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EP 0 099 254 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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07.12.1988 Bulletin 1988/49 |
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Date of filing: 08.07.1983 |
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International Patent Classification (IPC)4: D03C 3/20 |
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Heald control apparatus
Litzenkontrollvorrichtung
Dispositif de contrôle des lisses
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Designated Contracting States: |
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CH DE FR GB IT LI |
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Priority: |
10.07.1982 GB 8220129
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Date of publication of application: |
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25.01.1984 Bulletin 1984/04 |
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Proprietor: Textilma AG |
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6052 Hergiswil (CH) |
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Inventor: |
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- Griffith, John Dalton
Bonas Machine Company Ltd.
Sunderland. SR4 6SX (GB)
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(74) |
Representative: Monsch, René et al |
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E. BLUM & CO., Patentanwälte
Vorderberg 11 8044 Zürich 8044 Zürich (CH) |
(56) |
References cited: :
EP-A- 0 098 428 DE-A- 2 204 815
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BE-A- 643 612 GB-A- 2 047 755
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The present invention relates to a retention device for a heald rod.
[0002] The U.K. patent application No. 2 047 755 discloses a heald control means including
two flexible retention elements and an electromagnet located between said retention
elements in order to move the retention elements with regard to the electromagnet
and to engage the retention elements with the heald rods. The retention elements are
fixedly mounted to a support block, to which the electromagnet is mounted, too. The
retention elements are provided with a latch formation.
[0003] This device has the disadvantages that a relatively strong magnetic field has to
be generated in order to draw the retention elements against the pole of the electromagnet,
and that the speed of operation is limited.
[0004] The EP-A-98 428, which represents a state of the art according to article 54(3) EPC,
discloses a shedding mechanism for a loom, which mechanism includes two rods which
are recip- rocable between two end positions, two flexible retaining elements held
on a holder and associated to the rods and an electromagnet held between the retaining
elements.
[0005] The electromagnet has a double T-shaped core with flange sections of different width.
An armature body is fixed to the retaining elements such that on one side the armature
body abuts to the wider flange section and on the other side an air gap is provided
between the armature body and the smaller flange section.
[0006] If the rod is moved by means of the knife in the upper position, the retaining element
is deflected in order to adjust the air gap between the armature body and the smaller
flange section to a predetermined value. The mechanism works with two exact triggering
times at which the deflection of the retaining elements may be performed safely on
the side necessary for the function and the power consumption of the electromagnet
may be reduced and the heating may be reduced.
[0007] This mechanism has the drawback that the armature body is provided merely for optimizing
the magnetic circuit.
[0008] The invention as claimed is intended to provide a remedy. It solves the problem of
how to design a retention device for a heald rod, in which the response time for deflecting
the retention arm is quick due to the construction of the retention device and the
positive and reliable operation of retaining the selected heald rod is ensured at
high speed.
[0009] Various aspects of the present invention are hereinafter described with reference
to the accompanying drawings, in which:
Fig. 1 is a side view showing several side by side heald rod retention devices;
Fig. 2 is a perspective view of one of the retention devices shown in Fig. 1; and
Fig. 3 is a schematic illustration of the mechanism for operating the heald operating
knives.
[0010] The operation of the loom of the type to which the present invention particularly
relates is described in the published U.K. patent application No. 2 047 755 and reference
should be made thereto.
[0011] Each heald eye (not shown) is controlled by a pair of heald rods 14 in a similar
manner to that shown in Fig. 1 of U.K. patent application No. 2 047 755 and each rod
14 is provided near its terminal end with an aperture 38 for selective engagement
with a retention device 20.
[0012] A plurality of retention devices 20 is arranged in closely spaced rows, there being
one retention device 20 for each pair of heald rods 14. The retention devices 20 are
conveniently mounted on a common board (not shown) extending across the loom.
[0013] Each retention device 20 includes an electromagnet 22 which is removably mounted
on a support block 23 which is secured to the board. At the upper end of the electromagnet
22 as shown in Figures 1 and 2 an angled bracket 25 is provided, one arm 25a of which
is secured to the electromagnet and the other arm 25b of which seats upon the block
23 and is located on a projection 26. A similar projection 27 is provided on the support
block 23 and a retaining plate (not shown) is located on projections 26 and 27 and
retained in position by the bolt (not shown) passing through bore 24 in the support
23. Accordingly in the event of the electromagnet 22 failing it is a simple matter
to replace it without disturbing the location of the remainder of the retention device.
