Note: Descriptions are shown in the official language in which they were submitted.
` 2169~04
-- 1
ROO~lNG FA8, ~N~ AND DRIVING TOOL
FI~LD OF TH~ l~v~ ON
This invention relates generally to fasteners
and fastener driving tools, and more particularly to a
one-piece roofing fastener having a head with a
substantially large surface area for attaching a
relatively thin roof base sheet to a plywood roof and a
manual driving tool for housing a plurality of fasteners
and successively driving the fasteners into selected
areas of the base sheet and the underlying plywood
without driving the fastener through the base sheet.
BACRGROUND OF TH~ lNv~NllON
In constructing building roofs, a base sheet,
such as felt or the like, typically is attached to the
plywood surface of the roof by a plurality of fasteners
positioned about the surface of the base sheet.
Thereafter, asphalt is applied over the base sheet and
the fasteners to provide a moisture seal. A three ply
sheet then is applied over the asphalt as an additional
moisture barrier and is held in position by the asphalt
after it cools and hardens.
As FIG. 11 illustrates, fasteners for
attaching the roof base sheet to the plywood surface of
a roof typically are provided in two pieces including a
large planar head in the form of a disc or apertured
washer and a nail or screw extending through the disc or
washer. The large head assists in securing a
substantial amount of surface area of the base sheet to
the plywood to prevent tearing of the base sheet from
- the fastener and typically is attached with a hand tool,
such as a hammer or power drill.
An example of a tool designed specifically for
3s driving such a two-piece fastener is illustrated in U.S.
- - .
2169~og
Patent No. 4,033,499. That patent discloses both manual
and air activated tools having individual discs supplied
in a magazine that are successively advanced into a
driving position where a staple or a nail is driven
through the disc and into a desired surface.
Such two-piece fasteners and driving tools,
however, are not convenient since separate magazines and
feeding m~h~n;sms must be provided in the driving tool
for both the washers and the nails which makes the tool
very complex and bulky. Additionally, supplies of both
washers and nails must be monitored and resupplied which
can be inconvenient, especially when working on a
building roof.
FIGS. 13 and 13A disclose one-piece fasteners
that include a large disc shaped head from which one or
- more legs are struck. Such fasteners, however,
typically only are utilized for retention of wall board
to a stud since the legs are curved and do- not include
barbs. Thus, the curved legs displace wood when qriven
rather than provide a retention force against removal.
Additionally, existing fasteners do not
provide even weight distribution across the head. Thus,
when such fasteners are driven, they frequently are
driven at an angle other than perpendicular to the base
sheet and wood surface due to the uneven weight
distribution. This causes tearing of the base sheet
which is very undesirable.
It therefore would be desirable to provide a
one-piece roofing fastener for attaching a base sheet to
a roof support surface which provides substantially even
weight distribution across a rather large head for use
with a driving tool that can house a plurality of such
fasteners and can drive the fasteners in a straight line
perpendicular to the base sheet to avoid skewing of the
216~t~
~ ., ,
fastener during driving and prevent tearing of the base
sheet.
8~NMaRY OF THE INVENTION
The invention provides a one-piece roofing
fastener and an associated fastener driving tool. The
fastener preferably is utilized to attach a relatively
thin roof base sheet to a plywood roof and includes a
head portion having a substantially large surface area
with a plurality of legs struck from selected areas of
the head portion to form a plurality of apertures
through the head portion corresponding in shape to the
leg members, The drive tool preferably is manually
activated by a user to successively drive fasteners into
lS the base sheet and underlying plywood with a sudden shot
of a piston without driving the fasteners through or
otherwise damaging the base sheet.
The fastener is designed in one piece to
provide substantially even weight distribution abo,ut the
head of the fastener to reduce damage to the base sheet
when driven.
The drive tool is substantially light weight
for use on a building roof, can accommodate a number of
fasteners at a time and readily can be replenished with
additional fasteners when necessary. The drive tool is
designed with its own fastener advancing and positioning
mechanism which, upon activation of the tool to drive a
fastener, indexes a following fastener into a driving
position for subsequent driving into the roof surface.
The drive tool is manually activated and thus,
is self-contained. No electrical or air lines are
necessary which is a very desirable feature for use on a
building roof or other job site.
