Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED PINTLEPIN
BACKGR~DUND OF THE INVENTION
a1 Field of the invention
The present invention relates to improvements to the structure
of seam connectors hereinafter called "pintlepins", which are used for
connecting together adjacent ends of segments of an endless belt.
bf Brief description of the prior art
In some industries, especially the papermaking industry, use is
made of machines comprising endless belts. Such belts which are sometimes
called "felts", usually consist of segments of fabric whose ends are joined by
a fabric or metal seam. Each seam is made of loops that are integral to the
ends of the adjacent segments and positioned in such a manner as to
intermesh and form together a substantially tubular opening extending over the
full width of the belt. To close the seam, a lacing cable or yarn, called
"pintle"
in the trade, is inserted through the so-formed tubular opening.
To facilitate insertion (viz, threading) of the pintle through the
tubular opening when, for example, a worn or torn-out segment must be
replaced by another one for maintenance purpose, it is of common practise to
attach a rigid or semi-rigid guide wire, called "lead-in wire" or "leader" in
the
trade, to the front end of the pintle. Such leader is connected to the pintle
by
means of a metal sleeve or tubing, hereinafter called "swedger", in which the
adjacent ends of the leader and pintle are swaged. The resulting assembly
including the pintle, the leader and the swedger, is called "pintlepin" by
some
manufacturers, including the Applicant. For the sake of simplicity, this
expression will be used hereinafter to designate this assembly.
In use, the leader is inserted into one end of the tubular opening
and pushed through the seam until it reaches the opposite end of the opening
which, depending on the width of the belt, may be up to 12 meters long.
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Then; the tip of the leader may be grasped and pulled until the pintle is in
position.
From a practical standpoint, it is of the uppermost importance
that the outer diameter of the pintle used for closing the seam be
substantially
equal to the diameter of the tubular opening formed by the intermeshed loops.
Indeed, such permits to avoid slacks in the belt and to reduce the risk of
premature tearing out of the seam. Thus, it is of common practise to use a
pintle sized to snugly fit into 'the corresponding tubular opening.
It is also of common practise to use a leader of smaller diameter
that the pintle to which it is connected, in order to facilitate insertion of
the
leader into the intermeshed loops which are not necessarily well in line when
the leader is inserted into one end of the seam and pushed forwards.
It is further of common practise to use a leader having a mark on
its forward portion adjacent to its tip, in order to make this portion
immediately
visible if, by accident, one of the intermeshing loops is not engaged during
installation of the pintlepin. Such a mark may consist of a layer of paint of
bright or fluorescent colour that is applied onto the forward portion of the
leader to make it clearly visible if is moves out of the seam.
If all the above features are highly desirable and actually
requested by the pintlepin users, some of them have some inherent drawbacks
that have not be overcome so far.
A first one of these drawbacks is directly "associated" to the
above mentioned requirement that the outer diameter of the pintle be equal to
the diameter of the tubular opening defining the seam. When such a
requirement is met, the swedger which, as aforesaid, consists of a tubing
pinched or swaged onto the front end of the pintle, necessarily has at least
its
rear portion that is of a larger diameter than the front end of the pintle and
thus of a greater diameter then the tubular opening. As a result, the
pintlepin
is vary difficult to insert and push and may even be jammed if one may not
reach its tip to pull it.
A second drawback lies in the way the front edge of the swedger
is shaped. If, as has been done so far, this front edge is straight and thus
extends in a radial plane relative to the leader on which it is swaged, it
forms
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2~8U970
a "step" which reduces the above mentioned advantage deriving from the use
of a leader of smaller diameter. Such step may also "scratch" and damage the
loops under certain circumstances.
A third drawback lies in the way the paint has been applied so far
onto the forward portion of the leader to make it visible. As aforesaid, such
a
leader is made of rigid or semi-rigid material, which is preferably a metal
such
as stainless steel, an alltemper rod or a spring-wire. The paint is applied as
a
coating onto the leader and does not really "stick" on it. As a result, it is
often
scratched out by friction as soon as the leader is moved forwards in the seam,
thereby making its tip no more visible.
SUMMARY QF THE II~11/ENTIQN
A first object of the present invention is to provide an improved
pintlepin of the above mentioned type, which, thanks to its structure, does
not
have any more the first drawback mentioned hereinabove. In other words, the
first object of the invention is to provide an improved pintlepin which is
easy
to install in a seam having a tubular opening of the very same diameter as the
pintle of the pintlepin.
