[0001] The invention relates to a spool defined in the preamble of claim 1, meant for loop
metal wire.
[0002] Thin metal wires looped around a given assumed lengthwise axis, and particularly
so-called double loop metal wires are generally used for example in the binding of
books, calendars and exercise books. Thin loop metal wire is elastic in the sideways
direction, and owing to its spiral loop, it is spring-like in the direction of the
assumed lengthwise axis.
[0003] For usage and transport, metal wire is coiled on a spool, generally comprising an
elongate body made of hollow chipboard or hardboard, the ends of said body being provided
with end flanges likewise made of chipboard or hardboard, which end flanges are locked
by a metal fastener to the shell body. In order to facilitate the uncoiling of the
metal wire by automatic or semi-automatic uncoiling devices, the loop metal wire should
be coiled evenly on the spool, wherefore the outer surface of the spool body, as well
as that side of the planar flange that falls on the side of the spool body center,
should be essentially even. The loop metal wire is taken into use by uncoiling the
wire from the spool by an automatic uncoiling device and by cutting the wire into
suitable lengths. The uncoiling of the metal wire from the coil is made by uncoiling
elements that rotate the coil by gripping the flanges and by rotating the coil body
arranged on a suitable suspension rod at the flanges. For a successful uncoiling process,
the end flanges must naturally be fastened to the body.
[0004] In most cases, the coil manufacturer agrees to take care of the further treatment
of the empty coils returned by the user. This means that after usage, the coils are
either transported to be refilled, or they are disposed of. The latter solution is
a burden to the environment and causes extra expenses for the manufacturer in increased
dumping fees and expenses caused by the making of new coils. In case the coils should
be refilled with metal wire, they should be easily taken to their building elements
in order to reduce transport costs.
[0005] In the loop metal wire coils that are commercially available at present, where at
the end of a shell made of chipboard or hardboard there are attached flanges likewise
made of chipboard or hardboard, the joint between the shell and the end flanges is
made by means of a crimped joint realized by intermediation of a metallic fastener.
When making the crimped joint, the fastener is inserted through the ends of a body
provided with end flanges, so that the brim remains on top of the end flanges, whereafter
the fastener body is compressed against the inner shell surface by working the fastener
wall with a suitable impact tool. A problem with the fastening between the spool body
and flanges realized by this kind of crimped joint is that the fastening is difficult
to be released without breaking the elements forming the spool. There also are known
locking systems between a spool body and flanges realized by plastic fasteners, among
them the system introduced in the US patent 3,521,833, but the problem with these
is the weak holding capacity of the locking owing to the elasticity of the plastic;
the fastening between the spool body and end flanges is gradually weakened and creates
problems when uncoiling material from the spool, because the body may rotate in a
different rhythm than the flanges.
[0006] From the patent publication US 3,981,400 there is known the joining of a spool body
and end flanges meant for textile yarn by means of a plastic center element inserted
in a hollow tube, The center element is fastened to the end flanges by brackets inserted
through the flanges, and the hold of said brackets is secured by nuts fastened from
the inner surface of the flanges towards the brackets. When fastening the body tube
to the center piece, there are utilized ridges arranged on the outer surface of the
casing of the center piece, to be inserted in the tube. This kind of spool construction
might be suited for textile yarn, but it is not suited for loop metal wire, because
the bulges provided on the inner surface of the end flanges are obstructive for the
metal wire coiling. In addition, it is fairly improbable that the spool shell should
stay in the flanges, in case the spool is compiled and broken to pieces several times
in succession, because the crimped joint between the center part ridges and the tube
is gradually weakened.
[0007] From the patent application AU 67,213/81 there is known a cable coil where the end
flanges are attached to the tubular center part of the coil by a plastic joining piece.
The joining piece is cup-like in shape and provided with a round flange at the outer
end of the collar to be inserted in the tubular part of the coil; in said round flange,
there are attached spring-like legs that are thrust both into the holes arranged in
the end flanges and from outside to the holes located at the ends of the tubular part
of the coil. The spring-like legs remain in place in the apertures arranged in the
tubular body owing to the pressure directed to the coil body by the coiled cable.
This kind of joining piece, suited for cable coils for realizing the junction between
the end flanges and the tubular body, can be used for any material to be coiled that
keeps the spring-like legs in the apertures in place in the tubular body. On the other
hand, this kind of coil is not suited for storing thin, spring-like metal wire according
to the present invention owing to the elasticity of the metal wire, because the spring-like
legs would not stay in place in the apertures arranged in the tubular body.
