U.S. patent number 3,915,367 [Application Number 05/387,443] was granted by the patent office on 1975-10-28 for fastener strip and strip feeding apparatus.
This patent grant is currently assigned to Duo-Fast Corporation. Invention is credited to Frank R. Potucek.
United States Patent |
3,915,367 |
Potucek |
October 28, 1975 |
Fastener strip and strip feeding apparatus
Abstract
A strip of fasteners is formed by an elongated flexible web
having one or two rows of tabs projecting from one or both of the
longitudinal edges of the web. These tabs have fastener holding
means formed at their ends for removably carrying nails, screws, or
nuts. In one form, the holding means are detachable with the
fasteners to provide a washer, and in another form, the detachable
end of the holding means provides a locking insert for a
self-locking nut. The web is formed both as a strip and as a closed
loop. In some embodiments, the fastener is disposed at an angle
relative to the web to permit inclination of the strip of loop
relative to horizontal while presenting the fasteners to a driving
station in a vertical position. A fastener feeding mechanism
deflects or bends the strip at a point adjacent the drive path of a
fastener driver to "fan out" the fastener carrying tabs so that the
tab or tabs carrying the fastener in driving position are spaced
from adjacent tabs. In one embodiment, a reciprocating motor in the
feeding mechanism retracts the portion of the strip adjacent the
drive path to insure that the tab is not inadvertently fastened to
a workpiece by the driven fastener.
Inventors: |
Potucek; Frank R. (Des Plaines,
IL) |
Assignee: |
Duo-Fast Corporation (Franklin
Park, IL)
|
Family
ID: |
23529889 |
Appl.
No.: |
05/387,443 |
Filed: |
August 10, 1973 |
Current U.S.
Class: |
227/136;
221/74 |
Current CPC
Class: |
F16B
15/08 (20130101) |
Current International
Class: |
F16B
15/08 (20060101); F16B 15/00 (20060101); B27F
007/02 () |
Field of
Search: |
;227/136,137
;221/70,71,72,74,79,81,87,88,217,218,253 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Custer, Jr.; Granville Y.
Attorney, Agent or Firm: Mason, Kolehmainen, Rathburn &
Wyss
Claims
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. A fastener driving tool for use with an elongated, flexible web
with projecting adjacent tabs carrying fasteners comprising
a fastener drive movable over a drive path,
a web engaging structure adjacent the drive path for moving the web
through a path that bends the web about an axis transverse to its
direction of elongation to separate the tab adjacent the drive path
from adjacent tabs and to place the fastener on the separated tab
in said drive path,
said web engaging structure comprising at least one circular pulley
having a smooth periphery engaging said web,
and means for advancing the web to place successive fasteners in
the drive path.
2. The fastener driving tool set forth in claim 1 including
means coupled to the web engaging structure to move the web
engaging structure toward and away from the drive path.
3. A fastener driving tool for use with a loop of flexible web with
at least one row of spaced and projecting tabs removably carrying
fasteners extending generally parallel to the web comprising
fastener driving means movable over a drive path,
loop supporting means carrying the loop of web with the tabs
projecting outwardly from the loop, said supporting means including
guide means for deflecting the web around a corner adjacent the
drive path to separate adjacent tabs from each other,
drive means for advancing the loop to move successive fasteners on
successive spaced tabs into the drive path,
and moving means for moving the loop supporting means toward and
away from the drive path.
4. The fastener driving tool set forth in claim 3 in which
the moving means includes means coupled to and movably mounting the
loop supporting means.
5. The fastener driving tool set forth in claim 4 in which
the web includes spaced index means,
and the drive means includes a first stationary pawl means
engageable with the index means and a second pawl means engageable
with the index means and movable with the loop supporting
means.
6. An apparatus for feeding a closed loop of flexible web having
regularly spaced apertures and detachably carrying fasteners at
spaced positions thereon comprising
a supporting structure,
a pair of spaced supporting members mounted on the supporting
structure and removably mounting said loop,
fastener driving means movable along a given drive path,
indexing means carried on the structure for moving said loop
step-by-step relative to the supporting members to move successive
fasteners on said loop into said drive path,
said indexing means includes a first stationary pawl means
engageable with said apertures in said web and a second pawl means
engageable with said apertures and attached to the loop supporting
members, and
moving means for moving said supporting members toward and away
from said drive path.
