WO2017136670A1

WO2017136670A1 - Captive fastener

Info

Publication number: WO2017136670A1
Application number: PCT/US2017/016424
Authority: WO
Inventors: Joonho HONG; Xiaoping Luo
Original assignee: Southco, Inc.
Priority date: 2016-02-03
Filing date: 2017-02-03
Publication date: 2017-08-10
Also published as: KR20180103677A; CN209180176U; TWM552060U

Abstract

Aspects of the invention relate to captive fastener including a stud (100) having a head (110) and a shaft (120) that extends from the head. The shaft (120) has a fastener portion (140) and a stop ring (400) affixed thereto. A ferrule (300) that defines a passageway that extends along a longitudinal axis of the ferrule. The stud (100) is disposed within the passageway of the ferrule (300) and moveable relative to the ferrule (300). A proximal portion of the ferrule (300) has an inward flange (322) extending toward the stud (100). The inward flange (322) of the proximal portion of the ferrule (300) is positioned to engage the stop ring (400) upon displacement of the stud (100) with respect to the ferrule (300). The inward flange (322) of the ferrule (300) is configured to reduce misalignment of the longitudinal axis of the ferrule (300) and the longitudinal axis of the stud (100). The stop ring (400) is configured to reduce misalignment of the longitudinal axis of the ferrule (300) and the longitudinal axis of the stud (100) at a distal portion of the shaft (120) of the stud (100).

Description

CAPTIVE FASTENER

This application is related to, and claims the benefit of priority of, U.S. Provisional Application No. 62/290,682, entitled CAPTIVE FASTENER, filed on 3 February 2016, the contents of which are incorporated herein by reference in their entirety for all purposes.

FIELD OF THE INVENTION

This disclosure relates to captive fasteners and more particularly to captive plungers and captive screws.

BACKGROUND OF THE INVENTION

Captive fasteners, such as captive screws and captive plungers, are generally used to attach a first panel to a second panel or frame where it is desired to keep the fastener in position without loose items of hardware. For example, the captive fastener may be mounted on a first panel, such that the fastener stays attached to the panel even when the fastener, such as threads of a screw shaft, is fully disengaged from a second panel to which the first panel is attached.

Captive fasteners may be useful in the electronics industry. In certain applications, when doors or covers are opened or removed and a hazardous voltage exists behind these doors or covers, government regulations may require that the door or cover be opened or removed by using a tool. However, for the convenience of a worker, it may be desirable to also enable the captive fastener to be hand tightened.

SUMMARY OF THE INVENTION

Aspects of the invention relate to captive fasteners and applications thereof.

In accordance with one aspect, the invention provides a captive fastener for attachment to a panel. The captive fastener generally includes a stud having a head and a shaft that extends from the head along a longitudinal axis of the stud to a distal end of the stud. The shaft has a fastener portion. A stop ring is affixed to the shaft of the stud and spaced from the distal end of the stud. The captive fastener also includes a ferrule that defines a passageway that extends along a longitudinal axis of the ferrule from a proximal end of the ferrule to a distal end of the ferrule. The stud is disposed within the passageway of the ferrule and moveable relative to the ferrule along the longitudinal axis of the stud. A proximal portion of the ferrule has an inward flange extending toward the longitudinal axis of the stud. The inward flange of the proximal portion of the ferrule is positioned to engage the stop ring upon displacement of the stud with respect to the ferrule. The inward flange of the ferrule is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a proximal portion of the shaft of the stud. The stop ring is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a distal portion of the shaft of the stud.

According to another aspect, the invention provides a captive fastener that has a stud that includes a head and a shaft extending from the head along a longitudinal axis of the stud to a distal end of the stud. The shaft has a fastener portion. The captive fastener also includes a stop ring that is affixed to the shaft of the stud and spaced from the distal end of the stud. The captive fastener further includes a knob that has an inwardly extending flange and that defines an aperture that extends from a proximal end of the knob to a distal end of the knob. The head of the stud is disposed at least partially within the aperture defined by the knob. The captive fastener further includes a ferrule that defines a passageway extending along a longitudinal axis of the ferrule from a proximal end of the ferrule to a distal end of the ferrule. The stud is disposed within the passageway of the ferrule and moveable relative to the ferrule along the longitudinal axis of the stud. A proximal portion of the ferrule has an outward flange that is positioned to engage the inwardly extending flange of the knob upon displacement of the stud with respect to the ferrule and an inward flange that extends toward the longitudinal axis of the stud. The inward flange of the ferrule is positioned to engage the stop ring upon displacement of the stud with respect to the ferrule. The inward flange of the ferrule is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a proximal portion of the shaft of the stud. The stop ring is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a distal portion of the shaft of the stud.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed description when read in connection with reference to the accompanying drawings. According to common practice, the various features of the drawings are not drawn to scale unless otherwise indicated. On the contrary, the dimensions of the various features may be expanded or reduced for clarity. Included in the drawings are the following figures:

