U.S. patent application number 09/729706 was filed with the patent office on 2001-06-07 for flat key.
Invention is credited to Schwab, Dittmar.
Application Number | 20010002544 09/729706 |
Document ID | / |
Family ID | 7931635 |
Filed Date | 2001-06-07 |
United States Patent
Application |
20010002544 |
Kind Code |
A1 |
Schwab, Dittmar |
June 7, 2001 |
Flat key
Abstract
The invention relates to a flat key having a grip element (2)
and a key bit (3), the grip element (2) including a casing (4) and
the key bit (3) being arranged in a manner enabling it to be moved
into and out of the grip element casing (4) and to be fixed in its
respective extreme position. In order to provide a flat key (1)
with an axially displaceable key bit (3) which has an inexpensively
manufactured drive and requires relatively small dimensions, the
invention proposes that a spring (7) --preferably a scroll
spring--be disposed as the drive in the grip element casing (4),
the two end zones (8, 9) of said spring each being wound spirally
onto two holders (10, 11) arranged at the side of the key bit (3).
The central zone (12) of the spring (7) rests against a support
(13) on the end of the key bit (3) that is situated inside the grip
element casing (4), with the result that when the key bit (3) is
inserted into the grip element casing (4) the spring (7) becomes
uncoiled from the holders (10, 11) and thus tensioned.
Inventors: |
Schwab, Dittmar; (Rodgau,
DE) |
Correspondence
Address: |
Longacre & White
6550 Rock Spring Drive-Suite 240
Bethesda
MD
20817
US
|
Family ID: |
7931635 |
Appl. No.: |
09/729706 |
Filed: |
December 6, 2000 |
Current U.S.
Class: |
70/456R |
Current CPC
Class: |
A45C 11/328 20130101;
Y10T 70/7876 20150401; E05B 19/046 20130101; Y10T 70/8676
20150401 |
Class at
Publication: |
70/456.00R |
International
Class: |
A44B 015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 7, 1999 |
DE |
19958819.8 |
Claims
What is claimed is:
1. Flat key having a grip element (2) and a key bit (3), the grip
element (2) including a casing (4) and the key bit (3) being
arranged in a manner enabling it to be moved into and out of the
grip element casing (4) and to be fixed in its respective extreme
position, and incorporating the following features: a) the key bit
(3) is mounted in the grip element casing (4) in an axially
displaceable manner; b) arranged in the grip element casing (4) is
a spring (7), the two end zones (8, 9) of which are each wound
spirally around two holders (10, 11) arranged at the side of the
key bit (3) and the central zone (12) of which is arranged on a
support (13) for the end of the key bit (3) that is situated inside
the grip element casing (4), thereby uncoiling and thus tensioning
the spring (7) when the key bit (3) is being inserted into the grip
element casing (4).
2. Flat key according to claim 1, wherein said spring (7) is a
scroll spring.
3. Flat key according to claim 1 or 2, wherein said spring holders
(10, 11) are constructed as rollers against which said key bit (3)
is supported laterally.
4. Flat key according to claim 2, wherein said rollers (10, 11)
consist of rubber or plastic, at least in the zones in which said
key bit (3) rests against them.
5. Flat key according to any of claims 1 to 3, wherein said support
(13) for said key bit (3) consists of a peg-shaped element about
which the central zone (12) of the spring (7) is externally
wound.
6. Flat key according to claim 5, wherein said grip element casing
(4) incorporates a slot-shaped recess (16) extending in the
longitudinal direction (15) of the key (1), into which recess (16)
the peg-shaped element (13) projects and is guided in a positive
manner as said key bit (3) is being displaced.
7. Flat key according to claim 4, wherein said peg-shaped element
(13) incorporates a recess (17) in which there is mounted a
displaceably arranged, spring-loaded pin (18) which in the two
extreme positions of the key bit (3) engages positively in a
corresponding recess (19, 20) in said grip element casing (4).
8. Flat key according to claim 5, wherein at least one actuating
element (21) adapted to be pressed from the outside is arranged on
said grip element (2), which actuating element (21) operates on
said pin (18) in such a manner that when pressure is exerted on the
actuating element (2) said pin (18) can be pushed out of the
respective recess (19, 20) in said grip element casing (4) and into
said recess (17) in the peg-shaped element (13), thereby rendering
said key bit (3) axially displaceable.
9. Flat key according to claim 6, wherein said actuating element
(21) is a rocker-shaped construction and in its two extreme zones
incorporates projections (22, 23) directed towards said pin
(18).
10. Flat key according to any of claims 1 to 7, wherein said grip
element casing (4) consists of two shell-type casing halves (5, 6)
adapted to be clipped onto one another, said key bit (3), said
spring (7), said spring holder (10, 11) and said actuating element
(21) being secured in only one casing half (6) and the respective
other casing half (5) serving as a cover for sealing said grip
element casing (4).
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a flat key having a grip element
and a key bit, the grip element including a casing and the key bit
being arranged in a manner enabling it to be moved into and out of
the grip element casing and to be fixed in its respective extreme
position.
[0002] Flat keys of this type have the advantage that they take up
relatively little space and that when being carried, for example in
a jacket or trouser pocket, there is less risk of injury than is
the case with flat keys having a key bit that is rigidly fixed on
the grip element.
DESCRIPTION OF THE PRIOR ART
[0003] Normally in the case of the conventional flat keys of the
prior art, the key bit is folded out from the grip element casing
via a rotary spring, and swivelled into the grip element casing
against the pressure of the rotary spring. The key bit is secured
in the respective extreme position by means of a push-button
arranged on the grip element.
[0004] The drawbacks of these known flat keys include the fact that
as a rule it is necessary to use two hands to fold down the key
bit. In addition, the key bit requires a relatively large swivel
radius when swivelling it in and out, which means that problems can
frequently arise if the key bit is swivelled out by inadvertently
operating the push-button whilst the key is in the jacket or
trouser pocket, etc. It is also easy for fingers to become jammed
when swivelling in the key bit.
[0005] From German Patent Application No. 199 12 749. 2, which is
not a prior publication, a flat key is already known on which the
key bit is mounted in the grip element casing in an axially
displaceable manner. The key bit is displaced on the one hand with
the aid of a gearwheel disposed on a head element of the key bit,
which gearwheel engages in teeth integral with the casing and
extending in the direction of the key's longitudinal axis, and on
the other hand with the help of a spring which pushes the key bit
into its withdrawn extreme position and which is pretensioned by
pushing the key bit into the grip element casing.
[0006] The primary disadvantage of this flat key is the fact that
the drive consisting of the gearwheel, the teeth and the spring is
relatively expensive to make and takes up a lot of space.
SUMMARY OF THE INVENTION
[0007] It is the object of the invention to provide a flat key
having an axially displaceable key bit which has an inexpensively
manufactured drive and relatively small dimensions.
[0008] In accordance with the invention this object is achieved by
the features of claim 1. The subsidiary claims disclose additional,
particularly advantageous embodiments of the invention.
[0009] The invention is essentially based on the concept of
arranging, as the drive in the grip element casing, a spring whose
two end zones are each wound spirally onto two holders (cores)
disposed at the side of the key bit. The central zone of the spring
rests on a support on the end of the key bit that is situated
inside the grip element casing, with the result that when the key
bit is inserted into the grip element casing the spring is uncoiled
from the cores and is thus tensioned.
[0010] The spring may be a flat coil spring, the ends of which are
respectively joined to the cores. However, in practice it has
proved more advantageous to use scroll springs rather than standard
flat coil springs, the ends of the scroll springs not being gripped
(i.e. not rigidly joined to the barrel core). Springs of this type
allow relatively flat spring load deflection curves to be achieved,
with the result that even where the key bit has a long displacement
path a uniform force operates thereon.
[0011] It has also proved to be advantageous if the cores are in
the form of rollers against which the key bit rests laterally and
is thus guided in its movement into and out of the grip element
casing, since if the flat key is configured in this manner only
minor friction forces occur between the key bit and the grip
element casing. The rollers should be made of rubber or plastic, at
least in those zones in which the key bit rests against them.
[0012] In one embodiment of the invention the support for the key
bit consists of a peg-shaped element about which the central zone
of the scroll spring is externally guided. The peg-shaped element
engages positively by its end remote from the key bit into a
slot-shaped recess extending longitudinally down the key, with the
result that the key bit is guided axially in a corresponding
fashion during its displacement.
[0013] To secure the key bit in its two extreme positions, the
peg-shaped element incorporates a recess in which is mounted a
displaceably arranged, spring-loaded pin which in the two extreme
positions of the key bit engages positively in a corresponding
recess in the grip element casing. To release the fixing of the key
bit, at least one actuating element adapted to be pressed from
outside is arranged on the grip element, said actuating element
operating on the pin in such a way that when pressure is exerted on
the actuating element the pin is pushed out of the respective
recess in the grip element casing and into the recess in the
peg-shaped element and thus the key bit can subsequently be
displaced axially.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further details and advantages of the invention will become
clear on reading the detailed description below of a preferred
embodiment, taken only as a non-limitative example, making
reference to the attached drawings of which:
[0015] FIG. 1 is a longitudinal section through a flat key in
accordance with the invention, with the key bit situated in its
extended extreme position;
[0016] FIGS. 2 and 3 are two scaled-up cross-sections through the
flat key represented in FIG. 1, taken along the lines designated
therein as II-II and III-III;
[0017] FIG. 4 shows the longitudinal section through the upper half
of the flat key, rotated through 90.degree.in relation to FIG.
1.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0018] In FIG. 1, 1 designates a flat key which is made up of a
grip element 2 and a key bit 3. The grip element 2 includes a
casing 4, into which the key bit 3 can be inserted and which
consists of two shell-type casing halves 5, 6 (FIGS. 2 and 3) made
of plastic, which are clipped together.
[0019] Arranged in the grip element casing 4 is a scroll spring 7
whose end zones 8, 9 are respectively wound spirally around two
rollers 10, 11 arranged to the side of the key bit 3 and whose
central zone 12 is guided around a peg-shaped element 13 of a head
element 14 made of plastic and joined to the grip element casing 4.
The key bit 3 rests laterally against the plastics rollers 10,
11.
[0020] The grip element casing 4 incorporates a slot-shaped recess
16 (FIG. 4) which extends in the direction of the longitudinal axis
15 of the key 1, into which recess 16 the peg-shaped element 13
projects and is guided in a positive manner when the key bit 3 is
displaced. In addition, the peg-shaped element 13 possesses a
recess 17 in which is mounted a displaceably arranged,
spring-loaded pin 18 which in the two extreme positions of the key
bit engages positively in a corresponding recess 19, 20 in the grip
element casing 4.
[0021] The flat key 1 includes a rocker-type actuating element 21
arranged externally on the grip element casing 4, which element 21
in its two extreme zones incorporates projections 22, 23 directed
towards the pin 18, said projections operating on the pin 18 in
such a manner, when corresponding pressure is exerted, that said
pin 18 can be pushed out of the respective recess 19, 20 in the
grip element casing 4 and into the recess 17 in the peg-shaped
element 13, with the result that the key bit 3 is either pushed
into the grip element casing 4 by external pressure or out of the
casing 4 by the pressure of the pretensioned scroll spring 7.
[0022] As will be immediately apparent from FIGS. 3 and 4, the key
bit 3, the spring 7, the rollers 10, 11 and the actuating element
21 are secured in only one casing half 6, with the result that all
the essential elements of the key 1 can be preassembled in said
casing half in a straightforward manner. The respective other
casing half 5 is used exclusively as a cover for sealing the grip
element casing 4.
[0023] The cavity 24 formed between the casing halves 5 and 6 is of
such a kind that in the case of an electronic locking system the
electronic components that need to be arranged in the key can be
accommodated in said cavity 24.
* * * * *