Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF INVENTION
BOLTS, NUTS AND FASTENER SYSTEM
1. Field of the Invention
This invention relates to fasteners and particularly to bolts and nuts as well
as non-threaded fasteners intended to replace bolts and nuts.
2. Description of the Prior Art
At the present time there is a variety of known bolts and nuts, but they all
have the same serious shortcomings. They require the bolt head to be held
by a wrench when the nut is being tightened or untightened. That means a
worker needs two wrenches and both of his hands used to tighten or undo a
bolted connection and for larger bolt sizes frequently require two persons to
tighten or undo a bolted connection. They are very often extremely difficult
to assemble when the matching bolt holes on the parts being assembled are
not aligned, as usually happens when steel structures or piping networks are
being assembled in the field and for example for large pipes it may take a
team of workers, using hoists and jacks and/or cranes, several hours or even
the whole day to assemble one misaligned flange connection. Furthermore
the bolts and nuts for larger sizes holes are very heavy and when a large
number of them are used such as for example in pressure vessels or large
pipes connected by flanges they add considerable weight to the structure.
Thread overtightening routinely leads to thread damage or leveling and that
is partly caused by very uneven force/stress distribution acting on thread
coils with by far the largest load/stress being held by the first thread coil.
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Lastly the threaded connections are constantly at risk of coming undone due
to vibration causing the need for various types of lock-washers and other
securing means which sometimes fail. All of these shortcomings or
disadvantages require solutions.
3. Objects and Advantages
One object of the present invention is to provide a threaded connection that
doesn't need that the opposing side of the side being tightened or unscrewed
be held by a wrench.
Another object is to make possible to assemble connections where the
matching bolt holes are misaligned.
Another object is to provide the components for threaded connections that
are of much lower weight.
Another object is to provide the fastening system performing the same
functions as the bolted connections and having of the above objects realized
while not featuring any threads at all.
Another object is to provide the nut producing much more uniform
distribution of stress between thread coils.
Another object is to provide the nut with the self-locking capability.
4. Brief Description of the Drawings.
Fig 1 is the view of bolt of the first embodiment.
Fig 2 is the cross-sectional view of bolt of first embodiment.
Fig 1A shows bolt of second embodiment.
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Fig 2A shows a cross-sectional view of bolt of second embodiment.
Fig 3 shows bolt of third embodiment.
Fig 4 shows cross-section of bolt of third embodiment.
Fig 5 shows in assembly bolt and cut nut of fourth embodiment.
Fig SA shows a cross-section of bolt of fifth embodiment.
Fig 7 shows a spring like cut nut of fifth embodiment.
Fig 8 is the view of bolt of the fifth embodiment.
Fig 9 shows the bolt of sixth embodiment.
Fig 10 shows the bolt of seventh embodiment.
Fig 11 shows a fastener of the eighth embodiment in an assembly.
Fig 12 shows a version of eighth embodiment with worm gear on shaft.
5. Description
The first embodiment of this invention (Figs 1 and 2) consists of a bolt under
whose head (1) the unthreaded part of said bolt's shank has at least 1, but
preferably 2 or more, sharp rib(s) (2) tapered downward. Said ribs' edges are
at a distance from the bolt's axis and of hardness sufficient to assure that
they very slightly cut into the edges of bolt hole in part (3) which is being
held by that threaded connection. Since the torque is not expected to be
transmitted to the bolt head, optionally it can be made more cheaply; smaller
and optionally of round shape, but strong enough to withstand the axial force
in the threaded connection. It should be noted that the smaller bolts of this
embodiment can be easily produced by stamping just like many of known
bolts of comparable smaller sizes are.
The second embodiment of bolts of this invention (Figs lA and 2A) consist
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of a bolt under whose head there are two or more offshoots or branches (2a)
stemming from its shank which are elastically flexible the more the further
they are from their base. Said offshoots' tips are within a predetermined
distance from the shank's central axis to assure that they will enter the
round
hole in part (3) at the assembly time with said hole being of a predetermined
diameter for a specific bolt size. The other part being joined is (3a) and nut
(3b). The offshoots are curved so as to produce their elastic bending and
therefore pressure onto the sides of hole (3) when the bolt, and thus its
offshoots, is pressed or tapped to enter the hole (3) and thus also produce a
substantial and predetermined force of static friction to prevent the bolt
from
turning once the tightening starts. It should be noted that the smaller bolts
of
this embodiment can be easily produced by stamping just like many of
known bolts of comparable smaller sizes are. The features of the first and
second embodiments can be combined, so that the offshoots (2a) stemming
from the shank are elastically flexible along most of their length, but are
rigid and have sharp edges like rib edges (2) in the first embodiment in the
immediate vicinity of their attachment to the shank.
