US429159A

US429159A - Of same place

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Publication number: US429159A
Authority: US
Publication date: 1890-06-03
Anticipated expiration: 1907-06-03

Description

3 Shets-Sheet 1. 4 E. 0. SMITH.

LOGK.

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No. 429,159. Patented June 3, 1890.

IN VE/VTOR 3 Sheath-Sheet 2. E. 0. SMITH.

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.No. 429.159. Patented June 3, 1890'.

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Arm/27m UNITED STATES PATENT OFFICE.

EUGENE 0. SMITH, OF N E? YORK, N. Y., ASSIGNOR TO THE UNIVERSAL LOCK COMPANY OF NEWV YORK, OF SAME PLACE.

LOCK.

SPECIFICATION forming part of Letters Patent No. 429,159, dated June 3, 1890.

Application filed March 6, 1889. Serial No. 302,177. (ModeL) To all whom it may concern.-

Be it known that I, EUGENE 0. SMITH, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Combination Locks and Keys, of which the following is a specification.

My invention relates to shiftable wards in to key-locks, by the use of which obstructions to a false key are produced and changed at will by the simple turning of the true key, so that it is impossible to obtain impressions of the wards and make therefrom false keys to {5 open thelock; and the said Wards are capable of producing as many different obstructions in a single lock as there are combinations mathematically possible from the number of.

wards.

My invention also relates to the combinations of the wards and tumblers and to the key adapted to actuate the said tumblers and wards.

My invention also relates to a lock which 2 5 is adapted to the use of two keys in the possession of different persons, so that neither can lock or unlock the look without the cooperation of theother. When the lock is so used, one key is constructed to act on the 0 wards alone and the other key to act either on the tumblers alone or on the tumblers conjointly with the same wards as are acted on by the first-named key.

In practice the operations of the tumblers,

5 the wards, and the key are intimately connected together; but for clearness I describe in my specification hereinafter, first, the wards; secondly, the combinations of the wards and tumblers, and, thirdly, the key.

Referring to the drawings which accompany the specification, Figure 1 is a plan or front view of the lock with rectilinear shifting wards, and Fig. 1 is a view of the bolt and slide. Fig. 2 is a perspective view of the lock with wards, as in Fig. 1, the said wards being all grouped together to one side of the tumblers. Fig. 3 is a perspective view of the lock, showing the rectilinear shifting wards arranged in line with the spaces between the tumblers.

Fig. 4 shows a single ward and tumbler with locking-bars and bolt, the tumbler being in the unlocked position. Fig. 5 is a View of a lock with wards in shape of a circular segment and placed on the same axis as the tumblers. Fig. 5 is a view of a single ward and locking- 5 5 bar. Figs. 6 and 6 are views of the shield around the key-cylinder, showing the slots for the tumblers. Figs. 7, S, and 9 are views of three several keys. Fig. 10is adiagrammatic representation of the tumbler, locking-bar key, and key-cylinder, showing the mode of operation of the key. s

T he wards.-A ward is an obstruction placed in a lock to prevent the entrance or the turning of akey to engage with the mechanism, except said key have slots so placed as to permit the key to pass the wards. Hitherto such wards have been immovably secured in the look, so that it has been easy to obtain an impression of the wards and make therefrom a false key which would pass the wards and draw back the bolt. Experience has shown even complicated ward sytems to give so little security that in the better class of locks wards are either abandoned or only used as an auxiliary to tumblers. I have, however, invented movable wards, whereby the obstructions to false keys may be changed at will, either by knobs or levers accessible only to the person having charge of the So look, or, as is most convenient, automatically by the simple turning of the key in looking and unlocking, and by using different keys adapted to the look new combinations of obstructions will be formed which will prevent 8 5 the turning of any key, except it have slots similarly placed with the key which last locked the look. I also use the movable wards to prevent the locked tumblers against being brought back to the unlocked position, except by a key which will simultaneously move the wards which were previously set by the last-used key, or by levers, &c.,for such motion. Thus the wards in my lock have two purposes new in the art-first, of being shift- 5 able at will, and thereby producing a great number of variable obstructions in the lock, and, second, of holding the locking mechanism against movement, except by a key which will actuate the certain combination of wards.

A is the lock-case with front plates removed to show the mechanism.

