Cutter for shortening blinds

A cutter for shortening blinds of the type consisting of a top rail, a bottom rail and a plurality of suspended slats therebetween, the cutter comprising a framework, a stationary matrix fixed with respect to the framework and comprising a first opening for receiving the top rail of the blinds, at least one second opening for receiving the slats in a compacted position, and a third opening for receiving the bottom rail. The first and third openings have shapes corresponding with the cross-sectional shape of the respective top and bottom rails. A support member is slidable with respect to the matrix and comprises a first blade for cutting the top rail, at least one second blades for cutting the slats and a third blade for cutting the bottom rail, at least the first and third blades being flush with a surface of the matrix. The cutter further comprises a displacement mechanism for displacing the support member with respect to the matrix in a direction perpendicular to longitudinal axes of the openings.

FIELD OF THE INVENTION 
The present invention is in the field of cutting devices for shortening 
blinds and more specifically it is concerned with a device for shortening 
blinds of the type comprising a top rail, a bottom rail and a plurality of 
slats suspended from the top rail by strings. Such blinds are referred as 
"venetian blinds" or "mini blinds". 
BACKGROUND OF THE INVENTION 
Blinds of the specified type are highly desirable and may be manufactured 
in a variety of sizes. However, for reasons of standardizing, 
manufacturers prefer to produce their products at a selection of standard 
sizes which do not necessarily suit customers' requirements, and ordering 
blinds at non-standard sizes, usually turn out to be expensive. 
In order to provide the blinds "tailored" to customers' requirements, it 
has been known to provide blinds in a selection of standard sizes at 
distribution stations together with suitable cutting means for shortening 
the blinds to the specific size required by the customer. 
One example of such a cutting device is disclosed in U.S. Pat. No. 
4,819,530 which is an automatic apparatus for cutting off the ends of 
pre-assembled venetian blinds. The apparatus comprises a vertical bed for 
suspending a blind in an opened and taut condition and an automated 
mechanism for trimming both ends of the slats by twin cutters. After the 
ends of the slats have been trimmed, the top and bottom rails are 
shortened by a guillotine arrangement to match the trimmed slats. 
This apparatus requires an essentially large space and trained personnel 
for operating and trimming a blind and the process of shortening a blind 
is lengthy. Furthermore, the top and bottom rails are cut in a separate 
process which might lead to uneven trimming. 
U.S. Pat. No. 5,339,716 discloses a cutter for blinds comprising a 
framework which has a receiving area for receiving an end of the blind and 
a single blade attached to a bar slidably mounted in the framework. The 
slide bar is operated by an operating handle associated with a rack and 
gear mechanism, for sliding the single cutter through the end of the 
blind. 
This arrangement requires a long stroke of the operating handle and the 
blade cuts through different materials, whereby the force applied to the 
operating handle is uneven along an operating stroke. Moreover, the blade 
will more often require attending. Furthermore, no means are provided for 
preventing deformation of the rails during cutting. 
It is the object of the present invention to provide an improved cutter for 
shortening blinds of the specified type, with the above-referred to 
disadvantages substantially reduced or overcome. 
SUMMARY OF THE INVENTION 
According to the present invention there is provided a cutter for 
shortening blinds of the type consisting of a top rail, a bottom rail and 
a plurality of suspended slats therebetween, the cutter comprising a 
framework, a stationary matrix fixed with respect to the framework and 
comprising a first opening for receiving the top rail of the blinds, at 
least one second opening for receiving the slats in a compacted position, 
and a third opening for receiving the bottom rail; the first and third 
openings having shapes corresponding with the cross-sectional shape of the 
respective top and bottom rails; a support member slidable with respect to 
the matrix and comprising a first blade for cutting the top rail, at least 
one second blades for cutting the slats and a third blade for cutting the 
bottom rail, at least the first and third blades being flush with a 
surface of the matrix; and a displacement mechanism for displacing the 
support member with respect to the matrix in a direction perpendicular to 
longitudinal axes of the openings. 
