Dresser Industries, Inc.

Indresco Inc.

Richard E Eckman

Robert A Pennison

Robert F Golwas

Emory G Goldsberry

A pneumatic air feed peck drill adapted to drill in repetitive cycles including a rapid advance phase, a slower drilling phase, and a rapid retract phase. The rapid advance phase ends and the drilling phase begins at a set back position, an adjustable distance from the workpiece, to minimize a drill bit and workpiece damage. The drill includes a drill motor and feed cylinder powered by air to rotate and advance and retract the drill motor. The drill motor and feed cylinder is coupled with an air and mechanical control system including a hydraulic feed control unit having a piston rod coupled with the drill motor to dampen the advance of the drill motor during the drilling phase and to release for rapid retract and advance phases. A brake is mounted for control of the feed control unit piston rod to releasably engage the piston rod during the retract phase to limit the movement of the rod to an adjustable set back distance controlled by a set back nut limiting the distance the brake may move relative to the feed control unit when the brake engages the piston rod. A pneumatic system including a volume chamber is coupled with the air system to control the peck cycle rate. One embodiment of the drill includes an auxiliary thrust and retract piston assembly while another embodiment has only the primary drill motor and feed cylinder.

Air feed peck drill

A pneumatic air feed peck drill adapted to drill in repetitive cycles including a rapid advance phase, a slower drilling phase, and a rapid retract phase. The rapid advance phase ends and the drilling phase begins at a set back position, an adjustable distance from the workpiece, to minimize a drill bit and workpiece damage. The drill includes a drill motor and feed cylinder powered by air to rotate and advance and retract the drill motor. The drill motor and feed cylinder is coupled with an air and mechanical control system including a hydraulic feed control unit having a piston rod coupled with the drill motor to dampen the advance of the drill motor during the drilling phase and to release for rapid retract and advance phases. A brake is mounted for control of the feed control unit piston rod to releasably engage the piston rod during the retract phase to limit the movement of the rod to an adjustable set back distance controlled by a set back nut limiting the distance the brake may move relative to the feed control unit when the brake engages the piston rod. A pneumatic system including a volume chamber is coupled with the air system to control the peck cycle rate. One embodiment of the drill includes an auxiliary thrust and retract piston assembly while another embodiment has only the primary drill motor and feed cylinder. A further embodiment includes an interrupt valve in the pneumatic system to disable the drill when a safety shield is removed. The safety shield may be transparent plastic with incremental markings to aid in making adjustments.

Air feed peck drill with pneumatic safety system

A mechanical pecking method and device is provided wherein a spindle adapted to hold a tool such as a drill bit is mechanically reciprocated in a workpiece. Also provided is a control system and method for controlling the mechanical reciprocation of the spindle and a sensor for remembering the last point of advancement of the spindle during each peck cycle.

Mechanical peck drill and method

Mechanical peck drill

An improved automatic feed drill including a housing, a rotatable tool spindle located for reciprocating movement in the housing, driving means located in the housing operably connected with the spindle for rotating and reciprocating the spindle in feed and retraction movements, and structure for supporting the spindle including a nose assembly secured with the housing around the drilling end of the spindle having a telescoping section with a bore concentric with the spindle, and a bearing on the spindle drilling end fitted in sliding relation in the nose bore for piloting the spindle and a drill connected thereto during reciprocating movement of the spindle. A right angle form of the feed drill further include drive threads on the spindle having a flat crest, and a closely fitting bushing in the head of the drill around the upper end of the spindle, the bushing having a concentric bore fitting in close piloting relation with the drive thread crest for holding the upper end portion of the spindle against lateral movement as the spindle reciprocates.

Mechanical positive feed drill with supported spindle

A positive feed drill and method of operation is disclosed for drilling through a workpiece consisting of a softer overlay material on a harder base material. The positive feed drill includes a high-speed air motor and a low-speed air motor and will start and drill through the softer overlay material at the high speed but will shift to the low speed when the drill senses that the thrust on the drill bit has increased because the drill bit has contacted the harder base material. After drilling through the harder base material, the drill bit will shift to the high speed because the drill senses that the thrust on the drill bit has decreased. The drill will retract from the workpiece at high speed and will shut off. Control apparatus is provided to control the flow of air to the high-speed and low-speed air motors. Sensing apparatus senses the thrust on the drill bit and sends a signal to the control apparatus to switch between the air motors. Apparatus is included to sense the end-of-feed position, retract the spindle and shut the drill off.

Thrust-responsive two-speed drill and method of operation

A positive feed drill assembly having an air powered motor and an automatic drill feed and retract mechanism with a normal feed, drill, and retract sequence of operation is provided with an improvement to control the number of times the drill can be used to make a hole with a particular cutter. The improvement includes an apparatus associated with the automatic feed and retract mechanism for sensing the cycle of each drilling operation. A counter functioning with the sensing apparatus counts the number of drilling operations. A comparator associated with the counter compares the accumulated number of drilling operations with a predetermined number. A signaling apparatus connected with the counter provides a signal to the operator when the drill assembly has performed the maximum number of drilling operations for that cutter so the operator can replace the cutter before using the drill assembly again.

Positive feed drill use counter

A power drill and automatic control system includes a drill spindle for mounting a rotary cutter, a spindle rotation drive including a drive motor and an associated rotation drive mechanism operably connected to the spindle to rotate it; a spindle feed drive includes a feed motor and an associated feed drive mechanism operably connected to the spindle to feed it in a forward direction toward a workpiece and in a reverse direction retracting it away from the workpiece. Control is provided to start and stop the spindle rotation drive motor and the spindle feed motor independently. Control is provided for the spindle rotation drive to vary the rotational speed. Control is provided with the spindle feed drive to vary the rate of feed of the spindle. A sensor with the spindle rotation drive senses operational torque of the spindle. Another sensor with the spindle feed drive senses thrust force on the spindle and the associated cutter. A rotation sensor with the spindle rotation drive senses and monitors the spindle rotation. Another rotation sensor with the spindle feed drive senses and monitors the spindle feed drive rotation. A control circuit is operably connected to control rotational speed of the spindle, the rate of feed motion of the spindle toward and retracting from a workpiece, to control the displacement of the spindle to a predetermined depth and to control removal of the cutter from the workpiece on completion of the drilling operation.

Power drill and automatic control system therefore

The automatic feed drill includes a spindle mounted therein for rotating in reciprocating movement. The spindle is rotated by spindle rotation gear that is engaged with the main drive gear which is ultimately driven by an air motor or the like. The feed and retraction movement (reciprocation) is caused by a spindle feed gear that is threaded onto the spindle. The spindle feed gear is engaged with a feed gear which, during feed movement, is driven by the main drive gear, and during retraction movement, is shifted into a position wherein the feed gear is prevented from rotating. The spindle also carries a collar or other abutment that engages a shift lever at the end of the feed movement. The shift lever is moved by the collar, and, due to its interconnection with the feed gear, moves the feed gear out of engagement with the main drive gear and into the position wherein it is prevented from rotating. The apparatus also includes a yieldable stop device that holds the feed gear stopped during retraction movement. In the event that excessive torque is encountered, such as by a lower collar on the spindle engaging the housing, the yieldable stop member rotates at the same speed as the spindle feed gear and thus, prevents further retraction of the spindle and avoids damage to the drill.

Retraction apparatus for automatic feed drills or the like

Power tool reaction brace

A power drive screwdriver that is constructed to automatically stop when a predetermined torque is reached. The screwdriver includes a housing having a pneumatically driven motor therein and an output shaft that is linked to the screwdriver bit through a releasable clutch. A control valve is positioned in the housing to control air flow to the motor. The position of the valve is controlled by a rod that extends through the shaft. A transverse slot extends through the shaft intersecting the bore therein and the transverse slot contains a pair of balls that are retained within the slot by a sleeve encircling the exterior of the shaft. Further, a reset member engages the screwdriver bit and also engages the balls to displace the balls in the slot in a direction to open the valve. When the predetermined torque is encountered, the sleeve moves upwardly, permitting the balls to separate and thereby letting the valve rod move to permit the valve to close.

Screwdriver

The tool housing-air motor assembly includes an air motor that is of modular design, that is, it is constructed so that the motor rotor is journaled in the cylinder by the end plates, which retain the motor in its operational alignment condition. The tool housing is used in the 'as cast' condition without the necessity for performing any machining operations thereon. The assembly of the air motor and tool housing is possible since the motor is self-contained and does not rely on the tool housing for retaining the parts of the motor in assembled relationship or for retaining the motor parts in operational alignment.

Pneumatic tools

The automatic feed drill includes a spindle mounted therein for rotating and reciprocating movement. The spindle is rotated by a spindle rotation gear that is engaged with the main drive gear which is ultimately driven by an air motor or the like. The feed and retraction movement (reciprocation) is caused by a spindle feed gear that is threaded onto the spindle. The spindle feed gear is engaged with a feed gear which, during normal feed movement, is driven by the main drive gear, and during retraction and rapid feed movement, is shifted into a position wherein the feed gear is prevented from rotating. During rapid feed the motor direction is reversed by a reversing valve. The apparatus also includes a yieldable stop device that holds the feed gear stopped during retraction and rapid feed movement. In the event that excessive torque is encountered, such as by a lower collar on the spindle engaging the housing or the drill bit encountering the work piece during rapid feed, the yieldable stop member rotates at the same speed as the spindle feed gear and thus, prevents further retraction or feeding of the spindle and avoids damage to the drill.

Growing community of inventors

Houston, TX, United States of America

Richard E Eckman