FIG. 1 is a perspective view of an embodiment of a captive fastener having a ferrule in an extended position with respect to a knob in accordance with aspects of the present invention;

FIG. 2 is a cross-sectional view of the captive fastener of FIG. 1 in a retracted position coupled to a first and second panel;

FIG. 3 is an exploded view of the captive fastener of FIG. 1;

FIG. 4A is a perspective view of the stud of the captive fastener of FIG.

2; FIG. 4B is a side view of the stud of FIG. 4A;

FIG. 4C is a top view of the stud of FIG. 4A;

FIG. 4D is a bottom view of the stud of FIG. 4A;

FIG. 5 is a perspective view of another embodiment of a captive fastener having a ferrule in an extended position with respect to a knob in accordance with aspects of the present invention;

FIG. 6 is a cross-sectional view of the captive fastener of FIG. 5 in a retracted position coupled to a first and second panel;

FIG. 7 is an exploded view of the captive fastener of FIG. 5; FIG. 8 is a perspective view of the stud of the captive fastener of FIG. 7;

FIG. 9A is a first perspective view of the ratchet wheel of the captive fastener of FIG. 7;

FIG. 9B is a second perspective view of the ratchet wheel of FIG. 9A;

FIG. 10 is a perspective view of the C-spring of the captive fastener of FIG. 7;

FIG. 11A is a first perspective view of the ferrule of the captive fastener of FIG. 7;

FIG. 11B is a second perspective view of the ferrule of FIG. 11A; and FIG. 12 is a cross-sectional view of the ferrule of FIG. 11A.

DETAILED DESCRIPTION OF THE INVENTION

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and the range of equivalents of the claims without departing from the invention.

Captive fastener(s) can be utilized in various fields of endeavor to couple two or more objects. As an example, captive fasteners are often used to couple a cover to a surface and/or a panel and frame. Although embodiments of the invention are discussed herein with regard to coupling or securing a panel to a frame, one of skill in the art would recognize that captive fasteners may be advantageously utilized to couple or secure other objects or features together. The captive fasteners according to aspects of the invention may be coupled or attached to one or more objects such that unfastening the captive fastener with respect to one of the objects does not detach the captive fastener from all of the objects.

Referring to the figures generally, a captive fastener 10 generally includes a stud 100 including a head 110 and a shaft 120 that extends from the head 110 along a longitudinal axis 102 of the stud 100 to a distal end 104 of the stud 100. The shaft 120 has a fastener portion 140. A stop ring 400 is affixed to the shaft 120 of the stud 100 and spaced from the distal end 104 of the stud 100. A knob 200 defines an aperture 204, the head 110 of the stud 100 is disposed at least partially within the aperture defined by the knob 200. A ferrule 300 defines a passageway 304 that extends along a longitudinal axis 302 of the ferrule 300 from a proximal end 320 of the ferrule 300 to a distal end 306 of the ferrule 300, and the stud 100 is disposed within the passageway 304 of the ferrule 300 and moveable relative to the ferrule 300 along the longitudinal axis 102 of the stud 100. A proximal portion 320 of the ferrule 300 has an inward flange 322 extending toward the longitudinal axis 102 of the stud 100. The inward flange 322 of the proximal portion 320 of the ferrule 300 is positioned to engage the stop ring 400 upon displacement of the stud 100 with respect to the ferrule 300. The inward flange 322 of the ferrule 300 is configured to reduce misalignment of the longitudinal axis 302 of the ferrule 300 and the longitudinal axis 102 of the stud 100 at a proximal portion 124 of the shaft 120 of the stud 100. The stop ring 400 is configured to reduce misalignment of the longitudinal axis 302 of the ferrule 300 and the longitudinal axis 102 of the stud 100 at a distal portion 126 of the shaft 120 of the stud 100.

Referring to FIG. 1, the captive fastener 10 is provided for attachment to a panel in accordance with an embodiment of the present invention. As a general overview, captive fastener 10 includes a stud 100, a knob 200, a ferrule 300, and a stop ring 400.

Stud 100 has a longitudinal axis 102 by which a distal end 104 is spaced from a proximal end 106 along such longitudinal axis 102. Stud 100 also includes a head 110 and a shaft 120 extending from the head 110.