7. An apparatus for feeding a closed loop of flexible web having
fasteners detachably carried at spaced positions thereon
comprising
a pair of spaced supporting members carrying said loop,
fastener driving means movable along a given drive path,
indexing means for moving said loop step-by-step relative to the
supporting member to move successive fasteners on said loop into
said drive path,
and means for moving the loop toward and away from the drive
path.
8. The apparatus set forth in claim 7 in which
the web includes spaced index means,
and the indexing means includes a movable member engageable with
the index means on the web.
9. An apparatus for feeding fasteners to a driving point interposed
between a driver and a workpiece comprising
a flexible web with at least one row of tab portions projecting
outwardly from the web substantially transverse to the web, the web
having a pair of hinge axes for each tab portion extending
generally transverse to the web,
each said tab adapted to carry a fastener,
and web feeding means for feeding the web past the driving point to
place successive fasteners between the driver and the workpiece,
said web feeding means including means for moving the web through
an arcuate path and at least one cylinder having an uninterrupted
periphery for bending the web along successive pairs of hinge axes
adjacent the driving point to separate the fastener carried on one
tab portion from adjacent tab portions thereby to provide clearance
between adjacent tab portions for the driver.
10. In combination with an elongated flexible web having at least
one row of transversely extending tab portions each carrying a
fastener in a position extending generally parallel to and spaced
from the web,
fastener transfer means movable along a given line,
and web feeding means for feeding the elongated web relative to
said transfer means to move successive fasteners into said line,
said web feeding means including means for bending said elongated
web about an axis transverse to the direction of elongation of the
web to fan the tab portions adjacent said line relative to each
other so that the tab portion carrying a fastener disposed in said
line is spaced from adjacent tab portions, and
said web bending means includes at least two rotatable cylinders
having a smooth periphery for guiding movement of the web through a
generally arcuate path around a center disposed on the opposite
side of the web from the tab portions at each cylinder.
11. The combination set forth in claim 10 in which
the web feeding means includes means for moving the web toward and
away from said line.
12. The combination set forth in claim 10 in which
the fasteners are mounted on the web at a given angle thereto,
and the web feeding means includes means for feeding the web toward
said driving point at an angle corresponding to said given angle to
supply a fastener at said line in a position aligned with said
line.
13. The combination set forth in claim 10 in which
the elongated web is formed into a closed loop,
and the web feeding means includes spaced guide means engaging the
web portion of the loop on the side opposite the tab portions at
spaced positions along the loop so that the loop is fed along a
closed path.
14. A fastener driving tool for use with an elongated flexible web
which carries fasteners comprising
a fastener driver movable over a drive path,
a web engaging structure adjacent the drive path for supporting the
web for movement through a path wherein the web is bent about an
axis transverse to its direction of elongation to separate the
fastener adjacent the drive path from adjacent fasteners and to
place the fastener in said drive path, said web engaging structure
including means mounting said structure for movement relative to
said drive path,
means operated in response to said relative movement of said web
engaging structure for advancing the web along the path to place
successive fasteners in the drive path, and
means for moving the web engaging structure relative to said drive
path.
15. The fastener tool of claim 14 wherein said path through which
said web moves is generally semicircular in configuration adjacent
said drive path.
16. The fastener tool of claim 14 wherein said advancing means
includes means to prevent reverse movement of said web along said
path.
17. The fastener tool of claim 14 in which the web includes spaced
index means, said advancing means includes a first stationary pawl
means engageable with the index means and a second movable pawl
means engageable with the index means.
18. The fastener tool of claim 17 in which said index means
comprises apertures regularly spaced along the web.
Description
This invention relates to an assemblage of power-driven fasteners
and a fastener driving tool therefor and, more particularly, to a
new and improved strip of fasteners and assemblies for feeding and
driving such fasteners.
A strip of fasteners carried on a pair of tabs or legs projecting
from opposite edges of a flexible web is shown and described in
U.S. Pat. No. 3,438,487. These fasteners are driven, as shown in
said patent, by feeding the strip rectilinearly past a drive track
so that the heads of successive fasteners are disposed beneath a
driver element. When the driver element moves downwardly, the
fasteners are removed from the tabs or legs and driven into the
workpiece without trapping spurious material from the strip beneath
the heads of the fasteners. However, this feeding arrangement
requires the fasteners to be spaced apart no less than the
effective width of the driver element at the point of contact with
the fastener head. It would, therefore, be desirable to provide a
feeding arrangement in which the fasteners are spaced apart at the
point of contact with the driver element while permitting the
fastener heads to be closely adjacent or even overlapped in the
strip so as to increase the fastener density on the strip. It would
also be desirable to provide a strip of the type shown in the
above-identified patent in which different types of fasteners or
different sizes can be used and in which the strip is so formed as
to facilitate the provision of a clearance between the magazine for
the fastener driving tool and the workpiece.
