Drywall cutting device

A drywall cutting device adapted for use with a piece of conventional drywall. The device includes a slidetrack which can be mounted on an edge of a piece of drywall and guide rails which extend substantially perpendicularly from the slidetrack, such that when the slidetrack is placed on an edge of a piece of drywall, the guide rails extend out over the piece of drywall. Slidably mounted on the guide rails is a cutting means holding device, which holds a cutting means such as a knife blade or razor. The drywall cutting device cuts drywall as follows; the slidetrack is placed on an edge of a piece of drywall, the device is slid to the desired cut point, the cutting means is aligned in the desired cut direction, and the cutting means holding device is slide into position on the guide rails. The desired cut is then made by sliding the drywall cutting device along the edge. Use of the present invention will thus result in savings of time and cost to the user.

BACKGROUND OF THE INVENTION 
1) Technical Field 
This invention relates to drywall cutting devices and, more particularly, 
to drywall cutting device which can quickly and easily cut both 
horizontally and vertically, can efficiently cut right angles, and can cut 
drywall in measured lengths without the need for separate measuring, 
marking, and cutting steps. 
2) Description of the Prior Art 
Look in almost any building today, and in one place or another drywall can 
be found. Drywall is basically a compressed core of gypsum with heavy 
paper glued to both sides. It is used for everything from walls to 
ceilings. Drywall is usually formed in 4'.times.8' sheets, with 
thicknesses between 1/4" to 5/8". Drywall can also come in 10' or even 12' 
lengths. The problem with these sizes is that drywall often needs to be 
cut to fit certain areas. Before the present invention, four separate 
tools used in stages must be used to achieve a straight cut of drywall; a 
measuring tape, a pencil, a chalk-line, and a utility knife. The steps 
undertaken would be as follows: first, measure the desired length with the 
measuring tape and mark the drywall with the pencil at the top and bottom 
edges, second, stretch the chalk line between the marks and snap a line to 
guide the cut, and third, cut the drywall along the line with the utility 
knife. This tedious process results in inefficient use of time and thus is 
wasteful. Accordingly, an object of the present invention is to provide a 
device which easily and quickly cuts drywall. 
Another problem of the prior art is that right angle cuts are difficult for 
lay persons to do on drywall, and even present problems for professionals. 
A perfect right angle enhances the look of the drywall project, and also 
results in less wasted drywall, thus saving money for the consumer. 
Therefore, an object of the present invention is to provide an easy and 
simple device for cutting right angles in drywall. 
Another object of the present invention is to provide a device that ensures 
accurate cutting of drywall. 
Yet another object of the present invention is to provide a drywall cutting 
device which minimizes markings and scorings needed for cutting drywall, 
thereby lessening cleanup of the drywall. 
Still another object is to provide a drywall cutting device which is usable 
with standard drywall sheets of varying thicknesses. Finally, it is object 
of the present invention to provide a drywall cutting device which is of 
simple and inexpensive construction. 
SUMMARY OF THE INVENTION 
The present invention provides a method for cutting drywall and a device 
for implementation of that method to speed and ease the tedious task of 
drywall cutting. 
The device consists of a slidetrack, which is similar in shape to a piece 
of angle iron, which can be placed on an edge of a piece of drywall. To 
the slidetrack are attached guide rails which extend substantially 
perpendicularly from the slidetrack, and when the slidetrack is placed on 
an edge of a piece of drywall, the guide rails extend out over the piece 
of drywall. Slidably mounted on the guide rails is a cutting means holding 
device, which holds a cutting means such as a knife blade or razor. 
To cut a piece of drywall, the device is placed on a piece of drywall such 
that the slidetrack is mounted on an edge of the piece of drywall. The 
device is then slid to the starting end of the drywall and the cutting 
means holding device is slid along the guide rails to the desired cutting 
starting position. The cutting means is then aligned in the desired cut 
direction, and the desired cut is made. The procedure is repeated until 
all desired cuts are made. 
As can readily be seen from the above description, this method of cutting 
drywall is efficient, simple, and quick. The device also described above 
provides the most effective means for accomplishing the objects of the 
method described, and can be utilized in many different ways.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
For purposes of this description, inner shall mean adjacent the intended 
location of a piece of drywall to be cut, and outer shall mean opposite 
the drywall. Also, unless otherwise stated, the components of the drywall 
cutting device are preferably to be constructed of a lightweight metal 
such as aluminum, formed in the required shapes. 
The drywall cutting device 10 is shown in its preferred embodiment in FIGS. 