A second object of the invention is to provide an improved
pintlepin which, in addition to the above improvement, does not have any more
the second drawback above herein mentioned. More particularly, the second
object of the invention is to provide an improved pintlepin whose swedger does
not form a step that scratches the loops of the seam during its insertion.
A third object of the invention is to provide an improved pintlepin
whose visible mark is "applied'" in a much better way onto the forward portion
of the leader, thereby making such mark more difficult not to say impossible
to scratch out.
The pintlepin according to the invention is intended to be used for
connecting together adjacent ends of segments of an endless belt of a given
width, the adjacent ends having loops that are positioned in such a manner as
to intermesh and form together a tubular opening of a given diameter
extending over the full width of the belt.
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CA 02180970 2005-12-02
Like all the existing pintiepins like the one disclosed, by way of .
example, in Canadian patent No. 1,329.031 of 7994 to ASTEN GROUP INC.,
the pintlepin according to the invention comprises:
- a pintle consisting of at least one filament, the pintle
having a front end and an outer diameter substantially identical to the
diameter
of the tubular opening formed by the intermeshed loops at the adjacent ends
of the segments to be connected;
- a leader made of a rigid or semi-rigid material, the leader
being of a smaller diameter than the diameter of the tubular opening and
having a front end, hereinafter called "tip~, and a rear end, the leader
acting
as a guide to facilitate insertion for the pintle through the tubular opening
in
order to form together with the loops, a segment-connecting seam; and
- a swedger for connecting together the pintle and the
leader, the swedger consisting of a tubing having a front portion and a rear
portion in which the rear end of the leader and the front end of the pintle
are
respectively swaged.
In accordance with the first object of the invention as reported
hereinabove, the pintlepin disclosed hereinabove is improved in that the front
end of the pintle has a peripheral recess sized and shaped to receive the rear
portion of the swedger and thus prevent this swedger from having an outer
diameter exceeding the outer diameter of the pintle. As a result, the swedger
does not exceed in size the pintle and thus does not make its insertion into
the
seam more difficult.
In accordance with the second object of the invention, the
pintlepin disclosed hereinabove may also be improved in that the front portion
of its swedger in which the leader is swaged, has a front edge which is
forwardly downwardly bevelled. As a result, there is no more "step°
onto the
leader, which may damage the loops.
In accordance with the third object of the invention, the pintlepin
according to the invention may further be improved in that the forward portion
of the leader on which the paint is applied to, has a grated surface.. Such a
grated surface can be made by grinding, sanding or swedging, and causes the
paint to adhere to the leader in a much better way than before.
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CA 02180970 2005-12-02
The invention and its numerous advantages will be better
understood upon reading the following non-restrictive description of a
preferred
embodiment thereof given with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic plan view of the seam of two adjacent
fabric segments of an endless belt, showing the way such a seam is closed
with a pintle;
Fig. 2 is a perspective view of a pintlepin of conventional
structure;
Fig. 3 is identified as "prior art", is a partial view of a pintlepin of
known structure, wherein the tip of the leader and the swedger are shown in
cross-section; and
Fig. 4 is a view similar to the one of Fig. 3, showing the tip of the
leader and the swedger of a pintlepin according to the invention.
For simplicity's sake, the same reference numerals have been
used to identify the same structural elements in the accompanying drawings.
GENERAL DESCRIPTION OF THE INVENTION
As it has already been explained hereinabove in the "Background
of the invention", the present invention is concerned with improvements to the
structure of the pintlepins 1 (see Fig. 2) that are used for connecting
together
the adjacent ends of segments of fabric 3,3' (see Fig. 1 ) in order to form an
endless belt. Each of the adjacent ends includes loops 5 which are positioned
in such a manner as to intermesh and form together a tubular opening 7
extending over the full width of the belt. The intermeshed loops 5 defines a
seam closed by means of a pintle 9 which consists of one or more filaments
preferably made of a synthetic material such as Nylon (~) or polyester.