Accordingly, one object of the present invention is to provide a
new and improved assemblage or strip of fasteners.
Another object is to provide a fastener strip including an
elongated flexible web with at least one row of projecting tabs
removably mounting fasteners at an angle relative to the plane of
the web.
Another object is to provide a new and improved means for feeding
successive fasteners from a strip into the drive path of the
fastener driver in which the space between adjacent fasteners or
their supports is increased over that normally provided in the
strip.
A further object is to provide a fastener feeding assembly using an
elongated flexible web with at least one row of projecting tabs
carrying fasteners in which the assembly deflects or bends the web
to fan out the tabs adjacent the driver so as to position the
fastener in the drive path of the driver and spaced from adjacent
fasteners or fastener supports.
Another object is to provide such a fastener feeding assembly
including means for retracting the strip or strip tabs from the
drive path during the driving operation.
A further object is to provide a new and improved self-locking nut
and method of making a strip or assemblage of such nuts.
In accordance with these and many other objects, an embodiment of
the invention comprises a new and improved strip of fasteners
formed by an elongated flexible web having one or two rows of
spaced tabs projecting transversely from one or both longitudinal
edges of the webs. The free ends of the tabs which project
generally transverse to the plane of the web are provided with
fastener receiving or holding means for removably receiving a
fastener such as a nail, screw, or nut. This strip can be formed as
an endless length or as a closed loop. To permit the magazine for a
fastener driving tool to be inclined upwardly away from the
workpiece so as to provide greater clearance for reaching "tight
corners", the fasteners are disposed on the tab at an acute angle
with respect to the plane of the web. In strips or loops using two
projecting rows of tabs, the lengths of the tabs are made
differently to provide the inclination. In strips having only a
single row of tabs, the tabs project at an acute angle from the
plane of the web.
The holding means on the tabs are provided in various
configurations. In some, the holding means on the free ends of the
tabs releasably retain the fastener so that it is separated from
the strip during the driving operation. In other embodiments, the
holding means is joined to the fastener and is separated from the
tab or strip during the driving operation to provide a washer when
used with headed fasteners. In another embodiment, the holding
means comprises an elastic insert for a nut to provide a strip of
self-locking nuts.
To permit the fasteners to be disposed immediately adjacent each
other while affording a large clearance between adjacent fasteners
or fastener supporting tabs at the driving station, a new and
improved feeding assembly is provided which deflects or bends the
web about an axis parallel to the web immediately adjacent the
driving station. This fans out the tabs so that a fastener disposed
in the drive path of the driver element is spaced from adjacent
tabs or fasteners carried thereon. In those applications in which
the fastener is to become completely separated from the supporting
tab, a drive or motor in the feeding assembly retracts the strip
during the driving operation.
Many other objects and advantages of the present invention will
become apparent from considering the following detailed description
in conjunction with the drawing in which:
FIG. 1 is a plan view of the web used to make a strip of fasteners
in accordance with the present invention;
FIG. 2 is a perspective view of a partially assembled fastener
strip using the web shown in FIG. 1 wherein the fasteners are
nails;
FIG. 3 is a schematic plan view of a fastener feeding assembly for
feeding a closed loop made from the fastener strip shown in FIG.
2;
FIG. 4 is a fragmentary elevational view in partial section
illustrating a portion of the feeding assembly shown in FIG. 3
adjacent a driving station;
FIG. 5 is a perspective view of a modified form of the nail strip
shown in FIG. 2;
FIG. 6 is a fragmentary perspective view in partial section showing
the strip of FIG. 5 in a feeding assembly adjacent the drive
station;
FIG. 7 is a view similar to FIG. 6 illustrating the driving of a
fastener from the strip shown in FIG. 6;
FIG. 8 is a perspective view, partially exploded, illustrating an
embodiment of the invention using screws with a strip having a
single row of legs;
FIG. 9 is a sectional view of the strip shown in FIG. 8;
FIG. 10 is a perspective view, partially assembled, of another
single row strip embodying the present invention using a cap
screw;
FIG. 11 is a sectional view of the strip shown in FIG. 10;
FIG. 12 is a perspective, partially assembled, view of another
embodiment of the invention in which a portion of the strip tab is
separated to become a washer for a threaded fastener;
FIG. 13 is a sectional view of the strip shown in FIG. 12;
FIG. 14 is a perspective view, partially assembled, of a strip of
self-locking nuts embodying the present invention; and
FIG. 15 is a sectional view of the strip shown in FIG. 14.
