Cutter for fibrous compressible material

A cutting tool for cutting a sheet of compressible fibrous material. The cutting tool includes a blade which forms part of a cutting assembly which is mounted on a supporting base for movement between an upper position in which the blade is located above the material to be cut when the supporting base rests on the material which is to cut to a lower position in which the cutting blade extends below the supporting base. The cutting assembly is biased to the upper position and moved to the lower position by downward pressure from the hand of the operator which also causes the supporting base to compress the fibrous material so that when the cutting tool is moved longitudinally along the upper surface of the fibrous material, the material is cut by the blade.

BACKGROUND OF THE INVENTION 
The present invention is directed to a cutting tool for cutting fibrous 
compressible material, such as a sheet of fiberglass insulation. Cutting 
this type of material is a very difficult and awkward task even for 
professional installers of this material. The material can be cut with a 
large pair of scissors but this procedure is very time consuming. The 
conventional utility knife is usually the cutting tool of choice by most 
professionals. Due to the looseness and compressibility of the material, 
several passes of the knife are usually required to cut the material. An 
elongated straight edged tool is usually used to compress the fiber sheet 
of material and to guide the knife along a predetermined line of cutting. 
However, even this procedure is less than satisfactory. Care must be used 
to avoid hitting the guide edge of the compressing tool with the blade of 
the utility knife which increases the cutting time. Although the fibrous 
material is compressed along the guide edge of the compressing tool, the 
fibrous material extends upwardly abruptly from the guide edge of the 
compressing tool, thereby making it difficult to cut the fibrous material. 
Also, since the operator has one hand on the compressing tool and one hand 
on the utility knife, he or she is unable to grasp the portion of the 
fibrous material which is being cut off and to prevent it from being 
dragged forwardly by the knife and interfering with the execution of a 
smooth, clean cut. These and other difficulties experienced with the prior 
art insulation cutting tools have been obviated by the present invention. 
It is, therefore, a principle object of the invention to provide a cutting 
tool for fibrous compressible material which does not require the use of 
any other tool. 
Another object of this invention is the provision of a cutting tool for 
fibrous compressible material which simultaneously compresses and cuts the 
material. 
A further object of the present invention is the provision of a cutting 
tool for fibrous compressible material which simultaneously compresses and 
cuts the material and which utilizes a conventional utility knife. 
It is another object of the present invention to provide a cutting tool for 
fibrous compressible material which simultaneously compresses and cuts the 
material and which can be actuated with one hand so that the other hand of 
the operator can be used to hold the material which is being cut off or 
otherwise used to assist in the cutting operation. 
A still further object of the invention is the provision of a cutting tool 
for fibrous compressible material which is simple in construction, which 
is inexpensive to manufacture, in which is capable of a long life of 
useful service. 
With these and other objects in view, as will be apparent to those skilled 
in the art, the invention resides in the combination of parts set forth in 
the specification and covered by the claims appended hereto. 
SUMMARY OF THE INVENTION 
In general, the invention consists of a cutting tool for sheets of 
compressible fibrous material. The cutting tool has a supporting base and 
a cutting assembly which is mounted on the supporting base for movement 
between an upper position at which a blade, which is part of the cutting 
assembly, lies above the material to be cut and a lower position at which 
the cutting blade extends below the cutting assembly and the bottom 
surface of the supporting base. The cutting assembly is biased to the 
upper position and is moved to the lower cutting position by pressure from 
the operator's hand so that the cutting blade extends into the fibrous 
material and cuts the fibrous material as the cutting tool is moved 
forwardly along the upper surface of the fibrous material.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings, the cutting tool of the present invention which 
is generally indicated by the reference numeral 10, is shown as being of 
the type intended for use with a conventional utility knife which is 
generally indicated by the reference numeral 11. 