The third embodiment (Figs 3 and 4) features at least one lug or knob or
corner (4) on the bolt which enters into a matching profile of a hole in part
(3) being assembled in order to prevent torque transmission to the bolt's
head and thus to eliminate the need to hold the bolt's head while tightening
or unscrewing the threaded connection. Said lug(s) can optionally be made
thin enough to have a predetermined degree of flexibility in order to absorb,
if it were to happen due to thermal expansion of the part (3), a very small
creep of part (3). Since the tightening torque is not transmitted to the bolt
head it can be made more cheaply; round and smaller, but strong enough to
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withstand the axial force in the threaded connection. As today holes for the
fasteners are commonly cut by laser cutters, plasma cutters or various
punching machines, suitable non-circular hole shapes can be produced just
as easily and at the same cost as the circular ones. The same is true for the
holes in cast or stamped parts. In cases where holes are drilled, two
overlapping holes with the same or different diameters can be made one
after another resulting in one co-joined hole of non-circular shape suitable
for these bolts. It should be noted that the smaller bolts of this embodiment
can be easily produced by stamping just like many of known bolts of
io comparable smaller sizes are. Alternatively the bolt's pertinent cross-
section
can be made of other non-circular shapes such as oval, rectangle etc with the
hole on a part (3) being of a corresponding shape to that of said bolt's cross-
section. Clearly there can be a great variety of said non-circular shapes and
mutatis mutandis they are all considered to be within the scope and spirit of
this invention.
In the fourth embodiment (Fig 5 and Fig 5a) the non-circular hole is located
in the other part being assembled (3a) which is facing the nut (3b). As the
torque therefore is not transmitted to the length of the bolt, it only bears
the
axial tensile load and therefore it consists of a metal shank of predetermined
smaller diameter compared to known bolts for the same axial load.
Optionally instead of a metal shank it comprises a string or strut made of
materials vastly stronger and lighter than steel, such as graphene or carbon
fiber or Kevlar . Said string (4a) will preferably comprise a small diameter
metal wire to render said string (4a) stiffer and bendable for easier use and
can be tied or otherwise attached by known means to the threaded rod (4b)
and to the bolt head (5) which is also made round and of a pre-determined
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smaller size. Said bolt-head needs to be strong enough to withstand the axial
load. Bolt head (5) and/or threaded rod (4b) can optionally be made to be
hooked or otherwise attached by known means to string (4a) at the threaded
connection's assembly time or they would come pre-assembled. The
threaded rod (4b) has at least one segment on its side cut off (6), which
clearly decreases the strength of each thread coil. To mitigate that by means
of more evenly distributing the stress between thread coils, a nut (Fig 6) is
cut like a cut spring. Such cutting can be implemented for example by a
lathe and it is complete with a see-through cut (7) thereby turning the nut
into a variety of a very short cut spring. In first version the thread in the
nut
has pitch which is larger by a predetermined very small amount compared to
the thread of the bolt which will cause the helically cut nut to be compressed
while being forced onto slightly lower thread pitch bolt. Nut compression
will produce a force acting to counteract the very large force from the bolt's
thread coil pressing forward on the nut's first thread coils immediately
adjacent to the nut's face pressing forward against the part, that's being
assembled, surface. At the same time the rear thread coils of the nut will be
pressing on the bolt's thread coils rearward, thus distributing the force
acting
on the nut's thread along its length; which is our objective. That kind of nut
likely won't need lock-washers. Alternatively in a second version, the nut's
thread pitch will be the same as that of the bolt, the helical cut's direction
is
counterclockwise with a large predetermined pitch size, the cut is of
predetermined width and the holes through helically cut nut's coils are at
locations which line up when the tightening is completed and the nut is
twisted into position wherein the helical cut almost or practically "closes".
