Penn Engineering & Manufacturing Corp.

Pem Management, Inc.

Kenneth A Swanstrom

William P McDonough

Harold D Ross

Edward P Yeh

Richard C Green

James R Dickert

John L Nickerson

Thomas G Oei

Glen J Pierson

A three-sided, progressively-formed threaded fastener is comprised of a plurality of planar longitudinal faces intersecting at comer areas. Shank tabs extend downward from the bottom of each of the faces at the base of the fastener. Threaded regions along the inside surface of the planar faces are coined indentations applied during the formation of the fastener. A plurality of wedge-shaped protrusions extend downward from the comer areas at the base of the fastener. The combination of shank tabs and wedge-shaped protrusions form a clinch profile along the bottom of the fastener so that it may can be affixed to a sheet of metal by clinch fit.

Progressively-formed clinch nut

A light-controlled safety switch for an automated press includes an optical transmitter and receiver affixed to the press frame just above the press ram that redirects the light beam from vertical to horizontal. A light beam is directed downward from the transmitter to a 45-degree reflective surface on the ram. A cross-hole, perpendicular to the centerline of the ram, and a second 45-degree opposite-facing reflector opposite to the first reflective surface returns the light beam to the receiver. Thus, an optical path is achieved from the transmitter to the first reflector, through the ram, to the second reflector and then back up to the receiver. The opposing 45-degree reflectors are preferably provided by a 45-degree dished collar with a light-reflective interfacing surface fitted about the ram. The collar, and thus the reflective surfaces, stroke up and down with the movement of the ram, but maintains the optical path from the transmitter to the receiver because the send and receive light paths are parallel to the linear motion of the ram. A light-blocking shutter is connected to the top of a slidable punch holder assembly that breaks the horizontal light beam through the ram centerline whenever the punch contacts an object. Thus, the present optical system replaces the hard-wired punch contact safety switch of the prior art and its external wiring, thereby providing many advantages.

Light-controlled safety switch for a punch press

An insert for plastic sections is manufactured from a flat strip of metal by high-speed progressive die-stamping, which forms the strip into a threaded female insert. The metal strip is first cut into a flat blank and then thread regions are impressed on the face of the strip, providing a thread pitch profile. During the stamping operation, the strip is folded to form a triangular hollow tube with sharp-edged protrusions extending radially outward from each corner of the triangle. An interlocking side tab and interlocking cutout secure the abutting longitudinal side edges of the strip and ensures axial alignment of the thread regions. As a result of the folding and stamping process, the thread regions lie along the interior wall of the tubular construction and define a thread pitch diameter, which will accept the screw threaded into the center of the insert.

Threaded insert with flange tabs

Lobed fastener

An insert for plastic sections is manufactured from a flat strip of metal by high-speed progressive die-stamping which forms the strip into a threaded female insert. The metal strip is first cut into a flat blank and then thread regions are impressed on the face of the strip, providing a thread pitch profile. During the stamping operation, the strip is folded to form a triangular hollow tube with sharp-edged protrusions extending radially outward from each corner of the triangle. A tab and interlocking cutout secure the abuting longitudinal side edges of the strip and ensures axial alignment of the thread regions. As a result of the folding and stamping process, the thread regions lie along the interior wall of the tubular construction and define a thread pitch diameter which will accept the screw threaded into the center of the insert. The resulting triangular insert is sized so that a diameter describing the outside corners of the insert is equal to or slightly larger than the diameter of the intended receiving hole, while the barbs extend to a greater diameter than the hole. A closure may be included at the bottom of the insert to provide surrounding material from entering the insert channel as the insert is installed.

Progressively-formed threaded insert

A two-tiered punch having an extending imprint head with impact surfaces is employed to deform the top threads of a clinch-type nut during installation to create a lock-type nut. As the deforming imprint is applied, a shoulder on the punch supplies the installation pressing force against the top face of the nut. As the imprint head moves downward into the material of the nut, portions of the top thread are deformed, being compressed axially downward. The size of the imprint head and the distance that the imprint head projects from the shoulder determines the depth of imprint deformation and, hence, the degree of thread deformation. The imprint head is centered on the nut thread and is configured in the shape of a polygon extending from the face of the punch. During deformation and installation, the nut is held in a center position with regard to the coining edges of the imprint head by a centering pin which extends from the end face of the punch. The distortion of the threads provides the desired prevailing torque against a thread-in bolt.

Clinch-type lock nut installation and formation process

A panel fastener includes a smooth-surface cylindrical shroud encompassing the periphery of the screw head. The shroud is freely rotatable about the shank of the screw and has sides extending down around the barrel which is affixed to a panel. The shroud is fitted to the screw by an internal flange which is yieldably held between the underside of the screw head and the end of a spring. The top edge of the protective shroud does not extend above the head of the screw. The components are dimensioned so that the sides of the shroud are held away from the top side of the panel when the screw is fully compressed. The fastener may be press-fit into a panel as an assembled unit by applying ram pressure to the top of the screw assembly and barrel.

Shrouded captive screw

An improved electrical connector panel standoff fastener includes a panel-mounted stud with an affixed cap nut which is captive within the cable end connector shell. The stud includes a knurled head which is pressed into the chassis panel from the inside out. The stud includes a knurled head sized so that excessive bulging of the panel cutout does not occur upon pressing the stud into the panel. The desired standoff height is maintained by an end wall within the cap nut which acts as a screw stop. Also, the stud may be internally threaded to receive a screw from the opposite side of the panel to fasten the connector receptacle to the panel. The invention may further include a locking device such as a plug inserted into the threads of the stud.

Electrical connector panel fastener

An electronic thread tapper includes a cam-operated feed mechanism which drives the tap carriage rigidly in the advance direction only. Separate force means are employed to move the carriage in the retract direction when the tap is being withdrawn from the work material. Spindle and feed motors operate separately, but are cycle-coordinated during a dwell period between tapping strokes. By measuring any position error developed between the spindle and feed positions, a fault condition, such as a worn tap, a workpiece material defect, or an obstruction in the machine can be sensitively detected.

Cam-actuated thread tapper

A point of operation safety device for hydraulic or pneumatic presses. The safety device is computer controlled and limits the movement of the punch by employing two sensing devices. These sensing devices include both position and contact sensors which are used as dual input variables to satisfy computer monitored operational condition limits which, if not met, shut down the operation of the machine to prevent accident or injury to the operator. Both sensing devices are located within the housing of the press and the ram assembly so that no additional structures are required which might obstruct the working area and thereby hinder the efficient use of the press. Because the components of this safety device are located within the body of the machinery and include complicated electronic control circuitry, it is impossible to defeat the safety mechanism by disconnecting any of the components.

Press having a programmable ram with sensing means

Low profile panel fastener

A stud with a threaded shank at one end and a flat head at the other end. Between the threaded shank and the flat head is a collar of smaller diameter than the head, but of larger diameter than the threaded shank. The collar has a knurled portion adjacent the head to secure the stud to a printed circuit board. At the juncture of the collar with the threaded shank, the collar forms a shoulder or seat upon which the heat sink and the semi-conductor case rest in spaced relation with the printed circuit board. A nut is then threaded onto the shank to secure the stud, the heat sink, the semi-conductor case and the printed circuit board to each other.

Stud for mounting and method of mounting heat sinks on printed circuit

A self-clinching stand-off to be embedded into thin sheeted material. The stand-off comprises a base produced on a 'screw machine' and an extension molded thereto. The extension is formed from a material which is softer than that of the base. Further, the extension may vary in length for a given base.

Growing community of inventors

Doylestown, PA, United States of America

Kenneth A Swanstrom