Method Of Reproducing Flat Keys And Tools Used To This End

Abstract

This invention relates to a method of reproducing flat keys according to their number and code, and tools used to this end, wherein a number of gauges equal to the number of the notches of the key are successively reproduced, each of these gauges having a single notch whose shape, depth and relative distance correspond to those of the key to be reproduced.

Description

The invention relates to a method of reproducing flat keys according to their number and code, and to tools used to this end.

Flat keys are those obtained by cutting out from a strip of metal and which are used in many locks, particularly in those used in almost all motor vehicles.

In this type of key, the part intended for penetration into the lock generally comprises one or more longitudinal grooves and a plurality of notches on one side of the flat part and sometimes on both sides.

These notches are more or less deep and are made at determined distances both from the beginning of the key and between themselves.

A number of methods are known for copying the keys according to an existing model and starting from a blank, i.e., from a blank key having the suitable form but without the notches which, according to their shape and depth, permit the key to operate the lock.

Although it is relatively easy to copy a key, considerable difficulties are met with at present when a key has to be reproduced according to its number.

Even the keys of a determined series are theoretically different from each other. In order to differentiate them, the manufactures designate each key by a number. This number corresponds to a number X of notches generally separated by a determined distance which is identical for all the series, but having a depth which is different at least for one notch.

If it is considered that the absence of a notch corresponds to a zero notch depth and that nothing stops the same depth being repeated several times on the same key, the number of combinations is so great that practically all keys can be considered to be different from one another.

In order to reproduce the keys according to their number, the lock manufacturer establishes a code corresponding to a special machine which uses a cutting tool (milling tool) whose form is identical to the notch of the key. Consequently, in order to reproduce the key according to the number, in addition to the code which reproduces the number into technical data, a machine is presently required which is especially designed by the key manufacturer, and which uses cutting tools (milling tools) having the form of the notch.

The present invention provides a method of reproducing keys according to their number, using a conventional machine for reproducing keys by the pantograph process. All professionals are equipped with this machine.

The present invention provides, for reproducing a key according to its number, a set of gauges, a code indicating, according to the number, which are the gauges to be used and a conventional reproducing machine.

Consequently, the invention consists in a process of manufacturing, with gauges having determined characteristics and a code which translates the number of the key, not into technical data but into sets of gauges.

The invention will be described in greater detail with reference to the accompanying drawings in which:

FIG. 1 is a view of a gauge, generally made of steel, where I represents the notch and 2, 3 and 4 reference faces.

FIG. 2 is a diagram of a machine for reproducing keys by the pantograph system.

In this Figure, 1 represents the milling cutter having an angle smaller than the smallest of the angles to be reproduced, 2 represents the sensing member, 3 the vice or support for the master key or the gauge 4, 4 the gauge, 5 the support of the blank, 6 the blank, 7 the outer face of the gauge-holding vice, 8 the carriage.

FIG. 3 is a section through a gauge-holding vice (3 or 5 of FIG. 2) of the reproducing machine, where 9 represents the stop inside the vice.

The notch 4a of the gauge (FIG. 1) has the same shape, depth and is located at exactly the same distance from the reference face 4b, as that of the key to be reproduced. Obviously, there will be as many gauges as there are different shapes, depths and distances from the reference face 4b, as well as their possible combinations.

According to the present invention, for reproducing a key according to its number, it should firstly be sought in the pre-established code which are the gauges which correspond to the number of the key. If the key has, for example, five notches, five gauges will also be found.

Then, one of the gauges is placed, in any order, in the vice 3 (FIG. 2) by pressing the reference face 4c (FIG. 1) of said gauge against the face of the vice 7 (FIG. 2) whilst simultaneously ensuring that the reference face 4d (FIG. 1) is indeed against the reference face 9 of the vice (FIG. 3). Once the gauge is tightened by the vice in this position, the carriage (FIG. 2) is moved to cause the gauge 4 to bear against the sensing member 2 (FIG. 2) ensuring that the outer face of the sensing member bears against the reference face 4b of the gauge (FIG. 1). The blank 6 (FIG. 2) is placed in the vice 5 (FIG. 2), care being taken that the rear face of the blank abuts against the stop 9 (FIG. 3) and that the face 6b indicating the beginning of the blank abut against the outer face of milling cutter 1 (FIG. 2). In this position, the vice 5 is tightened. By actuating the carriage 8, the notch 4a (FIG. 1) of the gauge is reproduced in the blank 6 (FIG. 2).

Once this notch is reproduced, the carriage is disengaged from the milling cutter and is taken to the rest position. In this rest position, the gauge 4 (FIG. 2) is replaced by any other gauge of the set chosen, care being taken to place it in the same position, i.e., face 4d of the gauge (FIG. 1) against the reference face 9 of the vice 3 (FIG. 3) and the rear face 4c of the gauge (FIG. 1) against the face 7 of the vice 3. Thus the notch of the new gauge is reproduced by repeating the operation five times, if there are five gauges. The key will therefore be reproduced according to its number.

Claims

What is claimed is:

1. A method of reproducing a flat key from a blank according to number by the use of a set of gauges, in a conventional machine for reproducing keys by the pantograph process, said machine comprising a milling cutter, a gauge vice and a blank vice, said vices being mounted on a carriage in fixed relationship to each other, each vice being provided with at least two reference surfaces, a sensing member in fixed relationship to said cutter, each said gauge having at least two reference surfaces for locating a notch thereon of the shape and depth of the notch to be reproduced, the total number of gauges corresponding to the total number of notches to be reproduced on said blank, each blank having at least two reference surfaces, said method comprising the steps of: translating said number by means of a pre-established code into the specific gauges to be used to comprise said set of gauges; placing and securing one of said gauges in said gauge vice with said reference surfaces of said gauge and of said gauge vice collocated; placing and securing said blank in said blank vice with said reference surfaces of said blank and said blank vice collocated; moving said carriage so as to cause the gauge to bear against said sensing member and simultaneously causing said milling cutter to engage said blank; reproducing the notch of said gauge on said blank; disengaging the gauge from the sensing member and simultaneously disengaging said blank from said cutter; and replacing said gauge successively with each of the other gauges of said set and repeating the step of placing and securing each said other gauges in said gauge vice, causing the gauge to bear against said sensing member and said cutter to engage said blank, thereby reproducing the notch of each gauge successively on said blank.