1-4 as having a slidetrack 12 which is preferably of L-shaped 
cross-section so that it will fit easily on an edge of a piece of drywall 
14. Whereas in the preferred embodiment, the horizontal leg 16 of the 
slidetrack 12 slidably engages the edge of a piece of drywall, rollers 
could be added to assist in the motion of the slidetrack along the edge of 
the piece of drywall 14. 
As seen in FIGS. 3, 4, and 17, mounted to the horizontal leg 16 of the 
slide track 12 opposite the vertical leg 18 of the slidetrack 12 is a 
spring support 20 extending perpendicularly downwards from the horizontal 
leg 16. Mounted to the spring support 20 and substantially parallel to the 
vertical leg 18 of the slidetrack 12 is a butterfly spring 22 which is 
spaced apart from the vertical leg 18 such that most varieties of drywall, 
which varies in thickness, can be accommodated between them, yet the 
butterfly spring 22 will act to secure the slidetrack 12 against the piece 
of drywall regardless of thickness. 
Extending upwards from the spring support side of the horizontal leg 16 of 
the slidetrack 12 in the preferred embodiment is an L-shaped guide rail 
bracket 24, best seen in FIG. 1. The long leg of the bracket 24 is 
connected to the horizontal leg 16 of the slidetrack 12 such that the 
short leg of the bracket 24 extends out over and past the vertical leg 18 
of the slidetrack 12 and substantially parallel with the horizontal leg 16 
of the slidetrack 12. 
Connected to the underside of the short leg of the bracket 24, in the 
preferred embodiment, are a pair of generally parallel guide rail 
extensions 26a and 26b, which extend downwards. These guide rail 
extensions 26a and 26b, shown in FIGS. 5 and 12, are preferably tubular 
rails which fit inside of the guide rails 28a and 28b, which are 
rectangularly shaped in cross-section, hollow, generally parallel and 
slidably mounted on the guide rail extensions 26a and 26b. At the upper 
and lower ends of the guide rails are spacer struts 30a and 30b, which 
hold the guide rails 28a and 28b in the desired spaced apart relation. 
Shown in FIG. 12 are the tubular spacers 32a and 32b, which fill the space 
gap between the outer surface of the guide rail extensions 26a and 26b and 
the interior surface of the guide rails 28a and 28b, thus allowing better 
sliding and more accurate cutting. 
Shown in FIGS. 1-5 is a guide rail release latch 34 mounted to the top of 
the short leg of the guide rail bracket 24 directly above the connection 
point of the guide rail extensions 26a and 26b. The latch is designed to 
prevent the guide rails 28a and 28b from sliding down the guide rail 
extensions 26a and 26b by engaging and securing the top guide rail spacer 
strut 30a against the underside of the short leg of the guide rail bracket 
24. 
In the preferred embodiment, a tape measure holding device 36 would 
preferably be constructed of a flat piece of metal and mounted on and 
perpendicular to the vertical leg 18 of the slidetrack 12 as shown in 
FIGS. 5 and 6. One face of the device 36 would have a fastener 38, such as 
a hook and loop type, shown in FIG. 6, to which could be attached a 
similarly equipped tape measure 40 Measurements could be taken either by 
passing the measuring tape over the center cut line 42 of the device 10, 
which could yield direct readings, or by directing the tape in the manner 
shown in FIG. 1, and adding a constant to make up the difference from the 
end of the tape to the center cut line 42. 
Shown in FIGS. 7, 8 and 9 is the cutting means holding device 44 having 
three major components; a trolley 46, a trolley securing device 48, and a 
cutting means holder 50. 
The trolley 46 is preferably constructed of two rectangular metal plates 52 
and 54 extending between and extending slightly past the guide rails 28a 
and 28b on either side, thereby "sandwiching" the guide rails 28a and 28b 
between the plates so that the trolley 46 may slide up and down the guide 
rails 28a and 28b. The plates 52 and 54 would preferably be held in the 
proper position by both the trolley securing device 48 and the cutting 
means holder 50. In the preferred embodiment, the plates 52 and 54 are 
shaped to conform to the outer surfaces of the guide rails 28a and 28b, 
which allows for better sliding and lessens unwanted sideways motion of 
the trolley 46. 
The trolley securing device 48, as best seen in FIG. 16, is preferably 
constructed of a bolt 56 which passes through a hole 58 through the upper 
section of the outer plate 54 and is screwed into a threaded hole 60 in 
the upper section of the inner plate 52. The bolt 56 would preferably have 
a handle end 62 which would be knurled around the edges to facilitate 
gripping. The handle end 62 of the bolt 56 would be wider in diameter than 
the diameter of the hole 58 in the outer plate 54. By rotating the bolt 56 
in a clockwise direction, the bolt 56 pulls the inner and outer plates 52 
and 54 together as it draws down into the threaded hole 60, thereby 
frictionally securing the trolley 46 in one place on the guide rails 28a 
and 28b . To allow movement of the trolley 46, the bolt 56 is rotated 
counter-clockwise, thus separating the plates 52 and 54 slightly to allow 
sliding motion of the trolley 46 on the guide rails 28a and 28b. 