At that point a pin is inserted through the now aligned holes and the nut
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stays twisted and compressed because of the pin preventing its untwisting
upon tightening wrench removal. Alternatively such nut's untwisting can be
prevented by placing on it a retainer bracket shaped as a round or hexagonal
bracket. Said retainer bracket may be placed on the nut's narrower collar
(not shown). Nut's compression will produce the distribution of stress on
coil threads as described above. Third version of the helically cut nut (Fig
7)
features a bulge (8) which serves to put pressure onto the next spring-like
coil located across the cut from the beginning of the first coil which is
located just in front of the leading end of the nut's thread. Optionally in
this
version a narrow central core of nut material (such as steel) of predetermined
diameter is still left in place along the length of said cylindrical spiral
(helical) cut, so that the cut is not complete, to make the body of said nut
to
act more like an integral whole while still providing a possibility of very
small relative movement between the coils formed by this cut, compared to
known solid nuts and therefore better stress distribution between the thread
coils. As these nuts can be expected to have a higher load bearing capacity
compared to prior art nuts, they likely can be made of lower height, with
fewer thread coils. Naturally such helically cut nuts can also be used with
all
the other embodiments of this invention featuring the threaded bolts as well
as prior art bolts.
Fifth embodiment of this invention (Fig 8) is primarily intended for use on
the existing machinery and structures where there are no non-circular bolt
holes and where the use of ribbed bolts of first embodiment is not possible
due to unacceptability of making indentations in the bolt hole perimeter or
impossibility of tapping bolt into place due to lack of room for that,
fragility
of the part being connected etc. The bolt will have on its head's underside
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surface facing the part (3) a layer of rapid acting glue covered and sealed by
a removable plastic film (8a). The glue of known variety will preferably be
strong yet fragile so that when the bolt, when it needs to be removed, can be
easily loosened by tapping on its end once the nut has been unscrewed.
The sixth embodiment of this invention (Fig 9) features flexible bolts
suitable for assembling moderately misaligned flanges and connections. Said
bolts feature the shank, fully or partially threaded along its length, made of
relatively thick-walled tubing (9) along the length of which runs a helical
cut
(9a), similar to what was described for the nuts of fourth embodiment, with a
much larger pitch compared to the pitch of the thread. That cut is intended to
make the shank flexible, however the flexibility of such bolts will be
inversely proportional to said cut's pitch dimension. Said cut also weakens
the shank potentially making it susceptible to irreversible plastic tensile
deformation along its length in cases of relatively small cut pitch. To
is eliminate the possibility of this kind of axial deformation, optionally
the
stoppers (10) at both ends of the bolt are held by a suitable string (11) made
of materials of sufficient strength similarly to what was described for the
string (Fig 5, item 4a) and its hook ups and/or attachments in the fourth
embodiment. A helical cut nut as described in the fourth embodiment would
be preferable to use with this bolt. Clearly the bolt of this embodiment can
be implemented in conjunction with the features of other embodiments such
as the first, second or third embodiment or of conventional prior art bolts,
requiring the bolt head to be held by a wrench while the nut is tightened. As
this bolt will be relatively more expensive it is likely to be used only for
the
assembly process to be replaced with a cheaper bolt of other embodiments or
a conventional prior art bolt once the flanges or connections have been
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aligned and other bolts are in place holding them together.
The seventh embodiment of this invention is a highly flexible bolt (Fig 10)
for aligning and pulling together the significantly misaligned flanges and
other connections. It will comprise a flexible chain (12) similar to chains
used in chain drives which can easily flex within their plane, but cannot be
twisted and will transmit the tightening torque to the bolt head if it is
implemented as in a conventional prior art bolt. The chain will be welded,
hooked or attached by other suitable known means to the threaded rod (13),
onto which the nut is placed, and to the bolt's very short shank (14) or
optionally, if appropriate, to the bolt head directly. Alternatively instead
of a
chain a suitable flexible shaft can be used which will also transmit torque to
the bolt's head. Furthermore the bolts of this embodiment can also be
implemented with the features of other embodiments such as of the first,
second or third embodiment assuring that the bolt head stays in place and
does not turn during bolt tightening. When the chain (12) is hooked or
otherwise attached by easily removable means to the short shank (14) and
threaded rod (13) the length of all 3 components can be selected as needed in
each particular case.
The eighth embodiment is a threadless fastener system intended to replace
the threaded bolts and nuts (Figs 11 and 12) and is particularly well suited
to
replace the large, expensive bolts and nuts, typically with low- friction
coating, whose weight is often much more than one kilogram, used for
example for connecting by flanges large diameter pipes with various valves
in pipelines as well as in industrial piping networks and in pressure vessels.