216gJ01
BRIEF DE8CRIPTION OF T~E DRA~INGS
FIG. 1 is a perspective view of the driving
end of the drive tool of the invention illustrating a
plurality of fasteners of the invention aligned for
advancement and subsequent driving and including a cut-
away portion of the roof surface illustrating a previous
fastener driven into a roof surface and later covered
with one or more roofing layers;
FIG. 2 is a lateral cross-sectional view of
the driving tool taken along line 2-2 of FIG. 1 in the
direction indicated illustrating the driving ram release
structure;
FIG. 3 is a longitudinal cross-sectional view,
in partial section, of a portion of the driving tool of
the invention illustrated in a non-driving or at-rest
position;
FIG. 4 is a longitudinal cross-sectional view
of a portion of the driving tool, similar to FIG. 3,
illustrating the driving tool in an intermediate driving
position which spring-loads the driving ram;
FIG. 5 is a longitudinal cross-sectional view
of a portion of the driving tool, similar to FIGS. 3 and
4, illustrating a final driving position of the driving
tool where the driving ram is released to drive a
25. fastener positioned with a bore of the driving tool into
a surface;
FIG. 6 is a side elevational view of a driving
tool of the invention with a portion of the driving head
indicated in dotted lines to illustrate release of the
driving head to clear any fastener that may become
jammed within the bore or advancement mechanism of the
driving tool;
FIG. 7 is an enlarged side elevational view of
a portion of the driving head of the tool illustrating
21699 04
- 5 -
the operation of the fastener advancing mechanism on a
down stroke of the driving tool;
FIG. 8 is an enlarged side elevational view of
a portion of the driving head, similar to FIG. 7,
illustrating operation of the fastener advancing
mechanism on an up stroke of the driving tool;
FIG. 8A is a detail of the driving ram
striking a fastener;
FIG. 9 is a top plan view of a fastener of the
invention illustrating the enlarged head portion and the
apertures formed therethrough from legs, illustrated in
dotted lines, which are struck from the surface of the
head portion;
FIG. 10 is a front elevational view of the
fastener illustrated in FIG. 9;
FIG. lOA is a side elevational view of the
fasténer taken along line lOa-lOa of FIG. 10;
~ FIG. 11 is a cross-sectional view of a two-
piece prior art fastener having an apertured washer and .
separate nail therethrough illustrated driven through a
base sheet and into a plywood roof surface;
FIG. 12 is a cross-sectional view of the
fastener of the invention illustrated driven through a
base sheet and into a plywood roof surface;
FIGS. 13 and 13a are perspective and cross-.
sectional views, respectively, of a prior art fastener
utilized for wallboard retention; and
FIG. 14 is a perspective view of another
embodiment of the drive tool of the invention.
216~40~
- 6 -
DE8CRIPTION OF THE PREFERRED ~NBODIMENT~
Referring to FIG. 6, a drive tool of the
invention is designated generally by the reference
numeral 10. The drive tool 10 substantially includes a
drive mechanism 12 and a fastener storage and
advancement me~h~ism 14.
As FIGS. 9 and 10 illustrate, the drive tool
10 preferably is utilized with a fastener 16 made of
metal or the like. For ease of handling and loading
into the drive tool 10, the fasteners 16 preferably are
provided interconnected in a strip (not illustrated).
The drive mechanism 12, as FIGS. 3-6
illustrate, substantially includes a first movable tube
18 having two handles 20 connected thereto and a second
stationary tube 22 in operable communication with the
fastener advancing mechanism 14. In FIG. 3, the first
tube 18 is positioned in its at-rest position while in
FIGS-. 4 and 5 the first tube 18 is moved downward over
the second tube 22 to respective spring loading and
firing positions described in detail hereinafter.
As FIG. 6 illustrates, the fastener storage
and advancing mechanism 14 includes a fastener magazine
24, an additional bulk fastener storage area 26 and a
fastener feed chute or bar 28 which accepts fasteners in
succession from the magazine 24. As FIG. 1 illustrates,
fasteners 16 ride on the top of the centrally located
bar 28 and are aligned with legs of the fasteners 16
spanning the bar 28 for successive advancement by the
fastener advancement mechanism 14 as described below.
If desired, the bar 28 can include a non-stick
substantially slippery coating thereon, such as TEFLON
or the like.
Briefly, in operation, the first tube 18 is
pushed downward with respect to FIG. 6 over the outside
21 69~ o ~ .
_ 7 _
of the second tube 22 by an operator through the use of
the handles 20. On the downstroke, at least one spring
within the first tube 18 is compressed and a driving ram
is pre-loaded by the spring.
