U.S. patent number 3,748,940 [Application Number 05/172,182] was granted by the patent office on 1973-07-31 for portable punch.
This patent grant is currently assigned to DBM Industries Limited. Invention is credited to George Muri.
United States Patent |
3,748,940 |
Muri |
July 31, 1973 |
PORTABLE PUNCH
Abstract
A portable punch is described for cutting a key by selectively
removing material from a key blank. A punch and die sub-assembly is
preferably provided, being mounted in a housing on the punch to
facilitate reciprocal movement of the punch. An actuating handle
operatively connected to this sub-assembly is manipulated to drive
the punch on a cutting stroke. The key blank is supported on a
blank carrier on which two accurately oriented datum surfaces are
formed. The blank carrier is slidably movable in directions
parallel to these two surfaces. Movement of the blank carrier is
obtained from two cooperating locating means. One locating means
preferably includes a shaft element with a central section which
coacts with the blank carrier. The central section can be laterally
offset from an axis common to two end sections of the shaft element
which are journaled in the body of the punch. The other locating
means is preferably a lever member pivotally supported on the punch
body and having one free end thereof engaging the blank carrier.
Each locating means drives the carrier in a direction parallel to
one of the datum surfaces. Operating the locating means causes the
blank carrier and key blank thereon to be moved to a selected one
of a series of predetermined positions. A codified listing of a
combination of these positions will enable a key to be cut to a
selected configuration. Once the key blank is positioned, the
actuating handle is manipulated to drive the punch and remove
material from the blank. This invention relates to punch
constructions generally. More particularly, the present invention
relates to punches of the type which are suitable for cutting keys
from key blanks. In one preferred embodiment, the punch apparatus
to be described below is adapted to be set on a worktable or other
such surface, and is hand operated.
Inventors: |
Muri; George (Montreal,
CA) |
Assignee: |
DBM Industries Limited
(N/A)
|
Family
ID: |
22626679 |
Appl.
No.: |
05/172,182 |
Filed: |
August 16, 1971 |
Current U.S.
Class: |
83/414; 83/35;
409/81; 74/50; 83/917 |
Current CPC
Class: |
B21D
53/42 (20130101); Y10T 409/300952 (20150115); Y10T
83/0505 (20150401); Y10T 83/6566 (20150401); Y10S
83/917 (20130101); Y10T 74/18256 (20150115) |
Current International
Class: |
B21D
53/42 (20060101); B21D 53/00 (20060101); B26d
007/06 () |
Field of
Search: |
;33/199 ;74/48,50
;83/34,35,412-414,917,42 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Juhasz; Andrew R.
Assistant Examiner: Bray; W. D.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A punch apparatus for removing material selectively from a key
blank, the apparatus comprising;
a punch and die sub-assembly that is closely received and retained
in a housing provided on the apparatus;
an actuating handle operatively coupled to the punch of said
sub-assembly such that manipulation of the handle moves the punch
on a cutting stroke, to remove said material from the key
blank;
carrier means slidably mounted on the punch apparatus for
supporting the key blank thereon in operative relation to the
punch, said carrier means having first and second datum surfaces
disposed 90.degree. apart, and means for fixedly securing the blank
in abutting engagement with said surfaces, the carrier means being
positionable to locate said blank in a selected one of a series of
predetermined positions;
a first locating means including a shaft member supported by said
apparatus for eccentric movement, the shaft member being operably
connected to the carrier means to cause the carrier means and key
blank thereon to be movable in a direction parallel to said first
datum surface; and
a second locating means including lever means pivotally movable to
drive the carrier means in a direction parallel to said second
datum surface, whereby operation of the first and second locating
means cause the carrier means to be positionable for locating the
blank in said selected one of the series of predetermined
positons.
2. The apparatus of claim 1, wherein the punch and die sub-assembly
further includes biasing means operative for returning the punch
and actuating handle to a normal rest position.
3. The apparatus of claim 1, wherein said shaft member includes
oppositely disposed end sections having a common axis and mounted
in bearings provided on the punch apparatus, and a central section
having a central axis offset from said common axis, the shaft
member being rotatable to enable eccentric travel of the central
section to provide said movement in a direction parallel to the
first datum surface.
4. The apparatus of claim 3, wherein the carrier means is provided
with a slot extending transversely thereof and disposed parallel to
said second datum surface, the slot being on a surface opposite to
the surface on which the key blank is mounted, and so constructed
as to closely receive said central section of the shaft member the
eccentric travel of said central section causing the carrier means
to be moved along a path parallel to the first datum surface.