[0008] From the DE patent application 4,438,256 A1, there is known a bobbin designed mainly
for textile yarn, comprising a hollow body tube, two end flanges that can be fitted
at the ends of the body tube as well as fasteners (sleeves) connecting the end flanges
and the body tube. The outer surface of the tube is provided with recesses 6 and grooves
7, 8, and also the flange has recesses. The fastener is provided with projections
that can be fitted first in the tube recesses 6 and thereafter in the grooves 7 and
8. When the fastener is then wound, it is locked in the tube. The problem with this
kind of fastening method is that a) the flange is fastened to the fastener only by
a crimped joint, which easily allows motion between the flange and the fastener and
that b) the pin-groove joint between the fastener and the body tube in part allows
motions between the fastener and the body tube. In case a spool with a construction
like this would be used for storing thin metal wire, there would be problems both
when coiling metal wire on the spool and when uncoiling wire from the spool, because
the metal wire would easily be coiled in an uneven way on the spool axis, and when
uncoiling the wire, the wire feed in the binding machine would easily be uneven, as
the fastener and the flange could rotate at a different rhythm.
[0009] The object of the invention is to eliminate the drawbacks existing in the prior art
and to realize a spool meant for thin loop metal wire that can be uncoiled and coiled
for several times. At the same time the object of the spool is to be a spool that
enables an easy coiling and uncoiling of loop metal wire on and off the spool by using
currently available feed and uncoiling means.
[0010] The above enlisted objectives are achieved by a spool according to claim 1 and by
a method according to claim 7 for assembling said spool.
[0011] More precisely the invention relates to a spool meant for thin loop metal wire, comprising
a hollow cylindrical body, at the ends of which there are detachably connected two
end flanges by fasteners. Each end flange is provided with recesses belonging to the
locking means for locking a position between the end flange and the fastener, said
recesses being located at the edges of the flange center hole, and the body is near
the body ends provided with apertures belonging to the locking means for locking a
position between the body and the fastener. Each spool fastener has a cylindrical
casing, the bottom edge of which is connected to a bottom and the top edge of which
is connected to a brim-like protrusion. Immediately underneath the brim-like protrusion
of the fastener, the fastener casing is provided with a number of brackets that belong
to the locking elements of the position between the end flange and the fastener, which
brackets can be fitted essentially completely in the recesses located at the edges
of the aperture arranged in the middle of the end flange. Near the top edge of the
fastener casing, there are located spring-like tongue elements belonging to the locking
means of the position between the spool body and the fastener, which tongue elements
can at least partly be pushed from inside the hollow body into the spool body apertures
belonging to the locking means of the position between said hollow body and fastener.
[0012] The basic idea of a spool according to the invention is to utilize separate plastic
fasteners for locking the spool end flanges at the ends of the elongate hollow body.
Each plastic fastener has the shape of a shallow cup, and the top edge of the fastener
has a cylindrical brim element protruding from the body, which brim element is set
on top of the outer edge of the end flange, and each fastener is provided with separate
locking elements for the spool body and the end flange. Underneath the brim element
that is left outside the fastener body, in the fastener body, there are arranged brackets
that have corresponding recesses at the edges of the center hole of the end flange.
The brackets located underneath the fastener brim can be fitted in the recesses located
at the edges of the flange center hole, so that the fastener brackets remain inside
the flanges. Generally immediately underneath the bracket rising up from the fastener
body there is arranged a spring-like tongue element made of the body material, provided
with a protrusion protruding outwards from the fastener. The body end in turn is provided
with an aperture corresponding to the tongue protrusion. The fastener body can be
pushed inside the hollow spool body, so that the spring-like tongue element is inserted
in the aperture arranged at the end of the body from inside the body. The tongue element
is held in the aperture either owing to its structure or to a separate locking element.
[0013] A spool having the structure described above can be taken to pieces and recompiled
for several times, because the pneumatic tongue element made of the fastener material
can be connected to the apertures located at the spool body ends from inside the body
and held there either by a separate locking element and/or by the shape of the fastener.