According to a specific embodiment of the invention the distance between 
the openings is similar to or less than the distance between two adjacent 
loops of a ladder string linking the slats to the top and bottom rails. 
The framework may further comprise clamping means for fixing the blinds 
within the matrix, whereby the blinds may be rigidly fastened to the frame 
so as to ensure smooth and even shortening of the blinds' components. In 
order to improve support of the blinds within the framework during 
shortening, the framework further comprises guides corresponding with the 
openings for supporting the rails and slats, the guides having 
longitudinal axes parallel with axes of the openings. 
According to one application a preferred embodiment, the cutter is provided 
with blocking means for setting the size of the portion cut from the 
blind. Preferably, integral measuring means are provided. 
According to still a preferred embodiment, the at least one second opening 
of the matrix comprises a lateral projection with rounded edges and 
wherein the at least one second blade is flush with the lateral projection 
so that the shortened slats obtain rounded edges. For this purpose, the 
blinds may be clamped within the matrix so that the slats extend beyond 
the rails at a rate similar to the size of the lateral projection. 
In order to minimize the cutting force and to improve the face quality of 
the cut blinds, at least the first and third blades have a pointed edge. 
Preferably, the blades are disposed so as to gradually engage at least the 
top and bottom rail. 
The displacement mechanism for use with the cutter according to the present 
invention may be a manually operated lever or a hydraulic piston or an 
electrically operated solenoid.

DETAILED DESCRIPTION OF A SPECIFIC EMBODIMENT 
Reference is first made to FIGS. 1 and 2 of the drawings in which a cutter 
1 consists of a framework generally designated 2 having a base member 4 
and a bottom support member 6 having an inverted L-like shape secured to 
the base member 4 by bolts 8. A bracket 10 has an opening 12 and is 
attached to the bottom support member 6 by bolts 14. A top support member 
16, also having an inverted L-like shape, is secured at the top of the 
bracket 10 by bolts 18, whereby two parallel grooves 20 are formed, 
suitable for slidingly receiving a support member 22, as will hereinafter 
be explained in more detail. 
A matrix plate 24 is fixed to bracket 10 between the grooves 20 by bolts 
14, the matrix comprising first, second and third openings 26, 28 and 30 
respectively, being in register with the opening 12 of the bracket 24. 
Each of the openings have the respective shape of the cross-section of the 
top rail, slats and bottom rail of a venetian blind (as seen in FIGS. 5A 
to 5C). 
A support block 34 is secured to the back face of the bracket 10 by bolts 
36. The block 34 is formed with three grooves 38, 39 and 40 and is mounted 
at a suitable level for supporting the respective top rail, slats and 
bottom rail of the venetian blind in an essentially horizontal position 
and in alignment with the openings 26, 28 and 30 of the matrix plate 24. 
An insert 45 with rounded corners 46 is attached within opening 28 of the 
matrix 24 so that it projects beyond the inner surface 48 of the matrix 
24, the reason of which will hereinafter be explained. 
The sliding support member 22 is fitted with a first blade 50, a second 
blade 52 and a third blade 54, attached to the support member 22 by bolts 
56 and 58, the arrangement being such that the first and third blades 50 
and 54 are adapted for sliding flush over the surface 48 of the matrix 24 
over the openings 26 and 30 respectively, whereas blade 52 is elevated 
from the surface 48 and is adapted for sliding over the insert 45, the 
blade assuming the shape of the projecting portion of insert 45. 
A lever 55 is pivotally hinged by bolt 56 to the base member 4 and a link 
57 is hinged at 58 to the lever 55 and at 59 to the support member 22, 
whereby shifting the lever 55 to its forward position (as indicated by 
arrow 60 in FIG. 3) brings about displacement of the support member 22 
with the associated blades 50, 52 and 54. 