Conveniently the bracket 25 and support block 23 are plastics mouldings.
[0014] Secured on either side of the support block 23 and extending downwardly therefrom
is a pair of retention arms 40 which co-operate with the heald rods 14 to selectively
retain them in their raised position.
[0015] Each retention arm 40 includes two components, namely a resilient member 41 and a
rigid member 42 which are secured to one another for instance by riveting or welding.
The arms 40 may be considered to comprise three distinct portions, viz, an upper portion
43, an intermediate portion 44 and a lower portion 45.
[0016] The upper portion 43 is composed entirely of the resilient component and provides
a hinge connection between the arm and the support block and provides the arm 40 with
a resilient bias so that the arm 40 is normally spaced from the lower pole 46 of the
electromagnet. Varying the length of portion 43 varies the amount of bias. Conveniently
component 41 is a ribbon of spring steel.
[0017] The intermediate portion 44 comprises both components 41 and 42 which are rigidly
connected to one another. Component 42 is preferably composed of a material which
can be easily magnetised, such as soft iron, and basically acts as a pole piece for
co-operation with the lower pole 46, preferably the portion 44 is arranged so that
its upper end is in contact with the upper pole 47 of the electromagnet. Accordingly
the intermediate portion serves to rigidify the arm below the upper portion and also
provides a magnetic path so that the portion of component 42 adjacent the lower pole
will be a magnetic pole thereby creating a strong attractive force due to polar attraction.
Accordingly, the response time for deflection of arms 40 on energisation of the electromagnet
22 is very quick.
[0018] It is envisaged however that the portion 44 may be located in the region of the lower
pole 46 alone.
[0019] The lower portion 45 of each arm 40 serves to cooperate with the heald rods 14 for
selective retention thereof. The lower portion 45 includes a window 50 formed in component
41 and through which projects a hook formation 51 formed at the terminal end of component
42. The hook formation 51 on penetrating the aperture 38 formed in the operating rod
14 engages the upper edge of aperture 38 and thereby supports the rod 14. It is desirable
that the hook formation 51 is resistive to impacts caused by rapid downward movement
of the rods 14 and so the hook formation is constructed so as to be resistive to such
impacts. In the preferred embodiment illustrated the terminal end of each component
42 is case hardened so as to provide a hook formation 51 which is resistive to such
impacts.
[0020] The component 41 projects downwardly beyond the hook formation 51 and defines a guide
surface 53 for guiding the terminal end of rod 14 over the hook formation 51 during
upward movement of the rod 14.
[0021] In Figure 3 the mechanism for lifting the heald knives 60 is illustrated generally
at 61 and includes a pair of arms 62 pivotally connected at 63 and which are caused
to rise and fall relative to one another by a drive mechanism 64. Two pairs of arms
62 are provided with the knives 60 extending therebetween.
[0022] The drive mechanism 64 for each arm 62 includes a pair of cams 66 mounted on a drive
shaft, one cam serving to positively raise the arm and the other cam serving to positively
lower the arm. Each arm is therefore provided with a pair of cam followers 67, cam
follower 67a serving to positively raise the arm and cam follower 67b serving to positively
lower the arm.
[0023] The shape of cams 66 are chosen so that when each arm 62 is in its raised position
(which means that the rods 14 operated thereby have been lifted so that their terminal
end is above the co-operating arm 40 of the retention device) there is an extended
dwell time before lowering the arm. This dwell time is advantageous in that it extends
the period in which the retention device needs to operate to deflect is associated
arms 40. Accordingly, since the response time for deflecting the arms 40 is quick
due to the construction of the retention device and since there is a dwell time for
enabling such response to take place it is possible for the loom to operate at high
speeds whilst ensuring positive and reliable operation of retaining selected heald
rods 14.
1. A retention device for a heald rod which is reciprocated in a linear path, the
retention device including a retention arm (40) having at one end a latch formation
(51) for cooperating with said heald rod (14) and being hinged to a support block
(23) so that the latch formation is movable between a latch position and a non-latch
position, an electromagnet (22) having at least one pole (46) positioned adjacent
to the retention arm (40), a pole piece (42) mounted on the retention arm (40) to
be cooperative with said pole (46) of the electromagnet (22) and biasing means for
biasing the retention arm (40) so as to be normally spaced from said pole (46), said
retention arm (40) is attached to the support block (23) by a resilient portion (43),
which defines the hinge connection and said biasing means, said arm comprises a resilient
member (41) connected to the support block (23) and a rigid member (42) fixedly secured
to the resilient member (41), the rigid member (42) defining said pole piece and latch
formation.
