U.S. patent application number 10/275447 was filed with the patent office on 2003-08-07 for retractable leash for animals.
Invention is credited to Muller, Roland.
Application Number | 20030145803 10/275447 |
Document ID | / |
Family ID | 7941030 |
Filed Date | 2003-08-07 |
United States Patent
Application |
20030145803 |
Kind Code |
A1 |
Muller, Roland |
August 7, 2003 |
Retractable leash for animals
Abstract
The invention relates to a retractable leash for animals, having
a housing containing a spring-biased reel in which the remaining
length of leash can be taken up and which is stoppable by means of
an actuating mechanism. A retractable leash of this kind is
improved according to the invention by means of a device for
adjusting the maximum extension length of the leash as required,
and by providing for the slack section of the leash to be taken up
automatically by the reel when this maximum extension length is not
being used. This ensures that the leash is always taut without
restricting the animal's freedom of movement unnecessarily.
Inventors: |
Muller, Roland; (Gersheim,
DE) |
Correspondence
Address: |
HENRY M FEIEREISEN, LLC
350 FIFTH AVENUE
SUITE 4714
NEW YORK
NY
10118
US
|
Family ID: |
7941030 |
Appl. No.: |
10/275447 |
Filed: |
November 4, 2002 |
PCT Filed: |
May 3, 2001 |
PCT NO: |
PCT/DE01/01662 |
Current U.S.
Class: |
119/796 |
Current CPC
Class: |
A01K 27/004 20130101;
B65H 75/4431 20130101 |
Class at
Publication: |
119/796 |
International
Class: |
B65H 075/34 |
Foreign Application Data
Date |
Code |
Application Number |
May 5, 2000 |
DE |
20 08 014.8 |
Claims
1. A retractable leash for animals, having a housing (21a,b)
containing a spring-biased reel (1a,b) in which the remaining
length of the leash (11) can be taken up and which is stoppable by
means of an actuating mechanism (6), wherein the maximum extension
length of the leash (11) can be adjusted as required by means of a
device, and the slack section of the leash can be taken up
automatically by the reel (1a,b) when this maximum extension length
is not being used.
2. The device of claim 1, wherein means are provided with which
further retraction of the leash (11) is preventable once a certain
retraction speed is reached.
3. The device of claim 1, wherein means are provided with which
further retraction is preventable once the tension in the leash
(11) falls short of a predefined value.
4. The device of claim 1, wherein means are provided with which
further retraction of the leash (11) is preventable once a
predefined retraction acceleration is reached.
5. The device of claim 1, wherein means (13, 14) are provided for
indicating the amount by which the leash (11) can still extend
before the set maximum length is reached.
6. The device of claim 1, wherein a means (30) is provided with
which a sudden, jerk-like increase in the external pulling force in
the leash (11) is preventable.
Description
[0001] This invention relates to a retractable leash for animals,
having a housing containing a spring-biased reel in which the
remaining length of leash can be taken up and which is stoppable by
means of an actuating mechanism.
[0002] Compared to conventional leashes, retractable leashes have
the advantage that they automatically wind up excess leash on a
spring-biased reel. If desired, the length to which the leash can
extend can be set temporarily by actuating a key. By actuating
another push-to-lock key, the length to which the leash extends can
be set permanently. The advantage of setting a permanent leash
length is that the leash will be halted at the set length without a
key having to be actuated. The disadvantage, however, is that the
leash no longer winds up automatically. If the length to which the
leash is extended falls short of the length set, the leash will
drag on the ground and may get dirty. Moreover, the animal or the
person in charge of it can get their legs caught up in the leash,
or, since a leash dragging on the ground may be difficult to
detect, passers-by may trip over it.
[0003] The DE 85 09 585 U1 describes a device which seeks to
overcome the disadvantages described above. In this publication,
the basic problem was recognized and an initial approach to solving
it is described. With this device, the extension length of the
leash can be additionally limited to one particular length
predetermined by the design. For example, as is described in this
publication, the extension can be limited to about half the leash
length. This limitation, however, is dependent on the wind-up
diameter of the spring-biased winding reel, which means that the
accuracy of the limitation is determined by the number of layers of
leash on the reel. Depending on the kind of leash cord, one layer
corresponds to about one meter of unrolled leash. If the leash does
not roll up on the reel in strictly parallel windings, but in
superposed windings, the length of leash that can be extended can
vary by one to two meters. The device is designed in such manner
that the pawl described in the publication engages when the given
length of leash has been released, thus halting any further
release. However, on account of the hysteresis (difference between
engaging and disengaging) inherent in the design, the leash must
roll up by at least two layers, i.e. it must retract by about two
meters, before the pawl disengages again and falls back into its
initial position.
[0004] All in all, the described device has three major
disadvantages. Firstly, only one intermediate leash length can be
activated, which makes handling very inconvenient; after all, it's
a serious disadvantage if a leash measuring, say, 7 m in length,
can only be set to a single intermediate length. Secondly, even
this set length is subject to unpredictable and strong variation
depending on the way the leash winds up on the reel. This is
something the person in charge cannot influence. Accordingly, he or
she cannot rely on the leash's always blocking after the same
length of leash has been released. Particularly in town, this can
lead to an incalculable risk. The third disadvantage is that the
leash must retract (roll up) by a considerable amount in order for
the locking mechanism to disengage and allow the leash to be
released anew and stopped again when necessary. In practice, this
is contrary to the intended purpose of a retractable leash, which
is to allow the animal as much freedom of movement as possible, and
not to have to train it to behave in a certain way before it can be
taken for a walk on this kind of leash.
[0005] Sometimes an animal will bite through its leash close to its
point of attachment. The leash will then retract at very high
speed, with a danger of its loosely-jerking free end injuring
anyone nearby. At any rate, the leash will wind completely onto the
spring-biased reel and will no longer be accessible from outside
the housing.
[0006] To restore the leash to working order, the entire housing
has to be opened up. The reel's spring has to be tensioned again,
and the housing then reassembled part by part.
[0007] If the leash is not preset with a key, animals will often
bound away too quickly for the person in charge to stop them. They
may cover several meters--for example to chase after another
animal--before they are stopped. This can lead to unpredictable,
dangerous situations. The abruptness with which an animal is
stopped in such a situation, moreover, poses the risk of neck
injuries to the animal, with potentially serious consequences.
[0008] The object of this invention is thus to create a retractable
leash that does not have these disadvantages.
[0009] This object is established according to the invention by
means of a device for adjusting the maximum extension length of the
leash as required, and by providing for the slack section of the
leash to be taken up automatically by the reel when this maximum
extension length is not being used.
[0010] This ensures that the leash is always taut without
restricting the animal's freedom of movement unnecessarily.
[0011] A further development of the invention consists in the
provision of means with which further retraction of the leash is
preventable once a certain retraction speed is reached.
Alternatively, means can be provided with which further retraction
of the leash is preventable once the leash tension falls short of a
predefined value.
[0012] It is expedient to provide means with which further
retraction of the leash is preventable once a predefined retraction
acceleration is reached.
[0013] It is furthermore within the scope of the invention to
provide means for indicating the amount by which the leash can
still extend before the set maximum length is reached.
[0014] It is also beneficial to provide means which prevent a
sudden, jerk-like increase in the external pulling force when the
leash is halted automatically.
[0015] Embodiments of the invention will now be described by
referring to the drawings.
[0016] FIG. 1 and FIG. 2 are exploded views of a retractable leash
assembly according to the invention,
[0017] FIG. 3 and FIG. 4 show the same leash assembly with the
housing opened;
[0018] FIG. 5 shows the same leash assembly with the housing
closed;
[0019] FIG. 6 shows a further development of the opened leash
housing, with an alternative, tension-based brake.
[0020] The device of the invention is preferably contained in a
housing (21a, 21b) with a handle, from which housing the end of the
retractable leash (11) projects, said end being provided with a
toughened, chewable strap (30) and an attachment clip (31). The
leash (11) is wound up on a reel (1a,b) inside the housing (21a,
21b).
[0021] As is evident from the drawings, a gearwheel (2) is mounted
parallel to the reel (1a,b) onto which the leash (11) is wound. The
gearwheel (2) has approximately the same diameter as the reel
(1,b), with which it is releasably connected in a certain
transmission ratio via another gearwheel (3). The connection is
released by means of pressure on a lever (4a,b). As soon as
pressure on the lever (4a,b) causes the gearwheel (3) connected
therewith to disconnect the reel (1a,b) from the gearwheel (2), the
gearwheel (2) is restored by means of a spring (10) to a position
defined by a limit stop (7a,b). If, with the gearwheel (2) in this
position, the lever (4a,b) is released again in order to
reestablish the connection between the gearwheel (2) and the reel,
the leash (11) cannot be pulled out further because the gearwheel
(2) is located at its limit stop (7a,b), thus increasing the
external pulling or extension force in the leash (11). This in turn
causes more force to be exerted on the deflector roll (5) of the
stop key (6), so that the latter is urged towards the centre of the
reel (1a,b). If the external pulling force is great enough, the
stop key (6) will connect firmly with the reel (1a,b) and prevent
any further extension of the leash (11).
[0022] If the pulling force lessens, the connection between the
stop key (6) and the reel (1a,b) is released, and the leash (11) is
wound up by the reel (1a,b). In this case, the gearwheel (2) moves
away from its limit stop (7a,b) and thus does not influence further
functioning of the retractable leash assembly (20). Not until the
leash (11) is extended again and causes the gearwheel (2) to reach
its limit stop (7a,b) will the leash (11) be halted again. In this
way, it is ensured that even when just a small length of slack in
the leash (11) is retracted (wound up), and the leash is then
extended again, it will be stopped exactly at the previously set
position.
[0023] To prevent the leash (11) from being wound up completely by
means of the spring-biased reel (1a,b)--in which case it would
disappear into the housing and no longer be accessible--if an
animal bites through the leash (11) or if the leash breaks as a
result of a weak point, it is suggested according to the invention
that when the retraction speed of the leash (11) reaches a certain
maximum, further retraction is halted. This is effected by means of
centrifugal masses (8) that work in opposition to spring force. As
the speed at which the leash retracts increases, the diameter of
the centrifugal masses (8) also increases, such that the freely
movable part of the centrifugal masses (8) finally connects with
the inside stop-motion means (15) of the gearwheel (2) and thus
prevents any further retraction of the leash (11). If the leash
(11) is now pulled out again, the centrifugal masses (8) disconnect
from the gearwheel (2), and the retractable leash assembly (20) can
operate again in the normal way.
[0024] An alternative suggestion consists in a device of the kind
shown in FIG. 6, which prevents further retraction of the leash
(11) when the tension in the leash falls short of a predetermined
value. This is effected by having the leash (11) pass over the
underside of a centrally mounted deflector lever (22) which is
spring-biased in opposing direction and whose upper side engages
the toothing of the reel (1a,b). If the leash (11) is pulled out
again, the tension that develops in the leash opposes the spring
bias of the deflector lever (22). As a result, the deflector lever
disengages from the reel (1a,b), and the retractable leash assembly
(20) can operate again in the normal way.
[0025] As a further alternative, the spring-biased stop key (6) can
itself halt the reel (1a,b) and thus prevent further retraction of
the leash (11), which passes over the deflector roll (5) of the
stop key (6), when the tension in the leash falls short of a
predetermined value. This is effected in that the stop key (6)
moves away from the centre of the reel (1a,b), as a result of which
a portion of the stop key (6) engages the reel (1a,b) from the
inside.
[0026] To prevent an animal jerking away from the person in charge,
the invention provides for a device which actuates the stop key (6)
and thus prevents further release of the leash (11) when the
extension acceleration of the leash (11) reaches a predefined
maximum. This is effected in that, at a certain rotational
acceleration of the reel (1a,b) biased by means of a spring (9),
the external pulling force in the leash (11), which is reoriented
via over the deflector roll (5) in the stop key (6), becomes
greater than the force in the restraining spring (12) of the stop
key (6). As a consequence, the stop key (6) connects with the reel
(1a,b) and thus prevents the leash (11) from being extended
further. If the distance between the animal and the person in
charge lessens, the external pulling force in the leash (11)
decreases and the restraining spring (12) pulls the stop key (6)
back to its initial position, thus disconnecting the stop key (6)
and the reel (1a,b). The retractable leash assembly (20) can then
operate again in the normal way.
[0027] To prevent a sudden, jerk-like increase in the external
pulling force when the preset leash length is reached and the leash
(11) is halted automatically by the device of the invention, as a
result of which the animal's health can be impaired by injuries to
the neck region, the chewable strap (30) that connects the windable
section of the leash (11) with the attachment clip (31) on the
animal's collar, is made of a material which remains elastic until
it reaches a predetermined final length. This solution is not only
beneficial but also economical, since most commercially available
retractable leashes already have a chewable strap (30) and this
would simply need to be made of a different material which, at
least initially, has elastic properties.
[0028] The amount of leash (11) that can still be released is
indicated according to the invention by providing a window (13) in
the housing section (21a), through which part of the gearwheel (2)
is visible. The outer side of the gearwheel (2) is divided up into
defined colored zones (14). The zoning can, for example, be in the
form of a "red-yellow-green" sequence, with the red zone
corresponding approximately to the size of the window.
[0029] When the lever (4a,b) is pressed, the gearwheel (2) rotates
until it reaches its limit stop (7a,b). In this position the entire
red zone is visible. After the lever (4a,b) has been released, the
leash (11) is free to extend to the predefined maximum length. When
the entire red zone is visible, the leash (11) has been extended to
this maximum. If the distance between the animal and the person in
charge lessens, the window will first show "red-yellow", followed
by "yellow", "yellow-green" and finally "green". The different
color zones can correspond to certain extension lengths. For
example, red can correspond to an extension length of 0.5 m, yellow
to an extension length of 1 m, and green to the remaining leash
length. It is thus easy for the person in charge to see when the
leash (11) has been extended to its temporarily set maximum length,
or how much further away the animal can still go before the
retractable leash assembly (20) will stop it.
* * * * *