The cutting tool 10 includes a wire frame supporting base which is 
generally indicated by the reference numeral 12 and comprises a pair of 
spaced vertical guide posts 16 which are connected at the top by a 
horizontal connecting portion 14. The posts 16 are connected to a pair of 
generally horizontal slide runners 18 which extend forwardly from the 
posts 16. A pair of support rods 20 are connected to the slide runners 18 
and extend rearwardly in cantilever fashion from the slide runners 18 to 
the guide post 16. Each support rod 20 extends generally horizontally and 
has a free end to which is fixed a guide ring 24 which is slidable 
vertically on one of the guide posts 16. The guide ring 24 of one support 
rod 20 is slidable on one of the guide post 16 and the guide ring 24 of 
the opposite support rod 20 is slidable on the opposite guide post 16. A 
generally U-shaped cradle 22 is fixed to the rearward ends of the support 
rods 20 adjacent the guide rings 24 for supporting the utility knife 11. 
The utility knife 11, which is shown in the drawings, is as an example a 
standard utility knife which includes a body portion 26 and a cutting 
blade 28 which is mounted for longitudinal movement relative to the body 
26 between an extended position as shown in FIG. 1 to a retracted position 
wherein the blade is completely enclosed within the body 26. The movement 
of the blade 28 relative to the body 26 is accomplished by means of a 
finger operated slide button 30. When the utility knife 11 is mounted 
within the cradle 22, as shown in FIG. 1, the blade 28 extends rearwardly 
and downwardly relative to the cutting tool 10. The utility knife 11 is 
maintained on the cradle 22 in a fixed position by means of a pair of 
straps 32. In the particular embodiment shown in the drawings, the straps 
32 comprise a first portion 34 which has a fibrous outer surface and a 
second portion 36 which has an inner surface consisting of a plurality of 
small hooks of a textile material of the type shown in U.S. Pat. No. 
2,717,437. One end of the first portion 34 is fixed to the cradle 26. The 
other end of the first portion 34 extends freely so that it can be looped 
about the utility knife. One end of the second portion 36 is also fixed to 
the cradle 22. The other end of the second portion 36 extends freely so 
that it is looped around the utility knife 11 and secured to the first 
portion 34. Other types of fastening elements, such as snap fasteners can 
be used to secure the first and second portions 34 and 36, respectively. 
The wire frame 12 is made of a flexible resilient material, such as spring 
steel. The cradle 22 is normally biased in the upper full line position 
shown in FIG. 1 by the cantilever end support rods 20. The utility knife 
11 and the cradle 22 can be moved to the lower dotted-line position shown 
in FIG. 1 by applying downward pressure to the utility knife. 
The cutting tool 10 is utilized for cutting a sheet of fibrous material, 
such as fiberglass insulation, by placing the tool so that the slide 
runners 18 rest on the upper surface of the material to be cut which is 
indicated by the reference numeral 40 in FIG. 1. The operator utilizes the 
tool by grasping the utility knife 11 and applying downward pressure on 
the knife so that the slide runners 18 compress the fibrous material and 
moves the utility knife 11 from the full-line position to the dotted-line 
position shown in FIG. 1. This causes the rearwardly extending blade 28 to 
penetrate the fibrous material 40. The cutting tool 10 is then moved 
forwardly along the surface of the material 40 with the utility knife in 
the lowered position so that the fibrous material is progressively 
compressed and cut. The entire cutting operation can be accomplished with 
one hand, thereby leaving the operator's of a hand free to be utilized for 
assisting in the cutting operation. By simultaneously compacting and 
cutting the fibrous material, the material is cut easily and cleanly with 
one pass of the knife. 
In the embodiment shown and described, the cutting tool 10 is adapted to 
receive a conventional utility knife. If desired, the cutting element can 
be a permanent part of the tool wherein the cutting element comprises a 
body portion which is permanently fixed to the support rods 20 and a 
cutting blade which is mounted in the body, preferably in the same manner 
as the blade of a conventional utility knife. 
Another advantage of the cutter of the present invention is that the cutter 
makes a more compact and cleaner cut of fibrous material. This causes a 
substantial reduction in airborn fibers which help to make the work 
environment more comfortable. 
Clearly, minor changes may be made in the form and construction of the 
invention without departing from the material spirit thereof. It is not, 
however, desired to confine the invention to the exact form herein shown 
and described, but it is desired to include all such as properly come 
within the scope claimed. 
The invention having been thus described, what is claimed as new and 
desired to secure by Letters Patent is: