U.S. patent number 3,924,378 [Application Number 05/497,883] was granted by the patent office on 1975-12-09 for interlocking joint for overlying sheet material.
Invention is credited to Otto P. Hafner.
United States Patent |
3,924,378 |
Hafner |
December 9, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Interlocking joint for overlying sheet material
Abstract
To fasten together two or more overlying sheets of metal or
other material having plasticity or deformable properties by
partially piercing and deforming sections of the sheets, a fixed
pierce-and-forming punch is used in cooperation with a
double-acting press having two separately actuatable rams. For
displacing sections of the overlying sheets, one of the rams
carries a hollow cylindrical pierce-and-forming die the die cavity
of which is vertically aligned with, and cooperates with, a fixed
pierce-and-forming punch supported in the base. The other of the
rams carries a flattening punch which is slidably movable within
the central bore of the hollow cylindrical die. The
pierce-and-forming die is supported by means which includes fine
adjustment means so that the position of the die may be adjusted
for different thicknesses of sheets to be fastened, and also for
wear on the die and/or punch. The flattening punch is supported by
phase adjustment means which permits the angular relationship
between the flattening punch and the die to be adjusted for
different thicknesses of sheets to be fastened. The latter
adjustment is made such that the downwardly-moving flattening punch
engages the upper displaced section or sections just after the
lower displaced section is uncovered by the upwardly-moving
cylindrical die, thereby to spread the lower displaced section
while the upper section or sections are still constrained.
Inventors: |
Hafner; Otto P. (Cherry Hill,
NJ) |
Family
ID: |
27010615 |
Appl.
No.: |
05/497,883 |
Filed: |
August 16, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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384494 |
Aug 1, 1973 |
3862485 |
Jan 28, 1975 |
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Current U.S.
Class: |
403/274;
52/796.1; 29/521 |
Current CPC
Class: |
B21D
39/035 (20130101); Y10T 403/49 (20150115); Y10T
29/49936 (20150115) |
Current International
Class: |
B21D
39/03 (20060101); F16B 005/07 () |
Field of
Search: |
;52/758D
;29/522,521,622 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schroeder; Werner H.
Assistant Examiner: Shedd; Wayne L.
Attorney, Agent or Firm: Paul & Paul
Parent Case Text
This is a division of application Ser. No. 384,494, filed Aug. 1,
1973, now U.S. Pat. No. 3,862,485, granted Jan. 28, 1975.
Claims
What is claimed is:
1. An interlocking joint fastening together overlying sheets of
metal or other material having permanently deformable properties,
said sheets including at least a first sheet and an overlying
second sheet, said sheets having interior and opposed exterior
surfaces, said overlying sheets having been pierced discontinuously
along a boundary line defining a minor area, the material of said
first and second sheets within said minor area having been
displaced out of the respective planes of the major-area material
of said first and second sheets forming first and second overlying
bridge portions, material of said first bridge portion being spread
laterally over the exterior surface of the major-area material of
said second sheet beyond the piercings therein, the improvement
characterized by the material of said second bridge portion being
confined within the limits defined by said piercings during the
application of compressive force to the exterior surface of said
second bridge portion, whereby said first bridge portion is spread
laterally beyond the limits of said second bridge portion.
Description
BACKGROUND OF THE INVENTION
This invention relates to a machine for fastening together
overlying sheets of deformable metal or other material having the
property of yielding or flowing under load and of sustaining
appreciable permanent deformation without rupture. In some
instances there may be an intervening layer or film of another
material between the sheets to be fastened.
SUMMARY OF THE INVENTION
An object of the present invention is to provide, for a
double-acting press of the type disclosed in my U.S. Pat. No.
3,726,000, granted Apr. 10, 1973, adjustable support means for the
cutting-and-forming die and also the flattening punch so that
adjustment may be made for different thickness of sheets to be
fastened, as well as to adjust for wear of the die and/or
punch.