5 - Upon continued downward pressure, the first
tube 18 releases the driving ram from its loaded
position which propels the driving ram downward at a
desired speed. Upon reaching the bottom of the drive
tool 10, the driving ram squarely contacts a fastener 16
and drives it into a desired surface.
Upon release of the handles 20, the operator
pulls the first tube 18 back to its at-rest position.
As the first tube 18 moves on the up stroke, it
activates the fastener advancing mechanism 14 to index a
subsequent fastener 16 into position to be driven by the
driving ram on a subsequent drive stroke. Details of
the drive tool 10 now will be provided.
- As FIG. 6 illustrates, the first movable tube
18 includes a first closed end 30 and a second opposite
open end 32. To release the driving ram when loaded as
described below, the second end 30 includes an outwardly
extending engagement leg 33.
As FIGS. 3-6 illustrate, the first movable
tube 18 includes a compression plunger 34 and a drive
spring 36 positioned within the interior of the first
tube 18. Other springs can be included with the drive
tool 10 if desired, such as to provide a return force to
the first tube 18 after firing of a fastener 16 or for
any other reason. The compression plunger 34 includes
first and second opposite ends 40 and 4Z with the first
end 40 being positioned proximate the first closed end
30 of the first tube 18.
The drive spring 36 is positioned within the
first tube 18 with a first end 52 positioned against the
,. _ ' 2169~o~
-- 8 --
second end 42 of the compression plunger 34. A second
end 54 of the drive spring 36 is connected to a first
end 56 of a driving ram 58, the majority of which is
contained within the interior of the second tube 22.
The second tube 22 includes a first end 60 and
a second opposite end 62 connected to a housing member
64 having a barrel 66 through which the drive ram 58
extends when fired. The first end 60 of the second tube
22 fits within the confines of the first tube 18 which
slides along the second tube 22 during use. A flange
assembly 73 connects the second tube 22 to the housing
member 64.
To retain the second tube 22 connected to the
first tube 18, and also to return the driving ram 58 to
the start or rest position, the first tube 18 includes
an aperture 67 through which a retaining bolt 68
extends. The aperture 67 also extends inside the second
tube 22 sufficiently to be able to return the driving
ram 58 to the rest position~when the first tube 18 is
brought to the rest position. The second tube 22
includes a corresponding slot 69 extending along its
length within which the bolt 68 slides during movement
between the first and second tubes 18 and 22.
As FIGS. 1-4 illustrate, proximate the bottom
of the downward stroke of the first tube 18, the
engagement leg 33 contac~ts a lever 70 which is attached
to a spring loaded driving ram release key 72 secured to
the housing member 64. When positioned in the at-rest
position illustrated in FIGS. 1 and 3, the key 72 blocks
a portion of the barrel 66 to prevent the driving ram 58
from extending therethrough. When the key 72 is rotated
by engagement of the lever 70 with the engagement leg 33
to the position illustrated in FIGS. 2 and 4, an arcuate
cut out portion 74 of the key 72 is positioned within
~1 69404
the barrel 66 which enables the driving ram 58 to pass
into the barrel 66 under compression by the drive spring
36 to drive the fastener 16.
As FIGS. 1, 7 and 8 illustrate, the fastener
- advancing mech~ni~m 14 is activated by the first tube 18
to sequentially advance fasteners 16 into the barrel 66
for driving. Specifically, with reference to FIG. 1,
when the second open end 32 of the tube 18 reaches the
bottom of its down stroke it contacts a first end 76 of
an advancing cam 78 having an second end 80
substantially in the shape of a half of an arrowhead.
In its at-rest position, a point of the second
arrowhead end 80 is positioned between first and second
cam surfaces or rollers 82 and 84. The first cam
surface 82 is positioned on an outside surface of the
barrel 66 and the second cam surface 84 is positioned on
a triangular shaped fastener carrier 86.
~ The triangular carrier 86 includes first,
second and third corners 88, 90 and 92. The first
corner 88 is rotatably mounted to a flange 94 of the
barrel 66 by a pivotable connection 96.
The pivotable connection enables rotation of
the carrier 86 along the arc designated by arrow "A".
Thus, the carrier 86 alternates between a first
position, illustrated in FIGS. 1 and 8, and a second
position, illustrated in FIG. 7.
