CODE DUPLICATOR PARTIAL SILHOUETTE METHOD

Abstract: This invention relates to a method of reproducing a coded reference key by assembling a number of partial reference key silhouettes. The partial reference key silhouettes are prepared by cutting various vertical depths of cut at various horizontal key shank positions. Each partial reference key silhouette may have one (or more) vertical depths of cut at one (or more) horizontal key shank positions. Supplying a coded reference key silhouette by assembling a number of partial reference key silhouettes greatly increases the efficiency of reproducing a standard key for a lock whose coded depths and shank position cuts are known. The reference key silhouettes comprise a head (1) and a key shank (2). The horizontal key shank positions are numbered one through five from the head to the tip of the shank. Various depths of cut from a number nine cut (the deepest vertical cut) to a number one cut (the shallowest vertical cut) are made in the partial reference key silhouettes. These partial reference key silhouettes may then be assembled and placed in a standard key cutting/reproducing machine. The key cutting machine reproduces the desired reference key silhouette on a blank key thus reproducing the required reference key for use in the known coded lock. A locksmith may reproduce coded reference keys easily and economically by use of the partial reference key silhouette method.

Description: CODE DUPLICATOR PARTIAL SILHOUETTE METHOD I. TECHNICAL FIELD This invention relates to the field of locksmithing and mor particularly to the area of master keys and coded reference ke silhouettes. The invention described herein find its use i duplicating keys for a lock when the original key for the loc cannot be found. Using the method and silhouettes which ar described subsequently in this application a competent locksmith ma quickly and easily create a key for a lock if the given codes fo the lock are known. II. BACKGROUND ART During the normal locksmithing art, a locksmith is frequently called upon to produce a key for a particular lock without having the benefit of an original or reference key. A reference key is a key that has coded cuts which would unlock a known lock and is used as a reference in making other keys on standard key-duplicating machines. If the original or a reference key is available, the locksmith can use the original or reference key to produce a duplicate key on a key cutting machine. Such machines are common in the trade, and several have been patented, (e.g. Juskevic's key cutting machine, U.S. Patent No. 4,521,142 and Ferruzzi's Encipherment machine, U.S. Patent No. 4,545, 709) . As shown in Juskevic, to reproduce a new key if a reference key silhouette is available, one merely clamps the reference key in a standard key-cutting device. The cutting wheel is then driven across the key-blank to reproduce the reference key silhouette on the new key. See Juskevic, Column 3, 'lines 44-48 (guide means); column 4, lines 60-61 (key-blank); column 5, lines 1-17. These devices are in common usage throughout the United States. The Mini-Mite Key Machine manufactured by Ilco Unican Corporation of Rocky Mount, North Carolina, manufactures a common key reproducing machine. As shown in the Mini-Mite instruction manual, a standard reference key is inserted in one vise while a key-blank is inserted in a parallel vise. As the stylus moves across the reference key, the cutting wheel reproduces the reference key silhouette on the key-blank. In order to use this Mini-mite ke reproducing machine, one needs to have a reference key silhouett for the stylus to trace the silhouette and reproduce the new key. When a reference or original key is not available, a locksmit must refer to a manufacturer's manual and must make coded cuts a specifically described angles and depths and in specific positions along the key-blank. (A key-blank is an uncut key from which coded cuts are made to form a duplicate key.) This reproduction by hand of these coded cuts necessitates a great deal of time and tedious effort. If a complete set of pre-cut coded reference keys were available, duplicate keys for any standard lock could be produced quickly on any key duplicating machine. However, the sheer number and storage bulk of these reference keys would make the standard process of having a reference key for every possible variation of reference cuts impractical. Hundreds of possible reference keys would be needed to adequately stock a locksmith's shop. The current invention provides a unique method of making such reference keys available. An object of this invention is to provide a standard coded reference key silhouette in almost any instance when such reference key silhouette is needed to prepare a duplicate key for a lock. Another object of this invention is to provide a coded reference key with very few partial reference key silhouettes needed to be kept on hand, thus reducing the storage space required to duplicate standard keys. III. DISCLOSURE OF THE INVENTION The novel method described herein comprises first making a numbe of standard partial reference key silhouettes which are the selectively combined and assembled so as to create the complet silhouette of the coded key. For example, since there are fiv positions on many key shanks and nine depths of cut per position this invention requires only