U.S. patent number 3,786,659 [Application Number 05/306,695] was granted by the patent office on 1974-01-22 for lock key.
This patent grant is currently assigned to Schlage Lock Company. Invention is credited to George Elder, Hans F. Lehnhoff.
United States Patent |
3,786,659 |
Elder , et al. |
January 22, 1974 |
LOCK KEY
Abstract
A lock key having a shank elongated along an axis and having a
predetermined width also has a substantially flat bow integral with
the shank and extending laterally thereof for a much greater width
to provide extensions on opposite sides of the shank axis. A hard,
integral, non-frangible turning pad is preferably molded in
intimate contact with the bow and extends out from the margins of
the bow to encase the bow except at the junction of the bow with
the shank. The pad furnishes spaced torque zones that are supported
by the encased bow to resist yielding of the extended turning pad
under torque.
Inventors: |
Elder; George (Woodside,
CA), Lehnhoff; Hans F. (Moraga, CA) |
Assignee: |
Schlage Lock Company (San
Francisco, CA)
|
Family
ID: |
23186441 |
Appl.
No.: |
05/306,695 |
Filed: |
November 15, 1972 |
Current U.S.
Class: |
70/395;
70/408 |
Current CPC
Class: |
E05B
19/04 (20130101); Y10T 70/7876 (20150401); E05B
19/24 (20130101); Y10T 70/7802 (20150401) |
Current International
Class: |
E05B
19/04 (20060101); E05B 19/00 (20060101); E05b
019/04 () |
Field of
Search: |
;70/395,408,393,405,406 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wolfe; Robert L.
Claims
What is claimed is:
1. A lock key comprising a shank elongated along an axis and having
a predetermined width measured radially from said axis; a
substantially flat bow integral with and extending across one end
of said shank to a width greater than said predetermined width to
provide torque zones on opposite sides of said bow and on opposite
sides of said axis; and a hard, non-frangible, integral turning pad
in intimate contact with, extending beyond and encasing said bow
except at the junction of said bow and said shank and overlying and
supported by said torque zones against yielding under torque about
said axis.
2. A device as in claim 1 in which said turning pad is
substantially opaque.
3. A device as in claim 1 in which said bow is provided with
depressions and said turning pad substantially fills said
depressions.
4. A device as in claim 1 in which said bow is provided with
projections and said turning pad surrounds said projections and
leaves the ends thereof exposed.
5. A device as in claim 1 in which said shank and said bow are
metal of a predetermined coefficient of expansion and said turning
pad is plastic of similar coefficient of expansion.
Description
The fabrication of keys for locks, particularly pin tumbler locks,
has proceeded for a long time along fairly standardized paths. The
usual key is formed of a metal blank with an elongated shank having
an irregular cross-section in order to fit a particular lock and
having edge serrations for the purpose, also, of fitting and moving
the lock. The shank is usually integral with a somewhat wider bow.
The bow often has a perforation to serve as a key ring hole or hook
hanging hole. Frequently the bow carries indicia of various sorts,
such as the name of the key maker as well as a serial number of the
key and such as identifying indicia; for example, the name of a
hotel to which the key is appurtenant or a room number or the
like.
In recent years the security of many locks has been partially
compromised by the wide spread distribution of the corresponding
keys. A person surreptitiously obtaining such a key can immediately
read the location of the lock to which the key belongs and so can
gain access to the locked space. Instead, therefore, of following
the older preference of having various identifying indicia appear
on the key itself, especially on the key bow, the trend now is to
omit such indicia from the key. Should the key come surreptitiously
into the hands of an unauthorized person, there is no ready
identification of the lock to which the key belongs. There are,
however, many keys extant with such indicia already on them,
perhaps embossed or incised in the key bow metal. There are many
lock and key manufacturers extensively equipped to manufacture keys
of the present sort who would find great expense and difficulty in
changing the preset key style.
It is therefore an object of our invention to provide a lock key
which can generally be manufactured on present equipment and can
readily be handled by the existing set-ups of most locksmiths yet
which will prevent the ready identification of the lock associated
with the key.
Another object of the invention is to provide a lock key which can
readily be utilized in newer, high security locks requiring
substantially increased torque for their operation yet which will
not fail under such use.
A further object of the invention is to provide a lock key of
somewhat distinctive configuration and dimension in order that,
while principally following normal key techniques, it can be easily
distinguished from customary keys.
An additional object of the invention is to provide a key which can
be manufactured either as a key having indicia easily visible
thereon or as a key in which the indicia are concealed or not
visible.
