Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3548704 A
Publication typeGrant
Publication dateDec 22, 1970
Filing dateMar 24, 1969
Priority dateMar 11, 1969
Also published asCA849810A
Publication numberUS 3548704 A, US 3548704A, US-A-3548704, US3548704 A, US3548704A
InventorsEdward A Kutryk
Original AssigneeBarber Machinery Co Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Protective cap
US 3548704 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [72] Inventor EdwardA.Kutryk 2,819,642 1/1958 Refrigeri......................

CalprLAlberlmCuada 3,135,558 6/1964 Johnston,.|r.etal..

6 9 5 H 5 l s 5 Wm NB CGM Hm mu ns 6 oo 6 3 9 9 H H s n 7 2 2 3 4 8 1 6 4 9 2. 4 3

C mmm a mm o. e mm m. G. m AMhA mmmm Primary Examiner-Edward C. Allen Calgary, Alberta, Canada Attorney-Weir, Marshall, Mac Rae & Lamb [54] PROTECTIVE CAP ABSTRACT: A protective cap for placing over the end of a bolt, or similar threaded member, and its associated nut, to protect from corrosion and damage. An improved appearance is also provided. The cap has a main body portion, tubular: in construction, having its inner surface shaped to frictionally engage the circumference of a nut, and also has an inner projection which is adapted to engage with the thread of a bolt. Engagement with the thread prevents dislodging by axial movement and engagement with the nut prevents rotational move- 0 n e m '9 2 5 mmmmon m uuuwm a M 0m 5 .U 8 n5 3 m M3 m m m: m m Im m s 4 m Wm m n a & M 3 2U M M l I] l m mm m u PROTECTIVE CAP This invention relates to protective caps and particularly for protective caps for fitting over projecting ends of bolts to cover, and protect, the bolt ends and associated nuts. There have been many proposals for covering bolt ends ends and similar items, against corrosion, or damage, for decorative purposes, and other reasons, but generally the devices provided only fit over the end of the bolt, leaving the nut uncovered. Such devices may cooperate with the nut to give the appearance of a cap nut, or may leave a gap between the device and the nut. In either arrangement corrosion of the bolt thread can occur and generally some arrangement may be needed to prevent the removal of the device by widing off the thread. Also, the nut may be liable to corrosion.

It is an object of the present invention to provide a cap which covers both the threaded portion and also the nut, to protect both thread and nut. A further object is to provide a cap with an improved appearance. h

The present invention provides a cap which fits over the bolt end and also the associated nut. The cap has frictional engagement with the thread of the bolt for' retention of the cap on the bolt, and also has a part which engages with the nut to prevent inadvertent rotation of the cap. Thus the entire bolt end, and its associated nut, are covered. This gives improved corrosion avoidance, better protection and'also an improved appearance.

The cap of the present invention will accept a variation in the length of the threaded portion extending beyond the nut, without difficulty and without requiring any modification.

A cap, of the present invention, comprises; a tubular body having a closed end and an open end for passage over the bolt end and nut; the open end of the body shaped to frictionally engage the circumference of the nut; and an inner projection extending from the closed end of the body towards the open end and adapted to engage the thread of the bolt end.

Conveniently, the body is cylindrical with spaced ribs formed on the inner surface at the open end, the ribs engaging with at least some of the flats of the nut. The-inner projection may also be tubular and having its end, remote from the closed end of the body, shaped to engage the bolt thread.

The invention will be readily understood by the following description of one embodiment, by way of example, and modifications thereof, in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross section through a cap on the line 1--1 of FIG. 2;

FIG. 2 is an end view of the cap illustrated in FIG. I, viewed on the open end;

FIG. 3 is a cross section, similar to that of FIG. 1, illustrating the cap of FIGS. 1 and 2 in position on a nut and bolt end; and

FIG. 4 is a cross section on the line 4-4 of FIG. 3. I

As seen in FIGS. 1 and 2, the cap comprises a tubular main body closed at one end by an end part 11, and having an open end 12. Formed on the inner surface of the body 10, adjacent the open end 12, are ribs 13, the ribs extending axially. Extending from the inner surface of end part 11 is a tubular projection 14. Projection 14 extends towards the open end 12, part way of the distance between end part 11 and open end 12 and has an open end 15. At the open end 15 of the projection 14 is an inwardly projecting rib 16. I

The cap is conveniently made of a flexible plastic. The end part I l, in the example shown, is slightly domed.

Application of the cap is illustrated in FIGS. 3 and 4. As seen in FIGS. 3 and 4, the ribs 13 engage with the flats of a nut 21. The rib 16 engages with the thread 22 of bolt end 23.

' The flexibility of the material enables the rib to pass over the thread crests as the cap is pushed on and also permits slight distortion of the rib 16 to permit the rib 'to fitinto the thread groove.

Instead of being a complete tube, projection 14 can be in the form of separate fingers, allowing improved flexibility. Another alternative is for the projection 14 to be slit at several places the slits extending axially for a short distance.

