The Lamson & Sessions Co.

Russell, Burdsall & Ward Corporation

Terry D Capuano

Walter R Pamer

James A Zils

Edward J Rebish

John L Barkocy

An improved fastener has a head section and an axially extending shank section. A thread convolution is disposed in a coaxial relationship with the head and shank sections. An improved holding action against rotational and axial movement of the fastener relative to a metal base member is promoted by a plurality of radially extending wedge-shaped compression ramps. The compression ramps are disposed on the head section and slope radially and axially inwardly toward the shank section. The compression ramps are effective to force metal of the base member into an annular groove which circumscribes and undercuts at least a portion of the shank section. The metal which is received in the undercut portion of the groove is effective to hold the fastener against being pushed or pulled axially outwardly from the base member. The compression ramps also force the metal of the base member radially inwardly against corners formed on the shank section of the fastener to hold the fastener against rotation. In addition, the compression ramps are embedded in the base member to further hold the fastener against rotation relative to the base member. The compression ramps are separated by flat arcuate stop surface areas which limit the extent to which the fastener is pressed into the base member.

Fastener

A load indicating flange is provided either separately or on a nut or a bolt head. This load indicating flange has an axially directed face which has a wavy surface on which a plurality of crests are disposed for initial engagement with a work surface. A plurality of troughs are provided on the wavy surface one each between two of the crests. A gauge groove is provided at each trough and when the bolt and nut combination is properly tightened on a workpiece, the troughs are flattened toward the work surface to such an extent that a relatively thick gauge cannot enter the gauge groove. If the bolt and nut are improperly tightened, then the gauge will enter the gauge groove. A narrow band peripheral bearing surface is provided on the outer periphery of the face to prevent defacing the work surface. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.

Load indicating flange

A drive cavity for a threaded fastener which is compatible with a variety of wrench drivers having hexagon-based profiles. The drive cavity is a prismatic projection of a multi-, primarily flat-sided, profile having its radially inner margins defined by the mid-sides of a common base hexagon and its radially outer margins defined by six trapezoid sectors each centered on and outlying the corners of the base hexagon.

Socket drive

An improved fastener assembly may be used to mount a vehicle wheel on a hub. The fastener assembly includes a nut which is rotatable relative to a washer to enable the fastener assembly to be tightened without marring the wheel. The washer has an annular collar which is loosely connected with the nut by a retainer section which extends from one axial end portion of the nut. The nut and washer collar have abutting annular load transmitting surface areas. The washer also has an annular load transmitting and indicating section which extends radially outwardly from the collar. The load transmitting and indicating section includes a bearing section and a spring section. The spring section flares radially and axially outwardly from the bearing section. When the fastener assembly is tightened with a predetermined preload, the spring section is flattened to provide a visual indication that the desired preload has been applied. Flattening the spring section maximizes the surface area for transmitting the preload to the wheel. The resiliently deflectable spring section may be provided with undulations which are also flattened by the desired preload. In order to minimize the axial extent of the fastener assembly, an inner end surface of the nut is disposed radially inwardly of the top and bottom surfaces of the bearing and spring sections when the fastener assembly is tightened.

Fastener assembly

The present invention provides an improved method of forming improved dies for rolling an article, such as a lock thread convolution. The dies are formed by rolling a circular hob along a flank of a thread form ridge on the die. As the hob is rolled along the thread form ridge, teeth on the hob are pressed against the thread form ridge with a constant force to form uniform indentations and/or projections in the thread form ridge. The indentations and/or projections which are formed in the thread form ridge by the hob all have the same configuration since the hob is pressed against the thread form ridge with a force of a constant magnitude as the hob is rolled along the thread form ridge. During the rolling of an external thread convolution on a bolt blank with the improved die, the indentation and/or projections on the thread form ridge shape teeth on the flank of an external thread convolution on the bolt. Since the indentations and/or projections were originally rolled into the thread formed ridges on the die with a circular hob and since the indentations and/or projections on the die roll teeth on a circular bolt blank, the teeth formed on the flank of the external thread convolution have the same configuration as the teeth on the hob.

Rolling dies and method of forming the same

An improved fastener includes a polygonal rim which cooperates with an axially projecting center section to define a recess in which sheet material is forced by a die to hold the fastener against rotational and axial movement relative to the sheet material. To improve the gripping action between the fastener and the sheet material, the sheet material is stretched by a tool which extends through the center of the fastener. When a hole is cut in the sheet material by the fastener, the prestretched metal resiliently contracts to grip the center section of the fastener. The gripping action between the sheet material and the fastener is further improved by resiliently compressing the center section of the fastener with the die. As the center section is withdrawn from the die, the center section springs outwardly to decrease the size of the recess and grip the sheet material. In addition, the rim is resiliently deflected radially outwardly by the die as metal is forced into the recess. When the die is withdrawn from the recess, the rim springs inwardly to decrease the size of the recess and grip the sheet material. The holding action between the fastener and the sheet material is increased by providing the recess with indentations which project into the rim and center section. The holding action is also increased by having the center section flare axially and radially outwardly.