2. A retention device according to claim 1, wherein the electromagnet has a first
pole located near to the said latch formation and a second pole located adjacent the
arm but further from said latch formation, the pole piece extending along the arm
so as to be magnetically cooperable with both poles.
3. A retention device according to claim 1 or 2, wherein the pole piece has an extended
portion which forms a hook so as to define said latch formation.
1. Eine Haltevorrichtung für einen Litzenstab der entlang einer geradlinigen Strecke
hin- und herbewegt wird, welche Haltevorrichtung einen Haltearm (4) aufweist, der
bei einem Ende eine Hakenausbildung (51) hat, die zum Zusammenarbeiten mit dem Litzenstab
(14) bestimmt ist und an einem Tragblock (23) derart angelenkt ist, dass die Hakenausbildung
zwischen einer Verriegelungsstellung und einer Entriegelungsstellung bewegbar ist,
einen Elektromagneten (22) aufweist, der wenigstens einen Pol (46) neben dem Haltearm
(40) angeordnet hat, ein Polstück (42) aufweist, das auf dem Haltearm (40) angeordnet
ist, um mit dem Pol (46) des Elektromagneten (22) zusammenzuwirken und Vorspannmittel
aufweist, um den Haltearm (40) derart vorzuspannen, dass er in der Ruhestellung vom
Pol (46) entfernt ist, welcher Haltearm (40) mittels einem nachgiebigen Abschnitt
(43) mit dem Tragblock (23) verbunden ist, der eine Gelenkverbindung und die Vorspannmittel
bildet, welcher Arm ein nachgiebiges Glied (41) aufweist, das mit dem Tragblock (23)
und einem starren Glied (42) verbunden ist, das fest mit dem nachgiebigen Glied (41)
verbunden ist, welches starre Glied (42) das Polstück und die Reigelhakenausbildung
bildet.
2. Haltevorrichtung gemäss Anspruch 1, in der der Elektromagnet einen ersten Pol aufweist,
der nahe neben der Hakenausbildung angeordnet ist und einen zweiten Pol aufweist,
der neben dem Arm jedoch weiter weg von der Hakenausbildung angeordnet ist, welches
Polstück entlang dem Arm verläuft, so dass es magnetisch mit beiden Polen zusammenarbeiten
kann.
3. Eine Haltevorrichtung gemäss Anspruch 1 oder 2, in der das Polstück einen verlängerten
Abschnitt aufweist, der einen Haken bildet, so dass die Hakenausbildung gebildet ist.
1. Dispositif de retenue pour une barre de lisse qui est animée d'un mouvement de
va-et-vient en un trajet linéaire, le dispositif de retenue comprenant un bras d'arrêt
(40) qui comporte à l'une de ses extrémités un profil de verrouillage (51) destiné
à coopérer avec ladite barre de lisse (14) et qui est articulé sur un bloc de support
(23) de telle manière que le profil de verrouillage soit mobile entre une position
de verouillage et une position de non-verrouillage, un électro-aimant (22) dont au
moins un pôle (46) est placé à proximité immédiate du bras d'arrêt (40), une pièce
polaire (42) montée sur le bras d'arrêt (40) de manière à coopérer avec ledit pôle
(46) de l'électro-aimant (22), et des moyens de sollicitation qui agissent sur le
bras d'arrêt de telle manière que celui-ci soit normalement maintenu à distance dudit
pôle (46), le bras d'arrêt (40) étant relié au bloc de support (23) par une partie
élastique (43) qui constitue l'articulation et lesdits moyens de sollicitation, le
bras comprenant un élément élastique (41) raccordé au bloc de support (23) et un élément
rigide (42) fixé rigidement à l'élément élastique (41), l'élément rigide (42) constituant
ladite pièce polaire et le profil de verrouillage.
2. Dispositif de retenue selon la revendication 1, dans lequel l'électro-aimant comporte
un premier pôle placé près dudit profil de verrouillage et un second pôle situé à
proximité immédiate du bras, masi à plus grande distance dudit profil de verrouillage,
la pièce polaire s'étendant le long du bras de manière à pouvoir coopérer magnétique-
ment avec les deux pôles.
3. Dispositif de retenue selon la revendication 1 ou 2, dans lequel la pièce polaire
comporte une partie prolongée qui forme un crochet de façon à constituer ledit profil
de verrouillage.