forty-five (45) (9x5) pre-cut partia reference key silhouettes to cover such a key. Each partia reference key silhouette would have one (or more) depth of cuts i one (or more) positions. When a coded reference key is required all that is necessary is for the locksmith to assemble th appropriate pre-cut partial reference key silhouettes thu reproducing the required silhouette. The appropriate pre-cut partial reference key silhouettes ar selected according to the position/depth of cut requirements of th key desired to be reproduced. These positions and depths of cut can be taken from the standard locksmithing manual which describe the depth of cut and position for a particular lock and key. On the forty-five coded partial reference key silhouettes have be cut, any known coded key having five shank positions and nine dept may be reproduced by selecting the five appropriate pre-cut parti silhouettes and establishing the appropriate complete silhouette joining the five partial silhouettes together. The key to duplicated may then be reproduced by standard methods. IV. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a complete reference key silhouette with the depth of cut being 3-9-9-6-6. Figure 2 shows a partial reference key silhouette with a number 3 depth of cut in the number 1 space. Figure 3 shows a partial reference key silhouette with number 9 depth of cut in the number 2 and 3 positions. Figure 4 shows a partial reference key silhouette with a number 6 depth of cut located in the 4 and 5 positions. Figure 5 is an end view showing how the various partial reference key silhouettes are secured by a clip. Figure 6 shows how the completed silhouette may be secured by a nut and bolt. Figure 7 is a standard reference key reproducing device. Figure 8 shows a partial reference key silhouette with a number 2 depth of cut in the first space and a number 4 depth of cut in the fifth space. Figure 9 is a partial reference key silhouette showing a number 3 depth of cut 20 at the first and fifth shank positions. Figures 10 through 18 show partial reference key silhouettes with cuts made in the two, three and four positions. The depths of cuts illustrated in the two, three and four shank positions for each figure are as follows: Figure 10 shows 7-7-4 depths of cut, respectively. Figure 11 shows 1-6-6 depths of cut, respectively. Figure 12 shows 1-1-7 depths of cut, respectively. Figure 13 shows 1-4-7 depths of cut, respectively. Figure 14 shows 7-1-4 depths of cut, respectively. Figure 15 shows 7-4-7 depths of cut, respectively. Figure 16 shows 1-7-7 depths of cut, respectively. Figure 17 shows 7-7-1 depths of cut, respectively. Figure 18 shows 4-4-1 depths of cut, respectively. V. BEST MODE FOR CARRYING OUT THE INVENTION The method described herein is simple, yet unique and innovative. It involves preparation of partial reference key silhouettes and assembling and securing selected partial silhouettes together to create a completed reference key silhouette. As shown in Figure 1, a key comprises a head 1 and a shank 2. In the preferred embodiment of this invention, the partial reference key silhouettes also include a circular hole 3 in the head of each partial reference key silhouette. These holes are used to assemble and secure the various partial reference key silhouettes in place to create the complete reference key silhouette. As best shown on Figure 7, the standard key cutting device has a stylus 10 which traces a complete reference key silhouette 11. This complete reference key silhouette 11 is moved on a bar 13 which also moves the key blank 12. The key blank 12 is cut by the cutting wheel 14. The standard reference key silhouette 11 is thus reproduced on the key blank 12. The first step in this method is to cut various depths into a number of partial reference keys at the various positions as required by manufacturers of locks. Normally, each key shank has five horizontal positions, the position closest to the head of the key being number 1 and the position on the tip of the key farthest from the head being position number 5. Each position also has nine standard vertical depths of cut. This standard number of shank positions and depths are shown on charts well known in the trade, such as "National Depth and Space Charts." It is obvious that forty-five different partial reference keys would comprise a complete set of all standard five position/nine depth reference keys (5x9=45 positions) . However, many vertical depth cuts are not used for most standard keys and many reference keys utilize common horizontal/vertical cuts. Because a number of coded cuts are in common use, one partial reference key silhouette may contain common depth cuts at more than one common position, as shown on the partial reference key silhouettes in Figures 3, 4 and 10 through 18. These partial reference keys have more than one coded cut on each partial reference key. As few as fifteen pre-cut partial reference keys could be utilized to produce nearly eighty percent (80%) of all common coded reference keys required by manufacturer's specifications. In order to create a complete set of reference key silhouettes, it is only necessary to prepare one pre-cut coded partial referenc key for each depth and each position. As noted above, however, on partial reference key may contain more than one depth cut at mor than one position, as shown on Figures 3, 4 