Note: Descriptions are shown in the official language in which they were submitted.
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MATERIAL REMOVING TOOL
TECHNICAL FIELD
[1000] This invention is directed toward a manually operated tool for use in
removing material. The invention is more particularly directed toward a
roofing
tool for use in manually separating roofing material from roofs in the repair
of
roofs. The invention is also directed toward a blade for use in the roofing
tool.
BACKGROUND ART
[1001] Most manually operated roofing tools employ a thin, relatively long,
blade
with a handle extending upwardly and rearwardly from the top, rear of the
blade. The blade is generally longer than it is wider, the long blade thought
to be
desirable to be able to lift more of the shingles during each lift. The front
of the
blade can be tapered and is provided with slots that extend rearwardly a
relatively short distance from the front edge toward the rear edge of the
blade.
The slots are used to capture the shanks of roofing nails encountered by the
blade during operation of the tool, the blade being manipulated by the handle
to
lift the captured nails from the roof. Most of the known manual roofing tools
use
leverage to be able to lift the nails and the shingles away from the roofs.
The
handle of the tool is used to slide the blade, while all, or at least the
front part of
the blade, is flat on the roof, under the shingles. The handle can then be
manipulated to pivot the blade about its back edge to raise the front edge of
the
blade under the shingles to lift them. The blade often has a fulcrum under the
blade at its rear end. By pivoting the handle about the fulcrum while the
fulcrum
rests on the roof, the fulcrum aids in lifting the front of the blade, and any
shingles on the blade. The handle is normally located close to the back edge
and/or the fulcrum, well spaced from the slots, to allow the blade to move
forward under the shingles for a considerable distance before lifting the
shingles.
[1002] It has been found however that the relatively long blade makes for a
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heavy tool which is tiring to use and thus inefficient. Further, it has been
found
that the long blade makes the tool less efficient in lifting the shingles
since the
moment arm from the back pivot edge of the blade to the front edge is
relatively
long. The longer the blade, the more effort that must be expended to use the
tool.
BRIEF DESCRIPTION OF THE INVENTION
[1003] Applicant has discovered that a much more efficient and lighter tool
can
be effectively employed in lifting shingles by using a very short blade with
the
handle of the tool, extending from the blade, located between and adjacent
both
the rear edge of the blade and the end of the slots in the front of the blade.
The
blade is obviously lighter and obviously more efficient since there is a very
short
lever arm between the rear edge of the blade and the front edge making it much
easier to lift the shingles up. While the tool does not extend nearly as far
under
the shingles to lift them, as do the prior art tools, it has been unexpectedly
found
that the new tool can lift a given area of shingles quicker with less effort
than
the time needed to lift the same area of shingles using tools with a long
blade.
Applicant's tool loosens and partly lifts the shingles with the short front of
the
blade and then continues lifting the shingles with the handle as the blade is
pushed forward to loosen more of the shingles. Much less effort is required to
loosen and partly lift the shingles since applicant's tool blade is so short
and the
leverage is so great. What is unexpected is that the shingles can be easily
completely lifted in short forward and lifting movements using the tool handle
as
well as the blade. While the operator must use more forward and lifting
movements, the lighter tool and the more efficient lifting action more than
compensates for the increased tool activity.
[1004] The invention is particularly directed toward a manually operated
material
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lifting tool having a blade, the blade having front and rear edges, the front
and
rear edges joined by side edges, the front and rear edges being longer than
the
side edges to make the blade wider than it is longer. The blade has slots
extending inwardly from the front edge toward the back edge forming tapered
teeth. A handle is attached to the top of the blade approximately midway
between the side edges, the handle located between, and closely adjacent to,
the rear edge and the end of the nearest slot. The handle extends rearwardly
and upwardly from the top of the blade.
[1005] The invention is also directed toward a tool blade for a manually
operated material lifting tool, the tool blade having a front edge and a rear
edge,
the front and rear edges joined by side edges, the front and rear edges being
longer than the side edges to make the blade wider than it is longer. The
blade
has slots extending inwardly from the front edge toward the back edge forming
teeth between the slots. A hosel is attached to the top of the blade
approximately midway between the side edges, the hosel located between, and
closely adjacent to, the rear edge and the end of the nearest slot. The hosel
extends rearwardly and upwardly from the top of the blade, the hosel adapted
to
receive a handle member by means of which the tool is manually operated.
BRIEF DESCRIPTION OF THE FIGURES IN THE DRAWINGS
[1006] Fig. 1 is a perspective view of the tool;
[1007] Fig. 2 is a side view of the tool head;
[1008] Fig. 3 is a detail plan view of the teeth on the tool blade;
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[1009] Fig. 4 is a cross-section view taken along line 4-4 in Fig. 3;
[1010] Fig. 5 is a schematic view of the tool pulling up a nail;
[1011] Fig. 6 is a detail side view of another embodiment of the tool blade;
[1012] Fig. 7 is a detail side view of a further embodiment of the tool blade;
[1013] Fig. 8 is a side view of another embodiment of the tool head;
[1014] Fig. 9 is detail plan view of another embodiment of the tool blade; and
[1015] Fig. 10 is a detail perspective view of another embodiment of the tool
handle.
