Title:
Aerial boom bucket safety support bracket
Kind Code:
A1


Abstract:
A bucket tether system is described. The bucket tether system has a bucket for holding cargo and a boom for moving the bucket to a position for use. The cargo may include, for example, an individual along with the tools and material needed to perform the work. A support pin pivotally supports the bucket to the boom. A bucket actuator has a bucket end portion coupled to the bucket and a boom end portion coupled to the boom. The bucket actuator rotates the bucket and the support pin. A tether couples the boom end portion of the bucket actuator to the boom. An unintended force applied to the bucket may cause the coupling between the boom and the boom end portion of the bucket actuator to fail but avoid the failure of the coupling between the boom end portion of the bucket actuator and the boom via the tether bracket.



Inventors:
Dunican, Michael (Londonderry, NH, US)
Application Number:
11/484966
Publication Date:
01/17/2008
Filing Date:
07/12/2006
Assignee:
MFD Manufacturing, Inc. (Hooksett, NH, US)
Primary Class:
International Classes:
E04G3/00
View Patent Images:
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Primary Examiner:
CHIN-SHUE, ALVIN CONSTANTINE
Attorney, Agent or Firm:
BOURQUE & ASSOCIATES (MANCHESTER, NH, US)
Claims:
The invention claimed is:

1. A bucket tether system comprising: a bucket for holding cargo; a boom for moving the bucket to a position for use; a support pin for pivotally supporting the bucket to the boom; a bucket actuator with a bucket end portion coupled to the bucket and a boom end portion coupled to the boom wherein the bucket actuator rotates the bucket about the support pin; and a tether coupled to the boom end portion of the bucket actuator and the boom.

2. The bucket tether system of claim 1, wherein an excessive force applied to the bucket will cause the coupling between the boom and the boom end portion of the bucket actuator to fail and avoid failure of the coupling between the boom end portion of the bucket actuator and the boom via the tether.

3. The bucket tether system of claim 1, wherein the bucket end portion of the bucket actuator is coupled via a bucket actuator pin with a first end of the actuator pin coupled to the boom and a second end of the actuator pin coupled to the tether.

4. The bucket tether system of claim 1, wherein the tether is a metal plate.

5. The bucket tether system of claim 1, wherein the tether is 3/16 inch thick 304 stainless steel.

6. The bucket tether system of claim 1, wherein the tether is an angled bracket providing two lateral offset surfaces.

7. The bucket tether system of claim 6, wherein the tether has an additional support plate coupling the two lateral offset surfaces.

8. The bucket tether system of claim 1, wherein the tether has one or more bolts coupling the tether to the boom and one or more bolts coupling the tether to the bucket actuator.

9. A bucket tether bracket system comprising: a bucket for holding cargo; a boom for moving the bucket to a position for use; a support pin for pivotally supporting the bucket to the boom; a bucket actuator with a bucket end portion coupled to the bucket and a boom end portion coupled to the boom wherein the bucket actuator rotates the bucket and the support pin; and a tether bracket coupled to the boom end portion of the bucket actuator and the boom.

10. The bucket tether bracket system of claim 9, wherein an unintended force applied to the bucket causes the coupling between the boom and the boom end portion of the bucket actuator to fail and avoids failure of the coupling between the boom end portion of the bucket actuator and the boom via the tether bracket.

11. The bucket tether bracket system of claim 9, wherein the boom end portion of the bucket actuator is coupled via a bucket actuator pin with a first end of the actuator pin coupled to the boom and a second end of the actuator pin coupled to the tether bracket.

12. The bucket tether bracket system of claim 9, wherein the tether bracket is a metal plate.

13. The bucket tether bracket system of claim 9, wherein the tether bracket is 3/16 inch thick 304 stainless steel

14. The bucket tether bracket system of claim 9, wherein the tether bracket is angled providing two lateral offset surfaces.

15. The bucket tether bracket system of claim 14, wherein the tether bracket has an additional support plate coupling the two lateral offset surfaces.

16. The bucket tether bracket system of claim 9, wherein the tether bracket has one or more bolts coupling the tether bracket to the boom and one or more bolts coupling the tether bracket to the bucket actuator.

17. A container tether bracket system comprising: a container for holding a person; a boom for moving the container to a position for use; a support pin for pivotally supporting the container to the boom; a container actuator with a container end portion coupled to the container and a boom end portion coupled to the boom via an actuator pin wherein the container actuator rotates the container and the support pin; and a tether bracket coupled to the actuator pin and the boom.

