Patent Application
20130136561
This invention relates to an ice screw for forming a removable belay point, said screw comprising:
In the field of vertical sports, there are removable belay devices, notably of the ice screw type as shown in
Frequently, cutting edges 5 get blunt as bit 3 is used. In such case, a user may, as shown in
Further, the sharpening of the cutting edge oriented to face the screwing direction and that of another cutting edge of the tooth opposed to the preceding cutting edge, to delimit the top of the tooth, also allows to sharpen the top of the associated tooth in order to obtain a point.
EP 1491238 discloses an ice screw with a bit whose sharpening is complicated to perform.
SU 939891 relates to a tool for drilling a hole in ice. Such a tool does not have an elongated shaft with an external thread and is generally used by fishermen and not by mountaineers. It is to be noted that the tooth is not sharpened on the side. The sharpened area is at the bottom of the tooth.
The object of the invention is to provide an ice screw whose sharpening is made easier.
This object is neared in that a notch is formed in the bit at the base of each cutting edge in order to delimit a sharpening reserve of the associated tooth.
In an embodiment, the screw has an indicator defining en end-of-life status of said bit. The end-of-life status may be configured to be readied when the cutting edge of One of the teeth matches the bottom of the notch.
Advantageously, the cutting edge of a tooth extends from the top of said tooth to the associated notch.
The notch associated to a tooth may have a concave shape starting from the cutting edge base, opposite the top of the tooth, and ending at the base of the adjacent tooth facing the cutting edge.
In an embodiment, the bit teeth are formed in line with the shaft and each notch is formed along an axis perpendicular to the longitudinal axis of the shaft.
In particular, there may be four bit teeth angularly spaced about the longitudinal axis of the shaft so that the four notches are placed two by two respectively along a first axis and a second axis, said first and second axis being in the same plane and perpendicular to each other, said plane being perpendicular to the longitudinal axis of the shaft.
Other advantages and features will appear more clearly in the following description of particular embodiments of the invention, given by way of non-limiting examples and illustrated in the accompanying drawings, in which:
The ice screw is intended to form a removable belay point and differs notably from prior art in the shape of its bit. In point of fact, the bit is shaped so that each tooth has at its base a sharpening reserve to make easier the maintenance steps cited in the state of the art.
Thus, as in
The role of bit 3 is to assist the screw penetration in ice by drilling.
As shown in
The sharpening reserve allows to have a material reserve usable to reshape a sharp cutting edge 5 should the latter get blunt.
Advantageously, cutting edge 5 of a tooth 4 extends from the top 9 of said tooth 4 to the associated notch 8. In point of fact, base 5a of cutting edge 5, opposite the top 9, advantageously matches with an edge of notch 8. This cutting edge 5 may be delimited by a local bevel of tooth 4 forming a sharp and cutting blade on at least one side of the blade.
In a variant, the ice screw has an indicator defining en end-of-life status of said bit 3. This indicator may have any shape, for example a graduation which, when it is reached, means that bit 3 should not be sharpened anymore, and that the screw must be replaced for safety reasons. Advantageously, this end-of-life indicator may be implemented directly by notch 8 itself, thus the end-of-life status may be reached when cutting edge 5 of one of the teeth 4 matches bottom 8a of notch 8. Typically, though not shown, when a tooth 4 of bit 3 of the ice screw has been so sharpened that the entire sharpening reserve has been consumed, this leads to a situation as the one shown in
In a variant, notch 8 associated to a tooth has a concave shape, advantageously of the rounded type, starting from base 5a of cutting edge 5, opposite top 9 of tooth 4, and ending at base 4a of the adjacent tooth (
In an embodiment, teeth 4 of bit 3 are formed in line with shaft 1 and each notch 8 is formed along an axis perpendicular to longitudinal axis A3 of shaft 1. In other words, bit 3 and shaft 1 may be made in one piece.
Advantageously, in
In a particular embodiment, making easier notably the sharpening and the manufacture of the screw, two notches associated to the same first axis, or second axis, each have a circular arc shape whose circle center is located on the associated axis. Moreover, these two notches are advantageously symmetrical to the point of intersection between longitudinal axis A3 of shaft 1 and the first, or second, axis associated to said notches.
Within the context of a use as an ice screw, the tubular shaft is advantageously open at its both ends so that it forms an ice core upon screwing of the screw in ice and allows to draw out this ice core after the screw is taken out from the ice in which it was screwed.
The notch formed at each tooth allows to make easier the sharpening with a file on the entire cutting edge height. Moreover, the notch allows to clearly indicate a sharpening limit of the screw.
As described, bit 3 allows to drill ice, for example during the climb of an ice fall. Thus, bit 3 cooperates with thread 2 when screwing the screw in ice. The cutting edges, associated to the notches, of the different teeth are thus advantageously all oriented in the screwing direction of the ice screw by its end with bit 3.
Advantageously, in the drawings, the internal surface of the tube forming shaft 1 is delimited by a rotational body obtained by the rotation of a straight line about longitudinal axis A3 of tubular shaft 1.
Although a tooth with one cutting edge has been described, the tooth may have several cutting edges. For example, in
| Number | Date | Country | Kind |
|---|---|---|---|
| 1103633 | Nov 2011 | FR | national |