It is also suitable for use in a variety of other threaded connection
applications where it is advantageous to reduce said threaded connections
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weight; such as for example in aviation. It will comprise a round stopper-
head (15) with a function analogous to that of a bolt head with a flexible
strip or string (16) attached to it by known means similarly to what was
described for string (4a) in fourth embodiment. Said strip (16) may be flat
and its other end will be inserted through the elongated opening of the shaft
(17) and wound onto it. Alternatively said string (16) may be round and
wound onto shaft (17) which in that case will have helical groove (not
shown) on its otherwise cylindrical surface for the string coils. Shaft (17)
is
mounted on support structure of hoist (18) and has on one side either a
square or hexagon end (19) while on the other side it has a disc with a spiral
coil outline (20) and above it a lip (21) which is a part of support (18). On
said support (18) below said disc (20) is mounted a bendable strip (22) with
a wedge shaped tip in front of the gap between said disc (20) and lip (21).
Alternatively instead of disc (20) for preventing the unintended unrolling of
said strip or string (16) a sprocket can be used, with said sprocket being
coupled with a ratchet instead of a strip with a wedge (22).
Said stopper-head and the hoist assembly can be made of suitable light
weight materials such as for example carbon fiber for applications where
weight reduction is important. In the second version of this embodiment
(Fig 12) a worm gear (23) is mounted on shaft (17) instead of the faceted
ending (19) in mesh with a worm shaft (24) mounted onto support structure
(18) either horizontally or vertically. Said worm shaft (24) will have a
faceted ending (25), either square or hexagonal for the wrench. There are
other possible designs of the hoist mechanism with a lock and mutatis
mutandis they are all considered to be within the scope and spirit of this
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invention.
6. Sketches and Diagrams.
Sketches provided separately
7. Operation.
For the first embodiment the sharp edges of ribs (2) due to the wedging
effect will initially cut into the edges of bolt hole in part (3) when the
bolt
head is tapped in the beginning of tightening. As the tightening progresses
said edges (2) will cut more deeply into the hole's edges and thus will stay
in
place as the tightening torque increases.
The operation of bolts of the second embodiment is adequately described in
the Description Section and their description of operation will not be re-
iterated here, but is included by way of reference as if fully set forth.
The operation of bolts of the third embodiment is adequately
described in the Description Section and their description of operation will
not be re-iterated here, but is included by way of reference as if fully set
forth.
The operation of bolts and nuts of the fourth embodiment is
adequately described in the Description Section and their description of
operation will not be re-iterated here, but is included by way of reference as
if fully set forth.
The operation of bolts of the fifth embodiment is adequately described
in the Description Section and their description of operation will not be re-
iterated here, but is included by way of reference as if fully set forth.
The operation of bolts of the sixth embodiment is adequately
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described in the Description Section and their description of operation will
not be re-iterated here, but is included by way of reference as if fully set
forth.
The operation of bolts of the seventh embodiment is adequately
described in the Description Section and their description of operation will
not be re-iterated here, but is included by way of reference as if fully set
forth.
For the fastener of eighth embodiment; support structure of the hoist
(18) will be placed over the hole in part being assembled, whereas the
stopper-head (15) with attached flexible strip (16) are mounted by means of
putting said strip through the holes in the flanges being assembled and then
through the elongated opening of shaft (17) and wound onto it. On hexagon
end (19) of said shaft 17 will be placed a wrench socket, with said wrench
usually being hydraulic or pneumatic, also it can be manual. When the
desired degree of tightening is achieved, the bendable strip with a wedge tip
(22) is pushed forward into the narrow gap between the spiral outline disk
(20) and lip (21) and is wedged in said narrow gap thereby fixing the exact
position of disc (20) and thus also the shaft (17) preventing any slackening
of the strip (16). To undo the connection the wedge of bendable strip (22) is
pulled back releasing the disc (20) and the shaft (17) onto which said disc is
mounted, allowing either wrench controlled unwinding of strip (16) from the
shaft (17) or, if circumstances permit, unwinding it at once by pulling on
stopper-head (15). If an optional version of this embodiment (Fig 12) is
used which has built in worm gear for torque magnification, then the wrench
socket will be put onto faceted ending (25) of worm shaft. This fastening
system will permit the assembly, by using a small plurality of such fasteners
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intermittently tightened one after another, of a moderately misaligned flange.
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