A more specific object is to provide adjustment means so that the
upper sheet or sheets of the displaced section (displaced by the
die and fixed punch) is not engaged by the downwardly-moving
flattening punch until the lowermost sheet of the displaced section
is uncovered by the upwardly-moving die so as to allow the lower
sheet of the displaced section to be spread while the upper sheet
or sheets are still confined by the die.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view, largely in section, of the head
portion of a fastening machine incorporating the present
invention.
FIG. 2 is a fragmentary view, largely in section, looking along the
lines 2--2 of FIG. 1.
FIG. 3 is an enlarged fragmentary view, in section, of the lower
portion of the structure shown in FIG. 1.
FIG. 4 is a view looking down along the line 4--4 of FIG. 3.
FIG. 5 is an enlarged illustration showing that the lower sheet of
the displaced section is uncovered by the die at the instant the
downwardly-moving flattening punch engages the upper sheet, thereby
to spread the lower sheet of the displaced section.
FIG. 6 is a view, in section, looking downwardly along the line
6--6 of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a crank shaft 10, which is driven
rotationally by means not shown, has at its forward end a pair of
spaced-apart shear blocks 12 and 13 which are supported by a crank
housing 20.
Supported on crank shaft 10, within the housing 20, are three
eccentric discs 21, 22 and 23. The two outside discs 21 and 23 are
keyed to the crank shaft. The holes of the two outside eccentric
discs 21 and 23 are identically positioned and hence these two
outside eccentrics move in timed coincidence with each other. The
center eccentric 22 is supported free on shaft 10 and, by means to
be described, is maintained in out-of-phase relation with the two
outside eccentrics. This phase relationship is adjustable by a
phase selector drive plate 34. In a typical case, for a particular
metal thickness, the center eccentric may, for example, have a
delay angle of the order of 37.degree..
As clearly seen in FIGS. 1 and 2, the angular position of the
center eccentric disc 22 is determined and controlled by the phase
selector drive plate 34 which is fixed to crank shaft 10, as by set
screw 35 and key in keyway. Plate 34 is provided with a series of
holes 36 for receiving selectively a pin 37 which extends through a
hole in eccentric disc 22 and is spring-loaded by a spring 39 which
thrusts against a flange 38 on the pin. It will be seen that by
withdrawing pin 39 from the plate 34, moving the disc 22 angularly,
and then reinserting the drive pin 39 in a different hole 36, the
angular position, and hence the phase relationship, of the center
eccentric disc 22 may be adjustable relative to the two outside
discs 21 and 23. Spring 39 is retained by retainer 139.
The three eccentric discs 21, 22 and 23 carry, respectively, cranks
31, 32 and 33, suitably supported on bushings 131, 132, 133. In
FIG. 1, the outside eccentric discs 21 and 23 are illustrated in
such position that the outside cranks 31 and 33 are at the bottom
of their downward strokes. At this same instant, the center
eccentric disc 22 is in the position shown in FIG. 2. As seen in
FIG. 2, the center crank 32 has started its downward descent, but
will not reach its downward limit for another 37.degree..
The two outside cranks 31 and 33 each carries at its lower end a
stub-shaft, 41 and 43, respective, suitably journalled in bushings
141 and 143. The inward ends of the stub shafts 41 and 43 project
into opposing holes in the walls of a hollow rectangular ram or
slide 50 which is slidable up and down within, and is guided by,
the hollow rectangular lower guide portion 24 of the housing 20.
Guide portion 24 is secured to the upper portion of the housing, as
by bolts and dowels 25.
Referring now to FIG. 3, bolted as by bolts and dowels 52 to the
lower end of the rectangular slide or ram 50, and carried thereby,
is a hollow neck portion 53 the upper neck of which adapts to the
rectangular opening between rams 50 and the lower portion of which
is round having a central bore into which a cylindrical screw and
die holder 60 is inserted.