B is the bolt adapted to engage in the usual manner with a socket in the door-frame, boxcover, &e., and having a stump C, adapted to enter a slot in the tumblers when the bolt is drawn back. The bolt 13 has a slide I) with guide-slots 1. 2, which slide on fixed pins in the usual manner, and also a slot to enable the slide D to pass by the axis of the tumblers. In the said slide D is a talon a, to be engaged by a bit of a key which turns in an axiallyrotating longitmlinally-slotted key-eylindcr E,after the usual manner of flat keys. Around the key-cylinder is a shield F, fixed in the case by rivets, and preferably formed either as a complete cylinder or as circular segments, according to the arrangement of wards and tumblershereinafterdescribed. \Vhen formed as a complete cylinder, the said shield F has slots, as shown in Fig. 6, to permit the edges of the wards and tumblers to enter the shield and have their proper motions, and the said shield is so placed as to permit the bits of the key to engage with the key-slots of the tumblers and wards, but prevent a pick from reaching the lockingbars I and O. Adjacent to the key-cylinderE, and so as to be engaged by the bits of a key, are shiftable wards G, which may be of any number and suitable shape. In Fig. 1 they are shown as formed of fiat sheet metal approximately rectangular in shape. Each of said wards G has a guideslot 1) sliding on pins 0 c, the ends of the slot 1) forming shoulders to limit the motion of the wards. By reason of the said pins 0 c and the walls of the case the wards G have a true rectilinear motion when acted on by the key.

Each ward G has a true key-slot (Z and false slots (2 f to each side of (Z and distant therefrom equal to the travel of the wards, so that for all positions of the wards G there will be two rectilinear rows of key-slots across the edges of the wards adjacent to the keycylinder, and no indication will be given of the position in which any ward is set. Each ward also has recesses g g to engage with the free ends of springs II, the other ends of said springs being secured to the fixed pins 71.. On every ward is a projection or tooth 1', adapted to engage with an axially-rotating lockingbar I, which rotates on a longitudinal axis J, fixed in the case, and preferably perpendicular to the plane of the wards G.

U are pins to limit the movement of the teeth 1:; but the said pins U U may be omitted, since the movement of the wards G and teeth '1 is also limited by the pins 0. Said locking-bar I is straight longitudinally and of uniform cross-section throughout its length, and has arms 7' 7.: to engage with the teeth 2' of wards G, somewhat after the manner of a rack and pinion.

L is a spring fixed at one end bearing on flat sides of the locking-bar I in its several positions, as shown in the drawings, the said spring L serving both to accelerate and limit the motion of the locking-bar I.

Each ward G has a fixedly-connected arm M, carrying a dog N, situated to engage with a shoulder o of atumbler locking-bar 0 when said locking-bar is in the position shown on Fig. 1, and by reason of the sliding motion of the ward G the dogs N have a motion to and from the locking-bars O. The said lockingbar 0 is shaped similar to the locking-bar I, hereinbefore described, and rotates on a longitudinal axis 1, fixed in the case, preferably parallel to the axis .1, and the said lockingbar 0 has arms 1) q to engage with a cam r on each of a set of tumblers Q, said tumblers rotating on an axis R, fixed in the case parallel to the axis P. The said tumblers are preferably formed of sheet metal in shape approaching a circle, and each tumbler has a true key-slot S and false slots in to each side of the slot S and distant therefrom equal to the sweep of the tumblers Q as they revolve, whereby no indication will be given to a pick or waxed blank of the posit-i011 of any tumbler. Each tumbler Q also has recesses Q? r for the free end of springs S, the other ends of said springs being secured to fixed pins T. In each tumbler Q is a slot to, so placed as to permit the stump C to be drawn back into the slots to when all the tumblers are in unlocked position and adjacent to the said slots to. Each tumbler also has acam a: placed to come behind the stump 0 when the tumblers arein locked position and prevent drawing back the bolt. The tumblers Q, are situated ad jacent to the key-cylinder E, so as to be engaged by bits of a key.

V is a spring having its free end bearing on fiat sides of the locking-bar O, as hereinl)efore described with reference to the lockin g-bar I.

U are pins to check the tumblers Q. I may either arrange the wards G in a group to one side of the tumblers Q, as shown in Fig. 2, or I may place the said wards in line with the spaces between the tumblers Q, as shown in Fig. 3, or I may arrange the wards in any other manner, and I prefer to use washers of non-corrosive metal between the wards and the tumblers.