and 10 through 18. Whe a locksmith needs to prepare a duplicate key he merely assembles th appropriate pre-cut partial reference keys, as shown, for exampl in Figures 2, 3 and 4, to create the complete appropriat silhouette. Combining the partial reference key silhouettes shown in Figur 2, 3 and 4 and bolting them together as shown in Figure- 6 woul produce the full reference key silhouette shown in Figure 1. Th number three depth of cut 15 in the number one space on Figure 2 combined with the number nine depth of cut 16 in the numbers two an three positions, shown in the partial reference key of Figure 3 would also combine with the partial reference key shown in Figur 4 which has a number six depth of cut 17 located in the four an five positions, thus creating a complete reference key silhouett with the code of cuts being 3-9-9-6-6. Nine separate depths of cut at five separate positions creat 59,049 different combinations of horizontal shank positions/vertic depths of cut (9x9x9x9x9=59,049). However, only forty-five pre-cut partial reference key silhouettes could produce these 59,049 permutations. But, many depths of cut at many shank positions are not in common use. For example, a very deep depth of cut (number nine depth of cut) at the first shank position is hardly ever found as the key shank would then be very weak. Additionally, many other depths of cuts are not in common use. Because many depths of cut are not in common use at certain key shank positions, fewer than all depths of cut at all five horizontal positions are required for a practical set of partial reference key silhouettes. A practical set of partial reference key silhouettes would produce nearly all, but not every possible, combination of depths at horizontal shank positions. Turning now to Figures 8 through 18, it may be shown how a coded reference key silhouette may be reproduced by selecting the appropriate partial reference key silhouettes and clasping them together as shown in Figures 5 or 6. Figures 8 and 9 show alternative base key silhouettes. Figure 8 has a base key silhouette which has a number two depth of cut 18 at the number one shank position and a number four depth of cut 19 at the number five shank position. Figures 10 through 18 show different depths of cut at the shank positions in the center of the key shank, being positions two, three and four. Combining the partial reference key shown in Figure 8 with the partial reference key shown in Figure 10, produces a coded reference key with a silhouette as follows: 2-7-7-4-4. Combining the silhouette in Figure 8 with the silhouette in Figure 11, produces a coded reference key at 2-1-6-6-4. Combining the partial reference key in Figure 8 with the partial reference key of Figure 18 produces a coded key 2-4-4-1-4. Obviously, combining the base reference key shown in Figure 8 with each of the partial reference keys shown in Figures 10 through 18 produces nine separate coded reference key silhouettes. We have thus used ten partial reference key silhouettes to produce nine complete coded reference key silhouettes. Using the base reference key silhouette shown in Figure 9 would allow us to have a number three depth of cut at the number one shank position and a number three depth of cut at the number five shank position. Combining the second base key silhouette shown in Figure 9 with the partial reference key silhouette shown in Figure 10 produces a key coded 3-7-7-4-3. Combining the second base key reference silhouette in Figure 9 with the partial reference key silhouette shown in Figure 18 produces a complete coded reference key 3-4-4-1-3. Obviously, combining the second base reference key silhouette shown in Figure 9 individually with the partial reference key silhouettes shown in Figures 10 through 18 would produce anothe nine complete coded reference key silhouettes. We now have use eleven partial reference key silhouettes to produce eightee completed reference key silhouettes. Using a third base key reference silhouette, having variou depths of cut at the number one and number five shank positions, an combining them with the partial reference key silhouettes havin the various depths of cut shown in Figures 10 through 18 woul produce another nine complete coded reference keys. We have no used twelve partial reference key silhouettes to produce twenty seven fully coded reference key silhouettes. Following the permutations as demonstrated above, it can readil be seen how a small number of partial reference key silhouettes ca be combined to reproduce a large number of completed reference ke silhouettes. By selectively combining a small number of partia reference key silhouettes (anywhere from two to five partial reference key silhouettes will produce a completed reference key silhouette) the appropriate coded reference key silhouette can be produced. If the code of the key required to be reproduced is known, the correct selection of the appropriate partial reference key silhouettes can produce the completed coded reference key silhouette needed to be used in the vise on the mini-mite machine. For example, suppose we knew the coded reference key silhouette should be 2-7-1-4-4. Combining the base reference key shown in Figure 8 with the partial reference key shown in Figure 14 would produce a coded reference key 2-7-1-4-4. Once the partial reference keys are selected, they are then placed together