Note: Descriptions are shown in the official language in which they were submitted.
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WO 96125574 PCT,'US96~01519
PIN TUMRT~ CYLINDER LOCR
WITH Su~R~RT~ ASSEMBLY PINS AND
METHOD AND APPARATUS OF MANUFACTURE
Backqround of the Invention
~ 5 Prior cylinder locks have included a plurality of tumbler
pins and aligned driver pins urged by springs against the key.
The pins are separately manufactured to selected lengths prior
to lock assembly.
It has also been proposed to install one-piece pins in a
cylinder; accomplish selected elevation of the pins using a
notched key and thereafter shear each pin, as held in such
elevation by the notched key, into two lock pins (U. S. Patent
No. 1,953,535). Such prior method has the disadvantage that
15 any second randomly-selected insertable key would be capable
of elevating the pins and, if torqued, would again shear the
pins thus compromising security.
Summary of the Invention
Broadly, the present invention comprises a cylinder
having a body, a turnable plug, a shear line therebetween, and
a plurality of selectively weakened assembly pins for initial
positioning by a notched key. The assembly pins are sheared
by the manufacturer or locksmith using special machinery to
25 thereafter function as both driver and tumbler pins. Such
assembly pins are strong enough so that torquing or otherwise
forcing with an insertable key by the lock user or person with
an unauthorized key or similar tool will not shear them.
It is a feature of the invention that the assembly pins
have a plurality of selectively weakened portions or zones to
control shearings at selected points provided sufficient
shearing force is applied.
It is a further feature of the invention that the driver
and tumbler pins, though sufficiently weakened, are strong
enough so that torquing of a key by hand or with a tool will
cause the key or tool to fail before the pins shear.
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Brief DescriPtion of the Drawinqs
Fig. 1 is a side elevational cutaway view of the lock of
the present invention including shell, plug and key-positioned
assembly pins;
Fig. 2 is a side elevational view of an assembly pin of
the present invention;
Fig. 3 is a view similar to Fig. 1 in which the pins have
lo been sheared by relative lateral movement between the shell
and plug;
Fig. 4 is a plan view of the apparatus for shearing the
assembly pins and crimping the shell and plug together;
Fig. 5 is an elevational view of the apparatus of Fig. 4;
Fig. 6 is a partial sectional view along line 6-6 of Fig.
l;
Fig. 7 is a partial sectional view along line 7-7 of Fig.
6;
Fig. 8 is an elevational view of the pin of a second
25 embodiment;
Fig. 8a is an enlarged view of a pin groove of the pin of
Fig. 8;
Fig. 9 is a sectional view perpendicular to the
horizontal axis of the plug without pins;
Fig. 9a is a sectional view similar to Fig. 9 with pins
and with the plug slightly turned;
Fig. 10 is a plan view of a second shearing mechanism,
with a longitudinal axis A, for use at retail locations;
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Fig. 11 is a sectional view talcen at 11-11 through longit~l-lin,.l axis A of the
meçh~ni~m of Fig. 10;
Fig. 12 is a front elevational view of a key-operated padlock which is a further5 embodiment of the invention with the plug of the shell-plug assembly protruding,;
Fig. 13 is a side elevational view of the shell-plug assembly removed from the
padlock of Fig. 12;
Fig. 13a is a sectional view along 13a-13a of Fig. 13;
Fig. 14 is a view similar to Fig. 13 in which the plug has been tr~n~l~tecl in
direction Y;
Fig. 15 is a view similar to Fig. 12 in which the shell-plug assembly, after
translation, has been placed in the padlock; and
Fig. 16 is an enlarged sectional view along line 16-16 of Fig. 14.
20 Descliplion of the P,efelled Embodiment
In Figs. 1-3, lock 10 includes a shell-plug assembly comprised of a cylinder shell
11, turnable cylinder plug 13, with plug collar 13c, and five (S) vertical pin passageways
14a-e extending up into the shell 11 as shell passageways and down into plug 13 as plug
passageways. Also shown are five assembly pins 15a-e, plug tail 12, brass key 16,
25 cylinder shear line 18 and pin springs 20a-e for the assembly pins lSa-e. Each assembly
pin lSa-e has eight (8) cil~;ulllr~ ial we~ken~l zones defined by notches or grooves 17.
