U.S. patent application number 12/696259 was filed with the patent office on 2011-08-04 for greatest gutter guard.
Invention is credited to Jimmy J. DeHart, SR..
Application Number | 20110185642 12/696259 |
Document ID | / |
Family ID | 44340381 |
Filed Date | 2011-08-04 |
United States Patent
Application |
20110185642 |
Kind Code |
A1 |
DeHart, SR.; Jimmy J. |
August 4, 2011 |
Greatest Gutter Guard
Abstract
An elongated strip of extruded plastic or roll formed metal
material includes a rear securing plane that inserts beneath a
roofing membrane of a building structure. The rear plane integrally
connects to a reversed curved surface arranged longitudinally witch
connects to a forward extending perforated second plane by means of
a channel, one of two channels, which additionally serve to receive
and secure a lateral edge of a filtration membrane. The perforated
second plane contains intrinsic and intersecting vertical water
directing planes that extend above and beneath the surface of the
second plane and which serve to support and contact an overlying
insertable filtration membrane. The second plane interconnects to a
forward extending plane by means of a channel that serves to
receive and secure a lateral edge of a filtration membrane. The
plane connects to a second plane by means of a downward extending
channel. The second plane rests on the top front lip of a k-style
gutter and is adjoined by a downward angled plane the first reverse
curve plane serves take the brunt of the rain to disallow roof
water runoff from contacting the front face of a k-style gutter. A
combination of a reverse curve and a filtration membrane configured
for water permeability and debris repellency resting on vertical
planes serves to break the forward flow of water, at points of
contact between the reverse curve plane and filtration membrane,
and also serves to further channel water downward through an
underlying perforated plane into an underlying rain gutter. The
filtration membrane is readily inserted into the channels existing
on the forward and rear edges of a perforated first plane.
Inventors: |
DeHart, SR.; Jimmy J.;
(Landenberg, PA) |
Family ID: |
44340381 |
Appl. No.: |
12/696259 |
Filed: |
January 29, 2010 |
Current U.S.
Class: |
52/12 |
Current CPC
Class: |
E04D 13/076
20130101 |
Class at
Publication: |
52/12 |
International
Class: |
E04D 13/076 20060101
E04D013/076 |
Claims
1. A gutter shield device for mounting in an open top of a rain
gutter attached to an edge of a roof, said gutter shield
comprising: an elongated body of extruded or roll formed material,
the elongated body having a plurality of interconnected planes
including a second plane that supports the microfiltratson; a first
curved plane that is interconnected to the second plane and the
first plane extending at an angle that inserts under a roofing
membrane; first leg connected to the second plane, wherein the the
second plane, and the first leg define a front fastening member
configured to receive the lip of the rain gutter;
2. The gutter shield device according to claim 1, wherein said
plurality of spaced bumps are spaced from one another at a distance
equal to or less than four times their height in said first
direction.
3. The gutter shield device according to claim 1, wherein said
filtration element is secured at its lateral edges in said first
and second receiving channels, and wherein at least one of said
plurality of spaced bumps supports and contacts said filtration
element.
4. The gutter shield device according to claim 1, wherein said
first plane connected to the second reverse curve plane.
5. A gutter shield device for mounting to a rain gutter attached to
a building structure, the gutter shield device comprising: an
elongated body comprising: a first body portion; a second body
portion; the first and second body portions are interconnected.
Description
BACKGROUND
[0001] 1. Field of Invention
[0002] Gutter covering systems are known to prevent debris from
entering into the open top end of a rain gutter.
[0003] When debris accumulates within the body of a rain gutter in
an amount great enough to cover the opening of a downspout-draining
hole the draining of water from the rain gutter is impeded or
completely stopped. This occurrence will cause the water to rise
within the rain gutter and spill over its uppermost front and rear
portions. The purpose of a rain gutter: to divert water away from
the structure and foundation of a home is thereby circumvented.
[0004] 2. Prior Art
[0005] The invention relates to the field of Gutter Anti-clogging
Devices and particularly relates to screens with affixed fine
filter membranes, and to devices that employ recessed wells or
channels in which filter material may be inserted, affixed to
gutters to prevent debris from impeding the desired drainage of
water.
[0006] Various gutter anti-clogging devices are known in the art
and some are described in issued patents.
[0007] In U.S. Pat. No. 6,598,352 It includes a recessed perforated
angled well within a rigid main body that receives an insertable
flexible polymer support skeleton that supports overlying micro
mesh filtering membrane that is attached to the underlying support
skeleton. This insertable flexible filtration configuration is
manufactured separately from the rigid four or five foot length
body in fifty foot rolls and allows for a seamless filter
protecting an underlying gutter, over long gutter lengths. The
insertable support skeleton includes a perforated plane with
integral downward extending planes and integral upward extending
support planes, separated by unbroken air space, that contact an
overlying micro mesh filtering membrane on it's undermost surface.
Also the contacting of the undermost surface of a micromesh
filtering membrane by optimally spaced support planes encourages
the downward flow of rain water through said micro mesh filtering
membrane and into an underlying rain gutter. This gutter protection
system has been shown, in the field to be extremely effective at
preventing rain gutter clogs without a single known instance of
clogging. However, there are two known flaws first during heavy
rain the micromesh filtering membrane will reach its max flow
potential and water extrudes past the membrane and misses the
gutter entirely causing the gutters to fail. Second the insertable
flexible polymer support skeleton with attached filtering membrane
is somewhat heavy and has been found to be cumbersome, even
impossible, to install in the recessed angled well of the rigid
main body of the gutter protection system during cold weather as
the flexible polymer skeleton has been found to stiffen and becomes
inflexible. The insertable flexible skeleton also has been known to
expand and contract at a different coefficient that rigid main body
of the gutter protection system. This can cause areas of the main
body of the gutter protection to become exposed to potential debris
entrance due to relative shrinkage of the insertable polymer
support skeleton or, in other instances, the insertable filtration
configuration may expand and extend past the main body of the
gutter protection system and further expand past end caps of an
underlying gutter which home owners view as undesirable from a
cosmetic perspective.
[0008] U.S. Pat. No. 5,557,891 to Albracht teaches a gutter
protection system for preventing entrance of debris into a rain
gutter. Albracht teaches a gutter protection system to include a
single continuous two sided well with angled sides and perforated
bottom shelf 9 into which rainwater will flow and empty into the
rain gutter below. The well is of a depth, which is capable of
receiving a filter mesh material. However, attempts to insert or
cover such open channels of "reverse-curve" devices with filter
meshes or cloths is known to prevent rainwater from entering the
water receiving channels. This occurrence exists because of the
tendency of such membranes, (unsupported by a proper skeletal
structure), to channel water, by means of water adhesion along the
interconnected paths existing in the filter membranes (and in the
enclosures they may be contained by or in), past the intended
water-receiving channel and to the ground. This occurrence also
exists because of the tendency of filter mediums of any present
known design or structure to quickly waterproof or clog when
inserted into such channels creating even greater channeling of
rainwater forward into a spill past an underlying rain gutter.
Filtering of such open, recessed, channels existing in Albracht's
invention as well as in U.S. Pat. No. 5,010,696, to Knittel, U.S.
Pat. No. 2,672,832 to Goetz, U.S. Pat. Nos. 5,459,350, &
5,181,350 to Meckstroth, U.S. Pat. No. 5,491,998 to Hansen, U.S.
Pat. No. 4,757,649 to Vahldieck and in similar "reverse-curved"
inventions that rely on "reverse-curved" surfaces channeling water
into an open channel have been known to disallow entrance of
rainwater into the water-receiving channels. Albracht's as well as
previous and succeeding similar inventions have therefore notably
avoided the utilization of filter insertions. What may appear as a
logical anticipation by such inventions at first glance, (inserting
of a filter mesh or material into the channel), has been shown to
be undesirable and ineffective across a broad spectrum of filtering
materials: Employing insertable filters into such inventions has
not been found to be a simple matter of anticipation, or design
choice of filter medium by those skilled in the arts. Rather, it
has proved to be an ineffective option, with any known filter
medium, when attempted in the field. Such attempts, in the field,
have demonstrated that the filter mediums will eventually require
manual cleaning. German Patent 5,905,961 teaches a gutter
protection system for preventing the entrance of debris into a rain
gutter. The German patent teaches a gutter protection system to
include a single continuous two sided well 7 with angled sides and
perforated bottom shelf which rainwater will flow and empty into
the rain gutter below. The well is recessed beneath and between two
solid lateral same plane shelves close to the front of the system
for water passage near and nearly level with the front top lip of
the gutter. The well is of a depth, which is capable of receiving a
filter mesh material. However, for the reasons described in the
preceding paragraphs, an ability to attach a medium to an
invention, not specifically designed to utilize such a medium, may
not result in an effective anticipation by an invention. Rather,
the result may be a diminishing of the invention and its
improvements as is the case in Albracht's patent U.S. Pat. No.
5,557,891, the German Patent, and similar inventions employing
recessed wells or channels between adjoining planes or
curvatures.
[0009] U.S. Pat. No. 5,595,027 to Vail teaches a continuous opening
24A between the two top shelves. Vail teaches a gutter protection
system having a single continuous well 25, the well having a depth
allowing insertion and retention of filter mesh material 26 (a top
portion of the filler mesh material capable of being fully exposed
at the holes). Vail does teach a gutter protection system designed
to incorporate an insertable filter material into a recessed well.
However, Vail notably names and intends the filter medium to be a
tangled mesh fiberglass five times the thickness of the invention
body. This type of filtration medium, also claimed in U.S. Pat. No.
4,841,686 to Rees, and in prior art currently marketed as
FLOW-FREE.TM..
[0010] is known to trap and hold debris within itself which, by
design, most filter mediums are intended to do, i.e.: trap and hold
debris. Vail's invention does initially prevent some debris from
entering an underlying rain gutter but gradually becomes
ineffective at channeling water into a rain gutter due to the
propensity of their claimed filter mediums to clog with debris.
Though Vail's invention embodies an insertable filter, such filter
is not readily accessible for cleaning when such cleaning is
necessitated. The gutter cover must be removed and uplifted for
cleaning and, the filter medium is not easily and readily inserted
replaced into its longitudinal containing channel extending three
or more feet. It is often noted, in the field, that these and
similar inventions hold fast pine needles in great numbers which
presents an unsightly appearance as well as create debris dams
behind the upwardly extended and trapped pine needles. Such filter
meshes and non-woven lofty fiber mesh materials, even when composed
of finer micro-porous materials, additionally tend to clog and fill
with oak tassels and other smaller organic debris because they are
not resting, by design, on a skeletal structure that encourages
greater water flow through its overlying filter membrane than
exists when such filter meshes or membranes contact planar
continuously-connected surfaces. Known filter mediums of larger
openings tend to trap and hold debris. Known filter mediums smaller
openings clog or "heal over" with pollen and dirt that becomes
embedded and remains in the finer micro-porous filter mediums. At
present, there has not been found, as a matter of common knowledge
or anticipation, an effective water-permeable, non-clogging
"medium-of-choice" that can be chosen, in lieu of claimed or
illustrated filter mediums in prior art, that is able to overcome
the inherent tendencies of any known filter mediums to clog when
applied to or inserted within the types of water receiving wells
and channels noted in prior art. Vail also discloses that filter
mesh material 26 is recessed beneath a planar surface that utilizes
perforations in the plane to direct water to the filter medium
beneath. Such perforated planar surfaces as utilized by Vail, by
Sweers U.S. Pat. No. 5,555,680, by Morin U.S. Pat. No. 5,842,311
and by similar prior art are known to only be partially effective
at channeling water downward through the open apertures rather than
forward across the body of the invention and to the ground. This
occurs because of the principal of water adhesion: rainwater tends
to flow around perforations as much as downward through them, and
miss the rain gutter entirely. Also, in observing perforated planes
such as utilized by Vail and similar inventions (where rainwater
experiences its first contact with a perforated plane) it is
apparent that they present much surface area impervious to downward
water flow disallowing such inventions from receiving much of the
rainwater contacting them. A simple design choice or anticipation
of multiplying the perforations can result in a weakened body
subject to deformity when exposed to the weight of snow and/or
debris or when, in the case of polymer bodies, exposed to summer
temperatures and sunlight.
[0011] U.S. Pat. No. 4,841,686 to Rees teaches an improvement for
rain gutters comprising a filter attachment, which is constructed
to fit over the open end of a gutter. The filter attachment
comprised an elongated screen to the underside of which is clamped
a fibrous material such as fiberglass. Rees teaches in the
Background of The Invention that many devices, such as slotted or
perforated metal sheets, or screens of wire or other material, or
plastic foam, have been used in prior art to cover the open tops of
gutters to filter out foreign material. He states that success with
such devices has been limited because small debris and pine needles
still may enter through them into a rain gutter and clog its
downspout opening and or lodge in and clog the devices themselves.
Rees teaches that his use of a finer opening tangled fiberglass
filter sandwiched between two lateral screens will eliminate such
clogging of the device by smaller debris. However, in practice it
is known that such devices as is disclosed by Rees are only
partially effective at shedding debris while channeling rainwater
into an underlying gutter. Shingle oil leaching off of certain roof
coverings, pollen, dust, dirt, and other fine debris are known to
"heal over" such devices clogging and/or effectively
"water-proofing" them and necessitate the manual cleaning they seek
to eliminate. (If not because of the larger debris, because of the
fine debris and pollutants). Additionally, again as with other
prior art that seeks to employ filter medium screening of debris;
the filter medium utilized by Rees rests on an inter-connected
planar surface which provides non-broken continuous paths over and
under which water will flow, by means of water adhesion, to the
front of a gutter and spill to the ground rather than drop downward
into an underlying rain gutter. Whether filter medium is
"sandwiched" between perforated planes or screens as in Rees'
invention, or such filter medium exists below perforated planes or
screens and is contained in a well or channel, water will tend to
flow forward along continuous paths through cur as well as downward
into an underlying rain gutter achieving less than desirable
water-channeling into a rain gutter.
[0012] U.S. Pat. No. 5,956,904 to Gentry teaches a first fine
screen having mesh openings affixed to an underlying screen of
larger openings. Both screens are elastically deformable to permit
a user to compress the invention for insertion into a rain gutter.
Gentry, as Rees, recognizes the inability of prior art to prevent
entrance of finer debris into a rain gutter, and Gentry, as Rees,
relies on a much finer screen mesh than is employed by prior art to
achieve prevention of finer debris entrance into a rain gutter. In
both the Gentry and Rees prior art, and their improvements over
less effective filter mediums of previous prior art, it becomes
apparent that anticipation of improved filter medium or
configurations is not viewed as a matter of simple anticipation of
prior art which has, or could, employ filter medium. It becomes
apparent that improved filtering methods may be viewed as patenable
unique inventions in and of themselves and not necessarily an
anticipation or matter of design choice of a better filter medium
or method being applied to or substituted within prior art that
does or could employ filter medium. However, though Rees and Gentry
did achieve finer filtration over filter medium utilized in prior
art, their inventions also exhibit a tendency to channel water past
an underlying gutter and/or to heal over with finer dirt, pollen,
and other pollutants and clog thereby requiring manual cleaning.
Additionally, when filter medium is applied to or rested upon
planar perforated or screen meshed surfaces, there is a notable
tendency for the underlying perforated plane or screen to channel
water past the gutter where it will then spill to the ground. It
has also been noted that prior art listed herein exhibits a
tendency to allow filter cloth mediums to sag into the opening of
their underlying supporting structures. To compensate for forward
channeling of water, prior art embodies open apertures spaced too
distantly, or allows the apertures themselves to encompass too
large an area, thereby allowing the sagging of overlying filter
membranes and cloths. Such sagging creates pockets wherein debris
tends to settle and enmesh.
[0013] U.S. Pat. No. 3,855,132 to Dugan teaches a porous solid
material which is installed in the gutter to form an upper barrier
surface (against debris entrance into a rain gutter). Though Dugan
anticipates that any debris gathered on the upper barrier surface
will dry and blow away, that is not always the case with this or
similar devices. In practice, such devices are known to "heal over"
with pollen, oil, and other pollutants and effectively waterproof
or clog the device rendering it ineffective in that they prevent
both debris and water from entering a rain gutter. Pollen may
actually cement debris to the top surface of such devices and fail
to allow wash-off even after repeated rains. U.S. Pat. No.
4,949,514 to Weller sought to present more water receiving top
surface of a similar solid porous device by undulating the top
surface but, in fact, effectively created debris "traps" with the
peak and valley undulation. As with other prior art, such devices
may work effectively for a period of time but tend to eventually
channel water past a rain gutter, due to eventual clogging of the
device itself.
[0014] There are several commercial filtering products designed to
prevent foreign matter buildup in gutters. For example the
FLOW-FREE.TM. gutter protection system sold by DCI of Clifton
Heights, Pa. Comprises a 0.75-inch thick nylon mesh material
designed to fit within 5-inch K type gutters to seal the gutters
and downspout systems from debris and snow buildup. The
FLOW-FREE.TM. device fits over the hanging brackets of the gutters
and one side extends to the bottom of the gutter to prevent the
collapse into the gutter. However, as in other filtering attempts,
shingle material and pine needles can become trapped in the coarse
nylon mesh and must be periodically cleaned.
[0015] U.S. Pat. No. 6,134,843 to Tregear teaches a gutter device
that has an elongated matting having a plurality of open cones
arranged in transverse and longitudinal rows, the base of the cones
defining a lower first plane and the apexes of the cones defining
an upper second plane. Although the Tregear device overcomes the
eventual trapping of larger debris within a filtering mesh composed
of fabric sufficiently smooth to prevent the trapping of debris he
notes in prior art, the Tregear device tends to eventually allow
pollen, oil which may leach from asphalt shingles, oak tassels, and
finer seeds and debris to coat and heal over a top-most matting
screen it employs to disallow larger debris from becoming entangled
in the larger aperatured filtering medium it covers. Tregear
indicates that filtered configurations such as a commercially
available attic ventilation system known as Roll Vent.TM.
manufactured by Benjamin Obdyke, Inc. Warminster, Pa. Is suitable,
with modifications that accommodate its fitting into a rain gutter.
However, such a device has been noted, even in its original
intended application, to require cleaning (as do most attic screens
and filters) to remove dust, dirt, and pollen that combine with
moisture to form adhesive coatings that can scum or heal over such
attic filters. Filtering mediums (exhibiting tightly woven,
knitted, or tangled mesh threads to achieve density or
"smoothness") employed by Tregear and other prior art have been
unable to achieve imperviousness to waterproofing and clogging
effects caused by a healing or pasting over of such surfaces by
pollen, fine dirt, scum, oils, and air and water pollutants.
Additionally, referring again to Tregear's device, a lower first
plane tends to channel water toward the front lip of a rain gutter,
rather than allowing it's free passage downward, and allow the
feeding and spilling of water up and over the front lip of a rain
gutter by means of water-adhesion channels created in the lower
first plane.
[0016] Prior art has employed filter cloths over underlying mesh,
screens, cones, longitudinal rods, however such prior art has
eventually been realized as unable to prevent an eventual clogging
of their finer filtering membranes by pollen, dirt, oak tassels,
and finer debris. Such prior art has been noted to succumb to
eventual clogging by the healing over of debris which adheres
itself to surfaces when intermingled with organic oils, oily
pollen, and shingle oil that act as an adhesive. The hoped for
cleaning of leaves, pine needles, seed pods and other debris by
water flow or wind, envisioned by Tregear and other prior art, is
often not realized due to their adherence to surfaces by pollen,
oils, pollutants, and silica dusts and water mists. The cleaning of
adhesive oils, fine dirt, and particularly of the scum and paste
formed by pollen and silica dust (common in many soil types) by
flowing water or wind is almost never realized in prior art.
[0017] Prior art that has relied on reverse curved surfaces
channeling water inside a rain gutter due to surface tension, of
varied configurations and pluralities, arranged longitudinally,
have been noted to lose their surface tension feature as pollen,
oil, scum, Eventually adhere to them causing water to overshoot the
gutter. Examples of such prior art are seen in the commercial
product GUTTER HELMET.RTM. manufactured by American metal products
and sold by Mr. Fix It of Richmond, Va. In this and similar
Commercial products, dirt and mildew build up on the bull-nose of
the curve preventing water from entering the gutter. Also ENGLERT'S
LEAFGUARD.RTM. Manufactured and entering the gutter. Also ENGLERT'S
LEAFGUARD.RTM. Manufactured and distributed by Englert Inc. of
Perthamboy N.J. and K-GUARD.RTM. Manufactured and distributed by
KNUDSON INC. of Colorado are similarly noted to lose their
water-channeling properties due to dirt buildup. These commercial
products state such, in literature to homeowners that advises them
on the proper method of cleaning and maintaining their
products.