An advantage in comparison with the above described coil known from the patent publication
AU-67 213/81 - which coil has a somewhat similar tongue element as in the present
invention, but where the legs of the tongue element are inserted from outside the
coil into apertures provided in the coil body - is that in the spool according to
the invention, there is no need to use the specific pressure of the wire to be stored
for strengthening the crimped joint between the tongue and the body aperture, but
the crimped joint is strengthened owing to the pneumatic structure of the tongue provided
in the tongue element and owing to a possible separate support element supporting
the tongue.
[0014] The spool enables an easy coiling and uncoiling of loop metal wire on and off the
spool by current feed and uncoiling devices. In the invention, the joint between the
fastener and the flange is realized by brackets that can essentially completely be
fitted in the center hole recesses of the end flange. As for the joint between the
fastener and the spool body, it is realized by spring-like tongue elements, part of
which can be inserted, from inside the hollow body, manually in apertures belonging
to the locking elements of the position between the body and the fastener. Thus there
is achieved the advantage, for instance in comparison with the arrangement known from
the US patent 3,981,400, that neither the exterior surface of the spool body nor the
interior surface of the flange has grooves or bulges obstructing the coiling or uncoiling
of metal wire. The joints between the fastener and the spool body as well as between
the fastener and the flange are solid and allow several cycles of usage for the spool
(assembling and disassembling) and effectively prevent the fastener and the spool
body as well as the fastener and the end flange from rotating with respect to each
other.
[0015] In a preferred embodiment of the invention, the fastener tongue element is attached
immediately underneath the body bracket located below the brim-like projection surrounding
the top edge of the fastener.
[0016] In another preferred embodiment of the invention, each tongue element is provided
with an elongate, elastic tongue made of the body material, which tongue bends at
right angles with respect to the fastener casing, i.e. into the fastener and out of
the fastener, and on that side of the tongue that faces the spool body when assembling
the spool there is a bracket with such a size and shape that there is created a crimped
joint between the bracket and the body aperture, when said bracket is inserted in
the aperture provided at the end of said body.
[0017] In yet another preferred embodiment of the invention, the crimped joint between the
tongue element and the spool body is strengthened owing to the structure of the tongue
element; the tongue of the tongue element is fastened underneath the brim-like projection
arranged at the top edge of the fastener, and the lower end remains free. In addition,
the tongue element includes a separate support element that can be installed between
that side of the tongue that is turned inside the fastener body and the fastener body,
so that it prevents the tongue bracket from escaping from the spool body aperture,
when said bracket is pushed in said body aperture.
[0018] In another preferred embodiment of the invention, the crimped joint between the tongue
element and the spool body is strengthened owing to the shape of the tongue provided
in the tongue element. In that case the upper end of the tongue is attached underneath
the brim-like projection surrounding the top edge of the fastener, and the lower end
is attached to the fastener bottom.
[0019] The invention is described in more detail below, with reference to the appended drawings.
Figure 1 illustrates the elongated, hollow body of the spool in a perspective view.
Figure 2 is a front-view illustration of the end flange.
Figure 3 illustrates the fastener in a perspective view.
Figure 4 illustrates the tongue element of a fastener according to figure 3, seen
is perspective view.
Figure 5 is a side-view illustration of an assembled spool.
Figure 6 is a perspective-view illustration of part of a fastener provided with a
tongue element according to the first embodiment of the invention.
Figure 7 is a perspective-view illustration of a fastener provided with a tongue element
according to a second embodiment of the invention.
Figure 8 is likewise a perspective-view illustration of part of a fastener provided
with a tongue element according to a third embodiment of the invention.
[0020] Figure 1 illustrates the elongated, hollow body 2 of a spool 1 according to the invention.
In general form, the body 2 is a cylindrical tube made of cardboard, provided with
identical end elements 2c; 2c', 2c" and with a center hole 2d passing from end to
end through the body, said center hole being on one side defined by the inner body
walls 2e and on the other side, in the end elements 2c of the tube, by the end edges
2b; 2b', 2b". The inner diameter d1 of the center hole 2d is essentially equal to
the inner diameter D of the aperture 3a located in the middle of the end flange 3
described in more detail in figure 2.