The upper end portion of neck portion 53 has a recess 54 into which
is inserted a nut 55 which is non-rotatable in the neck 53. The
non-rotatable nut 55 is provided with fine threads 58 which receive
the fine threaded upper end portion 61 of the die holder 60. The
lower end 62 of die holder 60 has an enlarged diameter and is
externally threaded at 63 with threads which are much larger than
the fine threads of the upper end portion 61. An
internally-threaded clamping ring 65 is screwed onto the external
threads 63 and tightened against the end surface 57 of the neck
53.
The enlarged-diameter lower end portion of the die holder 60 has a
recess which receives the upper end portion of a hollow cylindrical
cutting-and-forming die 70. The lower end portion 71 of the
cutting-and-forming die 70 is of reduced diameter forming, at the
junction with the upper end portion, a shoulder 72. A lock cap 67
is fitted over the reduceddiameter portion 71 of die 70 and abuts
against the shoulder 72 of the die 70. Cap 67 is secured, as by
bolts 66, to the end surface of the die holder 60.
The cylindrical cutting-and-forming die 70 has cutting edges and
recessed portions which function as the forming portions. The die
70 may correspond to that disclosed and illustrated in FIG. 9 of my
aforesaid U.S. Pat. No. 3,726,000.
Positioned below the cutting-and-forming die 70 in the base 90 of
the press is a pierce-and-forming punch 80. The pierce-and-forming
punch 80 has cutting edges for piercing, and recessed portions for
forming. The punch 80 may correspond to the punch described in my
U.S. Pat. No. 3,726,000, and may be axially adjustable as there
shown. Surrounding the pierce-and-forming punch 80 is a stripper or
spring member 81 which may preferably be formed of urethane
material.
Positioned within the aligned bores of the die holder 60 and die 70
is the enlongated shank of a flattening punch 92. As seen in FIGS.
1-3, flattening punch 92 is supported by a punch holder 292
fastened to a center ram or slide 392 which is carried by pin 42
and adjustable member 44. Adjustable member 44 is supported
adjustably by a bolt 45 which in turn is supported by a plate 46
secured, as by screws 47 (FIG. 2) to the underside of center crank
32. Plate 46 has a depending portion 146 having therein a pair of
slots 48 which receive screws 49. In this way, the member 44 is
supported against rotation. Bolt 45 has an enlarged portion head
145 which is supported in a recess in plate 46. Bolt 45 also has an
integral enlarged round portion 245 with holes for pin which may be
engaged, as by a pin wrench, to turn bolt 45 to raise or lower
member 44, thereby to adjust the position of the head 192 of
flattening punch 92 relative to the pierce-and-forming punch 80. To
make this adjustment, it is, of course, necessary to loosen the
screws 49.
To adjust the position of the cutting-and-forming die 70 relative
to the fixed pierce-and-forming punch 80, the operator manually
unscrews clamping ring 65 and then manually grasps and moves die
holder 60 in one rotational direction or the other. Since nut 55 is
non-rotatable in the recess 54 in neck 53, when the die holder 60
in manually rotated, it turns on threads 58 and is therefore moved
adjustably upwardly or downwardly in neck 53, according to the
direction in which holder 60 is rotated. When holder 60 is so
adjusted upwardly or downwardly, the cutting-and-forming die 70 is
moved adjustably in corresponding manner since it is carried by the
holder 60. And, since threads 58 are fine threads, fine and
accurate adjustment may be made of the position of the
cutting-and-forming die 70.