Method of mounting a fastener

An internally threaded fastener, such as a nut, includes a body having an axially extending opening with a side wall. A coarse internal thread convolution is formed in the side wall of the nut body. A fine thread convolution is also formed in the side wall of the nut body. The turns of the coincident coarse and fine thread convolutions are intermingled to enable them to engage a fastener having either a coarse or a fine external thread. An improved tap has a first section for forming the fine thread convolution and a second section for forming the coarse thread convolution. The two sections of the tap are interconnected in a coaxial relationship by a connector section having an axial extent which is less than the axial extent of the coincident coarse and fine thread convolutions. When a plurality of nuts are to be tapped, the fine thread convolution is tapped first. This enables a leading nut to be moved away from a following nut during tapping of a coarse thread convolution in the leading nut and the tapping of a coarse thread convolution in the following nut.

Method of tapping dual thread fasteners

An improved fastener is provided with retainer elements which are utilized to prevent undesired movement of the fastener relative to an associated member. In one embodiment of the invention, the retainer elements are resiliently deflectable spring fingers having free end portions which penetrate the associated member to prevent reverse rotation of the fastener, that is rotation of the fastener in a direction tending to loosen the fastener. When the threaded fastener is being rotated in a first direction to tighten it, the spring fingers are deflected into recesses formed in the fastener to prevent gouging or marking of the member. Upon the application of a force tending to loosen the fastener, the free end portions of the spring fingers penetrate the member and dig in to prevent loosening movement of the fastener. In another embodiment of the invention, the retainer elements cooperate with an associated member to prevent both axial and rotational movement of the fastener relative to the member. In this embodiment of the invention each of the retainer elements includes a pair of spring fingers having free end portions which penetrate the member as the fastener is pressed against the member. As the spring fingers penetrate the member, curved side surfaces on the spring fingers cam them in opposite directions to hook the spring fingers into the member.

A nut having a plurality of thread convolutions is formed with a plurality of punches from a metal blank to eliminate time consuming tapping operations. To make the nut, a pair of punches are used to form recesses in opposite sides of the blank and to form projections which extend axially outwardly from the sides of the blank. The recesses are separated by a web which is shaped by another pair of punches to form an inner thread convolution. The two axially extending projections each contain a volume metal which is the same as the volume of metal contained in upper and lower thread convolutions. The upper and lower thread convolutions are formed by cold working the metal of the blank to eliminate the axial projections and form radially inwardly extending projections in the central opening in the blank.

Nut and method of forming the same

Disclosed is a lug nut 10 capable of manufacture on existing nut forming machinery having a continuous thread through the entire axially inner surface 12 while having suitable drive means placed upon the axially outer surface 14 such as a conventional hex 16. The lug nut 10 has a conical bottom section 18 for tight engagement and centering of a vehicle wheel upon a vehicle and an integrally formed flange 20 at the other end thereof along with seat 26 for acceptance of an insert 28 in tight engagement therewith. The insert 28 can have a highly reflective surface 32 to provide a safety feature for night time driving.

Lug nut

An improved thread convolution cooperates with a mating thread convolution to prevent reverse rotation between the thread convolutions in a direction tending to loosen a fastener. In order to prevent reverse rotation between the two thread convolutions while enabling them to be rotated in a forward direction to tighten the fastener, the improved thread convolution has a resiliently deflectable spring portion which forms part of a flank of the thread convolution. During relative rotation between the two thread convolutions in a direction tending to tighten the fastener, the spring portion is deflected from an extended position to a retracted position under the influence of a flank of the mating thread convolution. This enables relative rotation to occur between the two thread convolutions without gouging or excessive scratching of the flank of either of the two thread convolutions. Upon initiation of reverse rotation between the two thread convolutions, the spring portion moves outwardly and penetrates the flank of the mating thread convolution to prevent continued rotation in the reverse of loosening direction between the two thread convolutions.

Thread convolution

An improved thread tapping form is used to form an internal thread convolution in a member. The thread tapping form includes a plurality of projections which are disposed on a shank having a circular cross sectional configuration. Each of the thread forming projections includes a leading section which parts the material of the member to initiate formation of the flanks of the internal thread convolution. A side section of each thread forming projection presses against the flanks of the internal thread convolution to further form the flanks. A trailing section of each projection supports the side and leading sections of the projection.

Thread tapping form

An improved fastener assembly includes an externally threaded member or bolt having a thread convolution with a relatively long trailing flank surface and a relatively short leading flank surface. An internally threaded member or nut also has a thread convolution with a relatively long trailing flank surface and a relatively short leading flank surface. The nut is grooved to provide an expandable section. When the nut and bolt are tightened, the relatively long trailing flank surfaces of the thread convolutions cause the grooved portion of the nut to expand to completely fill a hole. The opposite end of the nut is contracted to clamp against a thread convolution on the bolt. In one embodiment of the invention, a relatively short leading flank surface of the bolt extends at an acute angle to the relatively short leading flank surface of the nut to provide clearance between the internal and external thread convolutions. In another embodiment of the invention, the grooves in the nut extend only part way through the thread convolution in the nut.

Growing community of inventors

Hinckley, OH, United States of America

Terry D Capuano