Head 110 has a cross-sectional area at 112 that defines a geometric shape, such as a circle, square, triangle, hexagon, octagon, or other geometric shape. Although cross-sectional area at 112 defines a circle at various points along longitudinal axis 102, as illustrated in FIG. 2, cross-sectional area at 112 may also define non- geometric shapes along longitudinal axis 102, For example, head 110 may be configured to have a non-geometric shape and, thus, may also have a non-geometric cross-sectional area. Additionally or alternatively, cross-sectional area 112 may vary along the longitudinal axis 102 of stud 100. For example, head 110 may include a protrusion 114 that has a cross-sectional area 116 that is different in at least one dimension than cross-sectional area 112 of head 110. Likewise, head 110 may include a recess or an indent that has a cross-sectional area that is different in at least one dimension than the cross-sectional area 112 of head 110. As discussed further below, head 110 may be configured to have protrusion 114 and/or an indent that is secured by one or more corresponding protrusions, indents, and/or flanges of knob 200. Referring to FIG. 2, head 110 defines a driver 118 at proximal end 106 of stud 100. According to one embodiment, however, head 110 of stud 100 does not define driver 118. Driver 118 may be configured to be a cavity and/or a protrusion that facilitates engagement of head 110 of stud 100 with a tool, which enables rotation of stud 100 by rotation of the tool. For example, driver 118 may extend from proximal end 106 of stud 100 inward to define a cavity or outward to define a protrusion. Driver 118 may be configured to engage a tool having, e.g., a Philips tip, a Frearson tip, a Torx tip, a square tip, a slot tip, or another type of tool.

Stud 100 includes a shaft 120 that extends from head 110 along longitudinal axis 102 of stud 100 to distal end 104 of stud 100. Although shaft 120 has a generally cylindrical shape in the embodiment illustrated in FIG. 3, shaft 120 may have other geometric shapes (e.g., a rectangular, triangular, or other geometric shape) or non-geometric shapes that includes one or more straight portions and/or rounded portions. Shaft 120 includes a proximal portion 122 and a distal portion 126, wherein the distal portion 126 is spaced further from head 110 than proximal portion 122.

Shaft 120 also includes a fastener portion 140 configured to enable stud 100 to be fastened to one or more objects, such as panels 12 and 14. Fastener portion 140 may include threads having a minor diameter 144 and a major diameter 147. Additionally or alternatively, fastener portion 140 may include one or more grooves and/or protrusions that are configured to engage the one or more objects, e.g., panels 12 and 14. According to one embodiment, fastener portion 140 has at least one vertical extending groove and another groove extending therefrom at an angle, such that captive fastener 10 is configured to fasten to the one or more objects, e.g., panel 14, upon a quarter-turn rotation of stud 100. Although fastener portion 140 is spaced from distal end 104 of stud 100 in FIGS. 2-4B, fastener portion 140 may extend to distal end 104. Furthermore, fastener portion 140 may extend to head 110. For example, in one embodiment, fastener portion 140 extends from distal end 104 of stud 100 along shaft 120 to head 110.

The distal portion 126 of shaft 120 may be spaced from or extend to distal end 104 of stud 100. Additionally and/or alternatively, fastener portion 140 may be disposed on distal portion 126 of shaft 120. Distal portion 126 has a cross-sectional area 128 that may be different than cross-sectional area 124 of proximal portion 122 of shaft 120. For example, distal portion 126 may have a cross-sectional area 128, or a diameter thereof, that is smaller than cross-sectional area 124, or a diameter thereof, of proximal portion 122 of shaft 120.

In one embodiment, cross-sectional area 128, or a diameter thereof, of distal portion 126 is smaller than cross-sectional area 124, or a diameter thereof, of proximal portion 122 along fastener portion 140 and equal to or approximately equal to cross-sectional area 124 of proximal portion 122 along the section of shaft 120 interposed between proximal portion 122 and fastener portion 140. According to another embodiment where the fastener portion 140 includes threads, the cross- sectional area 128 of distal portion 126 may be equal to or smaller than a minor diameter 144 of the threads of fastener portion 140,

The distal portion may also define a shoulder portion 130 that is adapted to receive a stop ring, e.g ., stop ring 400. For example, in one embodiment, shoulder portion 130 includes an optional knurl or other surface feature that is adapted for the attachment of a stop ring . The cross-sectional area 132 of shoulder portion 130 may be different than the cross-sectional area 128 of distal portion 126. For example, cross-sectional area 132 of shoulder portion 130 may be smaller than a section of cross-sectional area 128 of distal portion 126 interposed between shoulder portion 130 and proximal portion 122, such that a stop ring is impeded from sliding beyond shoulder portion 130 along shaft 120 toward head 110.

