Heavy duty adjustable prop with a ball-and-socket joint
AssigneeCharbonnages de France
InventorsGuy Blanpain, Pierre Grandfils
Life of this patent
Estimating the term…
Abstract
A ball joint for transmitting forces between the prop and the head-piece of a support unit has a spherical head received in the spherical internal surface of a dome. The dome is enclosed by a spherical ring which is fastened to the head. The rod of a prop carries a pivot which is mounted with radial clearance in a cylindrical cavity located within the sphericl head.
Claims9
A ball joint for transmitting supporting and tractive forces between a prop and a head-piece of a support unit, the ball joint comprising a support element arranged to be carried by a prop and having a spherical head, and a cooperating element arranged to be fastened to a head-piece, the cooperating element being in the form of a skirt-shaped dome and having an internal spherical concave surface extending over a hemisphere at maximum and an external spherical convex surface concentric to said internal surface, the internal surface of the dome having a shape which corresponds to that of the head and cooperating with said head, the support element having a support surface spaced from the head and having a spherical shape corresponding to that of the head, said dome being received in the space between the support surface and the head and the support surface surrounding and bearing against the external surface of the dome, wherein the support element has a cylindrical cavity located within the spherical head and a pivot is mounted with radial clearance within the cylindrical cavity, the pivot being arranged to be carried by the prop.
A prop unit comprising a prop having a body and a rod slidably received within the body, and a ball joint arranged to transmit supporting and tractive forces between the prop and a head-piece of a support unit, wherein the ball joint comprises a support element carried by the prop and having a spherical head, and a cooperating element arranged to be fastened to a head-piece, the cooperating element being in the form of a skirt-shaped dome and having an internal spherical concave surface extending over a hemisphere at maximum and an external spherical convex surface concentric to said internal surface, the internal surface of the dome having a shape which corresponds to that of the head and cooperating with said head, the support element having a support surface spaced from the head and having a spherical shape corresponding to that of the head, said dome being received in the space between the support surface and the head and the support surface surrounding and bearing against the external surface of the dome, and wherein the support element has a cylindrical cavity located within the spherical head and the rod of the prop carries a pivot which is mounted with radial clearance within the cylindrical cavity.
Dependencies are inferred from the claim text.