Pins 15a-e are made of selected material and their grooves 17 are shaped and
proportioned to accomplish assembly pin shearing by the manufacturer or lock~mith while
preventing colllprulllise in security while the lock is in service through use of an
30 lm~llthorized key or other instr~ment. Dirr~ "l m~mlf~cturers
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have differing non-notch key configurations which allow the
keys of a given manufacturer to be inserted in locks of that
manufacturer.
Assembly pins of the invention are notched or otherwise
selectively weakened to reduce the force taken to shear such
pins; however, they are not weakened such that an insertable
key (a key with the same keyway configuration on the lock key)
with a different cut could be tor~ued by hand or by a tool to
10 cause the driver and tumbler pins to shear prior to key or
tool failure. The pin notches have a depth and shape such
that only the force of factory or locksmith equipment applied
to portions of the plug, and not applied to the key, can shear
the pins. Forces applied to the key or directly to plug
15 collar 13c in a direction parallel to the axis of rotation of
plug 13 are resisted and absorbed by collar 13c engaging shell
11 .
The following assembly pins, with varying notch
20 diameters, were tested:
Inner NotchAverage Force Per
Diameter Pin To Shear
0.060 inch 95 lbs.
0.062 inch 105 lbs.
250.065 inch 120 lbs.
0.070 inch 140 lbs.
0.074 inch 155 lbs.
0.079 inch 180 lbs.
0.084 inch 205 lbs.
Inner notch diameter (ND) was less than overall diameter
or outside diameter D (see Fig. 2). An inner notch diameter
of 0.062 inch is preferred for padlock pins. In the above
tests D was 0.094 inch. Notch angle (C) was 20~ (degrees)
35 (Fig. 2). The ratio of ND to D is preferably in the range
63%-74~. The present invention also includes door hardware
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WO 96125S~J. . PCT~US96/Ol~il9
pins where an inner notch diameter of 0.074 inch is preferred
for pins having an outside diameter (D) of 0.114 inch.
In the manufacture of cylinder 10, assembly pins 15a-e,
~ 5 each with eight (8) weakened zones defined by circumferential
grooves 17, are fabricated for use in making a quantity of
locks. In the present system, preferably keys have eight (8)
different cut depths and five pin cylinders, creating thirty-
two thousand (32,000) combinations. Each groove 17 has a
10 width w (Fig. 2) of about .0060-0.010 inches and the series of
grooves 17 are spaced vertically (as shown in Fig. 2) about
0.0156 inch apart. In the assembly of lock 10, assembly pins
15a-e (each of which is the same within a tolerance of +
0.0005) are placed into passageways 14a-e and then sheared.
15 The series of spaced-apart grooves 17 are located in the
assembly pins 15a-e such that they are positioned at the shear
line 18 by a family of insertable keys.
Fig. 3 illustrates plug 13 being driven to the right to
20 shear pins 15a-e as further explained below. As sheared, each
assembly pin 15a-e breaks into an upper drive section 15u to
function as a driver pin and aligned lower tumbler section 151
to function as a tumbler pin. Cylinder shell 11 has end ring
portion 20 and plug 13 has angled portion 13a (Fig. 1). A
25 segment 20p (Figs. 6 and 7) of ring portion 20 is crimped
against portion 13a as later described.
Turning to Figs. 4-5, the pin shearing and crimping
apparatus 30 includes lock fixture 31 with a configured
30 aperture defining a lock holder recess 32. Lock 10, with its
shell 11 and plug 13 and unsheared assembly pins 15a-e, is
placed in aperture 32 with shell 11 abutting wall 32w. Plug
tail 12 is engageable with shiftable shear pin 41. Shift
shear pin 41 is shown in its rest position biased to the right
35 as viewed in Fig. 4 by spring 42. Also included in apparatus
30 is shearing plunger 36 mounted in a cylindrical opening 37
of a stationary mount block 38, spaced from fixture 31.
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Apparatus 30 further includes a crimper unit 50 inr~ in~ a c~ g ram 52 driven by a
solenoid unit E. Crimp shift pin 54 is shown in its rest position biased away from the
cylinder shell 11 by crimp pin spring 55.