and securely fastened by a screw 4 which is placed through the hole in the partial reference keys* heads and tightened securely by a nut. The complete silhouette as shown, for example, in Figure 1 is thus produced. The various positions on the key shank are shown in Figure 1. The number two shank position 5 and the number three shank position 6 and the number four shank position 7 are the central positions on the key shank. It is these central three positions that are used for the partial reference keys at various depths shown in Figures 10 through 18. The number five shank position 8 located furthest from the head 1 of the key blank is also shown on Figure 1. The bolt 4, shown in Figure 6, may be secured by means of a nut 9. An alternative method of combining the two or more silhouettes, three partial reference keys are combined in Figure 5, is the use of a U-clamp as shown on Figure 5. The best mode for carrying out this particular invention would utilize fifteen to twenty partial reference keys which could be combined to form most of the common coded key silhouettes. Once the coded key silhouette has been obtained this silhouette may be placed on the left side of the cutting machine shown in Figure 7. The stylus 10 then traces over the coded key silhouette thus assembled while the cutting wheel 14 cuts the key blank 12 in the same fashion as described previously to reproduce the required new key for the lock. VI. INDUSTRIAL APPLICABILITY This invention has applicability in all trades which utilize locks but is particularly useful in the locksmithing trade. The invention is used to reproduce keys for locks when the coded reference depths of cut and key positions are known. The invention would save a great deal of time and effort and eliminate tedious measuring when a locksmith is required to reproduce a key without having a duplicate key readily available. The equipment used to practice this device would include a key-making machine such as described previously and depicted in Figure 7 as well as a small lightweight set of partial reference key silhouettes. Quick, economical and efficient reproduction of keys if the coded key depths and positions are known may be accomplished by the use of this invention.

Claims: VII. CLAIMS I claim: Claim 1: A method of assembling a coded reference key, comprising the steps of: (1) cutting a first key-blank at a first vertical coded depth cut at a first horizontal key-blank position, thereby mechanically reproducing a partial reference key silhouette; (2) repeating Step 1 on successive key blanks for all nine vertical coded depths at all five horizontal coded positions thereby mechanically reproducing a set of partial reference key silhouettes of all coded horizontal cuts at all vertical coded depths; (3) mechanically assembling and securing the appropriate pre-cut partial reference key silhouettes together thereby mechanically reproducing a complete coded reference key silhouette; (4) mechanically reproducing the assembled and complete coded reference key silhouette by means of a standard reference key reproducing device; whereby a standard reference key reproducing device may be utilized when the code for the reference key is known even though the original reference key is unavailable. Claim 2: A method of making a coded reference key as in Claim 1, wherein said securing means comprises a U-shaped clip which is attached to the bottom of the assembled reference key silhouettes. Claim 3: A method of making a coded reference key as in Claim 1, wherein the head of each partial reference key silhouette has a hole therein and the securing means comprises a bolt inserted through the holes in the assembled partial reference key silhouettes and tightened by a nut. Claim 4: A method of assembling a coded reference key, comprising the steps of: (1) cutting a key blank at a first common vertical depth of cut at a first horizontal key shank position thereby mechanically reproducing a partial reference key silhouette; (2) repeating Step 1 on successive key blanks for each common vertical coded depth at each horizontal key shank position thereby mechanically reproducing a set of silhouettes which in partial combination can produce all common coded reference keys; (3) mechanically assembling and securing the appropriate pre-cut partial reference key silhouettes together thereby mechanically reproducing a completed coded reference key silhouette; (4) mechanically reproducing the assembled completed coded reference key silhouette by means of a standard reference key reproducing device; whereby, a standard reference key reproducing device may be utilized to duplicate a key when the code for the reference key is known even though said reference key is unavailable. Claim 5: A method of making a coded reference key as in Claim 4, wherein said securing means comprises a U-shaped clip which is attached to the bottom of the assembled partial reference key silhouettes. Claim 6: A method of making a coded reference key as in Claim 4, wherein the head of each partial reference key silhouette has a hole therein and the securing means comprises a bolt inserted through the holes in the assembled partial reference key silhouettes and tightened by a nut.

Inventors: BUSH ROBERT C, BUSH, ROBERT, C.
Applicants: BUSH ROBERT C, BUSH, ROBERT, C.
Application year: 1991
Main classification: B23C3
IPC codes: B23C3