A manually portable drilling system for the purpose of drilling earth bore holes. The drilling system will accommodate a lightweight drill pipe for air or mud rotary drilling, auger, or with use of air hammer percussion tools. The drilling system includes a self-contained mast which is detachable from a support base table. The mast contains an internal traveling shuttle to which a power unit is attached. The shuttle is manually driven by a conventional two speed, reversible hand winch modified t...

Apparatus is herein disclosed for controlling the quality of image development produced by a xerographic developing apparatus. Circuit means are provided to periodically sample a reference voltage on an exposed xerographic plate prior to image development and to provide an output signal indicative of the sampled voltage. The output signal is then applied to an adjustable power supply which is operatively connected to the development electrode and the electrode potential regulated in response to ...

A sighting system for a grenade launcher carried by a shoulder-supported earm includes a front sight mounted on the launcher for elevational adjustment by means of a track disposed at a predetermined angle relative to the vertical axis thereof to compensate for grenade drift as the front sight is moved along the track for range adjustment. The rear sight is adjustable for windage correction and is pivotally mounted on the firearm so as to be swung thereagainst, out of the way, when not in use.

An elongate frame, preferably comprising a pair of structural channels secured together in mutually spaced, back-to-back, parallel relationship, has a trackway along a longitudinal face mounting a carriage for reciprocation. An elongate, hydraulic power cylinder unit is secured to and extends along one end portion of the frame and carries at its work stroke extension end tandem idler sheaves about which are looped respective ropes that extend to and from respective idler sheaves at opposite ends...

A cable cylinder particularly suited for use in a rock drill guiding and supporting structure comprises an elongated member having a cylindrical bore extending therethrough. A carriage on which a rock drill, for example, may be detachably mounted, is guidedly supported on the outside of the elongated member and connected by cables to a piston disposed within the bore, such cables extending around pulleys at each end of the elongated member. Hoses serve to supply air under pressure to the bore on...

A drilling machine comprising a tower formed of elongated members in which a drilling head assembly is slidably disposed for movement relative thereto by means of slide brackets. The brackets are slotted, and slidably receive dowels extending from the drilling head assembly to effect a loss of motion between the drilling head assembly and the brackets. Power-operated feed chains, in a manner well known, translate the slide brackets along the elongated members.

A device for driving a hose or cable reel along a feed beam of a drilling machine at half the speed of the drilling machine. The device comprises a slide guided by the feed beam in which a sprocket wheel is journalled in the slide and is rotated by engagement with the drive chain or similar drive means for the drilling machine to move back and forth in engagement with a stationary member on the feed beam at half the speed of the drilling machine.

Rock drilling apparatus wherein a motor and chuck assembly is mounted for slidable movement on a mast and elevated and lowered by a pair of endless chains, the endless chains passing through openings in stabilizer units slidably mounted on the mast for vertical movement and which rotatably and slidably brace the drill stem. The chains carry detents which are arranged so that when the endless chains are operated to elevate the motor and chuck, the stabilizers are also elevated in spaced relations...

A safety device for a drilling rig of the type wherein a drill-carrying cradle is caused to move upwardly or downwardly on a tower by a chain which traverses sprockets at opposite ends of the tower. Shock loads and vibration cause premature failures in the chain when withdrawing a drill string as the cradle is pulled upwardly on the tower. The present invention minimizes shock loads on the chain to minimize the possibility of a chain failure and, at the same time, prevents a fall of the cradle a...

A drilling device has a drilling mast and a movable drifter thereon with a drill rod stabilizing device for stabilizing drill rods in position during drilling. The stabilizer travels along the mast along with the drifter, and includes a locking arm that automatically opens and closes the stabilizer to allow passage of drill rods into an out of the drill line from storage, while supporting the drill rods during drilling. In a substantially vertical drilling position, the stabilizer is moved downw...