The cutting means holder 50 is shown in the preferred embodiment in FIGS. 
10, 11, and 18-23. The holder 50 is located in the lower section of the 
trolley 46 directly below the trolley securing device 48 and in line with 
the center cut line 42 in a cylindrical hole formed through the two plates 
52 and 54. FIG. 18 shows a top view of the preferred embodiment of the 
cutting means holder 50, showing five major elements; a slidable holding 
member 64, a sleeve 66, a button 68, a blade location securing device 70, 
and a blade rotation device 72. 
In the preferred embodiment, the slidable holding member 64 has two ends, a 
slotted end 74 and a button end 76. The slotted end 74 has two 
perpendicular slots 78a and 78b, shown clearly in FIG. 9, which are 
approximately 1/4 of the length of the holding member 64 and slightly 
wider that the thickness of the non-cutting end of a knife blade 80 so 
that the non-cutting end of a knife blade 80 may be placed within One of 
the slots 78a and 78b. Also mounted on the slotted end 74 of the holding 
member 64 are small triangular-shaped extensions 86 on the outer surface 
of the slotted end 74. 
The button 68 is mounted on the button end 76 of the holding member 64, and 
perpendicular to the longitudinal axis of the holding member 64. Extending 
radially outwards from the edge of the button 68 is a corotation pin 82 
which makes the button 68 and holding member 64 rotate as the blade 
rotation device 72 is rotated, as the pin 82 extends into the body of the 
blade rotation device 72 in a channel 84 cut therein. 
In the preferred embodiment, encasing the holding member 64 is a sleeve 66 
whose inner diameter is slightly greater than the outer diameter of the 
member 64 so that the member 64 may slide within the sleeve 66. The sleeve 
66 has two ends, an inner end 88 near the slotted end 74 of the holding 
member 64, and an outer end 90 which is preferably extended into blade 
rotation device 72. The sleeve 66 is mounted in the blade rotation device 
72 with the outer end 90 extending into the device 72 such that when the 
device 72 is rotated, the sleeve 66 remains stationary, but when the blade 
rotation device 72 is pulled back, the sleeve 66 is pulled with it. 
Extending outward from the outer surface of the sleeve 66, near the inner 
end 88, and perpendicular to the longitudinal axis of the sleeve 66 are a 
pair of sleeve pins 92a and 92b, to which are attached a pair of pin 
springs 94a and 94b, described later. The sleeve 66 and holding member 64 
are extended within the holes through the trolley 46, the blade location 
securing device 70, and the blade rotation device 72. 
The blade location securing device 70 is preferably constructed of two 
concentric disks placed face to face, a first disk 96 of approximately 1/2 
the diameter of a second disk 98 each having a center hole drilled through 
of diameter slightly greater than the outer diameter of the sleeve 66, so 
that the sleeve 66 may slide through the holes. The first disk 96 is of 
slightly smaller diameter than the hole through the two plates 52 and 54, 
so that the disk 96 fits within the hole. The second disk 98 is mounted to 
the outer plate 54 such that the first disk 96 is within the hole. The 
second disk 98 is of a diameter approximately 2/3 the width of the outer 
plate 54. On the outer face of the second disk 98 there are preferably 3 
conical indentations 100a-c drilled into the disk, two 100a and 100b of 
larger and deeper size than the third 100c, the first two 100a and 100b 
spaced apart at a 90.degree. angle, the third 100c at a point halfway 
between the larger two 100a and 100b. All three indentations 100a-c have 
their center points on the same circle, one concentric with the outer edge 
of the second disk 98 and halfway between the outer edge and the inner 
edge of the second disk 98. 
Aligned with and along the longitudinal center line of the blade location 
securing device 70 is the blade rotation device 72, which is constructed 
of two concentric disks connected face-to-face having center holes. The 
first rotation disk 102 is preferably of the same diameter as the second 
disk 98 of the blade location securing device 70. The hole in the first 
rotation disk 102 is of the same diameter as the one in the second disk 98 
also. Extending outwardly from the inner face of the first rotation disk 
102 is a conical extension 104 preferably of the same size and on the same 
arc as the larger conical indentations 100a and 100b in the second disk 98 
of the blade location securing device 70, such that the conical extension 
104 will fit within and substantially fill the two large conical 
indentations 100a and 100b. However, only the tip of the conical extension 
104 will fit within the smaller third conical indentation 100c thus 
spacing apart the blade location securing device 70 and the blade rotation 
device 72. 
