Abstract: A screw having a main thread (2) to be screwed in and a sub-thread (3) formed in the direction opposite to the main thread, which is characterized in that a slant surface (3b) of the sub-thread on the screw-loosening side has a sharp slope whereas that (3a) on the screw-tightening side has a gentler slope.When such a tapping screw as above is screwed into a pre-drilled hole (4) and the sub-thread (3) advances in the direction opposite to the screwing-in direction thereof while acting like a wedge because the slope of the slant surface (3a) on the screw-in side is gentler.When the screw is subject to torque in the screw-loosening direction after tightened, the torque acts on the sub-thread (3) in the tightening direction thereof and, because of the sharp slope of the slant surface (3b) on the screw-loosening side, the sub-thread resists the unscrewing of the screw as if eating into the surface of the pre-drilled hole and prevents the screw from loosening.

Abstract: Threaded nipple for joining two electrode sections is provided with an integral ridge intermediate its threads for centering the electrodes in coaxial alignment.

Abstract: A tamper proof draw band bolt apparatus and method including a bolt for extending through the apertures in the first and second lugs of a draw band, the bolt including a shaft having a first end and a second end, the shaft of the bolt having a threaded portion and a fettered portion with no angular pitch; a nut having a threaded aperture for screwably receiving the threaded portion of the shaft of the bolt and for allowing the bolt and the nut to coact with one another to draw the first and second lugs of the draw band toward one another; and a sleeve for crimping to the lettered portion of the shaft of the bolt after the first and second lugs of the draw band have been drawn together by the coaction between the bolt and the nut and for preventing undetected subsequent separation of the first and second lugs of the draw band.

Abstract: A self-tapping screw has a cutting thread formed by two separate threads (3, 4). An imaginary envelope (5) defines a annular space (5) laterally enclosing the screw shank and has a section (5a) tapering inwardly along an inwardly tapering leading end section (1a) of the shank (1). The inwardly tapering section of the annular enclosing space an envelope forms an angle (B) considerably larger than the angle (A) formed by the tapering leading end section (1a) of the shank. The leading ends (3a, 4a) of the separate threads (3, 4) are located diametrically opposite one another for uniform distribution of the forces developed when the screw penetrates into a hard receiving material, such as concrete, masonry, gas concrete and the like.

Abstract: The present invention discloses a fastener for a trailer bed. The trailer bed is constructed of wooden planks placed on a metal frame. The screw has twin threads with a helix angle of substantially 10.degree. to a line perpendicular to the axis of the shank or the fastener, an included angle of substantially 60.degree., and a trilobular point which allows the screw to be drilled into wooden plank and swage threads in the wooden plank and metal frame. Torquing the threads forces the fastener into the metal frame and wooden planks and allows the screw head which is tapered to seat itself.

Abstract: A hand tool which comprises a fixed handle with a fixed jaw on the front portion and a movable jaw pivotally connected to the front portion of the fixed handle. A movable handle is connected to the movable jaw. An adjusting mechanism is provided for adjusting the position of the movable jaw relative to the fixed jaw and consists of a threaded opening in the rear of the fixed handle and a screw member received within the opening. The screw member has a plurality of multiple first individual threads with the same diameter and pitch that mate with the threaded opening in the fixed handle.

Abstract: A fastener which releasably retains a first member in relation to a second member. The fastener is frangible for fracture upon the application of a tensioning force thereto permitting the first and second members to which the fastener is engaged to be displaced relative to one another. The fastener, once fractured, is retained in the corresponding first and second members to which it was originally attached to prevent the generation of loose pieces. An installation tool is also provided for installing the fastener into the first and second members. The fastener includes a shank which fractures into a first and a second segment. A frangible portion of the fastener is spaced along the shank between the first and second segments and defines such segments for providing a predetermined fracture point. Non-planar engaging portions on the first and second segments retain the fastener in the corresponding first and second members once engaged therewith even after fracture of the fastener.

Abstract: A fastener for securing fixtures to concrete or masonry. The fastener includes a dual-thread first stage for engaging a bore in the concrete and stabilizing and centering the fastener as it taps its way into the bore. A single-thread second stage has a pitch larger than the threads of the first stage for receiving particulate cut from the bore so that the particulate will not interfere with driving the fastener completely into the bore.

Abstract: The invention herein is a roofing fastening device, with an optional liquid sealer to facilitate the process of affixing rectangularly-shaped sheets or rubber roofing material to the upper surface of a roof. Specifically, the invention is a longitudinally disposed fastening member in the general form of a screw or like member which is adapted to be inserted through the upper surface of the rubber roofing sheets and thence through the upper surface of the roof structure, serving thereby to anchor the rubber roofing sheets to the fixed roof structure. The fastening device has a longitudinally extending centrally located chamber which is coaxially aligned with the longitudinal central axis of the fastening member, and this chamber has a plurality of laterally disposed openings which extend from the chamber to the outer surface of the fastening member, said chamber being adapted to receive a liquid sealant at an opening in the upper surface and disperse same through such lateral openings.

Abstract: A stamping press (22, 22') includes an transfer mechanism (24, 24') for moving workpieces through progressive die stations. Two embodiments of a support structure (26, 26') are disclosed for supporting the transfer mechanism (24, 24') adjacent the press (22, 22'). Both embodiments of the support structure (26, 26') include a first screw shaft (34, 34') and a second screw shaft (38, 38') which fasten the transfer mechanism (24, 24') to the press (22, 22') in an operative position. The first screw shaft (34, 34') includes a first locking screw (40, 40') and the second screw shaft (38, 38') includes a second locking screw (54, 54') for retaining the respective first (34, 34') and second (38, 38') screw shaft in an unfastened condition to allow movement of the transfer mechanism (24, 24') from the operative position.

Abstract: A screw for fixation of a tendon/bone graft during an arthroscopic surgical procedure includes a smooth conical forward end having a rounded tip and a spiral thread running from a position behind the smooth rounded forward end to a rearward end of the screw. The depth of the thread is shallower than a conventional screw and the exterior edge of the thread is rounded to decrease cutting and fragmentation of the tendon and bone. The screw includes an internal bore with left- and right-handed threaded portions for engagement with insertion and extraction instruments. In the method, the bone graft is harvested and sized as desired. A graft socket is drilled in the bone and then serially sized with increasingly larger sizing instruments to compact the bone and size the graft socket to the graft. A smooth bore screw socket is created by serially dilating a space between the graft and graft socket with increasingly larger dilating instruments, thereby also compacting the graft.

Abstract: An article retention arrangement utilizing a drive-in expansion fastener having a generally cylindrical, hollow body with a tapered end formed from an angular truncation of the body. The body is reinforced by one longitudinal rib so as to permit drive-in penetration from the tapered end even if the fastener is formed from plastic materials. The fastener is retained within the wall by at least one pair of hinged flanges which expand circumferentially in response to the installation of an insertion element within the hollow portion of the body. The insertion element engages an inclined surface within the body to cam the expansion flanges circumferentially outward. The expansion flanges engage the back surface of the wall while the longitudinally slit portion of the body expands within the hole created by drive-in penetration. The insertion element preferably includes an enlarged head projecting from the fastener when the insertion element is fully installed within the fastener.

Abstract: A masonry screw anchor having two different constant diameter shank portions connected via a taper. Each portion has a set of constant diameter threads and intermediate smaller diameter protrusions with the threads and protrusions on the larger diameter shank portion being larger in diameter than the diameter of the threads and protrusions on the smaller diameter portion.

Abstract: A tie bolt comprises a shank provided thereon with equally pitched screw-threaded portions (16, 18) separated by a spacer portion (14) capable of sliding through a hole created by the leading screw-threaded portion (16) so as to permit rapid screw-engagement of the trailing screw-threaded portion with said hole, characterized in that said threaded portions are provided by separate components (16, 18) arranged at a predetermined distance apart.

Abstract: Boring apparatus includes a multiple start screw to secure a cutting piece to a boring bar. The multiple start screw prevents loosening of the cutting piece during use of the boring apparatus. The multiple start screw also enables easy changing of the cutting piece or repositioning of the cutting piece between periods of use of the apparatus.

Abstract: Improved terminal blocks having inserts comprising a spring-loaded stirrup for clamping electrical conductors, together with a screw for adjusting the clamping action of the stirrup and for releasably locking the stirrup in a fully open position to permit insertion of an electrical conductor, a mechanism for quickly and easily releasing the stirrup when the conductor is in a desired position, and an attachment member for releasably securing the block to a mounting rail.

Abstract: This invention relates to an improved captive screw and assembly, and particularly a screw which may be held loosely captive in the threaded hole of a support member. The invention comprises a machine screw or cold formed fastener with an unthreaded interrupted mid-section that separates two spaced-apart threaded portions of the fastener, with both threaded portions of the fastener preferably of a similar thread size, and with the unthreaded mid-section of the screw of a diameter less than the root diameter of the threaded sections. The screw may be completely removed or readily installed into threaded engagement with a female threaded hole in the support member, when necessary, by first manually aligning the fastener axis with the axis of the threaded hole, then rotating the fastener to engage the starting threads of the fastener with those of the female threaded hole, and further continued rotating of the fastener in a conventional manner. The fastener may clamp a panel member to the support member.

Abstract: A screw including a head and a shaft having a helically threaded portion and a barbed portion is provided. In operating the barbed portion driven into a hole by pressure on the head in the axial direction. When the barbed portion is completely driven into the hole, the threaded portion comes into contact with the wall of the hole for driving the screw slightly further into the hole in this manner tight engagement between the two members fastened by the screw can be achieved. The barbed portion is so formed as to prevent removal of the screw.

Abstract: Wood screw comprising a head for receiving a fastening tool and a shank extending from the head. The shank is provided at the tip thereof with a tip guide portion adapted to penetrate an article to be fastened while boring a hole into the article such as timber. The shank is provided at the head side thereof with a fastening screw portion having at least a single screw thread. A chips removing screw portion is disposed between the tip guide portion and the fastening screw portion. The chips removing screw portion has screw threads, the number of which is greater than that of the fastening screw portion. The screw thread lead angle of the chips removing screw portion is larger than that of the fastening screw portion.

Abstract: A plastic straddling or expansion plug having a closed plug neck and a closed plug foot both with a longitudinal aperture into which a screw can cut a thread. The plug includes a shank having a thin plug jacket on which a two-flight helix is integrally formed. In the region between the helices, the plug jacket is provided with longitudinal slits. On the outside of the helix, further ribs are provided which each extend over a 180.degree. arc and are integrally formed with the helix, alternating in orientation by a 90.degree. angle. The plug neck includes flange lugs oriented in the shape of a cross and adapted to be folded over.

Abstract: The screw is provided with a three-lobed thread crest, followed by a threaded portion with a three-lobed thread geometry, which passes into a threaded portion with a circular thread geometry. In all three threaded portions the flank angle of the thread is 60.degree. and the flank angle of the thread crests extending beyond the nominal diameter of the screw is 30.degree..

Abstract: A nut and bolt assembly includes a bolt having at least one external threaded portion and at least one adjacent unthreaded portion along its length and a nut having an internal threaded portion threadedly engageable with the threaded portion of the bolt, the unthreaded portion of the bolt having a diameter such that the nut can slide therealong in an axial direction without rotation and the axial length of the unthreaded portion being at least as great as the threaded portion of the nut, the arrangement being such that in a clamping position of the assembly the threaded portion of the nut wholly resides on the unthreaded bolt portion with one end of the nut threads abutting one end of the threads of the threaded bolt portion.

Abstract: A self-tapping screw (1) for use in fixing insulating boards (4) and waterproof sheeting (3, 3'), to a flat roof sheet panel (2), has a screw head (6), a self-drilling tip (10) and a screw shank which has a self-tapping thread (9) adjoining the self-drilling tip (10) and divided into sections (9/2, 9/3) by at least one smooth shank section (8). A further smooth shank section (7) directly adjoins the screw head (6). The diameter of the smooth shank sections (7, 8) is smaller than the root diameter of the self-tapping thread (9), and the end (15) of each thread section nearest the screw head (6), extends radially inwardly to the screw-shank diameter in the form of a flat radial surface (16) which is free of a thread run-out and is perpendicular to the axis of the screw shank. The screw (1) provides greater reliability against being unintentionally slackened, released and pulled out of its anchorage hole under the typical stresses experienced by flat roofs.

Abstract: A self-locking screw has a longitudinal axis and comprises a thread having an inner radial portion and an outer radial portion, the inner radial portion having a pair of opposite first side faces defining a flank angle of the screw. The outer radial portion has a pair of opposite second side faces extending from the first side faces and first and second outer radial faces extending respectively from the pair of opposite second side faces. The thread has a central buffer groove having two groove side walls, the groove side walls along with the second side faces and the first and second outer radial faces defining two axial spaced elastically deformable thread portions which are elastically deformable such that as the thread is threaded onto a counterpart threaded member, the elastically deformable thread portions are engaged by the counterpart threaded member to cause elastic deformation as the thread portions axially approach one another and reduce the spacing between the thread portions.

Abstract: A sheet metal screw is disclosed having an enlargement in the form of a helical ramp on the shank adjacent the head, which ramp extends for only about 180 degrees for providing an interfering fit with a workpiece to obtain an anti-stripping action while permitting the screw to provide an effective clamping action.

Abstract: A self-cutting fast construction screw for the fastening of fiber plates to a metal substructure carries on the screw shaft at least one turn of a thread. The screw core passes into a conical drill point. On the conical drill point two cutting edges are arranged in a symmetrical layout, said cutting edges cutting to a diameter located between the diameter of the screw core and the diameter of the outer thread tip. Upon impact on the metal substructure, the two cutting edges break off.

Abstract: A fastener for use in securing wallboard such as drywall to a supporting structure includes a shank having a bugle head at one end and a tapered point at an opposite end, an annular ring flange and anti-clockwise threads disposed on the shank adjacent the head portion to auger and recompact particulate material which exhausts from the tapping threads during insertion of the fastener, and to tuck the outer sheeting layer evenly beneath the bugle head of the fastener.

Abstract: Apparatus for adjusting the plate segment of an off-set lithographic printing machine drum relative to the drum has first and second blocks, each of which has a threaded bore for receiving the threads of a differential screw. One of the blocks is fastened to the frame of the drum while the other block is moveable on the screw relative to the first block. The threads of the bore in the moveable block have a smaller pitch than the threads in the bore of the fixed block so that the moveable block may be moved in controlled amounts toward and away from the fixed block. The blocks are disposed within a circumferential slot formed on a peripheral edge of the plate segment and as the screw is turned the moveable block acts against an edge of the slot to rotate the plate segment relatively to the drum. A clamp is provided for securing the blocks to the plate segment in adjusted positions.

Abstract: The screw has a conventional threaded body, and a tapered leading end for easy entry to a tapped hole. A projection extends radially from the tapered end portion and when the longitudinal center lines of the screw and hole are misaligned, makes first contact with the threads on the tapped hole. As the screw is turned, the projection follows the tapped threads of the hole to bring the machine screw into alignment. When the projection tracks the internal hole threads, the positional relationship between the projection and the first screw thread brings the starting point of the first screw thread into contact with the starting point of the first thread at the entrance of the tapped hole.

Abstract: A fastener for securing a sheet metal roof panel to a roof frame with a layer of compressible insulation between the two includes an elongated shank with a tip at one end and a driving head at the other. The shank either is inserted tip first through a preformed hole in the sheet or through a hole which the tip drills and the shank is driven through the insulation layer. A first thread on the shank adjacent the tip is driven into the frame and draws a flared portion of the shank through the hole to enlarge the latter and roll over the metal around the edge of the hole. The rolled over edge then is engaged by a second thread on an enlarged portion of the shank under the head and the plate together with a washer are compressed between the second thread and the head so as to prevent overdrive of the fastener and reduce the possibility of the sheet being dimpled. Longitudinally extending beads or a third thread on the flared portion produce a smooth and gradual rolling over of the edge of the hole in the plate.

Abstract: A device for spreading two flanges (1, 2) mounted in opposite position in a pipe system (3), which device mainly comprises a conical screw element (7) to be inserted into a continuous hole of a flange, said element having an axial opening, in which fits a pressure member (6) having a pressure head face for the axial displacement of the pressure member in said opening, wherein the screw element (7) has a screwthread with at least three leads in order to adapt said device for a greater variety of hole diameters in the flanges (1, 2) and to guarantee the necessary guiding of the conical screw element (7) during insertion thereof.

Abstract: A screw for soft material having an assymetrical thread form which includes an upper flank comprised of a plurality of continuous helical surfaces. The upper flank surfaces are configured such that a helical protrusion is formed on the upper flank which causes increased friction between the screw and the workpiece only after seating of the screw head has occurred.

Abstract: A thread forming screw made from a blank which has a tip with an assymetrical cross-section comprised of two oppositely disposed inner surfaces which gradually merge with two oppositely disposed outer surfaces. The inner surfaces may be arcuate or generally flat or a combination thereof. The inner and outer surfaces are generally parallel to each other and to the axis of the screw so that, when rolled, the tip has generally fully formed sharp crested threads which gradually deform workpiece material upon insertion and axially advancing rotation in a bore. The reduced frictional contact is achieved because of substantial unthreaded portions on the inner surfaces. Improved gripping action results from the formation of full threads which extend substantially the full length of the fastener.

Abstract: A rotary fastener is disclosed for use in attaching the first panel to a second panel. The fastener has a head and a shank, which shank has at least one helical thread thereon. Additionally, there is at least one helical ramp extending along the shank from the underside of the head. The underside of the head has a generally annular recess which may have helical ribs therein. The fastener is dimensioned so that as it is driven into the two panels, material of the two panels is drawn up into the recess and binds on the helical ramp along the shank. Additionally, a plurality of nibs located on the underside of the head and extending into the recess "rake" up material as the underside of the head encounters the top panel, which raked material is also drawn into the recess and binds on the helical ramp. This combined binding action by panel material and raked material significantly increases stripping torque of the fastener during installation.

Abstract: A rotary fastener for use in attaching sheet metal or attaching articles to sheet metal. The fastener has a serrated helical ramp forged in the undersurface of the head during the heading operation. The serrations have generally radially oriented surfaces which engage workpiece material to increase strip torque, removal torque or both. The ramp advances helically in an axial direction and the ramp is spiral in cross-section.

Abstract: The invention is a screw and nut assembly having a particular thread configuration. The externally threaded spindle has both a spiral threaded portion and a spiral non-threaded portion which separates the convolutions of the threaded portion. The threaded portion includes a plurality of individual threads, each individual thread extending only over a part of the periphery of the spindle body. The nut member also includes a spiral threaded portion and a spiral non threaded portion which nut portions match the respective portions of the spindle. Because of this arrangement, the nut may be rapidly moved along the spindle body when their respective non-threaded portion are engaged. Thereafter, the nut may be turned so as to engage its threaded portion with the threaded portion of the spindle.

Abstract: A plastic cap for glass or plastic carbonated beverage bottles is shaped so that in use pressure is exerted around the edges of a gasket to give enhanced sealing. A single cap can fit the different necks of standard glass and plastic bottles. Its heat-shrinkable skirt has longer portions between connectors.

Abstract: The self-locking threaded bearing is an externally threaded tubular member having a discontinuous thread to form thread sections which are spaced-apart axially on the bearing. In the bearing assembly, the thread sections engage portions of an internal thread in a bore of a housing for the bearing and, with the internal thread being more ductile than the thread sections of the bearing, portions of the internal thread are stripped to pack into the space between the thread sections and assist in locking the bearing into the housing.In the method of making the self-locking threaded bearing assembly, a tubular bearing is provided with a discontinuous external thread and a housing is formed with a bore having an internal thread of the same pitch as the external thread of the bearing and of material more ductile than that of the external thread.

Abstract: A threaded fastener designed for anchoring imbedment into masonry structures and more particularly into masonry structures which include relatively hard aggregate. A critical distinct relationship between parameters of a fastening system such as the lead angle of the thread, the included angle of the thread, the depth of imbedment of the crest of the thread in a bore of predetermined diameter exists in order to create an adequate effective fastening system for hard aggregate masonry or concrete.