18. The container tether bracket system of claim 17, wherein an unintended force applied to the container causes the coupling between the boom and the boom end portion of the container actuator to fail and avoid failure of the coupling between the boom end portion of the container actuator and the boom via the tether bracket.

19. The container tether bracket system of claim 17, wherein the container end portion of the container actuator is coupled via a container actuator pin with a first end of the actuator pin coupled to the boom and a second end of the actuator pin coupled to the tether bracket.

20. The container tether bracket system of claim 17, wherein the tether bracket is angled providing two lateral offset surfaces.

Description:

TECHNICAL FIELD

The present invention relates to aerial equipment and more particularly, relates to a safety bracket for buckets attached to the end of an aerial boom.

BACKGROUND INFORMATION

Many aerial lifts, cranes, or lifts have a boom portion coupled to a bucket. The bucket is used to hold cargo and move cargo to a location at which work is performed. The cargo may include, for example, an individual along with the tools and material needed to perform the work. The boom portion often uses hydraulic actuators to raise and lower the bucket located at the end of the boom. Typically, the work site is located at an elevated distance from the ground. The boom is used to raise the bucket from a location near the ground to an elevated position, for example, at the top of a utility pole or an elevated, exterior surface of a building.

The bucket may have boom controls to allow the individual within the bucket to maneuver the bucket to an appropriate location that allows the individual or user to access the work piece. The boom control may allow the user to raise and lower the boom along with controlling the angle of the bucket relative to the boom.

When an individual is performing work they may be focused on the task at-hand and may not be aware of objects around them and in the path of the bucket or boom. The user may accidentally hit an object while attempting to position the bucket. In another scenario, the user may improperly use the bucket to lift or push objects producing unintended forces on the bucket and boom. These unintended and accidental forces may cause the linkage between a bucket actuator and boom to snap and catastrophically fail. This break may result in the bucket swinging freely on the pivot pin of the bucket. If the majority of the weight is located above the pivot point, the freely swinging bucket may tip over, dumping the cargo. This may have fatal consequences for an individual in the bucket.

Accordingly, there is a need for an inexpensive device that may be installed efficiently and prevent the bucket actuator from becoming disconnected and allowing the bucket to swing freely.

SUMMARY

A bucket tether system is described. A support pin pivotally supports a bucket to a boom. A bucket actuator couples the bucket to the boom. The bucket actuator rotates the bucket on the support pin. A tether couples a boom-end portion of the bucket actuator to the boom. An unintended force applied to the bucket may cause the coupling between the boom and the boom-end portion of the bucket actuator to fail, but will avoid total separation of the coupling between the boom-end portion and the boom via the tether bracket.

Implementations may include one or more of other features. In one embodiment, the bucket end portion of the bucket actuator may be coupled via a bucket actuator pin with a first end of the actuator pin coupled to the boom and a second end of the actuator pin coupled to the tether. The tether may be a metal plate, for example, 3/16 inch thick 304 stainless steel. In another embodiment, the tether may be an angled bracket providing two lateral offset surfaces. An additional support plate may be used to couple the two lateral offset surfaces. The tether has one or more bolts coupling the tether to the boom and one or more bolts coupling the tether to the bucket actuator.

The general and specific aspects may be implemented using a system and device described herein. The system and device provides an inexpensive tether that may allow the connection of the bucket actuator to break free without the tether breaking and releasing control of the bucket swing. The system and device may allow quick and easy retrofitting of existing booms and buckets.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein:

FIG. 1 is a perspective view of a lift used to implement embodiments of the invention.

FIG. 2 is a perspective view of a boom and bucket illustrating a tether embodiment of the invention.

FIG. 3A is a top plane view of an exemplary tether bracket, according to an exemplary embodiment of the invention.

FIG. 3B is a profile view of the exemplary tether bracket, according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION

The invention provides a tether that prevents a bucket 102 from freely rotating when the connection between the boom 104 and bucket actuator has become broken. The bucket 102 and boom 104 may be coupled to a vehicle 106 to allow the transportation of the bucket 102 and boom 104 to worksites. The vehicle may be, for example, a truck or a trailer. In the example shown in FIG. 1, the bucket 102 and boom 104 are coupled to the frame or other structural support point of a truck. The boom 104 may have a first boom arm 108 and a second boom arm 109 with a first cylinder actuator 107 and a second cylinder actuator 110. The cylinder actuators 107, 110 may be hydraulic pistons that use hydraulic pressure to raise the boom 104 into an elevated position. As the boom 104 extends into an elevated position, the bucket 102 may need to rotate to maintain a level position.