5. The apparatus of claim 3, wherein replaceable knob means are
supported on an extension of one of the end sections of said shaft
member exteriorly of the punch apparatus, and a positioning plate
having a number of index locations thereon is provided in operative
relation to the lever means, said knob means having a series of
recesses on one face thereof to complement said index locations,
each complementary pair of recesses and locations defining one of
the series of predetermined positions reached by travel of the
carrier means.
6. The apparatus of claim 5, further including spring biased
retaining means on the punch apparatus for selectively and
releasably engaging one of said recesses to retain the shaft member
in position.
7. A portable punch apparatus for removing material from a key
blank, the apparatus comprising:
a base portion and a punch housing fixedly secured thereto;
a punch and die sub-assembly supported in said housing, the punch
being reciprocally movable to remove material selectively from the
said blank;
carrier means movably supported on said base portion of the punch
apparatus, and being provided with two datum surfaces that are
90.degree. apart, and means fixedly securing the blank in abutting
engagement with said surfaces, the carrier means serving to fixedly
support the key blank thereon in operative relation to the punch
and die sub-assembly, and being movable in directions parallel to
each of said datum surfaces to locate said blank in a selected one
of a series of predetermined positions;
first locating means including a shaft member journalled at
opposite ends thereof in bosses formed on said base portion of the
punch apparatus, the shaft member having a central section whose
axis is offset from an axis common to said opposite ends of the
shaft member to cause said central section to be movable
eccentrically of said common axis, said central section coacting
with the carrier means such that the eccentric movement of the
central section causes the carrier and blank thereon to be moved in
a direction parallel to a first of said datum surfaces; and
second locating means including lever means pivotally supported by
said base portions and operatively connected to the carrier means
to move the carrier means and blank thereon in a direction parallel
to the second datum surface, manipulation of the first and second
locating means causing the carrier means to be positionable to
locate the key blank in said selected one of the series of
predetermined positions.
8. The punch apparatus defined in claim 7, wherein an actuating
handle is provided, operatively coupled to the punch such that
manipulation of the handle moves the punch on a cutting stroke to
remove said material from the key blank.
Description
BACKGROUND OF THE INVENTION
It is well known that a key is commonly used to open a lock, with
most lock constructions involving pin or plate tumblers therein.
These tumblers are usually of a particular configuration, and are
rendered inoperative in the lock by manipulating a key having teeth
corresponding in configuration to the positioning of the tumblers
in the lock in an inoperative condition. Both the lock and key must
be manufactured to relatively close tolerances, say, of about
.+-.0.002 inches, or even less. One reason for such accuracy is
derived from the fact that many locks include a lock cylinder and
matching plug member received therein. Rotation of the plug member
is effectively prevented by those tumblers which protrude some
distance into each part. Even if that distance is very slight, the
protruding tumbler can disable rotation of the plug member and
hence unlatching of the lock. A more detailed description of
various lock structures can be located in textbooks or technical
encyclopedias which deal with this subject. The foregoing brief
description of many conventional locks is believed to suffice,
since lock constructions per se form no part of the present subject
matter.
One important criteria which precipitates many difficulties in
previous punch constructions is the desirability, if not the
necessity, of constructing locks and cutting mating keys to
sufficient accuracy that accidental or unintended opening of the
lock is effectively inhibited. Locks and keys are useful only to
the extent they prevent or reduce accessibility to something by
unauthorized persons.
Many attempts have been made in the past to provide apparatus which
can easily produce keys of high accuracy, consistently. Such
devices have often failed to gain a wide measure of acceptance.
Some devices have been too complicated and hence too costly. Others
have been too cumbersome, or too restricted in their usage. A brief
description will follow of two prior art punch constructions which
are intended for cutting keys. In one instance, the key cutter is
shaped and operated somewhat like a pair of conventional pliers.
Two handles are pivotally interconnected and arranged to be gripped
in an operator's hand. Squeezing these handles together causes a
punch to be moved. Movement of the punch element is intended to cut
material from a key blank positioned between the punch and a
backing member or anvil. This key blank is positionable to a number
of selected locations, each of which corresponds to a setting
derived from a coded disc element. A rack and pinion drive
arrangement is used to advance the key blank, and settings for
positioning the key blank are obtained through locating pins which
are received in pre-fixed apertures provided on the disc element.
The functional interrelationship between the many cooperating parts
is a source of inaccuracy in finally cutting material from the key
blank. It will be recognized that the various structural parts of
this key cutter have been made to within certain tolerances. Due to
the operative relationship of such parts, however, these tolerance
errors tend to be cumulative and hence the product, which is the
key produced thereby, is subject to this accumulation of errors.