Shaft 120 may also have a lead portion 150 interposed between distal end 104 of stud 100 and distal end 148 of fastener portion 140. Lead portion 150 may be configured to facilitate alignment of fastener portion 140 with one or more objects, e.g . , with a fastener portion of a mating panel . Lead portion 150 may have a cross- sectional area 152 that is equal to or smaller than cross-sectional area 146 of fastener portion 140 and/or a minor diameter 144 of the threads, if fastener portion 140 includes threads. Additionally or alternatively, cross-sectional area 152 of lead portion 150, or a diameter thereof, may be smaller than or equal to cross-sectional area 128 of distal portion 126, cross-sectional area 124 of proximal portion 122, and/or any diameters thereof.

Captive fastener 10 also includes a stop ring 400 affixed to shaft 120 of stud 100 and spaced from distal end 104 of stud 10. For example, stop ring 400 may be affixed to shaft 120 along distal portion 126 and/or shoulder portion 130. Stop ring 400 may be affixed to shaft 120 by way of mechanical means, such as press fitting, crimping, welding, threading, wedging, or the like or non-mechanical means, such as by applying adhesives or the like. According to one embodiment, movement of stop ring 400 with respect to shaft 120 of stud 100 is eliminated or inhibited by way of a knurl disposed along shoulder portion 130. In another embodiment, stop ring 400 is an integral extension of shaft 120 of stud 100. Stop ring 400 may extend toward ferrule 300. In one embodiment, stop ring 400 may optionally be configured to contact ferrule 300. Captive fastener 10 further includes a knob 200, which may have a longitudinal axis that aligns with longitudinal axis 102 of stud 100. Knob 200 defines an aperture 204. Head 110 of stud 100 is at least partially disposed within the aperture 204 defined by knob 200. In one embodiment, aperture 204 of knob 200 extends from a distal end 206 of knob 200 to a proximal end 208 of knob 200. In another embodiment, aperture 204 of knob 200 extends from distal end 206 of knob 200 to a portion of knob 200 interposed between distal end 206 and proximal end 208, such that proximal end 106 of stud 100 is enclosed by knob 200.

Head 110 of stud 100 may be secured within aperture 204 of knob 200 such that head 110 is moveable and/or rotatable within aperture 204. In one embodiment, however, head 110 is fixedly secured within head 110, such that head 110 is fixed with respect to knob 200. For example, head 110 may be fixedly secured within head 110, such that rotation of knob 200 in one direction rotates stud 100 in one direction and rotation of knob 200 in an opposite direction rotates stud 100 in an opposite direction. As illustrated in FIG. 2, protrusion 114 of head 110 may be fixedly secured by a corresponding indent 210 of knob 200 and by proximal flange 212 and an interior flange 214 of knob 200. In general, head 110 may be secured within aperture 204 of knob 200 by any suitable means of securing. Alternatively, knob 200 may be an integral extension of stud 100, e.g., head 110 of stud 100 may be configured to include the structure of knob 200 and/or the function of knob 200, such as being configured to be gripped by a user. For example, in one embodiment, it may be desirable to configure stud 100 to integrally include knob 200 where the shaft is fixedly secured with respect to the knob portion. Knob 200 may have a ferrule 300, or a portion thereof, disposed within aperture 204 of knob 200. Captive fastener 10 also includes a ferrule 300, which defines a passageway 304 extending along a longitudinal axis 302 of ferrule 300 from a proximal end 308 of ferrule 300 to a distal end 306 of ferrule 300. Stud 100, or a portion thereof, is disposed within passageway 304 of ferrule 300 and moveable relative to ferrule 300 along longitudinal axis 102 of stud 100. Ferrule 300 has a proximal portion 320 and a distal portion 310. Distal portion 310 and/or distal end 306 of ferrule 300 may include a panel attachment means. For example, distal portion 310 and/or distal end 306 may be configured for attachment to a panel by mechanical means, such as self-clinching, crimping, welding, threading, wedging, or the like, and/or non-mechanical means, such as by applying adhesives or the like.

Proximal portion 320 of ferrule 300 includes an inward flange 322.

Inward flange 322 of proximal portion 320 may be spaced from proximal end 308 of ferrule 300. Inward flange 322 extends toward longitudinal axis 102 of stud 100.