DETAILED DESCRIPTION OF THE INVENTION
[1016] The tool 1, as shown in Figs. 1 and 2, has a blade 3 with a handle 5
extending upwardly and rearwardly from the blade. The handle 5 comprises a
separate handle member 7, made from a wooden rod or a metal tube, attached
directly to a metal hosel 9 extending upwardly and rearwardly from the top 11
of
the blade.
[1017] The blade 3 is generally of a quadratic shape, having a front edge 15
and
a rear edge 17. The front and rear edges 15, 17 are normally straight and
parallel but could be slightly curved, or be at a slight angle, to each other.
The
front and rear edges 15, 17 are joined by side edges 19. The front and rear
edges 15, 17 are longer than the side edges 19 providing a blade that is
substantially wider than it is long. The length to width ratio of the blade is
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between about 2 to 3 and about 1 to 2. A preferred blade is about four inches
long and about seven inches wide. The blade is usually made from a steel plate
of uniform thickness, the thickness being about one eighth of an inch.
[1018] The blade 3 has teeth 21 formed in the front edge 15 as more clearly
shown in Fig. 3. The teeth 21 are separated by slots 23 extending inwardly
from
the front edge 15 toward the back edge 17. The slots 23 normally have a wide
entry mouth 25 with straight sides 27 that taper down to an elongated slot
extension 29. The slot extension 29 can have straight sides 31 that angle
slightly
toward each other toward the closed end 33 of the slot extension 29 so that
the
slot extension tapers toward the end 33. The tapered slot extension 29 allows
the tool to remove nails having different shank diameters. The slots 23 are
normally equally spaced apart and shape the teeth 21 to each have a tapered
front portion 35 ending in a rounded front end 37. The tapered front portion
35
is formed by the wide entry mouth 25 of the slots 23. The rounded front ends
37
of the teeth are aligned and define the front edge 15 of the blade shown by a
broken line in Fig. 3. The tapered front portion 35 connects to a main body
portion 39 that is slightly tapered toward the tapered front portion 35. The
main
body portion 39 is defined by the straight sides 31 of adjacent slots 23. The
main
body portion 39 is normally about one and a half times as long as the tapered
front portion 35. it follows that the slot extension 29 is normally about one
and a
half times as long as the entry mouth 25.
[1019] The teeth 21 can also taper in thickness toward their front end 37, the
bottom 41 of the teeth ground down from the bottom 43 of the blade so that the
front end 37 is generally aligned with the top 11 of the blade 3 as shown in
Fig.
4. The teeth are approximately one and a half inches long. The blade is
normally
one eighth of an inch thick with the teeth tapering in thickness to about one
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sixteenth of an inch at the front end 37.
[1020] The slots 23 receive the shanks of any roofing material nails
encountered
in the roof during removal of the roofing material and direct the shanks into,
and
to, the closed end 33 of the narrow, extension portion 29 of the slots with
the
head of the nails, wider than the extension portion 29 of the slots, resting
on the
top of the teeth. The nails can be easily levered up and out of the roof by
first
pivoting the blade 3 up about its front edge 15 using the handle 5, and then
about its back edge 17, if required. The teeth are relatively long to provide
sufficient leverage to be able to loosen and at least partly lift the nails
from the
roof using the front edge 15 of the blade as a pivot.
[1021] A preferred form of slots and teeth has been described. Others forms of
slots and teeth can be employed. For example, the teeth 21 can be made more
rounded with the connection between the straight sides 27, 31 of the slots
being
slightly rounded instead of angular and with the rounded end 37 being wider
and
flatter than shown. In a further embodiment, the slot extension 29 of the
slots
can have its sides parallel rather than slightly angled to each other. In
another
variation, the slot extension 29 can be shorter than one and a half times the
length of the entry mouth 25. The slot extension can even be shorter than the
entry mouth 25. At least one slot 23, and preferably two, one on each side of
the
handle 5, can be provided in the rear edge 17 of the blade as well to help
remove nails.