The second rotation disk 106 has a larger diameter than the first rotation 
disk 102 and also has a much larger center hole 108. This center hole 108 
is of slightly greater diameter than the diameter of the button 68. Also 
cut into the second rotation disk 106 is the channel 82 referred to above, 
which extends from the outer face of the second rotation disk 106 towards 
the inner face of that disk, and along a radius of the second rotation 
disk 106, such that the corotation pin 82 will fit within the channel 84. 
Furthermore, in the preferred embodiment, the outer edge of the second 
rotation disk 106 would be knurled, in order to facilitate gripping and 
turning of the blade rotation device 72. 
Extending between and connected to the outer face of the first rotation 
disk 102 and the inner surface of the button 68 are a pair of springs 110a 
and 110b, shown in FIG. 18, Which tension the button 68 and the connected 
holding member 64 away from the first rotation disk 102, thereby pulling 
the holding member 64 against the inner end of the sleeve 66, thus 
engaging the small triangular extensions 86 and narrowing the 
perpendicular slots 78a and 78b, and thus frictionally securing a knife 
blade 80 within the slot 78a and 78b. By pressing the button 68 into the 
center hole 108 of the second rotation disk 106, as shown in FIG. 10, the 
holding member 64 slides through the sleeve 66, the triangular extensions 
86 disengage the sleeve 66, and the slots 78a and 78b widen, thus allowing 
easy removal of an old knife blade or insertion of a new one. 
Extending between and connected to the sleeve pins 92a and 92b and the 
inner face of the first disk 96 of the blade location securing device 70 
are a pair of pin springs 94a and 94b which tension the sleeve 66 away 
from the inner face of the first disk 96. The blade rotation device 72 is 
thus pulled against the blade location securing device 70, preferably 
securing the conical extension 104 within one of the conical indentations 
100a, thereby preventing rotation of the blade rotation device 72 and thus 
rotation of the knife blade 80. 
To rotate a knife blade 80, the blade rotation device 72 is pulled and held 
away from the blade location securing device 70, as shown in FIG. 11, 
removing the conical extension 104 from the conical indentation 100a in 
which it was emplaced, the blade rotation device 72 is rotated about the 
longitudinal axis of the holding member 64 thus turning the knife blade 80 
as the holding member 64 connected to the button 68 is rotated also. The 
blade rotation device 72 is then released, allowing the pin springs 94a 
and 94b to pull the device 72 to adjoin the blade location securing device 
70, allowing the conical extension 104 to fit within and engage another 
conical indentation 100b. To secure the knife blade 80 in non-cutting 
position, the conical extension 104 would be placed in the third conical 
indentation 100c into which only the tip of the conical extension 104 will 
fit and thus the blade rotation device 72 would be held away from the 
blade location securing device 70, thus holding the sleeve 66 and the 
holding member 64 back away from the drywall to be cut, thus holding the 
knife blade 80 back away also. 
In cutting a piece of drywall 14, as shown in FIGS. 13-15, the slidetrack 
12 of the drywall cutting device 10 is placed on an edge of the piece of 
drywall 14, at the adjacent side where the cut is to begin. The knife 
blade 80 is rotated to the desired cut direction by the process described 
above, the trolley securing device 48 is tightened, thus securing the 
trolley at the desired cut level, then the cut is begun. The drywall 
cutting device 10 is slid along the edge of the piece of drywall 14, 
cutting the drywall along a line parallel to the edge being slid upon. As 
shown in FIG. 14, to Cut perpendicularly to the first cut made the knife 
blade 80 is rotated 90.degree., the trolley securing device 48 is 
loosened, and the trolley 46 is slide along the guide rails 28a and b for 
the desired cut length. As drywall often comes in 4' wide sheets, to cut 
across the entire piece of drywall 14, the guide rail release latch 34 is 
opened and the guide rails 28a and 28b can extend across the drywall 
along the guide rail extensions 26a and 26b. After cutting, the cut piece 
of drywall can then be removed from the original piece of drywall 14. 
As can be seen from the above description, this method and device for 
cutting drywall is a great improvement over prior methods and devices for 
achieving the same results. No separate tools, other than a utility knife 
for finishing the sectioning of the cut drywall, are needed to achieve the 
cutting of the drywall, thus resulting in saving of time and cost to the 
user of the present invention. 
It is to be understood that the above description is not intended in any 
way to limit the scope of the present invention, and that the scope of the 
invention shall follow from the claims set forth below. 
There has thus been set forth and described an invention which accomplishes 
at least all of the stated objectives.