According to one embodiment, inward flange 322 extends to contact shaft 120, or a portion thereof, such as proximal portion 122 of shaft 120. Inward flange 322 of proximal portion 320 of ferrule 300 is positioned to engage stop ring 400 directly (e.g., by way of contact) or indirectly (e.g., by indirect contact, such as by compressing spring 330 until the load on spring 330 equals or exceeds the displacing force) upon displacement of stud 100 along longitudinal axis 102 with respect to ferrule 300. As illustrated in FIG. 2, inward flange 322 of proximal portion 320 indirectly engages stop ring 400 by compressing spring 330 until the load on spring 330 equals or exceeds the displacing force or until either inward flange 322 or stop ring 330 fails under such displacing force. Accordingly, the engagement of the stop ring 330 by the flange is an indirect engagement in that the spring prevents direct contact. Alternatively, direct engagement is also contemplated such as by eliminating the spring or reconfiguring stop ring 330 and/or flange 322 to permit direct contact. The engagement between inward flange 322 of proximal portion 320 and stop ring 400 may secure stud 100, or a portion thereof, such as shaft 120, within passageway 304 of ferrule 300. For example, when ferrule 300 is attached to panel 12 and/or 14, displacement of stud 100 along longitudinal axis 102 of stud 100 may be impeded after a certain distance when stop ring 400 engages inward flange 322 of ferrule 300. In one embodiment, displacement of stud 100 along longitudinal axis 102 of stud 100 is impeded after stud 100 is displaced a certain distance, whereby the load on spring 330 is equal to the displacing force such that inward flange 322 of ferrule 300 indirectly engages stop ring 400.

Inward flange 322 of ferrule 300 may also be configured to reduce misalignment of longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100. For example, inward flange 322 of ferrule 300 may extend to shaft 120, thereby limiting displacement of shaft 120 of stud 100 in a direction transverse to longitudinal axis 302 of ferrule 300. According to one embodiment, inward flange 322 is configured to reduce the misalignment of longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100 at a proximal portion 122 of shaft 120 when captive fastener 10 is in its retracted state. The retracted state includes the position of the knob with respect to the ferrule when the ferrule is retracted into the aperture of the knob.

According to another embodiment, inward flange 322 is configured to reduce the misalignment of longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100 at a distal portion 126 of shaft 120 when captive fastener 10 is in its extended state. The extended state includes the position of the knob with respect to the ferrule when the ferrule is extended from the aperture of the knob. In another embodiment, the inward flange 322 is configured to coaxially align the longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100. Proximal portion 320 of ferrule 300 and/or inward flange 322 may be configured to define a slot that enables one or more protrusions or bumps extending from shaft 120 of stud 100 to pass there through. In one embodiment, for example, for the protrusions or bumps extending from shaft 120 to be moved through

passageway 304 at inward flange 322 of ferrule 300, the protrusions or bumps extending from shaft 120 are aligned with the slots defined by proximal portion 320 and/or inward flange 322. According to another embodiment, rotating stud 100 such that the protrusions or bumps extending from shaft 120 are misaligned with the slots of proximal portion 320 maintains captive fastener 10 in an extended position by impeding the displacement of stud 100 with respect to ferrule 300 so as to impede captive fastener 10 from being moved into a retracted position.

A spring 330 is, preferably, disposed within passageway 304 of ferrule 300. Spring 330 extends between inward flange 322 of proximal portion 320 of ferrule 300 and stop ring 400. Spring 330 may be a compression spring and may urge against inward flange 322 of ferrule 300 and against stop ring 400. For example, spring 330 may be configured to urge captive fastener 10 into a retracted state, such that when ferrule 300 is attached to an object, stud 100 is urged towards the one or more objects. Although spring 330 is a compression spring in FIGS. 2 and 3, spring 330 may be a spring other than a compression spring in other embodiments of the invention. For example, an extension spring may be utilized in captive fastener 10 to urge captive fastener 10 into an extended state by urging stud 100 away from the one or more objects when ferrule 300 is attached to the one or more panels.

Stop ring 400 may be configured to reduce misalignment of longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100. When captive fastener 10 is in a retracted state, stop ring 400 may reduce misalignment of longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100 at distal portion 310 of ferrule 300. When captive fastener 10 is in an extended state, stop ring 400 may reduce misalignment of longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100 at proximal portion 320 of ferrule 300. In one embodiment, stop ring 400 is configured to coaxially align longitudinal axis 302 of ferrule 300 and longitudinal axis 102 of stud 100. According to another embodiment, the displacement of shaft 120 of stud 100 in a direction transverse to longitudinal axis 302 of ferrule 300 is limited by stop ring 400.