[0021] Each end element 2c; 2c' and 2c; 2c" of the tube is provided with two round holes
4; 4" passing through the tube wall 2a. In the appended drawings, said holes 4; 4"
located at the end are spaced at the mutual distance of roughly 180 degrees, all at
the same distance from the end edges 2b' or 2b". Because of the view angle, the figure
only shows one of the holes 4; 4"a and 4; 4"b arranged at the ends 2c' and 2c". The
distance of the holes 4" from the end edge 2b of the tube end edge 2b is equal to
the distance of the bracket arranged in the tongue element from the fastener brim
(cf. figure 3). The (locking) holes 4; 4"a and 4; 4"b provided at the tube end 2c
belong to a set of identical but separate locking elements 4, 4", the purpose of which
is to lock the mutual position of the spool body 2 and the fastener 5, described in
more detail in figure. 3, when the spool is in the assembled form. The size and shape
of each locking hole 4; 4" is designed to be such that it can receive the protrusion
arranged in the fastener tongue element 4; 4' so that a crimped joint is created between
the locking hole and the protrusion.
[0022] The structure of the end flanges or plates 3 is described in figure 2. In the center
of each essentially round end flange 3 made of cardboard, there is arranged a generally
circular aperture 3a (below also called center hole 3a), and the inner diameter of
the space 3a of this aperture, defined by the mainly regular, circular edge 3b, is
D. Said end flange diameter D is equal to the inner diameter d1 of the center hole
2d of the body tube, so that the edge of the flange center hole 3a can be supported
against the edges 2b of the body tube 2. In shape, the edges 3b of the end flange
center hole 3a do not form completely regular circles, but they are provided with
two recesses 6; 6"a and 6; 6"b directed away from the end flange center. The recesses
6"a and 6"b are located at a mutual distance of 180 degrees on the edge 3b of the
center hole 3a. Said recesses belong to separate but identical locking elements 6;
6" that are used for locking the mutual motions of the end flange 3 and the fastener
5, described in more detail in figure 3, when assembling the spool. Each recess 6;
6" is designed, for the mutual locking of the end flange 3 and the fastener 5, so
that the size and shape of said recess 6" correspond to the brackets 6' rising upwardly
from the casing of the fastener 5, so that the brackets are nested essentially completely
inside the flange recesses, thus forming a tight fit (by intermediation of a crimped
joint) that prevents a mutual rotary motion of the end flange 3 and the fastener 5.
Here it is extremely important that the bracket 6' placed in the casing of the fastener
5 remains inside the end flange recess 6", at least on the side of the inner surface
3e of the end flange, i.e. on that side of the end flange that is turned towards the
other end flange, when the spool 1 is in assembled form (figure 5).
[0023] For locking the mutual position of the body 2 and the end flange 3 of the spool,
the invention uses a fastener 5 that generally resembles a shallow cup in shape and
is advantageously made of plastic; the structure of said fastener is described in
detail in figures 3 - 4 and 6 - 8. The fastener 5 has a cylindrical casing or body
5b, and the bottom edge of said body is connected to a bottom 5a and a the top edge
is provided with a brim-like protrusion 5c. Here the fastener bottom edge means that
edge of the casing that is first pushed in the center hole 2d of the spool body 2
when assembling the spool, and respectively the fastener top edge means that edge
of the fastener casing 5 that in the assembled spool 1 remains somewhat above the
edge 2b of the tubular body 2 or on the same level with it. The planar, smooth bottom
5a attached to the casing 5b of the fastener 5, and the cylindrical casing 5b have
a diameter d2 that is somewhat smaller than the inner diameter d1 of the center hole
2d of the tubular body 2 illustrated in figure 1, so that the fastener 5 can be smoothly
slid inside the hollow body 2. In the middle of the fastener bottom 5a, there is a
hole 7 by which the spool is rotated when uncoiling thread-like loop metal wire from
the spool body 2. A brim-like protrusion 5c surrounds the fastener top edge on the
same level with the edge; said brim is made of the same material (plastic) as the
fastener, and it should be so wide that the fastener can be supported against the
outer surface 3d of the end flange 3 at the brim. The outer surface 3d of the end
flange 3 is that end of the end flange that is turned away from the end flange attached
at the other end of the spool, when the spool is in its assembled form. Immediately
underneath the brim-like protrusion 5c, partly connected to said brim 5c, the fastener
casing is provided with upwardly rising brackets 6; 6'. In shape, each bracket 6'
is roughly a rectangular prism, and one of its sides is integrated with the brim 5c.