Furthermore, the very manner in which this key cutter is operated
is less than satisfactory. It is intended to be held in one or both
hands, and is actuated by gripping the handles and squeezing them
together. A great many people simply do not possess a grip
sufficiently strong to squeeze these handles together with enough
force to enable material to be cut from the key blank. As a result,
the effectiveness of this type of a key cutter is less than the
maximum possible.
Another prior art key punch is shown and described in Canadian
Patent 841,395 which issued May 12, 1970 to Fred J. Russel et al.
This patent shows a key punch in which a key blank is supported on
a blank holder to be advanced in one direction only past the punch
element which is intended to cut material from the blank at a
desired tumbler location. To digress briefly, it should be
mentioned that the location of teeth on a key is often described
with reference to tumbler positions in the lock with which the key
is to be used. Similarly, the teeth are formed by cutting notches
out of the blank, and the depth of cut of these notches is often
referred to as the bite. Keys and locks are commonly provided with
five, six or seven tumbler positions, and sometimes as many as
eight. The number of depths or amount of bite required of most keys
is generally three to six. That is to say, the notches cut into a
key blank will usually be of between three and six different
depths.
Returning to the prior art, the punch apparatus of the 841,395
patent mentioned above is in some respects an improvement over the
plier-like device first described. This later punch construction is
still thought to have certain disadvantages, however. It will be
seen, for example, that numerous cooperating cams are brought into
play in that punch in an attempt to accurately position the blank.
Such an arrangement does not seem to be entirely satisfactory, and
indeed, it was found necessary to provide an alignment shaft to
improve the accuracy of positioning of the key blank, lengthwise.
The net result appears to be a rather complex construction in which
a considerable number of coacting parts and surfaces are involved.
All of these parts and surfaces must be called upon to provide
accuracy in positioning which ultimately cannot exceed
approximately .+-.0.002 inches in tolerance error. Such accuracy is
believed to be difficult to achieve with such a construction. It is
also noted that because the key blank is advanced in one direction
only, any accidental actuation of the punch, say, by accidentally
bumping the operating handle requires repositioning of the key
blank to the initial starting position. From here, the punch is
actuated enough times to bring the blank back to the position
required, where the next notch will be cut. Further difficulties
can arise in the punch construction of this Canadian patent from
the manner in which the punch element is itself supported. The
punch is slidably mounted in a vertically extending passage formed
in a punch carrier, however, the carrier is itself movable in its
own slideway. All of the surfaces which involve sliding movement
are subject to at least some wear and misalignment which arises
from manufacturing tolerance errors and assembly. A construction
involving so many relatively movable parts can certainly introduce
many tolerance errors which make highly accurate positioning or
cutting of the key blank particularly difficult.
There seems to be a long-felt need in this art, therefore, to have
a punch apparatus which overcomes such deficiencies as those
mentioned previously in connection with prior art devices. A punch
apparatus which consistently and reliably positions a key blank to
within very close tolerances would constitute a considerable
improvement. This is especially so since past efforts, as described
above, do not seem to have solved this problem. The difficulty in
providing keys cut to a high degree of accuracy is further
complicated by the present-day requirement of key punches to cut
keys from blanks having many different cross-sectional shapes.
Considerable flexibility in this respect is also thought to be a
particularly desirable feature. Most automobile manufacturers, for
instance, use keys cut from blanks of cross-sectional shapes which
are different from one another.
SUMMARY OF THE INVENTION
The punch apparatus which embodies the present invention tends to
overcome many of the inadequacies of prior art devices. It is
fairly simply in construction, yet sturdy enough to provide a
marked improvement in the accuracy of positioning a blank carrier
and key blank relative to the punch element which cuts the key.
Applicant's punch apparatus also affords improved versatility in
being able to cut keys from blanks having a wide variety of
cross-sectional shapes.