A further object of the invention is to provide a key which has
improved, pleasant tactile and visual factors and which most people
prefer over the standard key from the aspects of feel and
appearance.
An additional object of the invention is to provide a key which
tends to remain clean despite handling by many different people and
which does not tend to accumulate grease, dust or other soil.
A still further object of the invention is to provide a key which
in many respects is standard but as ordinarily handled is a
non-conductor of static electricity.
A further object of the invention is in general to provide an
improved key.
Other objects together with the foregoing are attained in the
embodiments of the invention described in the accompanying
description and illustrated in the accompanying drawings, in
which:
FIG. 1 is a front elevation of a key constructed pursuant to the
invention;
FIG. 2 is a cross-section, the plane of which is indicated by the
line 2--2 of FIG. 1;
FIG. 3 is an elevation of a modified form of key pursuant to the
invention;
FIG. 4 is a cross-section, the plane of which is indicated by the
line 4--4 of FIG. 3;
FIG. 5 is a front elevation of a further modified form of key
pursuant to the invention; and
FIG. 6 is a cross-section, the plane of which is indicated by the
line 6--6 of FIG. 5.
In investigating the literature relating to the construction of
lock keys, we have examined patents obtained from the United States
Patent Office. The best references presently known to us are as
follows:
U.S. Pat. Nos. 2,200,454, Rahn, May 14, 1940; 2,759,279, Schlage,
Aug. 21, 1956; 2,759,280, Schlage, Aug. 21, 1956; 2,982,041, Kent,
May 2, 1961; 3,427,833, Lempke, Feb. 18, 1969; 3,481,168, Unter,
Dec. 2, 1969.
The Rahn and Schlage patents employ separate metallic or comparable
members which are clamped over or mechanically fastened to a key
either of a special shape or of a standard shape. The kent patent
has a thin plastic envelope formed on and heat sealed around part
of the bow of a key. The Lempke and Unter patents have plastic bows
on straight, metallic key shanks. Without analyzing each of these
patents in detail and while recognizing that each one is well
suited for the particular purpose for which it was designed, we
have nevertheless found that each of them has some shortcomings in
meeting the particular present-day conditions that we desire to
meet. These conditions include the considerably increased torque
necessary to operate modern high security locks, the desirability
of concealing indicia on the keys, the desirability of
manufacturing the keys so that they can be produced and serviced on
most current equipment and the desirability to keep them cleaner,
and make them better in appearance, pleasanter to handle and to
have various other improved attributes.
One form of key pursuant to our invention is constructed as shown
in FIGS. 1 and 2. In this instance there is afforded a key shank 6
of standard configuration in cross-section and standard in present
or potential bitting. The shank is elongated along a central axis 7
and has a predetermined width D with material disposed more or less
symmetrically on either side of the axis. The key shank 6 can be
made of any suitable substance but customarily is of a brass or
nickel-silver composition. The key shank is made integrally with a
key bow 8 usually of the same thickness as the original material of
the shank. While a sharp line of demarkation between the bow and
the shank is not usually defined, there can be a line 9 arbitrarily
chosen as such line of demarkation. The bow 8 sometimes is provided
with an opening 11 therethrough to serve as a hanging or ring hole.
The external configuration of the bow 8 is preferably such that the
bow extends to a substantial distance either side of the axis 7
when measured radially from the axis and so has a substantially
greater width than the predetermined width D. In some instances the
width of the bow is two to three times the width of the shank.
Although not illustrated herein, it is usual and customary to
provide on one or both of the faces of the bow and sometimes on
intermediate portions 12 of the shank 6 various indicia such as the
serial number of the key, the lock style or type, the name or
trademark of the manufacturer, the number of room the room a
building to which the key pertains, the name of the building
itself, sometimes lost key return information such as the address
of the building to which the key pertains and other, like
information related to the associated lock.
The configuration or outline of the bow may be of any desired kind
consistent with the provision of a substantial width and may
contain indicia as in standard practice or may be devoid of such
indicia. It is often the case that for manufacturing or for other
reasons and despite the presence or absence of other indicia, the
bow may be provided with a number of transverse grooves 13 or other
irregularities not as deep as the opening 11.
In any case, whether the key is virtually standard or is especially
made in accordance with the characteristics mentioned, the key of
our invention is particularly afforded a special turning pad 16.
This is conveniently an integral tablet preferably fabricated of a
plastic material having a hard, dense, non-frangible, substantially
inelastic, coherent material. The turning pad is disposed in
intimate contact with the surface of the bow, as particularly shown
in FIG. 2. The two are in closely abutting, virtually adhesive
contact with substantially no void or clearance between them. The
key and the pad have substantially the same coefficient of thermal
expansion.