[1022] The handle 5 is attached to the top 11 of the blade 3, centered between
the side edges 19 of the blade via the hosel 13. The handle 5 is attached to
the
blade 3 to have its leading or front, bottom, side 47, adjacent the end 33 or
ends
33 of the nearest slot 23 or slots 23. The blade is made only as long as
needed
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in order to be able to attach the entire bottom of the handle to the top of
the
blade. The trailing or rear, bottom, side 49 of the handle 5, is adjacent the
rear
edge 17 of the blade 3. The handle 5 extends upwardly and rearwardly from the
top 11 of the blade 3 at an angle 0 ranging from between 300 and 50 and
preferably around 40 . If the tool is used primarily to remove roofing
material
working down from the ridge of a roof, the handle can extend from the blade at
a high pitch angle ranging preferably between 40 and 45 . If the tool is used
primarily to remove roofing material working up toward the ridge of a roof,
the
handle can extend from the blade at a low pitch angle ranging preferably
between 35 and 40 . The angle of the handle is a compromise between having
the handle low enough to more easily push the blade 3 under shingles and
having the handle high enough to be able to work without having to bend too
far
over. The lower the handle is, the easier the loosened material will slide up
the
front of the handle. The handle 5 is also somewhat longer than normal, about
forty inches instead of a normal thirty four-thirty six inches, to make it
easier to
work without having to bend too far over. The longer handle also increases the
mechanical advantage of the tool in levering up the material. However the tool
can be effectively used with a short handle, one ranging between twenty four
and thirty inches, as well.
[1023] Locating the handle 5 of the tool adjacent the ends 33 of the slots 23
in
the blade 3 and adjacent the back edge 17 of the blade provides a tool 1 that
generates a powerful torque to be used in lifting nails and material. A
lifting force
F1 applied at the end of the lever arm L1 provided by the long forty inch
handle
5, about the rear edge 17 of the blade 3, provides a very strong lifting force
F2
to a nail N at the end 33 of the slots 23 due to the short lever arm L2 of
about
two inches between the rear edge 17 and the end 33 of the slots as shown in
Fig. 5. The lifting force F2 obtained is about twenty times the lifting force
F1
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applied. In the tools presently used, with a blade between six and eight
inches
long, the lifting force F2 obtained is only about a half or a third of the
lifting
force F2 obtained by applicant's blade. The difference is substantial in the
effort
needed to remove the roofing material.
[1024] Using a substantially shorter blade than normal, unexpectedly does not
affect the efficiency of the short blade in removing the roofing material. The
handle guides the material lifted and loosened by the blade upwardly on the
handle as the blade is moved further and further under the material still
attached
to the roof. The loosened and raised material riding up the handle can be torn
or
cut away when it gets too long and/or in the way. The shorter blade allows the
tool to be more easily and quickly manipulated to lift the roofing material
using
much less energy. More manipulation of the tool is required with the shorter
blade than when using a longer blade to properly position the blade for
lifting,
but much less effort is required to lift thus making it more efficient to
remove the
roofing material. A worker spends much less energy in removing the roofing
material using the tool of this invention with its short, and thus light
blade, than
when using a tool with a long, heavier blade and thus can work harder for a
longer period of time.
[1025] While the teeth 21 have been said to be ground down from the bottom
43 of the blade to taper the teeth in thickness, the teeth can instead be
ground
down from the top 11 to taper the teeth in thickness, the tip 37 of the teeth
in
this case generally aligned with the bottom surface 43 of the blade as shown
in
Fig. 6. The blade 3 can, if desired, be provided with a strengthening ridge 51
extending across the base of the teeth 21, adjacent the inner end 33 of the
slots
23, as shown in Fig. 7. The ridge 51 extends across the width of the blade
between its sides 19, is slightly raised, and serves to strengthen the blade.
The
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ridge 51 also initiates movement of the loosened roofing material upwardly
onto
the front side 47 of the handle. The ridge 51 could also be located between
the
ends 33 of the slots and the front side 47 of the handle 5. The use of a ridge
51
in this location will slightly reduce the efficiency of the blade since the
blade is
now slightly longer. The use of a ridge in this location would add about three-
quarters of an inch to the length of the blade.
[1026] The blade 3 has been shown as being of substantially uniform thickness
except for the taper in thickness of the teeth. The blade 3A could however be
tapered over its entire length reducing in thickness from about one quarter of
an
inch at its back edge 17A to about one sixteenth of an inch at its front edge
15A
as shown in Fig. 8. The tapered shape of the blade 3A allows the blade to
continue lifting, including on either side of the handle 5A, as the blade is
pushed
under the shingles.
[1027] The side edges 19 of the blade 3 have been shown in Fig. 1 as being
perpendicular to the front and rear edges 15, 17. The blade 3B could however
have the side edges 19B angle away from each other slightly in moving from the
front edge 15B to the rear edge 17B so that the rear edge 17B is wider than
the
front edge 15B as shown in Fig. 9. This shape of the blade makes it easier to
manipulate the blade under the shingles.
[1028] The handle 5 has been shown as a wooden shaft 7 attached to a hosel 9
on the blade 3. However, the handle 5C could also be a metal tube 55 attached
directly to the top 11C of the blade 3C as shown in Fig. 10. The tool has been
primarily described as being used to help lift and remove roofing material. It
could however also be used to help lift and remove other materials such as ice
on sidewalks, or flooring materials in a building.
A o