Accordingly, there is provided herein an improved punch apparatus
for removing material from a key blank, comprising punch means
supported for reciprocal movement in a housing provided on the
apparatus, and being operative to remove said material from the key
blank; carrier means slidably mounted on the punch apparatus for
supporting the key blank thereon, in operative relation to the
punch means, said carrier means having first and second datum
surfaces thereon and being positionable to locate said blank in a
selected one of a series of predetermined positions; a first
locating means operably connected to the carrier means to enable
moving the latter and a key blank thereon in a direction parallel
to said first datum surface; and a second locating means supported
on the punch apparatus being operatively connected to said carrier
means for moving it and the key blank thereon in a direction
parallel to the second datum surface whereby operation of said
locating means causes the blank to be positioned in said selected
one of the series of predetermined positions. The first locating
means is preferably a shaft member having a portion thereof in
engagement with the blank carrier. The shaft member is so mounted
in the punch apparatus as to cause the blank carrier to be moved
parallel to the first datum surface. The other locating means is
preferably a lever which is pivotally supported on the punch
apparatus. Each of these locating means is adjustable to a number
of pre-fixed index positions. The index positions on each of these
locating means cooperate to locate the key blank in one of the
series of predetermined positions, such positions being obtainable
from a codified listing of multi-digit numbers. Each digit in such
a code number corresponds to one of the index positions on either
of the two locating means.
Various features and advantages of such an apparatus will become
apparent from the detailed description below. That description
should be read in conjunction with the accompanying drawings which
illustrate by way of example only, one preferred embodiment of a
punch apparatus which encompasses the present invention, and
wherein:
FIG. 1 is a perspective view showing schematically one preferred
form of the punch apparatus herein;
FIG. 2 is a plan view taken in section along line 2--2 of FIG. 3,
and showing details of the punch apparatus of FIG. 1;
FIG. 3 is a side elevation view taken in section along line 3--3 of
FIG. 2;
FIG. 4 is a fragmentary elevation view taken in section to show
details of the punch and die sub-assembly of the apparatus of FIG.
1;
FIG. 5 is also a fragmentary elevation view showing details of
mounting a positioning plate in the punch apparatus of FIG. 1;
FIG. 6 is an elevation view showing some detail of one of the
locating means used in the apparatus of FIG. 1;
FIGS. 7 and 8 are plan and elevation views respectively, of an
optional stop assembly for use in the apparatus of FIG. 1; and
FIGS. 9A to 9D are fragmentary perspective views to illustrate
various tongue configurations on an insert used with the blank
carrier in the apparatus of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings and FIGS. 1-3 in particular, a
preferred form of the present punch apparatus is shown overall at
10. Briefly, this punch apparatus 10 comprises a boot-like body 12
which includes a base 14, a toe section 16 and a heel section 18.
These sections of the body 12 are commonly produced, say, as an
integral unit by casting of a ferrous material, or suitable
equivalent therefor. An actuating handle 20 is pivotally supported
on a pin 21 in the heel section 18, with manipulation downwardly of
this handle moving a punch 22 (see FIGS. 3 and 4) on its cutting
stroke. A key blank 24 is supported on a blank carrier 26 which is
preferably slidably movable to locate the key blank in a selected
one of a series of predetermined positions. Such positions are, of
course, in operative relation to the punch 22 which cuts material
from the blank 24 to produce the key desired. A first and second
locating means are indicated overall at 70 and 100, respectively,
and are manually operable. Each of the locating means 70 and 100 is
connected to the blank carrier 26 to enable moving the latter.
Choosing a position on each of the locating means which corresponds
to a digit in a code number listed in a book of such numbers, for
instance, causes the blank carrier 26 to be moved into the position
selected and allows material to be cut from the blank 24 carried
thereon.
Reference should now be had to FIGS. 2 and 3 for details of the
above construction. The heel section 18 can be seen in FIG. 3 as
being formed with a tubular punch housing 28 as an integral part of
the cast body 12. A guide sleeve 30 is closely received in the
housing 28 and functions to slidably support the punch 22 and an
associated die 32. These parts form a sub-assembly which is
initially put together exteriorly of the housing 28. The punch die
32 is inserted with a close fit into the sleeve 30, until a
peripherally extending shoulder 34 on the die abuts one end of the
sleeve. A compression spring 35 is next inserted into the opposite
end of sleeve 30, followed by the punch 22 and a retaining collar
36. The retaining collar 36 has a transverse borehole 37 extending
therethrough. See FIG. 4. This retaining collar 36 is then pressed
downwardly until the borehole 37 can be seen through a carefully
oriented slot 38 provided longitudinally of the guide sleeve 30. A
locking pin 39 is then tapped into place, as shown in FIG. 4. The
guide sleeve, punch, and die sub-assembly are now press-fitted into
the housing 28.
