Loom reed with preassembled packs of blade

A bladed loom reed comprising a support base onto which are placed a series of preassembled packs of blades. Each preassembled pack has blades fixed to an auxiliary support and the bladed loom reed is formed by combining the packs on a support base with or without intermediate spacers between packs.

This invention relates to a loom reed in the form of preassembled packs of 
blades with or without spacers, which besides being very economical to 
construct and extremely simple to assemble and maintain, allows optimun 
accuracy in the positioning of the blades themselves, as is particularly 
requested in the case of multi-phase looms in which the blades or dents of 
the fixed reed must always be perfectly aligned with the blades of the 
rotating reed. In this respect, in multi-phase looms it is known to use 
two separate reeds, of which one is fixed for the purpose of spacing the 
warp yarns equidistantly apart by means of its blades or dents, and the 
other rotates in order, by virtue of the particular shape of its blades 
between which the wrap yarns pass, to accompany the weft yarn and beat it 
against the edge of the already formed fabric. In order not to allow any 
wrap yarn deviation, which would result in an intolerably defective 
fabric, the respective blades of the two said reeds must be perfectly 
aligned with each others and thus in exactly predetermined position. 
For this reason, during the construction of each said reeds the pitch 
between the blades must be kept rigorously constant and equal to the 
theoretical pitch, over the entire reed lenght. 
The reeds are currently constructed by stacking on base support alternating 
blades and spacers which suffer from instrinsic constructional tolerances, 
especially in their thickness, with the result that after a certain number 
of elements have been mounted an inevitable considerable variavility in 
the blade positions arises. 
In the known art, in order to obviate this drawback, the support bases of 
reeds for multi-phase looms are provided with fixed locating devices at 
distances apart which are a perfect multiple of the theoretical blade 
pitch, these enabling positioning errors to be identified and the exact 
predetermined blade position reset. More especifically, in the rotating 
reed these fixed locating devices are nothing more than grooves for 
housing snap shoulder rings, the purpose of which is to limit the stacking 
to a predetermined constant number of blade-spacer elements. If it is 
found possible to stack a number of elements different from the 
predetermined number, a blade positioning error is indicated. This known 
method has however a series of drawbacks both of a technical nature and a 
time-consuming and thus cost nature, the most important of which derives 
from the fact that the precise stacking can only be attained after 
successive attempts. These require all the already stacked blades and 
spacers to be removed one by one and totally or partly replaced by like 
elements of suitably different thickness, with a consequent considerable 
time loss and the need to use qualified personnel, and resultant high 
costs augmented by the need to provide said fixed locating devices on the 
support base. 
A further drawback is due to the fact that each time the reed lenght 
requires changing to produce shorter or longer length fabrics, as is 
sometimes the case in weaving, it becomes neccessary to either remove or 
add blades, this being an operation which is not easy to carry out as it 
requires considerable accuracy and precision and therefore the use of 
qualified personnel to modify the reed, and in addition takes considerable 
time, involving consequent machine shut-downs and high costs. 
A similar situation arises whenever a damaged blade has to be replaced. 
Finally, further drawback with a consequent cost increase arises from the 
individual nature of the reed support base, which differs according to the 
required warp density in that if the blade pitch is changed, the distance 
between the fixed locating devices provided on said supports has to be 
correspondingly varied. 
The object of the present invention is to obviate said drawbacks by 
providing a loom reed offering high blade positioning precision without 
the need for fixed locating devices and thus with a standart support base, 
considerable ease of manufacture with consequent low costs, and simple and 
rapid maintenance in the case of blade deterioration 
This is attained substantially in that the reed is formed by combining 
packs each consisting of a succession of blades which are preassembled, 
with or without intermediate spacers, by being welded or bonded either 
together or to at least one auxiliary support, said packs being of 
predetermined length. 
The advantages of such a construction are immediately apparent. 
Firstly, there is considerable blade positioning precision in that any 
positioning inaccuracy is now determined by the number of packs used, this 
being considerably less than the number of blades used. Again, the reed 
assembly time is considerably reduced by virtue of the small number of 
elements to be assembled, with consequent cost reduction. Any required 
change in reed length or damaged blade replacement are now easily 
implemented by simply dealing with specific packs, which can be quickly 
interchanged. 
Any support base used to connect together the individual packs is in this 
case only an economical standard support, without the need for fixed 
locating devices to be provided in it for positioning purposes. A further 
advantage is that the reed can be dispatched more simply and cheaply, as 
it can be sent to a customer not in a single piece as is currently the 
case, but broken down into its constituent elements. 
The invention is described in more detail hereinafter with reference to the 
accompanying drawings which show a preferred embodiment thereof by way of 
non-limiting example in that technical, technological and constructional 
modifications can be made thereto but without leaving the scope of the 
present invention. Thus instead of being applied to the fixed and rotating 
reeds of a multi-phase loom as illustrated in the figures, it is apparent 
that the invention can be applied to any loom reed, and that the blades 
can be preassembled not only by being welded or bonded together or to an 
auxiliary support, but by any other method.

In the figures, the reference numeral 1 indicates the upper warp yarns and 
2 the lower warp yarns of a multi-phase loom, not shown in the figure, 
which by passing through the blades 3 and 4 of respectively the fixed reed 
5 and rotating reed 6 of said multi-phase loom, form the successive sheds 
7, 8 and 9 into which the weft yarns, not shown in the figure, are 
inserted to be beaten up by the rotating reed 6 against the edge 10 of the 
forming fabric 11. 
Said rotating reed 6 is constructed according to the invention by placing 
together on a central support 12 a series of packs 13, 14, 15 and 16 (four 
packs in FIG. 1 in which the different packs are shown by lines of 
different thickness for their easier identification) of predetermined 
length, each of which (see specifically FIG. 2) consists of a succession 
of internally supported blades 4 (eight in the figure) and intermediate 
spacers 17 which are preassembled by means of weld seams 18 provided in 
suitable cavities formed directly during the punching of said blades and 
spacers. Said punching operation also forms the positioning tabs 19 which 
cooperate with a guide groove 20 in said central support 12 in order to 
set the blades 4 in a helical arrangement as is clearly visible in FIG. 1. 
The fixed reed 5 consists according to the invention of two packs 21 and 22 
of blades 3 and spacers 23 fixed together by external weld seams 24 and 25 
along their upper and lower edges, at which the packs comprise through 
bores for the two removable connection pins 26 and 27. 
Finally, according to a modification of the invention (see specifically 
FIG. 3), the blades 3' of the pack are fixed spaced apart on two hollow 
auxiliary supports 28 and 29 into which removable pins 26' and 27' are 
inserted for connecting the blade packs together.