While conveniently o a plastic material, and made in one piece as by molding, a cap can be of other materials, and formed of, for example, two parts joined'together. For decorative, or other reasons, a cap may be stainless steel or anodised aluminum for example. In such cases, the projection 14 is like- Iy to be a separate part attached to the end part I]. The projection 14 could then be of a material dissimilar to that of the body 10. If the body 10 is of plastic material, the projection can be made as a separate part.

While the body 10 is shown as cylindrical, in the drawings, it is possible to make the body with other cross-sectional forms, particularly at the open end. Thus the part of the body at the open end 12 can be made hexagonal in cross section to suit the shape of the nut. Or, this part can be formed with, for example, two opposed flat surfaces which cooperate with flats on the nut. However, the provision of ribs, or similar projections, as at 13, facilitates positioning of the cap on the nut as it is not necessary to accurately align the cap with the flats as would be the case with flats or similar formations on thecap.

It will be appreciated that a cap of the present invention is also usable with nuts having other than hexagonal shapes. By suitably shaping at least the interior of the open end, caps can be applied to square nuts and nuts of otherforms.

The cap can readily be positioned by pushing on over the bolt end and over the nut. Similarly the cap is readily removed by pulling off axially. The whole of the thread beyond the nut is protected, as is also the nut. The cap will accommodate considerable variation in length of thread extending beyond the nut.

I claim:

1. In combination with a nut and bolt assembly including a bolt having a thread thereon, and a nut engaging said thread and having a plurality of flat side faces with meeting corner areas, said bolt having a threaded end portion extending beyond said nut, a cap therefor comprising a tubular body having a sidewall, a closed end and an open end, and a tubular member coaxially positioned within said body and having a sidewall fixed at one end to said closed end of said body, said sidewall of said tubular member being radially spaced from sidewall of said tubular body and terminating in an open end lying in a plane spaced axially inwardly from the plane of said open end of said tubular body, said tubular member having a radially inwardly projecting annular rib adjoining said open end thereof, said rib having a cross section complementary to that of said thread and projecting into a root of said thread, said sidewall of said tubular body having on the inside surface thereof a plurality of ribs extending axially between said planes and each of said axial ribs engaging one of said nut faces in spaced relation to said comer areas.