To ensure accurate alignment of the punch 22, now positioned
relative to the guide sleeve 30 by pin 39 in slot 38, a threaded
locating screw 40 is mounted in a threaded opening 41 in the
housing 28. This opening 41 has been carefully aligned in the wall
of housing 28 so as to be disposed at substantially 90.degree. to
the plane of a bearing seat to be described below. In assemblying
the punch and die sub-assembly in the housing 28, the initial fit
of the guide sleeve 30 may have been slightly out of line. That is
to say, the slot 38 might have been angularly displaced a small
amount, relative to the axis of threaded opening 41. To allow and
compensate for this, the nose of locating screw 40 includes a
tapered portion 42 which will seek out the slot 38. By providing
the width of slot 38 of a dimension that is substantially identical
to the diameter of the remaining part of the nose portion of screw
40, i.e., with what almost amounts to an interference fit, this
locating screw will bring the punch and die sub-assembly into the
correct alignment in the housing 28. This correct alignment enables
the nose of pin 40 to be fully seated in slot 38. This arrangement
also causes the cutting edge of punch 22 to be properly oriented
relative to the edge of key blank 24 in which notches are to be
cut. Such a construction, moreover, provides a very easily
replaceable sub-assembly. In particular, this sub-assembly is
re-positionable with the same high degree of accuracy as that with
which it was originally put together. This is very important since
it will be seen that each cutting stroke of the punch 22 must
travel the same path, without any lateral deviation other than that
arising from manufacturing tolerances. In the present instance, the
solid and well guided construction enable these tolerances to be
kept to within .+-.0.0005 inches, or even less. It will be seen
that the punch 22 is well guided over a considerable extent of its
length and is driven directly by manipulation of the handle 20.
Reliable and consistently accurate operation can therefore be
obtained. Should sharpening of the cutting edge of the punch 22 be
required, or replacement of the punch, this can be done rather
quickly by unscrewing the locating screw 40 and removing the guide
sleeve and punch and die sub-assembly in the reverse order to that
described above in connection with assemblying these parts.
Replacement of the punch 22 might be required, for instance, to
provide a punch having a rather V-shaped cutting edge, rather than
the shape of cutting edge seen here in FIGS. 2 and 7. It is again
emphasized that re-assembly of these parts will still enable the
punch to function with the same high degree of accuracy as it had
following original assembly.
The body 12 of the punch apparatus 10 is roughly boot-shaped, as
indicated earlier. In the region where the heel section 18 joins
base 14, the casting is provided with a cut out portion which is
roughly C-shaped in elevation, to define a bearing seat or surface
44 to which reference was made earlier. See FIG. 2. This bearing
seat 44 is machined to be disposed at an orientation or alignment
which is at 90.degree. to the longitudinal axis of the punch
housing 28, and hence of the punch 22. The bearing surface 44 is
therefore also at 90.degree. to the longitudinally extending slot
38 in guide sleeve 30 of the punch and die sub-assembly. A bearing
block 46 is subsequently securely fixed to this bearing surface 44,
as by fastening means 47. The top and bottom surfaces of the
bearing block 46 are smoothly finished and lie in planes parallel
to one another. An aperture 48 is formed in the bearing block 46 to
allow material cut from the key blank 24 to fall away.
Correspondingly, the cast body 12 has a central opening 50 with a
smaller extension 51 which lines up with the aperture 48. As seen
in FIG. 3, the bearing block 46 serves to slidably support the
blank carrier 26. To accommodate this, one of the long side edges
of the blank carrier 26 is formed with a slot or recess 52
extending completely across the blank carrier. The bearing block 46
is then closely received in the slot 52 with a snug, sliding fit.
The recess or slot 52 is of a sufficient depth to allow all of the
travel required to cut notches into the key blank 24 to any depth
or bite required. As mentioned earlier, notches in the key thus
formed might be cut to a number of different depths or levels,
commonly three to six different depths. The position of the blank
carrier 26 in FIGS. 2 and 3 is such as to enable a notch to be cut
to the maximum depth desired. The key blank 24 is seated in
position on the normally upwardly facing surface of the blank
carrier 26. This blank 24 is positioned against a first and a
second datum surface, 54 and 56 respectively, on the carrier 26. In
this particular embodiment, the surface 56 has been provided on an
optional insert 55. Here, the insert 55 is retained in a slot and
shoulder arrangement 57 which has been cut away from what is the
upper left corner of the blank carrier 26, as seen in FIG. 3. The
insert 55 is itself slotted as seen at 58 in order to receive a pin
59 which is mounted in a borehole provided in the blank carrier 26.
Such a structural configuration functions to hold the insert 55
securely in place, while still enabling easy replacement thereof
whenever a key having a cross-sectional shape different from that
shown, say, in FIG. 3 is to be cut. As stated earlier, the insert
55 is optional. The datum surface 56 could thus be formed directly
on the blank carrier 26 in another embodiment.