Referring to FIGS. 5-7, a captive fastener 20 is illustrated having a knob 200' that rotates a stud 100' in one direction. Solely for the convenience of the reader, the features of captive fastener 20 are described using reference numbers that are similar to the references numbers used to describe captive fastener 10. It should be understood that captive fasteners 10 and 20 are non-limiting, exemplary embodiments and, thus, the claims of the present invention are not constrained to the illustrations in the figures or the respective reference numbers discussed herein.

As a general overview, captive fastener 20 includes a stud 100', a knob 200', a ferrule 300', and a stop ring 400'. In addition, captive fastener 20 is configured such that rotation of knob 200' in one direction is configured to rotate stud 100' about longitudinal axis 102' of stud 100' and rotation of knob 200' in an opposite direction is not configured to rotate stud 100' in the opposite direction about longitudinal axis 102' of stud 100'.

Referring to FIGS. 6-8, stud 100' of captive fastener 20 has a longitudinal axis 102' by which a distal end 104' is spaced from a proximal end 106' along such longitudinal axis 102'. Stud 100' also includes a head 110' and a shaft 120' extending from head 110'. Stop ring 400' is affixed to shaft 120' of stud 100'.

Captive fastener 20 also has a knob 200', which may have a longitudinal axis that aligns with longitudinal axis 102' of stud 100'. Knob 200' defines an aperture 204' that extends from a distal end 206' of knob 200' to a proximal end 208' of knob 200'. Head 110' of stud 100' is at least partially disposed within the aperture 204' defined by knob 200'. Preferably, stud 100' is disposed within aperture 204' such that driver 118' of stud 100' is exposed and/or accessible by a tool. Knob 200' may have one or more flanges, such as proximal flange 212' and distal flange 216'. As illustrated in FIG. 6, protrusion 114' of head 110' may be secured by one or more flanges of knob 200', such that stud 100' is moveably fixed and, thus, is not displaceable along longitudinal axis 102' of stud 100' with respect to knob 200' but is rotatable about longitudinal axis 102' of stud 100' with respect to knob 200'.

Captive fastener 20 also includes a ratcheting means 500' disposed in aperture 204' of knob 200'. The ratcheting means 500' may include one or more ratchet teeth 510' and at least one detent 520'. Although the one or more ratchet teeth 510' are disposed on a ratchet wheel 512' in the embodiment illustrated in FIG. 9, the one or more ratchet teeth 510' may be disposed on and/or coupled to one of stud 100' or knob 200'. For example, in one embodiment, the one or more ratchet teeth 510' are an integral extension of stud 100' or knob 200.'

Detent 520' may be configured as, or a portion of, a C-spring 522'.

According to the embodiment illustrated in FIG. 10, C-spring 522' has a driver 524' that is coupled to stud 100', e.g., by way of being secured in indent 115' defined in protrusion ' 114 of head 110' of stud 100'. Additionally or alternatively, detent 520' may be disposed on and/or coupled to the other of stud 100' or knob 200'. According to one embodiment, detent 520' is an integral extension of stud 100' or knob 200'. The one or more ratchet teeth 510' may be directly or indirectly engageable with the detent 520'.

The detent 520' may be configured to allow rotation of stud 100' around longitudinal axis 102' in the one direction, e.g., by engaging the one or more ratchet teeth 510' upon rotation of knob 200' in the one direction and not engaging the one or more ratchet teeth 510' upon rotation of knob 200' in the opposite direction.

Accordingly, in one embodiment, rotation of knob 200' in one direction rotates stud

100' as a result of engagement between ratchet teeth 510' and detent 520', while rotation of knob 200' in the opposite direction does not rotate stud 100'. In another embodiment, where stud 100' includes driver 118', stud 100' may be rotated in one direction by rotating knob 200' and/or rotating driver 118', while stud 100' may be rotated in the opposite direction only by rotating driver 118'.

According to yet another embodiment, captive fastener 20 is configured to be hand tightenable, but requires a tool to be loosened once hand tightened.

Additional examples of ratcheting means that may be suitably employed in captive fastener 20 are described in U.S. Patent No. 5,642,972, which is incorporated herein by reference, in its entirety and for all purposes.

Referring to FIGS. 11A - 12, captive fastener 20 further includes a ferrule 300', which defines a passageway 304' extending along a longitudinal axis 302' of ferrule 300' from a proximal end 308' of ferrule 300' to a distal end 306' of ferrule

300'. Stud 100', or a portion thereof, is disposed within passageway 304' of ferrule

300' and moveable relative to ferrule 300' along longitudinal axis 102' of stud 100'.