The arrangement is such that rearward displacement of the support member 22 
(i.e, in a direction opposite to that represented by arrow 60 in FIG. 3) 
is restricted by the rear face 61 of the first blade 50 encountering the 
front face 62 of the insert 45. On the other hand, forward displacement of 
the support member 22 is restricted by the front facing flat portion 64 of 
the third blade 54 encountering the rear face 66 of the insert 45. 
Where the matrix plate is provided with more than one second opening, the 
distance between the second openings does not exceed the distance between 
two adjacent loops of ladder string, where said distance is standard for 
various types of venetian blinds, as known in the art. 
Attention is now directed to FIG. 4 in which a cutter 2 according to the 
present invention is mounted on a work bench 70. A positioning bar 72 is 
slidable over two parallel rods 74 having their longitudinal axes parallel 
with that of the openings of the matrix 24, and a fastener 76 for setting 
the bar 72 at a required position as measured over the scale 78 by 
indicator 80. The bar 72 has an indention 82 in register with the second 
opening 28 of the matrix 24. 
The work bench 70 further comprises an aperture 85 with a waste collecting 
compartment 86 for collecting cutting waste. 
In operation, the bar 72 is set to the required position and fixed by 
fastener 76 and a blind is introduced into the cutter 2 with the top rail 
90 accommodated within the first opening 26 of the matrix, the slats 92 
within opening 22 and the bottom rail 94 within openings 30, as seen in 
FIGS. 5A to 5C. The end of slats 92 are received in indention 82 of the 
bar 72 for obtaining an even length of the rails and slats, in spite of 
the projection of the insert 45 from surface 48 of the matrix 24. The 
blinds rest over the support block 34 in an essentially horizontal 
position and in alignment with the longitudinal axis of the openings of 
the matrix 24. If desired, a clamp (not shown) may be used for fixing the 
blind in position. 
Then, the lever 50 is shifted into its forward position as in FIGS. 3 to 5, 
wherein the second blade 52 slides over the slats 92 and over the insert 
45 to cut off the slats (as seen in FIG. 5A). Gradually, the first blade 
50 slides over surface 48 of the matrix, engaging the top rail 90 and 
beginning cutting same (as seen in FIG. 5B). Only after the slats are cut, 
the third blade 54 engages the bottom rail 94 and gradually cuts it (as 
seen in FIG. 5C). This arrangement of gradually cutting the components of 
the blind, ensures applying less force for cutting the blind. Furthermore, 
blades of different mechanical properties may be used for cutting the 
different components of the blind made of different material, thus 
ensuring improved surface quality of the cut blind and increased life time 
of the blades. The cutting waste falls through aperture 85 into the 
collecting compartment 86. Then, the process is repeated with the opposed 
end of the blind, whereby equal portions are cut at both ends of the 
blind. 
It should be obvious to a person versed in the art that other means may be 
used for displacing the sliding support member 22, e.g. a hydraulic 
piston, a solenoid, etc. 
Further attention is now directed to FIGS. 6 and 7 schematically 
illustrating, with parts omitted, different embodiments in accordance with 
the invention of displacing mechanisms for actuating a complete cutter 
assembly similar to that in FIGS. 1-4. 
In FIG. 6, the piston 102 comprises an inlet port 106 and an outlet port 
108 for ingress and egress of hydraulic fluid, respectively, as known in 
the art. Piston rod 110 is connected at 59 to the blade support member 22. 
Extension of the piston rod 110 from the piston 102 entails displacement 
(to the left in FIG. 6) of the blade support member 22 in a cutting 
stroke, and vice-versa. 
It is apparent that the piston 102 may be replaced with a known 
solenoid-type linear actuator 102, whereby the parts 106, 108 would 
instead represent electrical power leads. 
In FIG. 7, on the shaft 126 of a motor (not shown) there is mounted a cam 
member 128 eccentrically fixed to the shaft 126. The peripheral face 132 
of the cam member 126 is maintained in contact, with the blade support 
member 22, whereby rotating the shaft 126 of the motor about the axis 124 
provides reciprocating displacement (arrow 130) of the blade support 
member 22, as known per-se.