Referring now more specifically to FIGS. 1 and 2 of the drawings,
therein is illustrated a fastener strip which embodies the
invention and which is indicated generally as 20. The strip 20 is
formed of a length of flexible material of a suitable flexible
plastic material such as polypropylene having a generally uniplanar
and elongated web or web portion 22 and two rows of tabs 24 and 26
projecting from its opposite longitudinal edges. In the completed
strip 20, the tabs 24 and 26 are bent at right angles to the plane
of the web to receive and detachably support a plurality of
fasteners such as a nail 28. It should be understood that the
fastener or nail 28 could as well comprise threaded fasteners such
as screws of various types and other similar fasteners. In general,
the construction of the strip 20 including the parts 22, 24, and
26, is similar to that described in U.S. Pat. No. 3,438,487, and
the nails 28 can be collated on the web and tabs 22, 24, and 26
using any suitable means as, for example, the collating machine
shown in U.S. Pat. No. 3,538,673. Thus, the strip 20 can be formed
in a running length or in a coil as shown in U.S. Pat. No.
3,450,255.
Referring now more specifically to the plastic elongated member,
each of the tab portions 24, 26 is connected to the web 22 by a
hinge portion 22A of reduced cross section to facilitate bending
the tabs 24, 26 to a position extending generally transverse to the
plane of the web 22. In addition, each adjacent pair of tabs 24, 26
is spaced from each other, and the longitudinal edge of the web 22
is provided with a notch or recess 22B. This notch together with an
aligned opening 22C defines a transverse hinge portion in the web
22 to permit this web to be bent, flexed, or deflected. The
openings 22C can also be used to index or feed the strip assembly
20 and to facilitate tearing segments from the strip 20 following
the driving of the fasteners 28 carried thereon.
The outer free end of each of the tabs 24, 26 is provided with a
holding means indicated generally as 24A, 26A comprising a
generally circular opening for receiving the body of the fastener
28 such as a shank portion 28A of the nail 28. A pair of inclined
edges lead into the circular openings to facilitate insertion of
the fasteners in the holding means 24A, 26A during the collating
operation. Further, the tabs 24 and 26 are formed of different
lengths so that when a nail 28 or other fastener is disposed in the
holding means 24A, 26A with the tabs 24, 26 offset at right angles
to the plane of the web 22, the elongated fasteners 28 are held in
a position that is at an acute angle with respect to the plane of
the web 22. This inclination permits a length or loop of the strip
20 to be inclined upwardly from horizontal in the magazine for a
fastener driving tool while presenting the fastener or nail 28 in a
vertical position to a fastener driver as set forth in detail
below. In the illustrated embodiment, the tabs 24 are shorter than
the tabs 26.
FIGS. 3 and 4 of the drawings illustrate a novel feeding assembly
which is indicated generally as 32 for feeding successive fasteners
or nails 28 to a fastener driving means shown schematically and
indicated generally as 34 (FIG. 4). In the feeding assembly 32 a
length of the strip 20 is formed in a closed loop by securing
together overlapping ends of the strip 20, as indicated at 36 in
FIG. 3. These overlapped ends can be joined by any suitable means
such as adhesives or ultrasonic welding. In FIG. 3 the fasteners or
nails 28 have been removed from the holding means 24A, 26A on the
tabs 24, 26 to facilitate illustration, and the feeding assembly 32
has been shown in a plane, although as shown in FIG. 4 the assembly
32 is disposed upwardly inclined from the horizontal.