In operation, lock 10, including shell 11, plug 13, plug tail 12 and key 16, as an
assembly, is placed in aperture 32 of fixture 31. Shear pin 41 is hit by shearing plunger
36 to apply force F to cylinder plug tail 12 to move plug 13 in direction Y. Pins l5a-e
are thereby sheared (Fig. 3). Plug 13 is pushed back by hand, using key 16, to the
original position. Next, crimper unit 50 drives crimp shift pin 54 to crimp ring portion
se~,"i~n~ 20p of shell 11 against plug portion 13a (see Figs. 1, 6 and 7).
Turning to Figs. 8, 8a, 9 and 9a, a further embodiment of the invention is shown~~ in which pins have a certain notch configuration and the plug is shaped to facilitate
~h.o~rin~ and rotation. Each pin 60 of this embodiment has grooves or notches 61, for
example, the ten (10) circumferential grooves 61aj (shown in Fig. 8). Each groove 61
has beveled surface areas or chamfers 63 to facilitate plug rotation and to make picking of
the lock more difficult. Each chamfer 63 is sloped at angle C to a plane perpendicular to
pin 60's longitll~iin~l axis LA (Fig. 8a). The slope of chamfer 63 is parallel to tangent
line T which is perpendicular to radius R of plug 64 of shell-plug assembly 65 at the
~ntr~n-.e edge of the plug pin passageway 711 (Fig. 9). The selection of such a chamfer
slope optimizes the ease of plug rotation. Di~ es from the bottom key-engaged end
60b of pin 60 to the center of each groove is set out in Table 1 (see also Fig. 8).
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_
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Table 1
LetterDistance in Inches
A .166
B .181
S C .196
D .211
E .226
F .241
G .256
H .271
.286
J .301
Each notch 61 is comprised of a portion of a notch a above plane Z perpendicular-- to longi~l~lin~l pin axis LA and a notch portion b below line Z.
Plug 64 of shell-plug assembly 65 has a flat surface 66 positioned adjacent the
upper shell section 67u of shell 67 to define a plug shear line. After shearing, and with
20 the key (not shown) inserted, the formed tumbler pin 60t is raised which in turn raises the
driver pin 60d. As plug 64 is turned in either direction (such as the counterclockwise
direction; Fig. 9a), groove chamfer surfaces 63 assist in free turning when the lower
tumbler pin 60t is too high or the bottom of the upper driver pin 60d too low. Chamfer
surfaces 63 reduce the likelihood that pins will catch the sides of shell and plug
_5 passageways 71u, 711 in either the shell or in the plug.
Turning to Figs. 10 and 11, a pin shearing m~ch~ni~m 78 is shown having body
79, housing cavity 81, a turnable drive unit 82 mounted in cavity 81 for rotation about
the longi~ in~l axis A (Fig. 11). Turnable unit 82 includes hand wheel 83 and bolt 84
30 mounted in rotatable drive body 80. Bolt 84 is turnable by a wrench (not shown) to turn
drive unit 82. As drive unit 82 is turned it tr~n~l~tes plunger 87 through mating threads
88 on body 80 of unit 82 and threads 89 on plunger 87. Plunger 87 moves linearly in
direction AA. Plunger 87 is held from turning by indentation 91 having flat surface 92
and by vertical post 93 which engages surface 92 to
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prevent rotation. Mer-h~ni~m 78 includes lock holder recess 94 including shell support
wall 94a which holds the shell-plug assembly 65 against translation in direction AA. In
the operation of .nPch~ m 78, the shell-plug assembly 65 is placed in holder recess 94,
plunger 87 is advanced until it touches the plug 64 and a wrench is then used to turn bolt
84 to translate plug 64 relative to its shell until the assembly pins 60 shear. After the
pins have been sheared, handwheel 83 can be turned in the a~pl~pl;ate direction to rotate
drive unit 82 and thereby translate plunger 87 in a direction opposite direction AA. This
releases the shell-plug assembly 65 for removal from the mech~ni~m 78.
Example
A door lock constructed of five (5) assembly pin passageways 71u, 711, defined by
_ aligned shell and plug passageways and assembly pins 60 will, as explained, have each
-~- pin 60 sheared to form a pin set (a tumbler pin 60t and driver pin 60d in tandem). Each
assembly pin 60 has an outside ~ meter D of .114 inches and a reduced we~ke~e~ notch
~i~m~ter (ND) in the grooves of .076 inches (see Fig. 8). Each assembly pin 60 has ten
(10) grooves 61aj prior to shearing to create the tumbler-driver pin sets.