The shape and size of the brackets 6; 6' correspond to the shape and size of the recesses
6" provided at the center hole edge 3b of the end flange 3, so that each bracket 6'
can be completely nested inside the recess 6". Figure 3 shows only one of the brackets
6', because the brackets are placed at 180 degrees from each other, on the cylindrical
fastener body. The brackets 6' are made of the same material as the fastener casing
itself. Immediately underneath each bracket 6', on the casing 5b of the fastener 5,
there is arranged a tongue element 4; 4', by which the position between the fastener
5 and the body tube 2 is arranged to be non-rotating. Each fastener 5 has two identical
tongue elements 4' that are located at 180 degrees from each other, on opposite sides
of the casing 5b, and they are made of the same material as the fastener casing itself.
The tongue element 4' provided in the spring-like tongue element 4' that locks the
position of the spool body 2 and the fastener 5 to be mutually immovable can be realized
in several different ways, some of which are illustrated in more detail in figures
6 - 8.
[0024] As is observed in figures 3 and 4 and 6, the tongue element 4; 4' includes an elongate
tongue 4b made of the body material, which tongue element is at its top end connected
to the fastener body 5b, immediately underneath the bracket 6'. The tongue 4b is made,
owing to its pneumatic material (plastic) and structures, by removing some material
of the casing 5b at the location of said tongue 4b, so that in the body there is created
a rectangular aperture 4a behind the tongue 4b, and the tongue can be considered to
be fastened at one edge of said aperture. The tongue 4b is provided with an protrusion
4c rising upwardly from the surface of the tongue, at the fastening point between
the tongue 4b and the casing 5b, at the opposite end of the tongue 4b. Generally the
shape of the protrusion 4c is cylindrical, and its diameter is essentially equal or
somewhat smaller than the diameter of the circular locking hole 4; 4" arranged at
the wall 2a of the tube 2, in order to make the protrusion fit in said aperture 4;
4" for realizing a crimped joint between the protrusion 4c and the aperture 4" (cf.
figure 1). The protrusion 4c is placed on the outer side of the fastener casing 5b,
which outer side of the casing 5b is turned towards the inner wall 2e of the body
aperture 2; 2d, when the fastener is in the locking position, inserted in the body
center hole 2d. In the rest position, the tongue 4b of the tongue element 4' is on
the same level with the outer surface of the fastener casing 5b, whereas said protrusion
4c protrudes somewhat from the level of the outer surface of the casing 5b. When the
spool 1 is assembled, the protrusion 4c remains inside the wall 2a of the body tube
2 in the aperture 4", in which case it does not obstruct the coiling of metal wire
on or off the spool body.
[0025] Figure 5 illustrates a spool 1 in lengthwise cross-section, seen from the side. Two
end plates (flanges) 3; 3' and 3; 3" are connected respectively to the end elements
2c; 2c' and 2c; 2c" of the tube 2 by using the fastener 5 for connecting said elements
to be mutually non-rotating. Next we shall describe the locking mechanism of the locking
element 4 between the fastener 5 and the spool body 2, which locking element comprises
a tongue element 4' of the fastener 5 and a corresponding spool body aperture 4",
as well as the locking element 6 of the locking mechanism between the fastener and
the end flange, which locking element 6 comprises a bracket 6' provided in the fastener
body and a recess 6" arranged in the center hole 3a of the end flange 3.