The feeding assembly 32 includes a pair of guide structures,
wheels, or pulleys 38 and 40 rotatably mounted in a pair of
U-shaped brackets 42 and 44 by a pair of shafts 46 and 48. The
brackets 42, 44 are connected by a piston rod 50 carrying a piston
52 slidably mounted within a cylinder 54 defined by a housing
structure 56 forming a part of a fastener driving tool. The pulley
or guiding structure 40 is disposed immediately adjacent a driving
station indicated generally as 58 in FIGS. 3 and 4. A compression
spring 60 interposed between the piston 52 and a wall of the
structure 56 normally biases the piston against a circular
retaining ring 62 carried on the structure 56 to normally dispose
the pulleys 38 and 40 and the strip 20 carried thereon in the
position shown in FIG. 3.
With the feeding assembly 32 in the normal position shown in FIG.
3, the nail or fastener 28 at the driving station 58 (FIGS. 3 and
4) is disposed in vertical alignment with a driver blade or element
34A forming a part of the fastener driving means 34 even though the
strip 20 or the loop formed by the strip 20 is inclined upwardly
from the horizontal. This is due to the fact that the legs or tabs
26 on the web 22 are longer than the tabs 24. The axes of the
pulleys 38, 34 defined by the shafts 46, 48 are displaced from
vertical through an angle corresponding to the angle of inclination
of the fasteners or nails 28 to the plane of the web 22. This
permits the feeding assembly 32 to be inclined upwardly from the
horizontal, thereby permitting the nosepiece structure of the tool
through which the fastener or nail 28 is driven to be inserted into
corners and other relatively inaccessible locations.
In addition, by bending, deflecting, or displacing the web 22 of
the strip as it approaches the driving station 58, adjacent sets or
pairs of tabs 24, 26 carrying the fasteners or nails 28 are fanned
out with the result that the fastener or nail 28 carried in the
tabs 24, 26 located at the driving station 58 is separated from
adjacent pairs of tabs 24, 26 and/or fasteners carried thereon.
This permits the use of a driver 34A of substantially greater
dimension than a head 28B of a fastener or nail 28 without
encountering a problem of clearance between the driver and nails 28
or supporting tabs 24, 26 adjacent the ones at the driving station
58. The web 22 is deflected or displaced about an axis generally
parallel to the plane of the web 22 and located at the opposite
side of the web 22 from the tabs 24, 26. The degree of deflection
required to obtain separation varies in accordance with the spacing
of the fasteners 22 on the strip and the separation desired between
adjacent supporting tabs 24, 26. In general, as the tabs 24, 26
become shorter, the degree of deflection required to obtain a given
separation becomes greater. Conversely, as the length of the tabs
24, 26 becomes longer, the degree of deflection of the web 22
required to produce a given separation becomes less.
With the feeding assembly 32 disposed in the position shown in
FIGS. 3 and 4, operation of the driving assembly 34 moves the
driver element 34A downwardly (FIG. 4) so that it engages the head
28B of the fastener or nail at the driving station 58 without
interfering with adjacent supporting tabs 24, 26 or fasteners 28
carried thereon. As the engaged driver blade 34A and fastener 28
move downwardly, the tabs 24, 26 are deflected downwardly, and the
nail shank 28A is withdrawn from the holding means 24A, 26A on
these tabs in which it is frictionally retained. At the completion
of the driving stroke, the driver blade 34A is retracted by the
driving assembly 34, and the feeding assembly 32 is actuated to
index or advance the next fastener or nail 28 to the driving
station 58. In certain instances in which a very large driver blade
34A is used, it may be desirable to retract the strip 20 and more
particularly the supporting tabs 24, 26 at the driving station 58
during the downward movement of the driver blade 34A so as to
prevent any possibility that particularly the lower tab 26 might be
secured to the workpiece during the driving of the nail or fastener
28.
Accordingly, the feeding assembly 32 includes an arrangement for
retracting the tabs 24, 26 at the driving station 58 incident to
each driving stroke of the fastener driving means 34 and as an
adjunct to indexing the next fastener 28 to the driving station 58.