The bucket 102 is coupled to the boom 104 by a pivot pin 202, as shown in FIG. 2. The pivot pin 202 allows the bucket 102 to rotate about the boom 104. A bucket actuator 204 also couples the bucket 102 to the boom 104 to control the rotation of the bucket 102 and the pivot pin 202 of the boom 104. The actuators 107, 110, 204 may be maneuvered by a controller (not shown) by the user located in the bucket 102 or by a user located on the ground. The controller allows the user to position the bucket proximate to the worksite. The bucket actuator 204 may be used to rotate the bucket 102 to maintain a level position as the boom 104 raises the bucket 102, as well as allowing the user to better position themselves relative to the work piece. The controller may incorporate features that allow the actuators to work in sequence, maintaining the bucket's level position, or independently controlled allowing the user to individually control each actuator.

The pivot pin 202 may be designed to support the weight of the bucket 102 and cargo and allow the bucket 102 to rotate on the pivot pin 202. The bucket actuator 204 may be designed to rotate the weight of the bucket 102 and the cargo of the bucket. The bucket actuator 202 may have a bucket end portion 206 coupled to a frame portion 208 of the bucket 102. A boom end portion 210 of the bucket actuator 202 may be coupled to the boom 104 via an actuator pin 212. Since the actuator pin 212 is set slightly offset from the pivot pin 202, as the bucket actuator 204 extends, the bucket 102 rotates the pivot pin 202. The bucket actuator 204 also rotates about the actuator pin 212. The actuator pin 212 may be coupled to the boom 104 by a cast metal actuator pin coupling 214 that may allow the actuator pin 212 to rotate within the actuator pin coupling. A tether 216 also couples the other end of the actuator pin 212 to the boom.

The tether 216 may be designed to maintain a coupling to the actuator pin 212 and the boom 104 in the event that the bucket actuator 204 breaks apart from the pin coupling 214. The tether 216 may be coupled to the boom at one end and coupled to the actuator pin 212 at the other end. A variety of fasteners and coupling methods may be used to couple the tether 216, for example, but not limited to, bolts, welds, epoxies, or other coupling devices. The tether 216 is not limited to a coupling to the actuator pin 212. In another embodiment, the tether may pivotally couple directly to the bucket actuator 204 or other component of the bucket 102.

When the user accidentally hits an object while attempting to position the bucket 102 or improperly uses the bucket to lift or push objects, this may produce unintended forces on the bucket 102 and boom 104. These unintended and accidental forces may result in stresses on the coupling between the bucket actuator 204 and the boom 104. This stress may result in the pin coupling 214 or actuator pin 212 breaking. The tether 216 maintains the coupling between the boom 104 and the bucket 102, thus preventing the bucket 102 from freely rotating about the boom 104. The tether 216 may allow for deformation to reduce initial stress after breaking of the pin coupling. Although the tether 216 may deform, the connection is maintained allowing the user to be safely rescued and the equipment repaired without additional destruction to life and cargo.

According to an exemplary tether bracket embodiment, the tether 210 may be a metal plate that couples the boom 104 to the actuator pin 212, as shown in FIGS. 3A and 3B. The tether bracket 300 may be made of steel or other suitable material. The tether bracket 300 may be made of, for example, one-quarter inch thick 1008 steel or three-sixteenths inch thick 304 stainless steel. The tether bracket 300 may have an ultimate tensile strength of about 75,000 psi.

The sheet of material may be bent or formed to provide two offset parallel surfaces. A first portion 302 provides a first surface that may be coupled to the boom 104. Two holes 304 may be provided to couple the first portion 302 to a side surface of the boom 104. A second portion 306 provides a surface of the tether bracket 300 that may be coupled to the actuator pin 212. An actuator pin hole 308 may be provided to fasten a bolt to the actuator pin 212. The tether bracket 300 may be placed against the boom 104 and the actuator pin 212 and bolted into position. An additional support plate 310 may be provided to the tether bracket 300 to provide additional support between the first portion 302 and second portion 306. The support plate 310 may be welded into place at the two opposing ends of the support plate.

The shape and size of the tether bracket 300 may be designed based on the size and shape of the bucket 102 and the boom 104. Exemplary dimensions of the tether bracket 300 are shown in inches in FIGS. 3A and 3B, however, the invention may comprise a variety of dimensions and shapes depending on, for example, the equipment, location of coupling the tether bracket 300 or material used to construct the tether bracket 300.

Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims.