Tools – Wrench – screwdriver – or driver therefor – Slidable jaw adjustments
Reexamination Certificate
1999-07-29
2001-05-01
Smith, James G. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Slidable jaw adjustments
C081S165000
Reexamination Certificate
active
06223631
ABSTRACT:
The monkey wrenches consist in a set built up of a fixed clamp that forms a body of one only piece with the tool handle and a mobile jaw that is moveable in approach and separation regarding the mentioned fixed clamp, this mobile jaw is provided with a toothed rack, with which it engages a drive worm that is mounted in such a way it can turn freely on a shaft.
Conventionally, the mentioned drive worm is disposed on a rigid metallic shaft, incorporating, in one end of the worm housing, a pusher spring, so as to avoid this way the axial looseness of the worm. The movable jaw remains nevertheless with a certain looseness in the gear with regard to the worm, which causes undesirable noises when moving the key.
To avoid that problem of the looseness of the mobile jaw, a solution is known. It consists in preparing the drive worm divided into two axially consecutive parts, with a reduction of the separation between the fillet carvings of the gear thread with the mobile jaw, in the area of the mentioned worm division, with which, by virtue of the pushing of the spring, which eliminates the axial looseness the contact of the lateral parts of the fillets of the threading of one of the two parts of the worm components is produced, against the lateral faces of the rack teeth of the mobile jaw, avoiding with it the looseness of the mentioned mobile jaw. The execution and assembly of this solution is however complicated, being it moreover expensive to carry out the worm in two independent pieces.
A solution is also known to allow the separation of the drive worm regarding the gear with the mobile jaw, so as to allow the quick movement of the mentioned mobile jaw; in the way it is indicated in the U.S. Pat. Nos. 1,402,686 and 2,724,301. With this same concept, the Chinese patent 92242425 offers a solution according to which a helical spring is disposed as the shaft of the worm. It is compressed between two extreme balls that support against some inclined planes, with which, when pulling at the worm in the sense of their separation with respect to the rack of the mobile jaw, the sliding of the extreme balls of the shaft along the inclined supporting planes, makes that the spring that forms the shaft is compressed axially at the same time as it moves together with the worm in the separation sense respect to the rack of the mobile jaw, allowing this way the liberation of the mobile jaw with regard to the worm.
French Patent 2.126.534 discloses a solution in which the worm is forced by a flexible element to be always in engagement with the rack of the mobile jaw; this flexible element allowing that the worm may be pushed out of engagement with the rack (
3
).
In all the embodiments already known, the construction is in fact expensive and the assembly really difficult. Furthermore, in order to avoid that the worm is moved excessively in transverse direction, the flexible element must be complemented with a shaft, which is in fact formed in the support of the worm.
In accordance with the present invention a key is proposed which adopts a new assembly solution for the drive worm, to be able to join the two previously mentioned functions, eliminating the looseness and with the possibility to liberate the mobile jaw, obtaining some more advantageous constructive and functional characteristics than with the solutions up to now developed.
The new solution consists in preparing the drive worm on a flexible shaft of elastomer material, according to an assembly disposition so that this shaft, because of its flexion, pushes the mentioned drive worm towards the mobile jaw.
This way, a radial pressure of the drive worm is reached, against the mobile jaw, which, in combination with the inclination of the flanks of the teeth and the gear threads between both pieces, cancels the slackness of the gear, reaching this way a certain fixation of the mobile jaw, so that undesirable noises do not take place.
The own flexibility of the shaft allows, on the other hand that the drive worm can be moved in a forced way in the opposite sense of its pressure against the mobile jaw, thanks to the elastic deformation of the shaft.
This allows to liberate the mobile jaw from its connection with the drive worm, so as to leave this mobile jaw free from a quick displacement in the approaching or separating sense regarding the fixed clamp, with which the adjusting of the wished opening of the key is easier and quicker.
In combination with that displacement possibility of the drive worm, until the release of the gear between the worm and the mobile jaw is reached, a realization of the teeth and of the gear thread is foreseen with a lateral one according to some inclined planes, with an inclination orientated in the sense of approach of the mobile jaw towards the fixed clamp.
With it such a disposition is obtained that, by means of a simple push of the mobile jaw towards the fixed clamp, an elastic jump of the rack teeth of the mentioned mobile jaw takes place regarding the threads of the drive worm, due to the displacement in the separation sense to which the mentioned worm is subjected when sliding the inclined lateral plane of its fillets on the inclined lateral plane of the rack teeth of the mobile jaw, reaching this way a ratchet effect that allows the quick closing of the key by means of only the push of the mobile jaw towards the fixed clamp.
This particularity supposes a great advantage for the handling of the key, since it allows its quick closing for its approach to the measure of the object on which it has to act, being able to carry out that closing in an easy way, even in uncomfortable and difficult positions, since it is only necessary to push the mobile jaw towards the fixed clamp, which is executable by the user with a single hand, allowing this way the performance of the wrench in a much easier way in places where the access with both hands at the same time is difficult or impossible. It is worth pointing out in this respect that the approaching movement of the jaws is the one which particularly interests in a quick way when using the wrench, since the wrench should be prepared with a sufficiently open width, to insert it on the actuation element, on which it is adjusted once inserted; while to retreat the wrench, once carried out the performance, only a slight separation of the jaws is necessary to be able to retire the wrench without difficulty.
The liberation of the mobile jaw regarding the gear with the drive worm, by the movement of the latter, allows that this mobile jaw can even be extracted out of its housing assembly in the wrench, in combination with which a realization with the provided mobile jaw of a plane front in one of its parts and with incorporation of a toothed piece in the opposed front, in such a way that, by means of the extraction of the mentioned mobile jaw out of its assembly housing, the position of the same can be inverted regarding the fixed clamp, allowing this way the adaptation of the wrench to act on polygonal elements and also to act on cylindrical elements.
The flexible elastomer shaft of the drive worm is built up of a compact cylindrical body of a diameter in correspondence with the assembly housing of the wrench, being the fixed disposition of the mentioned shaft foreseen in a preferable way by means of the gluing of its ends in the assembly housing; although also, without modifying the essential of the invention, the mentioned shaft body can incorporate a threaded head in a solidary way joined in one end, for the fastening by means of a threaded assembly in the corresponding housing.
The shaft body can moreover incorporate, in an optional way, inside the elastomer material, reinforcements with the help of bars or metallic plates, by means of which at the same time the flexion strength of the mentioned shaft can be reinforced.
In view of all this, the mentioned monkey wrench object of the present invention indeed has some very advantageous characteristics as compared to the conventional monkey wrenches.
REFERENCES:
patent: 1402686 (1922-01-01), Trabold
patent: 2724301 (1955-11-
Nath Gary M.
Nath & Associates PLLC
Novick Harold L.
Smith James G.
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