More specifically, the feeding assembly 32 includes a control
arrangement shown schematically in FIG. 3 as a pneumatic valve 64
coupled to the right-hand end of the cylinder 54 and normally
connecting this right-hand end of the interior of the cylinder 54
to the atmosphere. The valve 64 which can comprise, for example, a
port in the cylinder in the driving assembly 34 or a valve
mechanically actuated or pneumatically actuated in dependence on
the position of the driver blade 34A is operated to an alternative
setting supplying pressurized fluid to the cylinder 54 at a point
during the fastener driving stroke of the driver blade 34A. The
admission of compressed air to the right-hand end of the cylinder
34 moves the piston 52 and the connected pulleys or wheels 38, 40
to the left in FIG. 3. As the wheels or pulleys 38, 40 move to the
left, the loop of the fastener strip 20 carried thereon is also
moved to the left, and thus the pair of tabs 24, 26 at the driving
station 58 are also retracted from the path of movement or the line
of the path of movement of the driver blade 34A. This actuation of
the valve 64 is preferably so timed that the fastener 28 is at
least partially embedded in the workpiece at the time that the tabs
24, 26 carrying this fastener are retracted. This movement of the
wheels 38, 40 to the left also condition the feeding assembly 32 to
advance the next nail or fastener 28 to the drive station 58.
More specifically, a one-way pawl 66 is pivotally mounted on the
piston rod 50 by a pivot pin 68 and is biased by a torsion spring
70 so that a bight or offset portion 66A on the pawl 66 normally
bears against the top of the piston rod 50. The free end of the
pawl 66 is engaged within an opening 22C in the web 22. A second
one-way pawl assembly including a pawl member 72 is pivotally
mounted in fixed position on an extension 56A of the housing
structure 56 by a pivot pin 74. A torsion spring 76 biases an
extension 72A against the upper wall of the extension 56A to hold
the lower or free end of the pawl 72 in the normal position
illustrated in FIG. 3 in which it is disposed within another of the
openings 22C in the web 22.
When the piston rod 50 is moved to the left in the manner described
above, the engagement of the pawl 66 with the adjacent wall of the
web 22 maintains the position of the web 22 with respect to the
pulleys 38, 40. During this movement, the pawl 72 which is pivoted
about the fixed position axis provided by the pivot pin 74 is
pivoted in a clockwise direction against the bias of the torsion
spring 76. The stroke of the piston 52 is equal to the distance
separating adjacent openings 22C. Thus, at the end of the stroke of
the piston 52, the torsion spring 76 pivots the pawl 72 in a
counterclockwise direction into the next following opening 22C. In
the feeding assembly 32 illustrated in FIG. 3, the pawls 66 and 72
would occupy adjacent openings 22C in the web 22 at this time.
At the conclusion of the driving operation and when the driver
element 34A has been retracted sufficiently to provide complete
clearance for the next nail 28 to be moved into the driving station
58, the control valve 64 is released, and the pressurized fluid
from the right-hand end of the cylinder 54 is exhausted to the
atmosphere. The compression spring 60 then moves the piston 52 to
the right so that the piston rod 50 and the pulleys 38 and 40 are
moved to the right to the position shown in FIG. 3. During this
movement, the pawl 72 engages the wall of the web 62 to retain the
strip 20 in a fixed position. Further, during this movement the
pawl 66 is pivoted first in a clockwise direction against the bias
of the torsion spring 70 and then in a counterclockwise direction
by this spring so that its outer free end now engages the next
adjacent opening 22C in the web positioned to the right of the one
previously engaged. Since the fastener strip 20 was held in a fixed
position by the pawl 72 during return movement of the pulleys 38
and 40, the strip 20 is advanced one step by rotating the pulleys
38, 40 in a clockwise direction about the shafts 46 and 48. This
moves the next set of tabs 24, 26 carrying a nail 28 into the
driving station 58 and moves the set of tabs 24, 26 from which the
nail 28 was just driven to the position indicated generally as 79
in FIG. 3.
This operation can be continued until such time as all of the
fasteners or nails 28 on the loop of the fastener strip 20 have
been depleted. At this time, the loop of the strip 20 is removed
from the pulleys 38, 40, and a new strip is placed thereon. The
feeding arrangement 32 can also be used with such items as threaded
fasteners or nuts mounted on the fastener strip 20. In addition,
instead of using a loop of the fastener strip 20, the arrangement
using only the pulley 40 can be used to feed a strip from a length
or a coil thereof. This arrangement generally requires the
provision of a biased take-up on the portion of the fastener strip
20 moving toward the wheel 40. Further, by using legs or tabs 24,
26 of uniform length, the feeding assembly 32 can be disposed
substantially perpendicular to the line of movement of the driver
34A or in a horizontal position relative to the vertical movement
of the driver 34A.
FIGS. 5-7 of the drawings illustrate a modified form of the strip
20 which is indicated generally as 80 and which provides a plastic
washer beneath the head of the fastener. More specifically, the
fastener strip 80 is formed in the same manner as the strip 20
except that the holding means 26A for releasably retaining the
shank 28A of the nail 28 is modified in the strip 80 to provide a
holding means indicated generally as 26B. The holding means 26B
comprises a detachable end portion having a center opening 82 and a
line of perforations 84 which permit the end portion of the tab 26
to be separated from the remainder thereof during a fastener
driving operation. When the strip 80 is formed, the upper portion
of the nail shank 28A is detachably or removably mounted in the
holding means 24A on the outer end of the tab 24, and the shank 28A
is inserted into the opening 82. When the nail 28 is driven, the
end portion of the tab 26 becomes severed along the line of
perforations 84, and the holding means 26B becomes the plastic
washer interposed between the head 28B of the nail and the
workpiece.
FIGS. 6 and 7 illustrate an assembly indicated generally as 86 for
feeding the strip 80 to the driving station to permit the nail 28
to be driven by the driver blade 34A in the fastener driving means
34. The fastener feeding assembly 86 includes a feed wheel 88
having a plurality of sprocket teeth 88A formed thereon spaced to
engage the openings 22C in the web 22. The feed wheel 88 is coupled
to a conventional indexing or continuous drive means 90. When the
drive means 90 is operated to index or rotate the feed wheel 88,
the tabs 24, 26 on the web 22 are fanned in the manner described
above so that a single fastener or nail 28 is disposed in the drive
station with its head 28B aligned with the driver blade 34A and
spaced from the remaining tabs 24, 26 and the fasteners 28 carried
thereon.
With the nail at the driving station 58 disposed in the position
shown in FIG. 6, the fastener driving assembly 34 (FIG. 7) is
placed in operation, and the driver blade 34A begins to move
downwardly toward the head 28B of the nail 28 with the nail 28
disposed above a workpiece indicated generally as 92. During the
initial portion of the movement of the driver blade 34A, the head
28B of the nail is engaged, and the nail 28 moves downwardly with
the shank sliding within the opening 82. After some movement, the
head 28B and the shank 28A are cammed out of the holding means 24A
in the upper tab 24 as this tab is deflected downwardly as shown in
FIG. 7. Further movement moves the head 28B into engagement with
the holding means 26B on the lower tab 26. The velocity at which
the driver 34A and the nail 28 are moving is sufficient to sever
the end portion of the tab 26 along the line of the perforations 84
so that this generally circular or annular end portion moves with
the nail 28 beneath the head 28B so as to be driven against the
workpiece 92 interposed between the head 28B of the nail and the
upper surface of the workpiece 92. When the driver blade 34A is
retracted, synchronized operation of the drive means 90 indexes the
feed wheel 88 through an additional step to feed the next nail into
the driving station 58 with the head 28B of this next nail disposed
beneath the driver blade 34A. As indicated above, the strip 80 can
be formed with threaded fasteners such as screws which require a
rotary movement of the driver 34A as well as reciprocating motion
thereof.
FIGS. 8-15 of the drawings illustrate various fastener strips
designed for use with fasteners of relatively short axial length.
All of the strip configurations illustrated therein can be fed and
driven by the means described above with reference to FIGS. 1-7 of
the drawings.
Referring now more specifically to FIGS. 8 and 9 of the drawings,
therein is illustrated a fastener strip construction which is
indicated generally as 100 and which includes an elongated flexible
web 102 along the lower edge of which extend a plurality of
transverse tabs or legs 104. The legs 104 extend at an acute angle
relative to the plane of the web 102 to adapt the strip 100 for use
in feeding assemblies which are inclined upwardly relative to the
horizontal. The legs or tabs 104 also can be formed to extend
substantially at right angles to the plane of the web 102 in the
manner of the tabs shown in the above-identified patents. The web
102 is provided with a rib 102A along its upper edge to provide
slight stiffening of the web. The web 102 is also provided with
indexing or feed openings 102B positioned in the same manner as the
openings 22C and designed to provide a hinge axis extending
transverse to the length of the web 102 between adjacent pairs of
tabs 104. This facilitates the fanning of adjacent tabs 104 when
the strip 100 is deflected, as by movement around the curved
surface of a feed pulley 48, 88 shown in dot-and-dash outline in
FIG. 9. The strip 100 can also be fed rectilinearly using feed
mechanisms of the type shown in the above-identified patents if the
advantages of fanning the legs or tabs 104 are not required.
The legs 104 are provided with holding means 104A corresponding to
the holding means 24A, 26A provided on the tabs 24, 26. These
holding means 104A detachably or removably mount a fastener such as
a screw 108. The screws 108 extend at an acute angle relative to
the plane of the web 102 to permit inclined feeding in the manner
described above. The direction of elongation of the screws 108
could be such as to extend parallel to the plane of the web 102 in
those applications in which inclined feeding is not desired, and
the tabs 104 extend generally perpendicular to the plane of the web
102.
FIGS. 10 and 11 illustrate a fastener strip 110 quite similar to
the strip 100 except that the transversely extending legs or tabs
104 are provided with a fastener retaining means 104B adapted for
use with cap screws 112 having, for example, a hexagonal head 112A.
The holding means 104B utilize a bifurcation or slot 114 extending
lengthwise through the tab or leg 104 and having an outwardly
flared cup defining structure 116 for receiving the head 112A of
the fastener 112 and an opening 118 through which the shank or body
of the fastener 112 extends. The cup defining structure 116 is
outwardly flared to provide a clearance between the head 112 and
the structure 116 to permit rotary nut runners to engage the head
112A during a driving operation. As the rotating driver moves
downwardly and couples with the head 112A, further downward
movement splits or separates the two legs of the tab 104 formed by
the slot 114 to permit the separation of the fastener 112 from the
tab 104.
FIGS. 12 and 13 of the drawings illustrate a fastener strip
construction which is indicated generally as 120, again using the
web 102 and the transversely extending tabs 104. However, the free
end portions of the tabs 104 are provided with an improved fastener
retaining structure 104C that is designed to be removed or
separated from the tab 104 during the driving operation to provide
a plastic washer for a threaded fastener 122. The improved holding
means 104C includes an opening 124 through which the shank of the
fastener 122 extends with a head 122A on the fastener resting on
the upper surface of the free end portion of the tab 104. One or a
number of perforations 126 are provided in the body of the tab 104
to facilitate separation of the holding means 104C. During a
driving operation when a downwardly moving and rotating driver
couples with the recess in the head 122A of the screw 122, this
rotary motion coupled with the downward movement of the driver
shears the holding means 104C along the perforation 126 so that a
plastic washer is provided immediately beneath the head 122A. Thus,
when a screw 122 is driven into a workpiece, a plastic washer is
interposed between the head 122A and the workpiece.
FIGS. 14 and 15 of the drawings illustrate a fastener strip
indicated generally as 130, again using the web 102 with the
plurality of transversely extending tab or leg portions 104.
However, the free end portions of the tabs 104 are provided with an
improved holding means indicated generally as 104D which mounts a
nut 132 and is removable with the nut 132 during driving to provide
an elastic body so that the nuts 132 are self-locking. More
specifically, the holding means 104D comprises an upwardly
extending body 134 of plastic material through which an opening 136
extends. The body 134 includes a circular rib 134A adjacent its
lower end. The body 134 is formed integral with the tab 104 and at
its upper end comprises a generally truncated conical section. One
or a number of perforations 138 detachably connect the holding
means 104D with the remainder of the tab 104.
The nut 132 is of substantially convention construction in
including an internally threaded and centrally disposed opening
132A. A conical opening 132B is formed in the lower end of the nut
132 of dimensions slightly smaller than that of the body 134. The
opening 132B also includes a groove matching the rib 134A formed on
the body 134. Thus, when the strip 130 is manufactured, successive
nuts 130 are snapped onto the fastener holding means 104D so that
the plastic bodies 134 are disposed within and slightly compressed
within the openings 132B with the rib 134A received in the matching
groove in the wall of the cavity 132B.
When the nuts 132 are driven, the rotating driver moves downwardly
to couple with the outer surface of the nut 132. This rotary
movement shears the holding means 104D from the free end of the tab
104 and moves the nut 132 containing the elastic or plastic body
134 downwardly over a threaded post. The body 134 is distorted by
the threads of the threaded member on which the nut 132 is driven
to provide a self-locking nut of the type well known in the
art.
Although the present invention has been described with reference to
a number of illustrative embodiments thereof, it should be
understood that numerous other modifications and embodiments can be
devised by those skilled in the art that will fall within the
spirit and scope of the principles of this invention.
* * * * *