US 4,472,002 AGranted

Retractable bit guide for a drilling and bolting slide

AssigneeEimco-Secoma Societe Anonyme

InventorsGilbert Beney, Michel Combet

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Abstract

The body of a bit guide assembly is mounted on a base which pivots on a frame about a first pivot point and may thus be retracted in order to allow the passage of the anchoring bolt screwed after drilling a hole. A double-acting jack has its rod pivoted on the base, whereas its body is pivoted on a dog, in turn mounted to pivot on the frame about a second pivot opposite the pivot point. The dog comprises a locking tooth which cooperates with the end of the base remote from the first pivot point. The free end of the dog cooperates with a retaining tooth formed on a connecting-rod, mounted to pivot about a fixed pin and biased by a spring against a stop. The same jack thus controls the retraction of the bit guide, for bolting and its locking in the lowered position, for drilling.

Claims10

Dependent claims

A bit guide assembly for a drilling and bolting machine adapted to guide a drill bit in an operative position and adapted to clear a bolt in a retracted position, said assembly comprising:

a support;
a guide body pivotally mounted on said support for swinging displacement between an operative position within an opening formed in said body traversed by a drill bit and a retracted position wherein said body is out of the path of a bolt;
a locking pawl pivotally mounted on said support for swinging movement into and out of engagement with said body for locking said body in its operative position and for clearing said body to enable same to swing into its retracted position;
a double acting jack on said support pivotally connected at one of its ends to said body and at the other of said ends with said pawl whereby hydraulic actuation of said jack displaces a pawl to release said body and swing said body into said retracted position;
and
a spring loaded keeper on said support engageable with said pawl for retaining same in a position of said pawl whereby it clears said body to enable return of said body into its operative position before said pawl is displaced to lock said body in said operative position.

3 more elements

Dependencies are inferred from the claim text.