[0018] None of these above-described systems keep all debris out of
a gutter and can handle water flow under all conditions. Some allow
lodging and embedding of pine needles and other debris is able to
occur within their open water receiving areas causing them to
channel water past a rain gutter. Others allow such debris to enter
and clog a rain gutter's downspout opening. Still others,
particularly those employing filter membranes, succumb to a paste
and or scum-like healing over and clogging of their filtration
membranes over time rendering them unable to channel water into a
rain gutter. Pollen and silica dirt, particularly, are noted to
cement even larger debris to the filter, screen, mesh, adhering
debris to prior art in a manner that was not envisioned.
[0019] Accordingly, it is an object of the present invention to
provide a gutter shield that employs the effective properties of
the fine filtration in combination with the reverse curve system. A
gutter shield device that employs a fine filtration combination
that is not subject to gumming or healing over by pollen, silica
dust, oils, and other very fine debris, a gutter shield device that
provides a filtration configuration and encompassing body with the
reverse curve system together that eliminates any stand alone
forward channeling of rain water that over shoots the gutter, a
gutter shield that will accept more water run-off into a five inch
K-style rain gutter than such a gutter's downspout opening is able
to drain before allowing the rain gutter to overflow (in instances
where a single three-inch by five-inch downspout is installed to
service 600 square feet of roofing surface).
[0020] Another object of the present invention is to provide a
gutter shield with the above noted properties that incorporates and
makes integral within it's main rigid body the features and
structure of the insertable flexible polymer support skeleton
thereby eliminating the most prominent expansion and contraction
coefficients found to exist between a rigid main body utilizing an
insertable flexible polymer filtration configuration.
[0021] Another object of the present invention is to provide a
gutter shield with the above noted properties that utilizes a
stainless steel or aluminum micromesh filter cloth that may be
inserted into a main body with integral recessed and perforated
wells that incorporate integral upward extending planes allowing
for a lower cost of manufacture by eliminating a separately
manufactured flexible polymer support skeleton and allowing for a
lighter, more stable under varying temperatures, and more easily
installed insertable filtering component.
[0022] Another object of the present invention is to provide a
gutter shield that employs a filtration membrane and a reverse
curve the will handle water flow under all conditions.
[0023] Other objects will appear hereinafter.
THE DRAWINGS
[0024] FIG. 1. is a sectional top view displaying the profile of
the main body of the present invention as it would appear extruding
from a roll forming machine or plastic extrusion die.
[0025] FIG. 2. is a side view displaying the profile of the main
body of the present invention as it would appear extruding from a
roll forming machine or plastic extrusion die.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Main Body
[0027] Referring now specifically to the drawings, a gutter cover
(protector) body with intrinsic with an insertable metallic micro
mesh filtering membrane 3 with the reverse curve 5 is illustrated
in FIG. 1 can be seen clearer in FIG. 2-2.
[0028] As a polymer body, is composed of poly vinyl chloride (PVC)
that is reduced to liquid form through screw compression of PVC
"tags". This liquid plastic mixture is then extruded through a
profile forming die, then through a cooling tray and cut to 5 foot
lengths. The extruded body material is rigid and has a thickness of
approximately 0.06 inch. The extruded body is interconnected FIG.
2-5 to reverse curved plane FIG. 1-5 and FIG. 2-2. The second plane
of the extruded body has intrinsic channels FIG. 2-4 that receive
an insertable 130 "thread count" stainless steel wire cloth with
hemmed lateral edges and having a width of 1 inch FIG. 1-3 and FIG.
2-1. The first plane FIG. 2-2,6 of the extruded body is
interconnected to the second plane FIG. 2-5,4,3 that extends
outward to come to rest on the top lip of a k-style gutter FIG. 2-3
and FIG. 1-1,2 the reverse curve FIG. 1-5 and FIG. 2-2 or the first
plane FIG. 1-4,5 and FIG. 2-2,6 continues to the rear securing
plane FIG. 1-4 and FIG. 2-6 that inserts beneath a roofing membrane
of a building structure.
[0029] Referring to FIGS. 1 and 2, a profile of the main body of
the present invention is illustrated having two major
interconnected planes, (5) with a total width of both planes that
may vary between 5.4 and 7 inches (illustrated at 7 inches wide)
and a height measured from the lowest point FIG. 2-4 to the
uppermost point of the curve FIG. 2-2, of approximately 1 1/16
inch.
* * * * *