Prior to shearing the door lock cylinder is shipped to a locksmith. A customer of
the lock~mith provides the lockcmith with a key used by the customer in operating other
locks of the customer. The l~ckcmith inserts the customer's key in the lock, places the
~_, lock in the mech~ni~m 78 and shears the assembly pins 60. The customer then installs
the door lock in his home, which lock can be served by the customer's existing key.
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W~ 96)25574 PCT/US96~01S19
Table 2
Pin Characteristics
Outside Notch In Line F Torque To
Tvpe Diameter Diameter To Shear Shear
' 5 (D) (ND)
Padlock .094 in. .076 in. 210 lb. 200 in lb.
Door Lock .114 in. .076 in. 210 lb. 200 in lb.
The pin notch diameter ND of each of the grooves is
selected to provide sufficient strength so that the assembly
10 pins 60 will not fail when a key (or tool of cross section to
permit penetration into the keyhole) is torqued. The key (or
tool) will fail through breaking, shearing or twisting before
the pins 60 shear. As an example, a hardened steel key was
inserted into the keyhole of a lock of the present invention
15 and a torque of 240 lb/in was applied to the key. The tool
broke without shearing the pins 60. The pin grooves 61a-j are
also shaped to create fracture or shear surfaces on both
tumbler and driver pins which are non-flat and which
facilitate lock operation. Finally, grooves 61a-j are shaped
20 so that upon fracturing during manufacture or customizing by a
locksmith, tumbler and driver pins 60 having end
configurations including chamfer surfaces 63 are formed which
assist in plug rotation during subsequent operation.
Turning to the embodiment as shown in Figs. 12-16,
padlock 103 includes lock body 104 having shell-plug assembly
104a comprised of plug 105 and shell 106. Also shown is
shackle 107, key 108 and serrated assembly pins 110.
Plug 105 includes collar 105c, plug circumferential
undercut 109, plug surface 105s, and plug tail 111. Undercut
109, having bottom 109b and sides 109s, circumscribes plug 105
(see Fig. 13a). Shell 106 includes upper housing portion 113
and lower housing portion 114. Upper housing portion 113
- 35 includes five shell pin passageways 116. Plug pin passageways
117 in the lower housing portion are aligned with shell
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W096/25574 PCT~S96/01519
passageways 116. The serrated pins llo are disposed in these
passageways. Key 108 includes four (4) notches 108a, which
are aligned with the bottoms of the pins 110 when the key is
inserted into the keyway of the plug 105. The distance
5 between laterally adjacent centers of passageways 116 and 117,
as shown in Fig. 13, is distance X. Also shown in Figs. 13
and 14 are springs 112 engaging the tops of the pins 110 and
urging them downwardly toward the key 109.
Turning to Fig. 14, plug 105 has been translated in
direction Y by a force necessary to shear pins 110 at selected
serrations 115 along shear line (SL). By such shearing upper
driver pins ll9a-e and lower tumbler pins 121a-e are formed.
In addition, the four lower tumbler pins 121a-d nearest the
15 keyhole entrance are each moved a distance X to align with the
four upper driver pins ll9b-e. Upper driver pin ll9a drops
down into plug undercut lO9 where it is held against undercut
bottom lO9b by spring 112a. With upper driver pin ll9a so
positioned, plug 105 can turn but cannot be withdrawn from
20 shell 106 because sides lO9s engage upper driver pin ll9a.
This anti-withdrawal feature adds to the security of padlock
103. Lower tumbler pin 121e becomes inactive in its plug
passageway 117, which serves as pin section entrapment hole.
As is seen in the Figures, passageways 116 and 117 have
diameter dimensions of d. Pins 110 are substantially the same
but slightly less in diameter than the passageways. The
spacing between the passageways is small enough so that an
adjacent pin, such as tumbler pin 121a supports an upper
30 driver pin such as driver pin ll9b before tumbler pin 121b has
moved out from under driver pin ll9b (see Fig. 14).
Alternatively, the anti-withdrawal feature of the present
invention is also useful in conventional pin tumbler locks
35 where tumbler and driver pins are first formed and then
assembled. In such a lock an additional shell passageway and
aligned plug passageway are formed into which is placed a
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WO 96125574 PCT/US96J(~15J9
shearable pin. The plug includes an undercut. When the plug
and a shell are assembled, the pin is sheared and a portion
enters the plug undercut to prevent plug withdrawal while
permitting plug rotation in the shell.