2. A nut and bolt assembly as defined in claim 1, said cap being a unitary member of plastic composition.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3978761 *Jun 26, 1975Sep 7, 1976Thomas & Betts CorporationFastener assembly
US4070048 *Jul 6, 1976Jan 24, 1978Philip YoungReleasable window guard
US4121700 *Jun 22, 1977Oct 24, 1978Girling LimitedDisc brakes for vehicles
US4191068 *Jun 22, 1978Mar 4, 1980Webasto-Werk W. Baier Gmbh And Co.Drive arrangement for sliding roofs, window panes and other similar members in motor vehicles
US4211283 *Dec 12, 1977Jul 8, 1980C. Van Der Lely N.V.Soil cultivating implements
US4557654 *Aug 7, 1984Dec 10, 1985Fuji Seimitsu Mfg. Co., Ltd.Cover of a nut in engagement with a bolt
US4582462 *Sep 27, 1984Apr 15, 1986Horst ThielPlastic protecting cap for a polygon nut
US4784555 *Mar 12, 1987Nov 15, 1988Cantrell Roger MProtective and ornamental cover for nuts and bolts
US4786224 *Feb 22, 1988Nov 22, 1988Maron Products, Inc.Wheel lug nut cover
US4818476 *Feb 25, 1988Apr 4, 1989Westinghouse Electric Corp.Reactor vessel stud thread protector
US4840547 *Aug 10, 1988Jun 20, 1989Tecumseh Products CompanyCompressor including protective cap for hermetic terminal
US4905931 *Feb 18, 1988Mar 6, 1990The Boeing CompanyArc suppression around fasteners
US4907929 *Nov 25, 1986Mar 13, 1990Johnston Jr Raymond BBolt and nut cover
US4923348 *Feb 13, 1989May 8, 1990Tremco IncorporatedProtective cap construction and method
US5044599 *Apr 27, 1990Sep 3, 1991Outboard Marine CorporationCover for transom bracket mounting screws
US5180266 *Apr 30, 1992Jan 19, 1993Metal Flow CorporationThreaded sheet metal decorative cap
US5297854 *Oct 19, 1992Mar 29, 1994Big Rapids Products, Inc.Wheel cover retention system
US5590992 *Apr 18, 1995Jan 7, 1997Aluminum Company Of AmericaCover for a bolt and nut
US5624218 *Sep 12, 1995Apr 29, 1997Dauwalter; Charles G.Safety lock device for screw fasteners
US5642973 *Dec 26, 1995Jul 1, 1997Pretty; Daniel GlennPlumbing cleanout cover
US6196637 *Dec 3, 1998Mar 6, 2001American Chrome Chicago CompanyNutcover and hubcap locking system
US6238158Mar 22, 2000May 29, 2001Alcoa Inc.Hub retention for lug nut covers
US6654436 *Oct 8, 2001Nov 25, 2003Westinghouse Electric Company LlcStud enclosure and method of use
US6667438Dec 5, 2001Dec 23, 2003ErmcoPadmount transformer enclosure
US6802681Nov 19, 2002Oct 12, 2004Itw LimitedFastening element
US6910355 *Feb 4, 2003Jun 28, 2005Richard C. SwansonFastener lockout device
US8002508Sep 26, 2008Aug 23, 2011Griptight Bolt Cover Co.Protective cover for fasteners
US8209789 *Nov 11, 2008Jul 3, 2012Ldr Industries Inc.Quick-release structure of a toilet cover hinge
US8528534 *Nov 17, 2009Sep 10, 2013Mcp Ip, LlcArchery bow axle
US8959672Dec 10, 2012Feb 24, 2015Centoco Plastics LimitedToilet seat hinge with sliding keyway
US9033633 *Mar 26, 2014May 19, 2015John A. HenryTall toilet bolt cap
US9163656Nov 1, 2012Oct 20, 2015Mitsubishi Aircraft CorporationLightning protection fastener and cap for lightning protection fastener
US9416811May 9, 2014Aug 16, 2016Airbus Operations LimitedInjectable nut cap
US9500165 *Jul 1, 2013Nov 22, 2016Ford Global Technologies, LlcSealing cap using o-ring for vehicle intake manifold
US9528788Jul 30, 2015Dec 27, 2016Mcp Ip, LlcArchery bow axle with fastener
US9528791 *Sep 10, 2013Dec 27, 2016Mcp Ip, LlcArchery bow axle
US9541118 *Sep 23, 2013Jan 10, 2017The Boeing CompanySystems and methods for use in covering a portion of a fastener protruding from a surface
US20020192052 *May 17, 2002Dec 19, 2002Renzo RuspaCover for a threaded connecting member
US20040148985 *Feb 4, 2003Aug 5, 2004Swanson Richard C.Fastener lockout device
US20100080667 *Sep 26, 2008Apr 1, 2010Larry ReedProtective cover for fasteners
US20100132686 *Nov 17, 2009Jun 3, 2010Mcpherson Mathew AArchery Bow Axle
US20110067170 *Nov 11, 2008Mar 24, 2011Lawrence GreensponQuick-Release Structure of a Toilet Cover Hinge
US20120267270 *Mar 22, 2012Oct 25, 2012Denso CorporationProtective sleeve for spark plug
US20140007858 *Sep 10, 2013Jan 9, 2014Mcp Ip, LlcArchery Bow Axle
US20140294533 *Mar 26, 2014Oct 2, 2014John A. HenryTall Toilet Bolt Cap
US20140373261 *Mar 11, 2014Dec 25, 2014Carole TriantafillosDecorative Toilet Bolt Cover
US20150000625 *Jul 1, 2013Jan 1, 2015Ford Global Technologies, LlcSealing cap using o-ring for vehicle intake manifold
US20150082603 *Sep 23, 2013Mar 26, 2015The Boeing CompanySystems and methods for use in covering a portion of a fastener protruding from a surface
US20150086295 *Sep 23, 2013Mar 26, 2015The Boeing CompanySystems and methods for use in covering a portion of a fastener protruding from a surface
DE3033714A1 *Sep 8, 1980Mar 26, 1981Fuji Seimitsu Mfg Co LtdProtective elastomer cap fitting over nut and screw bolt - has lower portion shaped to located on nut and upper portion fitting bolt thread
DE3335723A1 *Oct 1, 1983Apr 11, 1985Radolid Thiel GmbhKunststoffschutzkappe fuer eine mehrkantmutter
EP0040667A1 *Feb 13, 1981Dec 2, 1981Trailer Marine Transport CorporationTire security cap
EP1258641A3 *May 17, 2002May 21, 2003Ruspa Officine S.P.A.Cover for a threaded connecting member
EP1312812A2 *Nov 8, 2002May 21, 2003ITW LimitedFastening element
EP1312812A3 *Nov 8, 2002Dec 3, 2003ITW LimitedFastening element
WO2000057069A1Mar 22, 2000Sep 28, 2000Alcoa Inc.Two-piece cover for bolt and nut assembly and clip thereof
WO2013065311A1 *Nov 1, 2012May 10, 2013Mitsubishi Aircraft CorporationLightning-proof fastener and cap for lightning-proof fastener
WO2015121624A1 *Feb 6, 2015Aug 20, 2015Airbus Operations LimitedLobed nut cap
U.S. Classification411/373, 411/927
International ClassificationF16B37/14, F16B39/08
Cooperative ClassificationY10S411/927, F16B37/14, F16B39/08
European ClassificationF16B37/14, F16B39/08