In the punch apparatus of FIGS. 1 and 3, the insert 55 is provided
with a laterally extending flange 60 disposed on the side opposite
to the slot 58. This flange 60 provides, in this instance, adequate
support to the key blank 24 which has the cross-sectional shape
shown here. Digressing momentarily, it was mentioned earlier that
present-day key punches often require considerable versatility.
This is due largely to the fact that key blanks come with a variety
of cross-sectional shapes. The blank 24 in FIG. 3 has a certain
shape, which includes a semi-circular slot or channelway on both
its upper and lower surfaces. Another form of a key blank is shown
in section in FIG. 8, and has channelways which are V-shaped. Still
other blanks might be provided with channelways having a square
cross-section. Key blanks provided by manufacturers, say, in North
America or in Europe have laterally extending tongue sections such
as that shown at 61 and 63 which may be of varying width. This
width will be at least somewhat dependent upon the number of depths
to which notches are to be cut therein, and on the spacing used
between successive depths or levels. This spacing is commonly
identical, with the possible exception that the first level may be
coincident with the longitudinally extending edge of the key blank
24, or slightly spaced inwardly therefrom. All of the other levels
or depths to which the notches are to be cut will be measured in
equally spaced apart steps from that first reference level. If the
remaining part of the body of the key blank 24 between the tongues
61 and 63 is rather narrow, the blank 24 may not be adequately
supported on the flange 60 of insert 55, as shown in FIG. 3.
Accordingly, the insert 55 may have a cross-sectional configuration
which corresponds to one of those illustrated in FIGS. 9A to 9D.
The provision of inserts such as those will allow considerable
variation in the "body width" of the key blank 24 to be
accommodated. Each of the inserts 55 shown schematically in FIGS.
9A to 9D still enable the blank to be secured firmly to the blank
carrier 26. It should also be noted here that all key blanks such
as that seen at 24 in FIG. 2, or at 124 in FIGS. 7 and 8 have a
reference shoulder 126. The distance to each tumbler position,
taken lengthwise of these key blanks, is measured from this
shoulder 126.
Normally, it will be adequate to position the reference shoulder
126 as shown in FIGS. 2 or 7 abutting against the first datum
surface 54 on the blank carrier 26. In other instances, it is
convenient to provide a separate and positive key stop shown at 128
in FIGS. 7 and 8. This stop 128 is pivotally secured to the base
member of a clamp assembly 62 by means of a conventional threaded
fastener 130, and is spring-biased, say, by a Bellville-type washer
132. The clamp assembly 62 is spring-biased and pivotally mounted
on the blank carrier 26, functioning to fixedly secure the key
blank 24 on the carrier and/or insert 55.
The lower surface of the blank carrier 26 opposite clamp assembly
62 is cut away to define a channel or slot 64 which extends
completely across the carrier. A second slot or cut-out 65 extends
at right angles from the channel 64 towards the left as seen in
FIGS. 2 and 3. The purpose of this second slot 65 will become
apparent below. The channel 64, however, is intended to closely
receive a central section 66 of a shaft element 68. In this
preferred embodiment of the present punch apparatus, the shaft
element 68 forms an important part of a first locating means 70.
The shaft element 68 includes two enlarged end sections 71 and 72
which are journaled as shown, in two laterally disposed bosses 73
formed integrally of the base 14. A washer and locking circlet 74
secure the end section 72 in place in one of the bosses 73. It is
to be emphasized that the longitudinal axis of the central section
66 is offset from the axis common to enlarged end sections 71 and
72. In this way, rotation of the shaft element 68 about that common
axis will cause eccentric movement of the central section 66. Since
this central section 66 is received in the channel 64, that
eccentric movement will be transformed into linear movement of the
carrier 26, in a direction parallel to the datum surface 54. It
will of course be apparent that the amount of separation between
the axes of the central section 66 and end sections 71 and 72 will
determine the amount of travel of the blank carrier 26. It is of
course necessary to ensure that this travel is sufficient at all
times to accommodate the maximum depth to which a notch is to be
cut in any of the key blanks 24.