After the fine adjustment just described has been made, clamping
ring 65 is replaced and tightened. The threads 63 of clamping ring
65 and of the lower enlarged portion 62 of the die holder 60 are
large and heavy in comparison with the fine threads at the upper
end of the die holder 60. Thus, when the cutting-and-forming die 70
is lowered by its slide ram 50 to pierce and form the overlying
metal sheets, the reactive load or thrust is upward through the
heavy threads 63. The thrust path may be traced from the
cutting-and-forming die 70 through shoulder 68 of die holder 60,
holder 60, the large heavy threads 63, the clamping ring 65, the
abutting end surface 57 of neck portion 53, the rectangular slide
ram 50, stub shafts 41 and 43 and their associated bushings 141 and
143, the cranks 31 and 33 and their associated bushings 131 and
133. It is to be noted that this upward thrust or load during the
cutting and forming operation is not placed on the fine threads 58
which are employed for adjusting of the cutting and forming die
70.
As already indicated, adjusting of flattening punch 92, relative to
the fixed pierce-and-forming punch 80, is made by loosening screws
49 (to allow them to move up or down in the slots 48) and then
rotating the threaded bolt 45 in the member 44. This is done by
inserting a pin in a hole of enlarged portion 245 and rotating the
part.
At a section 4-4 of FIG. 3, the flattening punch 92 may have a
shape such as is shown in FIG. 4. To maintain proper orientation
between the flattening punch 92 and the annular terminal end of the
cylindrical cutting-and-forming die 70, the outer surface of the
shank of the flattening punch 92 and the inner wall of the hollow
cylindrical cutting-and-forming die 70 may each be provided with
flats (flat surfaces). These flats are clearly seen in FIG. 4,
which is a view taken along the line 4--4 of FIG. 3. The flattening
punch 92 is maintained in its proper oriented position by punch
holder 292 which is secured to the center ram 392.
The fixed pierce-and-forming punch in the base 90 of the machine is
supported in a punch holder 180 which has a flat 181. The flat on
the punch 80 is oriented to correspond with the flat 181 on the
punch holder 180.
FIG. 5 illustrates two overlying sheets 28 and 29 at a time instant
in the operating cycle of the fastening machine just after the
sections or bridge portions 128 and 129 have been displaced by the
downwardly-moving cylindrical cutting-and-forming die 70 in
cooperation with the fixed pierce-and-forming punch 80. In FIG. 5,
the cylindrical cutting-and-forming die 70 is now rising and
flattening punch 92 is moving downwardly. The end face 192 of the
downwardly-moving flattening punch 92 has just engaged the upper
surface of the upper displaced section or bridge portion 128. At
this instant, the upwardly-moving cylindrical die 70 has just
cleared the lower displaced section or bridge portion 129. The
upper displaced section or bridge 128 is still encased. This
represents a desirable timing relationship. It allows the
flattening punch 92 to transmit its energy through the still
encased upper displaced section or bridge portion 128 to the lower
displaced or bridge portion 129 to spread the lower section or
bridge portion 129 over the upper sheet 28.
One means for achieving the desirable timing relationship just
described between the cylindrical casting-and-forming die 70 and
the flattening punch 92 is illustrated in FIGS. 1 and 2, and has
already been briefly described hereinbefore. It will be seen that
the phase relationship between the flattening punch 92 and the
cylindrical die 70 is adjustable by means of the phase selector
drive plate 34. To adjust the phase relationship, the drive pin 37
is pulled out of the hole 36 in which it had been positioned, the
freely-mounted disc 22 is rotated adjustably on the shaft 10, and
the drive pin 37 is reinserted in a different hole 36 of the series
of holes provided in the phase selector drive plate 34. The phase
adjustment allows the desirable timing relationship described
above, and illustrated in FIG. 5, to be maintained for different
thicknesses of sheets.
As has already been indicated, the relationship between the
pierce-and-forming punch 80 in the base of the machine and the
flattening punch 92 may be adjusted for different thicknesses of
sheets, and/or for wear, either by adjusting the flattening punch
92 as described in the present application or by adjusting the base
punch 80 as described in my earlier-filed application. In either
case, adjustment of the phase relationship between the flattening
punch 92 and the cylindrical die 70, as by means such as have been
described herein, is desirable in order to achieve the advantageous
timing relationship illustrated in FIG. 5 and described above.
* * * * *