheel system 24 and the cutting blade 26 can be stopped. In this manner, an operator who grabs the first elongated structure 36 while facing the infeed chute 20, or from within the infeed chute 20, can simply push or pull the first elongated structure 36 downward and rotationally inward, as would be the natural reaction of one trying to leverage oneself against the first elongated structure 36 to pull oneself out of the infeed chute 20. Similarly, an observer outside of the infeed chute 20 may push or pull the second elongated structure 42 rotationally inward, toward the opening 38 of the infeed chute 20, to stop motive operation of the feed wheel system 24 and the cutting blade 26. Thus, by varying the position of the first elongated structure 36 and the second elongated structure 42, and thereby varying the operable position of the actuator 56, the operable state of the wood chipper 10 can be varied.
The safety device 34 can include a “lockout” mechanism to insure that it is safe to resume operations before the actuator 56 can again allow the flow of hydraulic fluid to operate the feed wheel system 24 and the cutting blade 26. For example, in one embodiment, once the pin is repositioned with the movement of the first and second elongated structures 36, 42, the actuator valve is closed to stop the flow of hydraulic fluid, and the motive operation of the feed wheel system 24 and the cutting blade 26 is stopped. Once the actuator valve has been closed, the interface between the actuator pin and valve must be reset, or realigned, in order for the first and second elongated structures 36, 42, respectively, to be moved back to their respective first positions 57, 59. In this way, the actuator valve can be re-opened only with an active step by an operator, rather than by merely returning the first and second elongated structures 36, 42, to their respective first positions 57, 59 to allow the flow of hydraulic fluid. This safety feature helps to eliminate any accidental reactivation of the hydraulic system and unintended re-powering of the feed wheel system 24 and the cutting blade 26. Thus, by assuring that the safety device 34 is operable prior to restarting the feed wheel system 24, the safety device 34 provides an additional level of safety to operation of the wood chipper 10.
The first elongated structure 36 and the second elongated structure 42 may be operably connected to the actuator 56 via a linkage 58, such as with one or more arms, as shown in
The first elongated structure 36 and the second elongated structure 42 are advantageously positioned to improve the operational safety of the wood chipper 10. The first elongated structure 36 is positioned relative to the infeed chute 20 such that an operator caught in the feed wheel system 24 and/or the cutting blade 26, especially one falling with a backwards motion, may readily grasp the horizontally-extending portion 40 of the first elongated structure 36 and pull vertically downwards and/or radially inwards towards the opening 38 of the infeed chute 20, stopping the motive operation of the wood chipper 10. That is, in an emergency situation in which an operator may become panicked, all the operator must do to stop the feed wheels 32 is to grab the safety device 34 and pull it downward. The second elongated structure 42 is positioned relative to the infeed chute 20 such that an observer may readily grasp the horizontally-extending portion 44 of the second elongated structure 42 and push or pull opposite the feed direction 48 of the wood chipper 10 or radially inwards towards the opening 38 of the infeed chute 20, also stopping the motive operation of the wood chipper 10. Thus, the safety device 34 can be readily accessed from both the operator's position and from the direction of the wood chipper 10 engine, giving a person substantially 360 degrees from which to activate the safety device 34 outside the infeed chute 20. In this way, the safety device 34 can prevent both personal injury and equipment damage by providing a simple mechanism that can be readily accessed to instantly stop the feed wheel system 24.
The American National Standards Institute (ANSI) promulgated industry safety criteria for arborists in ANSI standard Z113. According to ANSI Z133, all controlled feed chippers are required to have a control bar (similar to the feed system control bar 70 shown in
Because the feed system control bar 70 is used repeatedly, it can possibly become damaged or misaligned, which can affect the operation of the control bar 70. Relying on a single mechanism that may not operate effectively increases the risk that an operator or others may not be able to stop the feed wheel system 24 quickly, or at all, in case of an emergency. As shown in
Conventional wood chippers may include safety mechanisms that rely on electronic sensors or other electrical components that may require frequent adjustment to operate properly and/or may be prone to failure. In an embodiment of the present invention, the safety device 34 has the advantage of operating by utilizing a simple mechanical mechanism that does not involve electronic components. For example, the safety device 34 can act as a “lockout” mechanism by pulling, or otherwise moving, a pin to stop the flow of hydraulic fluid and thereby effectively prevent the wood shipper 10 engine from powering the feed wheel system 24 and cutting blade 26 until the pin is reset. As a result, the safety device 34 provides a quick, simple, active, and reliable mechanism to instantly stop the feed wheel system 24. Thus, the safety device 34 advantageously provides a means for reducing accidents during operation of the wood chipper 10.
In some embodiments of the present invention, the configuration and orientation of the safety device 34 can vary. As shown in
In another embodiment, the safety device 34 can include a single elongated structure, for example, the first elongated structure 36, which can operate as described herein. In yet another embodiment, the safety device 34 can include three or more elongated structures, or bars, similar to the first and second elongated structures 36, 42. In such an embodiment, a third elongated structure 69 (as shown by the phantom lines in
The safety device 34 can be configured and positioned to reduce false activation by feed material entering the infeed chute 20 accidentally coming into contact with the device 34. Preferably, the safety device 34 is made of durable components to reduce damage from possible contact with feed materials, such as brush.
The safety device 34 can have a color distinct from other parts of the wood chipper 10, including the feed system control bar 70, to differentiate it from wood chipper 10 and the feed system control bar 70, thereby facilitating quick access and operation of the safety device 34. In one embodiment, the safety device 34 can be distinctly colored using a powder coating to increase the longevity of the distinct color on the safety device 34.
Although the present invention has been described with reference to preferred embodiments, other embodiments may achieve the same or similar results. Variations in and modifications to the present invention will be apparent to those skilled in the art. For example, the wood chipper 10 may include any suitable controlled feed or waste reducing machinery used to chip, grind, cut, or otherwise reduce bulk products. While the preferred embodiments incorporate opposed, horizontally-aligned feed wheels 32, any feed system 24 may be incorporated into the present invention, including a single feed wheel or opposed, vertically-aligned feed wheels. Additionally, while the preferred embodiments incorporate hydraulic systems, the wood chipper 10 and its feed and cutting systems may be powered by any other suitable means including, but not limited to, electricity, gas, or diesel power. The following claims are intended to cover all such equivalents.
This application is a Continuation-in-Part application of, and claims the benefit of, co-pending U.S. patent application Ser. No. 09/821,904, filed on Mar. 30, 2001, which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 09821904 | Mar 2001 | US |
| Child | 11496318 | Jul 2006 | US |