Returning now to FIGS. 2 and 3, it should be noted that the
enlarged end section 71 of the shaft element 68 has a rotationally
adjustable knob 75 removably secured thereto by means of a threaded
fastener 76. A corrogated washer 77 is provided between this knob
75 and the outer surface of the boss 73, in order to provide a
spring-loaded arrangement. A locating pin 78 is press-fitted into a
suitable aperture in the end section 71. This pin 78 is very
carefully positioned, having its longitudinal axis coplaner with
the plane containing the axes of end sections 71 and 72, and the
axis of central section 66. The reason for this orientation will
become apparent shortly. With reference to FIG. 6, it will be seen
that a number of notches or grooves 79 are provided on the inwardly
facing surface of the knob 75. These notches could alternatively be
formed in a disc which is itself secured to that surface of the
knob 75. Either way, each of the grooves 79 will correspond to an
index position 80 (FIG. 1). A reference datum mark 81 is provided
on the top surface of the boss 73, to which the "zero" or first of
the index positions 80 is to be set. The locating pin 78 mentioned
earlier is intended to be seated in a recess 82 cut into the
surface of knob 75 containing the grooves 79. Recess 82 is oriented
so that setting the first index position 80 at the datum mark 81
will also simultaneously position the blank carrier 26 and key
blank 24 thereon at the proper position for cutting the correct
depth of the notch or bite at the first of the various levels to
which notches might be cut. It will be recalled from previous
remarks that the notches cut into present-day keys are commonly at
any one of from three to six different levels spaced equally apart,
but starting in each instance from a given reference or first
level. It is that first level to which the blank carrier 26 and key
blank 24 thereon will be located or set when the first of the index
positions 80 is lined up with the datum mark 81. It will of course
be apparent from the operative relationship between the central
section 66 and blank carrier 26, that rotation of the knob 75 to
set another of the index positions 80 against datum mark 81 will
cause the central section 66 to be driven with eccentric rotational
movement. That eccentric movement will subsequently cause the blank
carrier 26 to be moved. As seen in FIG. 3, the knob 75 is retained
in the position to which it has been set, related to datum mark 81,
by engagement or seating of a spring-loaded ball 84 in the groove
79 associated with the index position 80 that has been selected.
The spring-loaded ball 84 forms part of a pin assembly 85. In
addition, this ball 84 is preferably laterally offset from the
overall longitudinal axis of the pin assembly 85 in order to allow
for a slight amount of initial adjustment. The ball and pin
assembly 85 could, of course, be coaxially oriented. In the event
that the spring-loaded ball 84 does have some lateral spacing, the
slight adjustability available by rotating the pin assembly 85 will
accommodate, say, some slight wearing of the cutting edge of punch
22 due, for example, to sharpening or the like.
It was mentioned earlier that a second locating means 100 provides
for movement of the blank carrier 26 in a direction parallel to the
datum surface 56. To do so, the slot or recess 65 which extends
transversely from the channel 64 is adapted to receive a drive pin
86. This drive pin 86 is securely housed in a boss 87 provided on
the shorter end section of a pivotally mounted lever 88. The lever
88 is itself rotatably secured to the body 12 of the punch
apparatus 10 by means of a pivot pin 90. The pivot pin 90 is firmly
mounted in the base portion 14. The outwardly extending end of the
lever 88, opposite drive pin 86, is provided with an aperture 92
and beyond that, a locating pin 94. This pin 94 is to be closely
received in one of a corresponding series of openings 96 formed in
a replaceable positioning plate 98. A second series of index
positions 99 (see FIGS. 1 and 2) is provided on the positioning
plate 98 and these can be seen through the aperture 92. The
openings 96 are spaced equally apart along the circumference of a
path having a radial dimension from pivot pin 90 which is equal to
twice the radial distance between pivot pin 90 and driving pin 86.
Another embodiment of the punch apparatus 10 could utilize some
other ratio for these two distances. In all instances, however, it
will be recognized that the spacing between the openings 96 must be
equal and must be of such a distance as to ensure precise movement
of the key blank 24 longitudinally of itself to enable placement of
that blank to the correct tumbler position, both accurately and
consistently. In addition, it will be recognized that the location
of the aperture 96 which corresponds to the first or zero index
position 99 must be so located as to effect placement of the key
blank 24 in the exact position required to enable cutting a notch
at the first tumbler position on that blank. It will be recalled
that most keys and locks normally have from five to seven tumbler
positions, and occasionally go as high as eight. In the embodiment
illustrated herein, keys having up to eight tumbler positions can
be cut with the present punch apparatus 10.
FIG. 5 shows one method for securely fastening the positioning
plate 98 in position on the punch apparatus 10. Accordingly, the
plate 98 is provided with apertures 101 and 102. These apertures
101 and 102 are intended to receive a locating pin 103 and a
spring-loaded biasing ball 104. As seen in FIG. 3, each of the
bosses 73 is slotted as shown at 105 in order to accommodate
positioning of the plate 98. It will be recognized that the
aperture 102 will be of such a size as to receive a portion of the
ball 104 sufficient to ensure that plate 98 is held securely in
place. The locating pin 103 has, in any event, a snug fit with the
aperture 101.
