Tool driving or impacting – With work engaging means supporting drive – Anchored to work
Reexamination Certificate
2000-02-10
2001-08-21
Smith, Scott A. (Department: 3721)
Tool driving or impacting
With work engaging means supporting drive
Anchored to work
C173S186000, C173S132000, C175S122000, C166S096100
Reexamination Certificate
active
06276464
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to horizontal directional drill machines. It relates particularly to the stakedown assembly for a horizontal directional drill machine.
BACKGROUND OF THE INVENTION
A horizontal directional drill machine is commonly employed for installing pipes beneath the ground and generally parallel to the surface. These machines are used in many different applications and are available in a wide range of sizes. Typical applications where a horizontal directional drill machine might be used include the installation of fiber optic cables, electrical cables, gas lines, water systems, or sewer systems. Horizontal directional drill machines are commonly rated in terms of pull-back capacity. Some machines for smaller applications have as little as five thousand pounds of pull-back capacity. Other machines are available with a pull-back capacity of as much as one million pounds.
One alternative to a horizontal directional drill machine is the traditional trencher machine. A trencher machine simply digs a trench into the ground, and after (for example) pipe is laid down in the bottom of the trench, the trench is filled and the pipe is buried. The advantage of a horizontal directional drill machine over a trenching machine is that a pipe can be buried in the ground over long distances without digging a trench. Thus, a horizontal directional drill is particularly desirable when a trench would be difficult or too costly to dig. For example, a horizontal directional drill machine finds particularly advantageous application for installing pipes under roadways, where destruction of the road is expensive and inconvenient to travelers, or under a waterway like a river, where trenching would be impossible.
A unique aspect of a horizontal directional drill machine is the special drill head that is attached to the front end of a pipe to be laid. The drill head has an angled shape which allows the operator to change the direction of the pipe after it has entered the ground. Direction changes are achieved by stopping the pipe and drill head rotation and orienting the drill head at a desired angle. Then, by pushing on the drill pipe without rotating it, the drill head and attached pipe will veer in the desired direction. Thus, by effecting directional changes to pipe travel, a pipe might enter the ground at one angle, travel horizontally over a long distance, and exit the ground at another angle. This ability to change the direction of pipe travel also allows the operator to steer the pipe around underground obstacles like boulders.
In addition to pushing forces which must be applied to the pipe as it is inserted, it is often necessary to pull back on the pipe. This may be necessary when a direction change is not completely successful on the first attempt, or when an underground obstacle like a boulder is encountered. The machine then pulls the pipe and drill head back to permit a direction change.
The push and pull forces that a horizontal directional drill machine must apply to the drill pipe frequently exceed the weight of the machine itself. Therefore, a system is required to anchor the machine and resist these forces. The most common system for anchoring the drill machine comprises the use of stakes mounted on the machine body which are screwed into the ground. The stakes have flighting on their tips and are driven into the ground by applying simultaneous rotational and vertical driving forces to each stake. To drive and remove these stakes, a stakedown assembly is conventionally provided on the end of the drill machine where the drill head enters the ground.
A common stakedown assembly in the prior art includes a single drive head which is fixed in one position. This type of stakedown assembly provides a single location, predetermined by the manufacturer, at which a stake can be driven. Other stakedown assemblies, also in the prior art, have two drive heads so that two stakes can be installed into the ground for extra holding strength, or a single stake can be installed in either of the two available locations. Depending on the push-pull forces required and the texture of the ground material, however, a single stake may not be adequate to securely hold the machine in place. Several stakes may be required. The subsurface of the underlying ground may contain obstacles such as large rocks or previously buried pipes or lines which limit the locations where a stake may be installed. So, the two drive head assembly is frequently inadequate. Furthermore, the two drive head assembly is limited in the number of possible stake installation locations and suffers from the higher cost and added complexity associated with the use of dual components.
In a recently developed stakedown assembly, however, a single drive head can drive stakes into a variety of locations. This stakedown assembly is described and illustrated in Draney et al. U.S. patent application Ser. No. 09/495,136. This type of stakedown assembly reduces cost by requiring only a single drive head, but also provides added flexibility by allowing multiple stakes to be installed in varying locations. This added flexibility allows the stakes to be optimally placed to avoid underground obstacles and to gain maximum holding strength.
Because a variable position drive head assembly, as previously described, must be able to drive several different stakes, the stakes can not be rigidly attached to the drive shaft, but instead must be releasably connected to the drive shaft. It is therefore desirable to have a coupling that will allow quick and easy attachment and detachment of the stakes from the drive head.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new and improved releasable coupler for coupling stakes and the drive shaft of a stake assembly drive motor.
It is another object to provide a coupler which facilitates simple and rapid coupling and decoupling from the stake.
According to the invention, the coupler includes an upper coupler member and a lower coupler member. The upper coupler member includes a cylindrical fitting having a cylindrical attachment pocket formed upwardly into its lower end. A pin is installed transversely through the socket and extends.
The lower coupler member comprises a cylindrical fitting having an outer diameter which is slightly smaller than the inner diameter of the socket, so as to permit a sliding fit between the two members.
The lower coupler fitting has a transverse, vertical slot that extends through, and longitudinally downward, from the top of the member. It has two circumferential horizontal slots which each extend around a portion of the circumference of the lower fitting coupler. The vertical slot intersects the horizontal slots at about the midpoint of the fitting.
The lower coupler fitting is fastened to a stake. Its fitting is slidably received upwardly into the upper fitting until the pin in the upper coupler fitting is seated in the bottom of the vertical slot. Then, the upper fitting is rotated on its axis in its driving direction and the fittings are interlocked.
REFERENCES:
patent: 3834761 (1974-09-01), Ray et al.
patent: 4343370 (1982-08-01), Chatard et al.
patent: 4474488 (1984-10-01), Pinkerton et al.
patent: 4625804 (1986-12-01), Allen, Jr.
patent: 4986690 (1991-01-01), Cooksey
patent: 5168944 (1992-12-01), Andersson
patent: 5253961 (1993-10-01), Geissler
patent: 5542476 (1996-08-01), Hansen
patent: 5741084 (1998-04-01), Del Rio et al.
patent: 5901799 (1999-05-01), Koenig
patent: 6102135 (2000-08-01), Shaw
patent: 6126359 (2000-10-01), Dittrich et al.
patent: 6131674 (2000-10-01), Draney et al.
Draney Robert G.
Sassor Donald C.
Volden Jeffrey S.
Brinks Hofer Gilson & Lione
Case Corporation
Lione Richard G.
Smith Scott A.
LandOfFree
Stake coupler for a horizontal directional drill does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stake coupler for a horizontal directional drill, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stake coupler for a horizontal directional drill will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2477615