Abstract: A mounting element for mounting an object on a support structure has an elongated expansion sleeve member insertable into a mounting hole of the support structure and having a longitudinal opening, and an elongated expander member insertable into the longitudinal opening so as to expand the expansion sleeve member and having a round thread and a pointed profile thread arranged on the peaks and/or valleys of the round thread and having a pitch corresponding to the pitch of the latter.

Abstract: A threaded member has an external helical thread 18a presenting a crest 24 of spiral outline whose trailing end is in the form of an abutment 26 for resisting withdrawal from a resiliently deformable workpiece. In a preferred application, the threaded member is a die-cast grub screw S and locates within a hinged plastics furniture fastener F. Advancing the grub screw S by 1/2-turn from its initial position in the fastener F breaks a frangible locating web 28 and allows the abutment 26 to pass an abrupt shoulder 64. This gives a tangible warning to the user that a ridge 12b on the grub screw S is correctly located beneath a head H of an anchor A.

Abstract: A replacement stud for an original stud damaged in existing equipment consists of an oversized section having a threaded diameter larger than the original stud and a nominal section having a threaded diameter identical to that of the original stud. The nominal section is topped by a frangible, necked-down diameter capped by a suitable drive head for use with conventional hand or power drive tools. When the original stud has been damaged so as to preclude removal of a segment of it from the original stud hole, the stud hole is counterdrilled, enlarging its diameter and eliminating the broken segment. The larger threaded diameter of the snap-stud invention is set by the original stud's threaded diameter and the drill size predetermined for counterdrilling the original stud hole.

Abstract: A self-drilling and self-extruding fastener having a constant cross section stem and a tapering end portion terminating in a sharp point. The stem is provided with a pair of screw threads of like configuration. The tapering portion is provided with a third thread which begins at the pointed forward end in a very steep lead angle which functions as a drilling portion and thereafter the lead angle decreases so that the third thread may function to extrude the metal surrounding a guide opening formed by the drilling portion. Depending upon the screw thread configurations, one or both of the screw threads cooperate with the third thread to further extrude sheetmetal surrounding the guide opening into a cylindrical bore, after which the screw threads self-tap into the wall of the cylindrical bore of the projection and thereby firmly grip the sheetmetal.

Abstract: A self-drilling screw having a single screw thread or a plurality of screw threads of the same angle and height, wherein at least one cutting edge of a drill shape is formed by form rolling at an end face of a forward end of the screw thread at a tapering forward end portion of the self-drilling screw, the cutting edge having a lead angle distinct from that of other portions of the self-drilling screw. The self-drilling screw is formed at the root of the screw thread with elevated areas and depressed areas or major diameter areas and minor diameter areas of polygonal configuration in a zone of a shank extending across the boundary between a parallel portion and a tapering portion to reduce the transverse cross sectional area of the screw thread.

Abstract: A fire resistant floor and ceiling assembly comprising in combination; a plywood layer; a gypsum floor underlayment extending adjacent below said plywood layer; a series of steel joists located below said underlayment and supporting the plywood and underlayment; a space-apart multiplicity of self-drilling self-tapping screws extending downwardly through the plywood and underlayment, and engaging said steel joists thereby attaching the plywood and underlayment to the steel joists, said screws having upper threads and lower threads with an interrupting non-threaded mid-portion therebetween, the non-threaded mid-portion extending a distance substantially the same as the thickness of said plywood layer; and, at least one layer of third generation fire resistant gypsum board connected to, and supported below, said steel joists by connecting means; whereby said assembly contains no combustibles in the plenum between said underlayment and fire resistant gypsum board, and whereby said assembly attains at least a one

Abstract: A masonry screw anchor having two different constant diameter shank portions connected via a taper. Each portion has a set of constant diameter threads and intermediate smaller diameter protrusions with the threads and protrusions on the larger diameter shank portion being larger in diameter than the diameter of the threads and protrusions on the smaller diameter portion.