Specifically, when the second arrowhead end 80
of the advancing cam 78 is moved downward in the
direction of arrow "B" of FIG. 7 from contact with the
first tube 18, the arrowhead 80 forces the first and
second cams 82 and 84 apart. This causes upward
rotation of the carrier 86 about the pivotable
connection 96 along the arc "A".
.
216g~
-- 10 --
FIG. 7 illustrates the bottom of the stroke of
the arrowhead 80. Accordingly, on the upward return of
arrowhead 80 in the direction of arrow "C", as
illustrated by FIG. 8, the carrier 86 rotates back to
its original position with the aid of a spring 98.
In order to advance fasteners 16 along the bar
28 from a first position 16a proximate the top of the
bar 28 to a second position 16b proximate the bottom of
the bar 28, first and second pawl members 100 and 102
are included with the carrier 86. As FIG. 8
illustrates, each pawl member 100 and 102 is rotatably
mounted by a pivot pin 104 to a respective corner 90 and
92 of the carrier 86 and loaded with a spring 106.
The springs 106 bias the pawls 100 and 102 in
an outward direction with respect to the carrier 86 for
engagement with and advancement of the fasteners 16.
Thus, as the carrier 86 rotates in the direction of
arrow "A" as illustrated in FIG. 7, the pawls 100 and
102 move to the left and slide over one fastener 16 due -
to the designed dimensions of the advancing mechanism14.
Upon return of the carrier 86 to the position
illustrated in FIG. 8, the pawls 100 and 102 engage a
subsequent fastener 16 and advance the fasteners 16
along the chute 28 to the right. A leading fastener 1-6b
then is positioned within the barrel 66 for subsequent
driving by the driving ram s8.
As FIG. 6 illustrates, in order to clear any
jammed fasteners 16 from the bar 28 or barrel 66, the
bar 28 is releasably connected on one end 28a to a frame
member lOS and on an opposite end 28b to a rotatably
mounted muzzle member 107. Thus, the bar 28 can be
rotated to the position illustrated in dotted lines to
clear any jammed fasteners 16.
- ~1 69 ~
As FIG. 12 illustrates, the fastener 16
preferably is utilized to secure a base sheet 108,
typically made of roofing felt, to a plywood surface
110, such as a surface of a roof or the like. The
fastener 16 includes a head 112, three engagement legs
or prongs 114, 116 and 118 which preferably are driven
through the base sheet 108 and are retained within the
plywood 110, and a peripheral edge 119. In a preferred
embodiment, the edge 119 is upturned or bevelled
approximately 1/32 inch.
For ease of handling and loading, the
fasteners 16 are preferably interconnected in a strip
and are separated when driven by the drive tool 10.
In order to finish the roof and make it
substantially waterproof, a layer of asphalt 120 then is
- spread over the base sheet 108 and fasteners 16. A top
sheet or three-ply sheet 122 then is placed over the
- asphalt 120.
Due to the holding abilities of the fastener
16, no additional ballast, such as gravel, stones or the
like, is necessary. The fastener 16 thus maintains
holding power even during extreme wind conditions which
exert an uplifting force on the fastener 16.
Additionally, the edge 119 prevents an otherwise sharp
edge of the fastener 16 from cutting the sheet 122 and
enables the asphalt 120~to fill the top of the fastener
16 and also to provide a cushion between the upturned or
bevelled edge 119 of the fastener 16 and the base sheet
108. Alternatively, the edge 119 may just be rounded at
its lower periphery.
As FIG. 9 illustrates, the legs 114, 116 and
118 are "coined" from the head 112 of the fastener 16
for reasons described herein. Thus, first, second and
third corresponding apertures 124, 126 and 128 are
21699Q~
formed through the head 112, each of which substantially
is in the shape of the corresponding leg 114, 116 and
118.
As FIG. 12 illustrates, during use, the
S - asphalt 120 can flow within the apertures 124, 126 and
128 to increase the bonding between the fastener 16 and
the base sheet 108. This also enables a better seal
about the legs 114, 116 and 118 to resist water
infiltration.
It is to be noted that the shape of each leg
114, 116 and 118 as well as its position with respect to
the head 112 is specifically selected to enhance the
performance of the fastener 16. In order to increase
the retaining power of the fastener 16 yet enable
driving into the plywood 110, each leg 114, 116 and 118
is provided with an intermediate offset portion as well
as two barbs 130 and 132 as FIG. lOa illustrates.