Distal portion 310' and/or distal end 306' of ferrule 300' may have a panel attachment means.

Ferrule 300' has a proximal portion 320' that includes an inward flange

322' and outward flange 324'. Inward flange 322' and/or outward flange 324' may be spaced from proximal end 308' of ferrule 300'. Inward flange 322' extends toward longitudinal axis 102' of stud 100'. Inward flange 322' of proximal portion 320' of ferrule 300' is positioned to engage stop ring 400' directly (e.g., by way of contact) or in directly (e.g., by indirect contact, such as by compressing spring 330' until the load on spring 330' equals or exceeds the displacing force) upon displacement of stud 100' along longitudinal axis 102' with respect to ferrule 300'. The engagement between inward flange 322' of proximal portion 320' and stop ring 400' may secure stud 100', or a portion thereof, such as shaft 120', within passageway 304' of ferrule 300'. For example, when ferrule 300' is attached to panel 12' and/or 14', axial displacement of stud 100' may be impeded after a specified distance when stop ring 400' engages inward flange 322' of ferrule 300'. Inward flange 322' and outward flange 324' of ferrule 300' may also be configured to reduce misalignment of longitudinal axis 302' of ferrule 300' and longitudinal axis 102' of stud 100'. For example, inward flange 322' and outward flange 324' of ferrule 300' may extend to shaft 120' and knob 200', respectively, thereby limiting displacement of shaft 120' of stud 100' in a direction transverse to longitudinal axis 302' of ferrule 300'. According to one embodiment, inward flange 322' and outward flange 324' are configured to reduce the misalignment of longitudinal axis 302' of ferrule 300' and longitudinal axis 102' of stud 100' at a proximal portion 122' of shaft 120' when captive fastener 20 is in its retracted state.

Outward flange 324' of ferrule 300' extends outwardly toward knob 200'.

Outward flange 324' may be positioned to engage an inwardly extending flange, e.g., distal flange 216', of knob 200' upon displacement of stud 100' with respect to ferrule 300'. Stud 100', or a portion thereof, may be secured within ferrule 300' by the engagement of outward flange 324' and proximal flange 216' of knob 200', upon displacement of stud 100' with respect to ferrule 300'. According to one embodiment, outward flange 324' may engage proximal flange 216' of knob 200' as inward flange 322' of proximal portion 320' engages stop ring 400'.

In another embodiment, engagement occurs between outward flange 324' of ferrule 300' and proximal flange 216' of knob 200' when the engagement between inward flange 322' of ferrule 300' and stop ring 400' fails to impede the displacement of stud 100' with respect to ferrule 300'. In yet another embodiment, engagement occurs between inward flange 322' of ferrule 300' and stop ring 400' when the engagement between outward flange 324' of ferrule 300' and proximal flange 216' of knob 200 fails to impede the displacement of stud 100' with respect to ferrule 300'.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

Claims

What is claimed :

1. A captive fastener for attachment to a panel comprising :

a stud including a head and a shaft extending from the head along a longitudinal axis of the stud to a distal end of the stud, the shaft having a fastener portion;

a stop ring affixed to the shaft of the stud and spaced from the distal end of the stud;

a knob having an inwardly extending flange and defining an aperture that extends from a proximal end of the knob to a distal end of the knob, the head of the stud being disposed at least partially within the aperture defined by the knob; and

a ferrule defining a passageway extending along a longitudinal axis of the ferrule from a proximal end of the ferrule to a distal end of the ferrule, the stud being disposed within the passageway of the ferrule and moveable relative to the ferrule along the longitudinal axis of the stud, a proximal portion of the ferrule having :

an outward flange positioned to contact the inwardly extending flange of the knob upon displacement of the stud with respect to the ferrule, an inward flange extending toward the longitudinal axis of the stud, the inward flange of the ferrule being positioned to engage the stop ring upon displacement of the stud with respect to the ferrule, wherein the inward flange of the ferrule is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a proximal portion of the shaft of the stud, and wherein the stop ring is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a distal portion of the shaft of the stud.

2. The captive fastener of claim 1, wherein the head of the stud defines a driver.

3. The captive fastener of claim 2, wherein rotation of the driver of the head in the one direction rotates the stud in a first direction and rotation of the driver of the head in the opposite direction rotates the stud in a second direction, and wherein rotation of the knob in the opposite direction does not rotate the stud in the second direction.

