Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Having separate expander means – Frangible member
Reexamination Certificate
1997-09-08
2001-05-22
Saether, Flemming (Department: 3627)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Having separate expander means
Frangible member
C411S060100
Reexamination Certificate
active
06234734
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a blind fastener device, and also to a method of clamping a component to a support plate using a blind fastener device.
2. Description of the Related Art
It is of course well-known to provide anchor bolts for fixing to concrete, and in which an expanding sleeve is engaged by a conical head as the fixing is tightened, with the component parts of the sleeve moving radially outwardly into firm gripping engagement with the wall of the passage formed in the concrete to receive the fixing.
However, the invention is not primarily concerned with fixings of this type, (to anchor devices to concrete or brick work), but to the clamping of components to “rolled hollow metal sections” of the type being used increasingly as part of the supporting structure in current industrial building work. Support columns can be formed by square or rectangular box sections, built up from four metal rolled plate sections. When it is desired to secure fixing brackets, pipe supports, electrical conduits, (or any other components of the type used in an industrial building), to a hollow section, it is of course necessary to use “blind fasteners”, since access cannot readily be obtained to the interior of the hollow section to complete the fastening operation. Therefore, using blind fasteners, an expanding sleeve is introduced through aligned openings in the section and the component to be clamped thereto, and a threaded portion is then rotated to draw a conical head into engagement with the inner end of the sleeve to expand the sleeve radially outwardly. The sleeve is usually slotted, so that it is composed of a number of axially extending portions forming separate “legs”, each of which can be deformed outwardly by the conical head and thereby anchor the entire sleeve in the hollow section.
Conveniently, the conical head is temporarily attached to the inner end of the sleeve, so that the sleeve and conical head can be introduced as a single assembly through the opening in the hollow section, and then a threaded fastener can be taken through the component (to be clamped to the hollow section), pass through the head of the sleeve and into threaded engagement with an internal thread in the conical head, and further rotation of the threaded portion pulls the conical head into the inner end of the sleeve so as to expand the sleeve “legs” radially outwardly.
One known design of blind fastener for use with metal sections comprises a slotted sleeve, a conical head temporarily attached to the inner end of the sleeve e.g. by shearable connections, and a specially formed sleeve head at the opposite end of the sleeve to the conical head. The sleeve head comprises a gripping ring formed with a series of radially projecting teeth or other knurling, the purpose of which will be described below.
Evidently, once the sleeve has been introduced into the opening in the hollow section, and the threaded fastener e.g. a bolt is introduced into the sleeve, it is necessary to provide some means whereby rotation of the conical head is prevented so that the sleeve can be moved axially into the interior of the sleeve. In the known construction, in which the conical head is attached to the sleeve, the means for preventing rotation of the conical head comprises the specially formed sleeve head which is able to make gripping engagement with the wall of the opening in the hollow section. This works generally satisfactorily, but evidently it is important that the tolerances in the formation of the sleeve, and the opening in the hollow section, should be relatively close, so that the sleeve is a relatively tight sliding fit as it is introduced. This is necessary so that the surface formation on the sleeve head can make suitable gripping engagement with the wall of the opening in the metal section. This imposes a manufacturing cost, and also care and attention in the formation of the receiving holes in the hollow metal section. Evidently, if the sleeve is introduced into an over-sized opening, and the sleeve rotates freely in this opening while attempt is made to tighten the bolt, there will be idle rotation of the sleeve and the conical head and therefore no axial inward movement of the conical head.
BRIEF SUMMARY OF THE INVENTION
The invention therefore seeks to provide an improved method of clamping a component to a support plate using an improved blind fastener device taken through aligned openings in the component and in the support plate, and which in preferred use of the invention will comprise clamping of any suitable structural component e.g. a support plate or bracket to a hollow metal section.
The improvement which the invention seeks to provide is in ease of completion of the fixing assembly, and avoidance of any need for the sleeve to have to make a gripping i.e. non rotational fit within the opening.
According to one aspect of the invention there is provided a method of clamping a component to a support plate using a blind fastener device taken through aligned openings in the component and in the support plate, said fastener device comprising a slotted sleeve; an apertured sleeve head at one end of the sleeve and which head is over-sized relative to the opening in the component; a threaded fastener portion which can be taken through the aperture in the sleeve head and through the sleeve; a tightening fastener head engaging with the fastener portion; and a diverging sleeve-expanding head mounted on the fastener portion and engageable with the opposite end of the sleeve, said method comprising:
introducing the fastener device to the component in such a way that the sleeve, the threaded portion and the sleeve-expanding head project to one side from the opening in the component, and with said apertured sleeve head and said tightening fastener head being located on the other side of the opening in the component;
presenting said fastener device to the support plate so that the sleeve is received by the opening in the support plate, and said apertured head engages the surface of the component; and
tightening the fastener head in order to draw the diverging head into engagement with the opposite end of the sleeve to expand the latter radially, in which a holding device is engaged with said apertured head to prevent rotation of the latter while said fastening head is being tightened.
The method of the invention therefore allows for easy fixing of a component to a support plate, in that close tolerances are not necessary (as is required by known blind fastener devices), and the fastener device can be a relatively loose fit in the openings in the component and the support plate, provided only that the sleeve head is over-sized relative to the opening in the component so that the sleeve head can seat on a bearing surface surrounding the entrance to the opening.
Any suitable holding device may be used to prevent rotation of the sleeve head, such as a spanner, or a special tool, provided that the sleeve head has a complementary formation to enable it to be engaged by the holding device.
The invention may be used to facilitate the assembly of industrial building structures, in which rolled hollow metal sections are being used, whereby support brackets and other components can be readily clamped to a hollow section e.g. a column, using the invention.
The formation on the sleeve head may comprise one or more flats or any other suitable formation off set from the axis of the threaded portion and engageable by a tool to prevent rotation of the sleeve.
The tightening head of the threaded fastener may take any suitable form, including a bolt head, or a head having a driving socket e.g. a hexagonal socket of the type driven by an Allen key.
The sleeve head may be formed, if required, with a recessed seating in which the tightening head can be entirely received, so that a flush assembly is obtained upon completion of the fixing.
According to a further aspect of the invention there is provided a blind fastener device for use in clamping a component to a support plate, by ta
Glynwed International PLC
Saether Flemming
Workman & Nydegger & Seeley
LandOfFree
Blind fastener and blind fixing method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Blind fastener and blind fixing method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Blind fastener and blind fixing method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2527569