Moling apparatus
AssigneesAberdeen University, University of Bradford
InventorsAlbert Alexander Rodger, Gavin Stuart Littlejohn
Life of this patent
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Abstract
A moling apparatus comprises a housing having a head for penetrating ground, an anvil in the housing connected to the head, and a hammer in the housing and spaced therefrom by a spring. A vibrator unit is spaced from the hammer and arranged to transfer vibration to the housing and the hammer. In a first mode of the apparatus, vibration transmitted to the housing causes fluidization of the surrounding ground to allow progressive penetration of the apparatus. In a second mode, the braking effect of the ground on the head causes the hammer to move against the spring and impact the anvil thereby driving the head through the ground, the apparatus being operable at or between each mode.
Claims6
A moling apparatus comprising:
- a housing having a head for penetrating ground;
- an anvil disposed in the housing connected to the head;
- a hammer disposed in the housing and spaced from the anvil by resilient restraint means;
- and
- a vibrator unit spaced from the hammer and arranged to transfer vibration to the housing and the hammer,
- wherein the resilient restraint means and the space between the hammer and the anvil are so dimensioned that in operation in looser ground the hammer does not strike the anvil so that vibration transmitted to the housing causes fluidization of the surrounding ground and penetration of the apparatus,
- while in progressively harder ground the braking effect of the ground results in progressive compression of the resilient restraint means which is sufficient to allow the hammer to strike the anvil and drive the apparatus forwardly in a predominantly percussive mode.
Dependencies are inferred from the claim text.