4. The captive fastener of claim 1, further comprising a compression spring

disposed within the passageway of the ferrule and extending between the inward flange of the proximal portion of the ferrule and the stop ring, the compression spring urging against the inward flange of the proximal portion of the ferrule and against the stop ring .

5. The captive fastener of claim 1, wherein the distal end of the ferrule has a panel attachment means.

6. The captive fastener of claim 1, wherein the inward flange of the proximal end of the ferrule extends toward the longitudinal axis of the stud, thereby limiting displacement of the shaft of the stud in a direction transverse to the longitudinal axis of the ferrule.

7. The captive fastener of claim 1, wherein the inward flange of the ferrule and the stop ring are configured to coaxially align the longitudinal axis of the ferrule and the longitudinal axis of the stud.

8. The captive fastener of claim 1, wherein rotation of the knob in one direction is configured to rotate the stud about the longitudinal axis of the stud and rotation of the knob in an opposite direction is not configured to rotate the stud in the opposite direction about the longitudinal axis of the stud.

9. The captive fastener of claim 8, further comprising :

one or more ratchet teeth disposed on one of the stud or the knob; and a detent disposed on the other of the stud or the knob and engageable with the one or more ratchet teeth ;

wherein the ratchet teeth are configured to allow rotation of the stud around the longitudinal axis of the stud in the one direction; and

wherein the detent engages the one or more ratchet teeth upon rotation of the knob in the one direction and wherein the detent does not engage the one or more ratchet teeth upon rotation of the knob in the opposite direction.

10. The captive fastener of claim 1, wherein the fastener portion includes threads.

11. The captive fastener of claim 1, wherein the fastener portion of the shaft is

spaced from the distal end of the stud.

12. The captive fastener of claim 1, wherein the shaft of the stud has a distal

portion a cross-sectional area of which is smaller than a proximal portion of the shaft.

13. The captive fastener of claim 10, wherein the shaft of the stud has a distal

portion the cross-sectional area of which is equal to or smaller a minor diameter of the cross-sectional area of the threads of the fastener portion.

14. The captive fastener of claim 1, wherein the shaft of the stud has a lead portion interposed between the fastener portion of the shaft and the distal end of the shaft, thereby facilitating alignment of the fastener portion with a fastener portion of a mating panel.

15. A captive fastener for attachment to a panel comprising :

a stud including a head and a shaft extending from the head along a

longitudinal axis of the stud to a distal end of the stud, the shaft having a fastener portion;

a ferrule defining a passageway extending along a longitudinal axis of the ferrule from a proximal end of the ferrule to a distal end of the ferrule, the stud being disposed within the passageway of the ferrule and moveable relative to the ferrule along the longitudinal axis of the stud; and a proximal portion of the ferrule having an inward flange extending toward the longitudinal axis of the stud, the inward flange of the proximal portion of the ferrule being positioned to engage the stop ring upon displacement of the stud with respect to the ferrule,

wherein the inward flange of the ferrule is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a proximal portion of the shaft of the stud, and wherein the stop ring is configured to reduce misalignment of the longitudinal axis of the ferrule and the longitudinal axis of the stud at a distal portion of the shaft of the stud.

16. The captive fastener of claim 15, further comprising a knob defining an

aperture, the head of the stud being disposed at least partially within the aperture defined by the knob, wherein the knob has an inwardly extending flange and the proximal portion of the ferrule has an outward flange, the outward flange of the ferrule being positioned to contact the inwardly extending flange of the knob upon displacement of the stud.

17. The captive fastener of claim 15, further comprising a compression spring

disposed within the passageway of the ferrule and extending between the inward flange of the proximal portion of the ferrule and the stop ring, the compression spring urging against the inward flange of the proximal portion of the ferrule and against the stop ring.

18. The captive fastener of claim 15, wherein the distal end of the ferrule has a panel attachment means.

19. The captive fastener of claim 15, wherein the fastener portion of the stud is spaced from the distal end of the stud.

20. The captive fastener of claim 15, wherein the shaft of the stud has a distal portion a cross-sectional area of which is smaller than a proximal portion of the shaft.

21. The captive fastener of claim 15, wherein the fastener portion includes threads.

22. The captive fastener of claim 21, wherein the shaft of the stud has a distal portion the cross-sectional area of which is equal to or smaller a minor diameter of the cross-sectional area of the threads of the fastener portion.

23. The captive fastener of claim 15, wherein the shaft of the stud has a lead

portion interposed between the fastener portion of the shaft and the distal end of the shaft, thereby facilitating alignment of the fastener portion with a fastener portion of a mating panel.