Animal husbandry – Animal controlling or handling – Hitching or tethering
Reexamination Certificate
2002-02-15
2003-03-04
Jordan, Charles T. (Department: 3644)
Animal husbandry
Animal controlling or handling
Hitching or tethering
Reexamination Certificate
active
06526918
ABSTRACT:
This invention relates to a retracting leash for dogs, which supports in a housing a cable drum, which is under tension in the winding-up direction and is connected coaxially with a gear wheel and for which a pawl stop, having a stop at the housing, is provided for blocking the rotation of the gear wheel in one direction.
A retracting leash for dogs of the above type is the object of U.S. Pat. No. 3,693,596. For the retracting leash for dogs, described in this publication, two oppositely acting pawl stops are provided, which can be made active alternatively by actuating a lever.
The pawl stops each have a spring-loaded pawl, which reaches the gearing, for which the gear wheel is rotated in one direction and ratchets over the gearing wherein it is rotated in the other direction. It is a disadvantage of such pawl locking mechanism that, in the releasing direction of rotation, the locking pawl ratchets over the gearing and generates relatively much noise, which is highly disturbing for retracting leashes for dogs. Moreover, due to the ratcheting of the locking pawl over the gearing, there is wear of the gear wheel and of the locking pawl. Quite apart from this, in the case of a retracting leash for dogs with a locking pawl, the return spring would have to be relatively strong, in order to be able to overcome the friction of the locking pawl. As a result, the retracting leash for dogs would be undesirably sluggish.
EP 0 488 074 A1 also shows a cable drum for an electric cable, for which the pawl stop has a friction wheel, the shaft of which is held movably in a groove in such a manner that, when the direction of rotation is reversed, the friction wheel automatically reaches a position, in which the cable drum is blocked unless a push button is depressed.
SUMMARY OF THE INVENTION
It is an object of the invention to develop a retracting leash for dogs of the type above, which operates with as little noise and as little friction as possible and is subject to little wear. Furthermore, the possibility of an unintentional unloading of the retracting leash for dogs is to be precluded.
Pursuant to the invention, this object is accomplished owing to the fact that the pawl stop is formed by a pinion, which meshes with the gear wheel and has a shaft, which is mounted displaceably in a guide of the housing, extending at least approximately coaxially to the axis of rotation of the gear wheel, and that the pinion or a pawl, connected with the pinion, in an end position of the shaft, lies against a stop at the housing, yet is held freely rotatable when the shaft is shifted in the opposite direction and that means, acting counter to the force of a spring, are provided for separating the stop and the pinion.
In the case of such a retracting leash for dogs, the pinion cannot rotate freely in one direction of rotation of the gear wheel. It therefore does not cause any noise and does not lead to increased wear. If the direction of rotation is reversed, the shaft of the pinion moves into such a position, that the pawl comes up against the stop at the housing and the gear wheel is blocked reliably by these means. The blocking principle of the previously customary retracting leash for dogs, for which the blocking action is achieved by depressing a pushbutton, is reversed by the invention. If the inventive retracting leash for dogs is held merely at the handle, it is ensured that the leash cannot be unwound from the cable drum. If the dog deliberately is to be granted more space to roam, the slide must be shifted against the force of the spring. Accordingly, the invention ensures that the dog cannot suddenly run off and distance himself from the person holding the inventive leash. In addition, the inventive retracting leash for dogs has the advantage that, for fetching the dog, it is only necessary to move the part, held by hand, repeatedly in the direction of the dog and back. In so doing, the leash is rolled up correspondingly and cannot be unrolled once again unless the push button is depressed.
In a structurally particularly simple embodiment, the stop is provided at a slide, which protrudes partly from the housing and is disposed so that it can be shifted by guides against the force of the spring from a blocking position into a position, in which the pinion is released.
Alternatively, it is, however, also possible that the shaft protrudes out of the guide of the housing, so that it can be shifted manually.
If large forces act on the retracting leash for dogs, a further development of the invention is advantageous, for which there are two gear wheels, which are disposed parallel to one another, and two pinions, which are disposed correspondingly parallel to one another and for which the pinions are connected with one another by a cylinder having a pawl. By these means, space is gained for a pawl, the width of which corresponds to the mutual distance between the gear wheels, and a correspondingly wide stop, so that particularly high forces can be transferred in the blocked position and the pawl does not break off even when it strikes against the stop at a relatively high speed.
The safety function, which prevents an unintentional unrolling of the leash, can be canceled temporarily if a manually operated stopper for blocking the slide, having the stop, is disposed at the housing in a position in which the pinion is released.
The teeth of the pinion and of the two gear wheels are able to withstand particularly high forces if, in accordance with a further development of the invention, the pinions and the gear wheels in each case on one side of their teeth have a disc, which is connected at the front side to the teeth.
REFERENCES:
patent: 3693596 (1972-09-01), Croce
patent: 3853283 (1974-12-01), Croce et al.
patent: 3937418 (1976-02-01), Critelli
patent: 4762089 (1988-08-01), McNulty
patent: 5377626 (1995-01-01), Kilsby et al.
patent: 5887550 (1999-03-01), Levine et al.
patent: 0 464 725 (1991-06-01), None
patent: 0488074 (1992-06-01), None
Crowell & Moring LLP
Jordan Charles T.
Smith Kimberly S.
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