In the following description, reference is made exclusively to a
pintle consisting of a monofilament, such being the most preferred embodiment
of the invention because of the simplicity of its manufacture. However, it
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CA 02180970 2005-12-02
t
must be understood that the invention is not restricted to this embodiment and
could easily be adapted to pintles consisting of more than one filaments, as
is
disclosed in the above mentioned Canadian patent No. 1329,031 , or with
pintles made of strands of synthetic fibers braided together, as is disclosed
in
Canadian patent No. 944,183 of 1974 to FILZTUCHVERWALTUNGS-
GESELLSCHAFT.
To facilitate insertion of the pintle 9 though the tubular opening
7 defining the seam, a rigid or semi-rigid guide wire 11 called "leader" is
connected to the front end 13 of the pintle 9 by means of a metal tubing 15
called "swedger". The leader 11 has a tip 17 which is preferably rounded to
facilitate its insertion. It is preferably made of metal, such as stainless
steel,
and is of such a length as to make it easy to push through the tubular opening
until its tip 17 can be grasped and pulled.
As aforesaid, the swedger 15 which connects together the pintle
9 and the leader 13, is made of a metal which is preferably stainless steel,
brass or copper. It has a rear portion 19 in which the front end 13 of the
pintle
is swaged. It also has a rear portion 21 in which the rear end 23 of the
leader
is swaged.
The leader 13, swedger 15 and pintle 9 altogether forms the
pintlepin 1 referred to hereinabove, which is sold as such to those who have
to connect end-to-end segments of a fabric endless belt. As can be
understood, after completion of the connection, the leader 13 and any excess
of the pintle 13 must be cut out.
In practice, the pintle 9 is selected in such a manner that its outer
diameter "D" is substantially identical to the diameter of the tubular opening
7 formed by the intermeshed loops 5 at the ends of the adjacent segments 3,
3' to be connected. Such is important to avoid slacks in the belt and to
reduce
the risk of premature tearing out of the seam. The leader 13 is also selected
in such a manner that its outer diameter "d" be smaller than "D", in order to
facilitate its insertion into the intermeshed loops 5.
In the existing pintles, like the one shown in Fig. 3, the swedger
15 always has a rear portion 19 which is of a larger diameter than the front
end 13 of the pintle 9. As was explained hereinabove, this can be a problem
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2180970
when the pintle 9 is of the same diameter as the tubular opening 7, because
the outer diameter of the pintle 9 is "increased" by the thickness "t" of the
metal sheet forming the swedger.
In accordance with the invention, this problem is very simply yet
efficiently solved by making a peripheral recess 25 all around the front end
13
of the pintle 9. Such recess 2.5 can be made by cutting, scraping or molding
the front end 13 of the pintle 9. It is sized and shaped to receive the rear
portion 19 of the swedger 15 and thus to prevent it from having an outer
diameter that exceeds the outer diameter of the pintle which itself
corresponds
to the inner diameter of the tubular opening 7.
Preferably, the depth of the recess 25 is selected so as to be
substantially equal to the thickness "t" of the metal sheet forming the
swedger, so that the outer surface of the swedger 15 extends flat with the
one of the pintle 9, as is shown in Fig. 4.
It has been found out by the Applicant that this "solution" solves
very efficiently the above problem, without affecting the strength of the
connection between the swedger 15 and the pintle 9.
In accordance with a preferred embodiment of the invention,
another problem noticed with the existing pintlepins is solved by using a
swedger 15 having a front edge 27 which is forwardly downwardly bevelled,
as is shown in Fig. 4. As a result, there is no more step onto the rearward
portion leader, which may damage the loops 5.
As aforesaid, it is of common practice to apply a layer or coating
29 of paint of bright or fluorescent colour onto the forward portion of the
leader 13, adjacent to its tip, in order to "mark" this portion and make it
clearly
visible if, by accident, one of the loops 5 of the seam is not engaged.
In accordance with another preferred embodiment of the
invention, such a coating of paint 29 is applied onto the leader 13 after the
forward portion of the same has been grated by sanding, grinding or swedging.
Such a grating causes the paint to adhere to the leader in a much better way
and not to exceed the outer diameter of the remaining portion of the same.
This solves a further problem encountered with the existing pintlepins like
the
one shown in Fig. 3.
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Of course, numerous other modifications could be made to the
preferred embodiment of the invention broadly disclosed hereinabove without
departing from the scope of the invention as defined in the appended claims.
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