The turning pad has an outline 17, in this instance rectangular
with curved corners and extends to either side of the axis 7
substantially more than the width of the original bow. Preferably,
the pad extends to a transverse location on the bow at the line 9.
The pad is extended also in length and thickness beyond the normal
bow. The entire bow is encased in the turning member and is
extended in height (or length) and width and thickness by the
turning member. The extent of the turning member is sufficient to
establish a pair of widely spread and elongated torque zones 18 and
19 on the pad on opposite sides of the center line 7 or shank 6.
These zones are provided not only on the obverse face of the
turning pad, but on the reverse side thereof as well. This is for
the reason that a person exerting the additional torque now
required to operate high security locks has additional area over
which to distribute finger pressure and has more than the usual
grip or purchase or leverage on the turning pad. The user also is
protected from what sometimes are relatively sharp ridges or
projections on the key bow, more noticeable when high turning
effort must be used.
The material of the turning pad, being quite hard is readily given
and retains a surface that is preferably planar and very
smooth.
A convenient way of depositing the pad material in intimate contact
with the bow is to mold the plastic material in the indicated
position. Sufficient material is used so that any grooves such as
13 on the key bow and any openings such as 11, as well as any
raised or incised indicia are well covered by the pad material.
There is, in effect, an interlock between the turning pad and the
key bow.
Even when the key bow is initially smooth and plain, devoid of
indicia and devoid of an opening, the turning pad material is so
intimately associated therewith that a firm, permanent
interengagement is afforded. This is particularly important since
in some of the earlier devices separate layers are attached to the
key bow. Some play or motion may then result and this becomes
aggravated in time. The clearance spaces afford places for the
retention of lint, dirt, grease and the like. The key bow portion
may eventually become quite unsightly. In the present instance, the
configuration and surface of the turning bow are smooth and hard so
as to resist soil and grease, or the like. The new pad does not
retain a static charge. Particles do not adhere. The pad material
chosen is preferably repellent to such extraneous coatings.
Furthermore, it is feasible to provide a turning pad of material
that is of low conductivity thermally and electrically. The normal
metal key bow conducts electricity and imparts a static shock to
the user and may under variant temperatures feel either hot or
clammy. With the turning pad, the bow is insulated and no
electrical or thermal shocks are transmitted to the user.
The turning pad is likewise made of relatively stiff material. Some
of the prior art key covers are limp or flexible for excellent
reasons in their environments but the provision of yielding covers
or bows in keys for building or dwelling locks of high security
makes operation difficult and after a short period of use often
results in a permanent curvature or set or cracking in the key bow.
This is quite undesirable. In the present instance, the pad is made
of relatively hard and stiff material. This may tend sometimes to
be brittle. But since the torque zones 18 and 19 or pressure zones
are disposed largely over the outer extremities of the metallic key
bow, the turning pad is substantially supported and reinforced. The
pad is not subjected to bending or yielding under torque and so is
protected from cracks that might spoil it.
In addition, the provision of the turning pad as a later-added, but
integral item permits the manufacture and handling of the metallic
portion of the key by standard equipment and standard mechanism
without change. It is possible in this way easily and without
expenditure for substantial new equipment to make a key bow of any
desired new size and shape and having substantial advantages. This
is particularly true when the key turning pad is made of opaque
material and is put on keys already having indicia thereon, since
then the indicia are hidden and do not appear to the ordinary
observer.
In a few instances there are indicia which it is desired to show.
As particularly illustrated in FIGS. 3 and 4, the arrangement is
precisely as described in connection with FIGS. 1 and 2, except
that on one or perhaps both faces of the turning pad the bow area
is not entirely opaque. There may be an open window 21, as shown in
FIG. 3. Or, the window may be filled with a clear plastic material
so that the surface is quite smooth and coplanar. In either case an
indicium 22 such as a trademark on the key bow can easily be
discerned.
Alternatively, as shown particularly in FIGS. 5 and 6, the material
of the key bow 23 can be provided in relief to afford a plateau 24
upstanding from the general plane of the key bow. This is
surrounded by the material 26 of the turning pad. In this instance,
it is easy to stamp numbers or other characters, if desired, on the
plateau 24 without affecting any other portion of the key bow.
Alternatively, the plateau may have the shape of letters or other
indicia.
In many instances the pad can be left imperforate, as shown in some
of the figures, but if desired an opening 27, as shown in FIG. 5,
can be provided, preferably in an area clear of the underlying
metal key bow.
* * * * *