- Each leg 114, 116 and 118 also is slightly
tapered and includes a first distal surface engagement
portion 134, a second intermediate offset portion 136
and a third proximal portion 138. The combination of
the taper, the offset and the barbs 130 and 132 provides
the desired strength to the legs 114, 116 and 118 for
driving as well as the required retention.
Furthermore, the positioning of the legs 114,
116 and 118 with respec~ to the head 112 enables proper
weight distribution of the fastener 16 to ensure
straight driving of the fastener 16 and enable the
fastener 16 to be pushed with substantially an equal
amount of force on each leg 114, 116 and 118, similar to
a tripod. Additionally, the longitudinal axis of each
leg 114, 116 and 118 is-positioned equidistant from the
center of the head 112 of the fastener 16. Thus, the
length of radii R" R2 and R, from the center to
9 ~ o ~
- 13 -
- respective axes 114a, 116a and 118a of each leg 114, 116
and 118 are the same.
In certain applications, the dimensions of the
fastener 16, particularly the dimensions of the legs
114, 116 and 118, can be critical to insure ease of
driving and required retention. For example, with a
fastener 16 having a head 112 with a diameter of
approximately 1", the legs 114, 116 and 118 are
approximately .60" long with the barbs 130 and 132, and
hence the offset portion 176, being approximately .010 +
.002" and most preferably .011".
Although placement of the barbs 130 and 132
can vary, barb 132 preferably is positioned .25" from
the head 112 while barb 130 preferably is positioned
.33" from the head 112. Additionally, first and second
indentations 140 and 142 which form the offset portion
136 extend inward approximately .011 + .002" at a
distance of .27" and .36", respectively, from the head
112.
It is to be noted that coining of the legs
114, 116 and 118 has the net effect of moving material
from one side of each leg 114, 116 and 118 to the other.
Accordingly, such coining provides the relatively
shallow indentations 140 and 142 on one side of each leg
114, 116 and 118 while forming the rather sharp pointed
barbs 130 and 132, respectively, on the opposite side of
each leg 114, 116 and 118.
Furthermore, the coining process maximizes the
cross-sectional width "w" along the entire length of
each leg 114, 116 and 118. This design in turn
maximizes the column strength of each leg 114, 116 and
118 and provides for high driveability of the fasteners.
In making the fasteners 16 from a steel strip,
the legs 114, 116 and 118 are cut out, the barbs 130 and
216~Q~
- 14 -
132 are coined onto the legs, and the circular shapes of
the heads 112 are made. Moreover, the legs 114, 116 and
118 are bent approximately perpendicular to the heads
112, the edges 119 are turned up 30 at a 1/32 inch
bevel, and perpendicularity of the legs 114, 116 and 118
is checked. Strips of 25 fasteners are cut off from the
steel strip.
Although the fastener 16 has been described
for use with the manual drive tool 10 of the invention,
it is to be understood that the fastener 16 can be used
with a powered tool or the like, which typically is
powered by compressed air, electricity or a combustible
material, without departing from the teachings of the
present invention.
In use, the fastener magazine 24 is loaded
with fasteners 16 without regard to orientation of the
fasteners 16. The fasteners 16 extend onto the bar 28
- and a fastener is positioned within the muzzle 107.
Upon placement of the muzzle 107 in a desired
position on a roof surface, the first movable tube 18 is
depressed by a user by extending downward pressure on
the handles 20. Such downward movement compresses the
drive spring 36.
Continued downward movement of the first
movable tube 18 enables the engagement leg 33 to contact
the lever 70 which rotat~es the release key 72 to fire
the driving ram 58 and drive the fastener within the
muzzle 107 into the roof surface.
As the first movable tube 18 is depressed, the
fastener advancing mechanism 14 is rotated upward by
engagement between the arrowhead 80 and cam rollers 82
and 84. After driving of the fastener, a user moves the
first movable tube 18 upward which simultaneously
21 69~ 04
- 15 -
advances a subsequent fastener into the muzzle 107 for
driving .
FIG. 8A shows the driving ram 58 separating a
driven fastener from the strip of fasteners. In the
fastener embodiment including the upturned peripheral
edge 119, the driving ram 58 has a complementary bottom
surface.
Modifications and variations of the present
invention are possible in light of the above teachings.
It is to be understood that within the scope of the
claims the invention may be practiced other than
specifically described.