[0026] As was already maintained, the outer diameter of both the even, round bottom 5a that
is seamlessly connected to the casing 5b of the fastener 5, and the outer diameter
of the cylindrical casing 5b is d2, which diameter is somewhat smaller than the diameter
d1 of the center hole 2d of the tubular body 2 illustrated in than figure 1. The inner
diameter d1 of the hollow body 2 of the spool 1 in turn is essentially equal to the
inner diameter D of the aperture 3a provided in the center of each end flange 3. For
assembling the spool, the fastener 5 can be slid through the aperture 3a provided
in the center of the end flange 3 to inside the hollow spool body 2 by inserting the
fastener bottom 5a first, so that the brim-like protrusion 5c of the fastener will
at the end of the thrusting motion be supported against the outer side 3d of the end
flange 3. At the same time, the inner side 3e of each end flange 3 is in turn supported
against the edge 2b of the center hole 2d of the spool body 2. During the thrusting
motion of the fastener into the aperture 2d of the body 2, the protrusion 4c protruding
at right angles from the top of the tongue 4b of the tongue element 4' meets the inner
surface 2e of the center hole 2d of the body 2, which motion pushes said pneumatic
tongue towards the inside of the fastener 5. When the thrusting of the fastener 5
into the body tube 2 is continued, the protrusion 4c provided on the surface of each
elastic, pneumatic tongue 4b fits in the round aperture 4; 4" provided at the end
2c of the body tube. In this position, said protrusion 4c is pushed, owing to the
spring-like features of the tongue 4b, into said aperture 4", so that a friction-based
crimped joint is created between the protrusion and the aperture, and this crimped
joint locks the mutual position of the fastener 5 and the body tube 2. In the mutually
locked position, all mutual motions of the fastener 5 and the body tube 2, particularly
rotary motions, are prevented. The crimped joint between the tongue element 4; 4'
and the round aperture 4" passing through the wall of the spool body 2 can be reinforced
in many ways, some of which are described by way of example in figures 7 - 8. At the
same time, when the crimped joint is created between the tongue element 4' and the
aperture 4" provided in the wall of the body 2, each bracket 6; 6' provided in the
fastener body gets into contact with the recess 6; 6" located at the edge 3b of the
center hole 3a of the end flange. Each bracket 6' is pushed in a recess 6" corresponding
to the size and shape of the bracket, so that said bracket 6' remains completely inside
the recess 6", thus locking the mutual position of the fastener 5 and the end flange
3 to be non-rotating. These kind of brackets 6' do not create on the inner sides 3e
of the flange 3 any formation obstructing the coiling of metal wire on or off the
spool. In the mutual locking position, the mutual motions of the fastener 5 and the
end flange 3, particularly rotary motions, are prevented.
[0027] The uncoiling of the spool 1 takes place simply and rapidly; the fastener body 5b
is subjected to an external (traction) force, by which the fastener body is pulled
upwardly through the aperture 2d of the spool body 2, towards the aperture edge 2b'
or 2b" and simultaneously the protrusions 4c belonging to the fastener elements 4
between the fastener 5 and the spool body 2 are pressed through the holes 4" provided
in the walls of the body end 2c, so that they are pushed back into the aperture 2d
passing along the inside of the spool body 2. Thereafter the fasteners 5 can be removed
from the ends 2c of the tube 2, and the end flanges 3 can in turn be released from
the body 2.
[0028] The locking element 4 locking the mutual motions between the body 2 and the fastener
5 can also be realized in other ways. In an embodiment of the invention (not illustrated
in figures), the crimped joint created between the protrusion 4c of the elastic, spring-like
tongue 4b and the aperture 4; 4" provided at the body end 2c is secured by a safety
pin that is pushed through part of the protrusion 4c extending to the outer surface
of the casing of the spool body 2, so that it prevents said protrusion 4c from being
pressed back into the aperture provided inside the body 2.
[0029] In another preferred embodiment of the invention, the crimped joint between the protrusion
4c provided in a tongue element 4, 4' according to figures 3 and 6 and the aperture
4; 4" located at the end 2c of the body 2 is secured by a separate thin locking pad
4d included in the looking element 4, as is illustrated in figure 7. The locking pad
4d is pushed between the tongue 4b of the tongue element 4' and the inner surface
5b' of the fastener casing 5b through the aperture provided behind the tongue 4b,
so that the locking pad is supported against inner surface 5b' of the body, simultaneously
preventing the tongue 4b from moving back towards the inside of the fastener.
[0030] In a third preferred embodiment of the invention (figure 8), the tongue 4b of a tongue
element 4; 4' made of the material of the casing 5b of the fastener 5, used as the
locking element 4; 4', is at the top end connected to the top edge of the fastener
casing 5b provided with a brim-like protrusion 5c, at the bottom end seamlessly to
the round fastener bottom 5a. The elasticity of the tongue 4b of the tongue element
4' in the radial direction of the fastener 5 (= the direction of the radius of the
circular bottom 5a and of the radius of curvature of the casing 5b) is achieved first
of all by making the tongue 4b relatively long and thin in comparison with the vertical
width and peripheral length of the cylindrical casing 5b of the fastener. Here the
vertical width means the distance between the fastener bottom 5a and the brim 5c when
proceeding along the surface of the casing 5b. Another factor connected to the spring-like
quality is that the first part 4b' of the tongue is connected immediately below the
brim-like protrusion 5c of the fastener and proceeds there on the level of the casing
5b at right angles towards the fastener bottom 5a. From around the first part 4b'
of the tongue 4b, there is extracted material in order to make a clearance 4a between
each lengthwise edge of the tongue and the fastener casing 5b. The second part 4b"
of the tongue 4b is connected to the circular bottom 5a of the fastener, so that each
lengthwise side of the second tongue part 4b" is separated by a gradually narrowing
groove 4f arranged in the bottom 5a. The grooves 4f proceed fairly far towards the
center of the bottom 5a, when observed from the junction of the bottom 5a and the
casing 5b. Now the junction point of said parts 4b' and 4b" of the tongue 4b is made
inwardly elastic at the border of the bottom 5a of the fastener 5 and the casing 5b.
When a fastener 5 according to figure 8 is now pushed, in the assembling step of the
spool 1, bottom 5a first into the center hole 3d of the end flange 3, inside the tubular
spool body 2, where the diameter of the inner aperture 2d is equal to the outer diameter
of the fastener casing 5b, the protrusion 4c of the tongue element 4; 4' pushed at
right angles outwardly from the tongue 4b gets into contact with the inner surface
2e of the body 2. Now said protrusion 4c creates a pressure that pushes the pneumatic
tongues 4b to inside the fastener 5, as was already described, but in this case the
tongue 4b is mainly flexible at the junction between its first part 4b' and second
part 4b", not along the whole length as in the tongues 4b of the fastener illustrated
in figures 6 and 7, where the other end of the tongue 4b is free. By using this kind
of tongue 4b illustrated in figure 8, there is achieved the advantage that when the
protrusion 4c is pushed into the aperture 4" provided in the end wall of the body
2 and has created a friction-based crimped joint with the aperture, said crimped joint
need not be separately reinforced. This is due to the fact that when the second part
4b" of the tongue 4b is directly connected to the bottom 4c, it prevents the flexing
motion of the tongue 4b towards the inside of the fastener 5 in the direction of the
plane of the bottom 5a.
[0031] In the above specification, the invention is described with reference to exemplary
embodiments of the invention, and for a man skilled in the art it is obvious that
the invention can be realized also in many other ways within the scope of the appended
claims.
[0032] Consequently, the outer wall of the casing 5b of the fastener 5, and/or the inner
wall 2e of the center hole 2d of the spool body 2, can be provided with various control
arrangements, such as grooves or shoulders that guide the fastener 5 inside the body
2 in a position where the protrusion 4c of the tongue 4b is pushed directly inside
the aperture 4; 4" located at the end of the body. Likewise, the number and shape
of the locking elements 4; 4', 4" and 6; 6', 6" used for locking the mutual positions
between on one hand the fastener 5 and the spool body 2, and on the other hand between
the fastener 5 and the flange 3, may vary. Thus for instance the end wall of the spool
body 2 can be provided with 3 - 6 holes 4", and in shape they can be for example circular,
quadratic or truncated cones, in which case respectively the shape of the protrusion
4c of the tongue 4b in the tongue element 4; 4' must correspond to the shape of said
holes 4", and the number of the tongues 4b provided in the fastener 5 must correspond
to the number of holes 4" provided at the ends 2c of the body 2. At the edges of the
center hole 3a of the end flange 3, there may also be recesses 6" used as locking
elements 6; 6" that are greater in number and different in shape than the ones shown
in the above described examples. The number and shape of these recesses 6; 6" should
correspond to the number and shape of the brackets 6; 6' rising upwardly from the
outer surface of the casing 5b of the fastener 5. It is particularly important that
said brackets 6' are such that they fit completely in the recesses 6" and do not form
on the inner side 3e of the end flange 3 any obstructive formations that could hinder
the coiling or uncoiling of the metal wire.
1. A spool (1) meant for thin loop metal wire, comprising a hollow cylindrical body (2),
at the ends of which there are detachably connected two end flanges (3) by fasteners
(5), so that each end flange (3) is provided with recesses (6; 6") belonging to the
locking elements (6) for locking the position between the end flange (3) and the fastener
(5), said recesses being located at the edges (3b) of the flange center hole (3a),
and the body (2) is in the vicinity of the body ends (2c; 2c",2c') provided with apertures
(4; 4") belonging to the locking elements (4) for locking the position between the
body (2) and the fastener (5), and each spool fastener (5) has a cylindrical casing
(5b), at the bottom edge of which there is connected a bottom (5a) and at the top
edge a brim-like protrusion (5c),
characterized in that
- the fastener casing (5b) is immediately underneath the brim-like fastener protrusion
(5c) provided with a number of brackets (6; 6') belonging to the locking elements
for locking the position between the end flange (3) and the fastener (5), which brackets
can be fitted essentially completely inside the recesses (6,6") provided at the edges
of the aperture (3a) located in the center of the end flange,
- in the vicinity of the top edge of the fastener casing (5b), there are arranged
spring-like tongue elements (4; 4') belonging to the locking elements for locking
the position between the spool body (2) and the fastener (5), which tongue elements
can be fitted at least partly, from inside the hollow body (2), in the spool body
apertures (4; 4") belonging to the locking elements of the position between said hollow
body (2) and fastener (5).
2. A spool (1) according to claim 1, characterized in that each tongue element (4; 4') includes an elongate tongue (4b) made of the material
of the cylindrical fastener casing (5b) that is elastic in the direction of the radius
of curvature of the casing (5b), i.e. at right angles to the casing surface, that
side of the tongue that is nearest to the spool body (2) being provided with a protrusion
(4c), the shape and size of said protrusion being such that a crimped joint is created
between said protrusion (4c) and the aperture (4; 4") in the body (2), when the protrusion
(4c) is pushed in said aperture (4").
3. A spool (1) according to claim 2, characterized in that the tongue (4b) of the tongue element (4; 4') is immediately fastened underneath
the bracket (4; 4') provided in the casing (5b), and that said tongue (4b) is, with
respect to the width and peripheral length of the fastener casing (5b) relatively
long and thin and made of the material of the casing.
4. A spool (1) according to claim 3, characterized in that the upper end of the tongue (4b) of the tongue element (4; 4') is fastened underneath
the brim-like protrusion (5c), and that the lower end is free and that said tongue
element possibly also includes a separate support element (4d) such as a safety pin
or a locking pad that prevents the protrusion (4c) of the tongue (4b) from escaping
from the body aperture (4; 4") back towards the inside of the fastener (5).
5. A spool (1) according to claim 3, characterized in that the upper end of the tongue (4b) of the tongue element (4; 4') of the fastener is
fastened underneath the brim-like protrusion (5c), and the lower end is connected
to the fastener bottom (5a).
6. A spool (1) according to any of the preceding claims, characterized in that at the edges (3b) of the aperture (3a) provided in the center of the end flange (3),
there are arranged two recesses (6; 6") that are arranged at angles of 180 degrees
with respect to each other, and that the casing (5b) of the fastener (5) is provided
with two brackets (6; 6') that are placed at angles of 180 degrees with respect to
each other, immediately underneath the brim (5c), which brackets can be fitted in
said recesses (6; 6").
7. A method for assembling a spool according to claim 9, characterized in that the end flanges (3) are supported at the opposite ends (2c) of the hollow spool body
(2), so that the aperture (3a) provided at the center of each end flange (3) is aligned
with the center hole (2d) of the body (2), whereafter at both ends of the body (2)
there is fitted a fastener (5), so that said fastener (5) is inserted bottom (5a)
first through the aperture (3a) provided in the center of the flange, and thereafter
through the aperture (2d) provided in the center of the body, and the pushing of the
fastener (5) is continued, until the fastener brim (5c) gets into contact with the
outer surface (3d) of the spool end flange (3), whereafter the brackets (6; 6') arranged
in the fastener casing (5b) are fitted essentially completely in the recesses (6;
6") of the edge of the aperture (3a) arranged in the center of the end flange, and
the spring-like tongue elements (4; 4') or part of them (4c), belonging to the locking
elements (4) of the body (2) and fastener (5), are fitted from inside the hollow body
(2) in the apertures (4; 4") belonging to the locking elements (4) of the position
between the body (2) and the fastener (5) for creating a crimped joint between said
apertures (4") and tongue elements (4') or part (4c) of them.
8. A method according to claim 7, characterized in that the crimped joint of the locking element (4) for locking the position between the
fastener (5) and the spool body (2) is supported by a separate support element (4d)
belonging to the locking element, or by intermediation of the structure of the tongue
element (4').
9. A method according to claim 8, characterized in that the crimped joint is supported by placing a separate support element (4d) between
that side of the tongue (4b) that is turned away from the spool body and the spool
body (2).
10. A method according to claim 8, characterized in that the crimped joint is supported so that the tongue (4b) of the tongue element (4;4')
is at both ends arranged to be integrated in the general structure of the fastener
(5).