To move the blank carrier 26 in a direction parallel to datum
surface 56, an operator grips lever 88 lifting the outer end
thereof, simultaneously extracting the locating pin 94 from the
aperture 96 in which it had been received. The lever 88 is then
pivoted about the axis of pin 90, and in so doing, drive pin 86
causes the blank carrier 26 to be moved correspondingly. It will be
noted that the length of the channel or slot 65 is of a depth
sufficient to provide for a certain amount of lost motion of the
drive pin 86 as it moves along a circular path. That curvilinear
movement of pin 86 is thus transformed into linear movement of the
blank carrier 26 and key blank 24 thereon. The second locating
means 100 has been so positioned in FIG. 2 as to place the key
blank 24 in the last tumbler position at which material is to be
cut from that blank.
In using the punch apparatus 10, reference must be made to a
listing of code numbers, each of which applies to a particular lock
and key combination. These code numbers will normally have a number
of digits therein, each digit corresponding to one of the index
positions 80 or 99. Since a listing of these code numbers will have
been supplied, say, to an automobile dealer, a garage, or the like,
it is assumed for purposes of this disclosure that adequate
instruction would have been given by the supplier of those code
numbers to enable them to be properly used. It will suffice at this
time to state simply that reference is made to these code numbers
to enable a particular key blank 24 to be placed, say, in a series
of eight different tumbler positions in which notches are to be
cut. The exact orientation of the key blank 24 relative to the
cutting edge of the punch 22 is determined by the setting used on
each of the locating means 70 and 100. If a notch is to be cut, for
instance, at the first tumbler position on the key blank 24, the
lever 88 is lifted and moved to enable placement of the locating
pin 94 in the first opening 96 in plate 98; while the knob 75 is
likewise turned to set the first index position 80 opposite the
datum mark 81. Such manipulation of each of the locating means 70
and 100 will cause correct placement of the key blank 24 to enable
a notch of a desired depth to be cut at the first tumbler position.
Manipulating the knob 75 and lever 88 thereafter will subsequently
cause movement of the blank carrier 26 to move key blank 24 to the
next tumbler position required where a notch of a preselected depth
can now be cut. There are various techniques used by manufacturers
in this art for altering the number of key and lock combinations
which can be made, independently of any others. It can be seen, for
instance, that displacement of the zero or initial index position
80 or 99 from one knob 75 or plate 98 to another will produce keys
having slightly different tooth configurations. This displacement
can be very slight, say, in the amount of five or 10, one
thousandths of an inch. Similarly, the exact cross-sectional shape
of the key blank 24 can be varied from one make of car, for
instance, to another. Further yet, the spacing between each of the
grooves 79 or openings 96 could also be varied. This spacing could,
for instance, be 10, 15, 25 or 30 thousandths of an inch and could
be selected at the discretion of the manufacturer of the lock with
which a particular key is to be used. Finally, the cross-sectional
shape of the punch 22 itself could be varied, although it is known
that a shape such as that shown in FIGS. 2 and 7 is commonly used
in North America, while in Europe a more pointed V-shape is
frequently used. It will in any event be readily apparent that a
great many permutations and combinations can be employed to provide
a tremendously large number of configurations for teeth on a key,
each being sufficiently different from the next configuration to
effectively inhibit usage of a given key in anything other than the
mating lock for which it was originally cut.
The foregoing description has made reference to one preferred
embodiment encompassed by the present invention. Modifications and
variations to the structure shown herein will be apparent to those
skilled in this art. The shaft element 68, for instance, could be
so designed that the end sections 71 and 72 have a cam-shaped
cross-sectional area. Rotational movement of a shaft element having
such a structural configuration would still provide the lateral
displacement needed to move the blank carrier 26 to the position
where a notch is cut to any desired depth or bite. Similarly, the
exact configuration of the lever 88 could also be altered, as could
the manner by which that lever engages the blank 26 to effect
movement of the latter. It will also be recognized that although
the present body 12 of this punch apparatus is described as being a
one-piece casting, the base and heel sections mentioned herein
could in fact be formed separately. It will be apparent, however,
that more machining and therefore higher manufacturing costs would
be encountered in a punch apparatus having a body made from a
number of parts joined together. It is therefore intended within
the spirit of this invention to encompass all those changes and
modifications as would be apparent to those skilled in this art,
and falling within the scope of the appended claims.
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