Referring to Fig. 1, the operation is as follows: Suppose the lock to be open, the wards and tumblers being in the position of Fig. 4, and that a key having a bolt-bit z and tumbler-bits 7 S (J, and a ward-slot 10, as in Fig. 7, to be used to lock, the said slot 10 being wide enough and deep enough to pass by all the wards G without touching any of them. The said key being inserted in the lock and turned in the direction of the arrow, its bit .2 will first shoot the bolt 13, then asit continues to turn its bits 7 8 9 will actuate a corresponding combination of tumblers and set the same in the locked position shown in Fig. 1, and the cams at of such locked combination of tumblers will come behind the stump O and prevent the withdrawal of the bolt B. During the aforesaid motion of the tumblers Q their cams 0' have engaged the arm 1) of the locking-bar O, turning the said locking-bar to the position shown in Fig. 1, the shoulder 0 of said locking-bar 0 coming to a position to be engaged by the dogs N of wards G. The key continningits rotation, its slot 10 passes freely by all the wards G without moving any of them. slot in the case and withdrawn. To unlock, the same key is used and turned in the reverse direction. Its slot 10 first passes freely by the wards G, then its bits 7 8 9 engage the same combination of tumblers, as before, bringing said tumblers back to the unlocked position, the cams of such tumblers acting on the arm (1 of the locking-bar O and turning the said locking-bar to the position shown in Fig. 4, and finally the bit 2 draws back the bolt, the stump C entering the slots 10 of the tumblers Q. The wards G prevent any key, except one which has the same arrangement of ward-slots and ward-bits as the lockingkey, from opening the lock. Suppose the key Fig. 7 were used in locking and a different key, as Fig. 8, is used to try to unlock, the said key Fig. 8 has exactly the same bolt and tumbler-bits z '7 8 9 as the key, Fig. 7, but it has its ward-slot 10 narrower and has shoulders or bits 11 12 to engage with certain wards G. Such a key being turned in the direction of unlocking, its shoulders 11 12 will engage with false key-slots of certain wards G, and will tend to move said wards in the direction of the small straight arrow, Fig. 4.; but such motion of the wards is impossible by reason of the pins 0 bearing against the shoulders Z). Consequently the key Fig. 8 will not be able to reach the tumblers Q nor open the lock. Again, suppose the key Fig. 8 had been used to lock. Then its shoulders 11 1.2 would have acted on a certain combination of wards G and set such combination in the position G Fig. 1, and the dogs N would have engaged upon the shoulders 0 of the locking-bar 0, so as to prevent the said locking-bar 0 from turning back to the unlocked position of Fig. 4. During the aforesaid motion of the wards G their teethz' would have engaged the arm j of the locking-bar I and turned said locking-bar to the position shown in Fig. 1, the bolt of course having been shot and the certain combination of tumblers locked, as before described. Now if key Fig. 7 is used to unlock, said key having its slot 10 wide and deep enough to pass all the wards, then said key being turned to unlock will first pass all the wards, leaving said wards in the combination in which they were set by the previously-used key, and its bits 7 8 9 will engage the key-slots in the locked tumblers and begin to rotate such tumblers back to the unlocked position; but immediately the locking-bar 0 will begin to turn and its shoulder 0 will bear upon the dogs N, whereby its further motion will be prevented. Consequently it will be impossible for the locking-bar C to turn to free the cams r of the tumblers Q, and

consequently the said tumblers cannot return to their unlocked position and the bolt cannot The key may now be turned to the be withdrawn. These illustrations show that all combinations of wards mathematically possible to the number of wards may be set in either the position G or G, and that only that key having similar ward-slots and wardbits with the key last used in looking will be able to pass the wards or free the locked tumblers. Hereby a new principle of great utility is introduced in looks and a very great security given, entirely independent of the tumblers. The locking-bar I prevents moving the wards G by a pick in the following manner: Suppose certain wards were set in the position G and certain others in the position G, and that an effort is made with a pick to bring one of the wards G to the position G. The tooth v." of such ward will begin to rotate the locking-bar I, whereby the arm j of said locking-bar will be brought hard down on the other cams t" of the wards G, so that no one of such wards G can pass to the position G. Conversely, if a pick try to move a ward G to the position G, the tooth i will push the arm 7.; of the locking-bar I against the teeth 1." of wards G; but said wards G may not move in that direction, by reason of the pins 0 bearing on the shoulder 19. Consequently the locking-bar I will prevent the wards G from being brought to the position G. Thus it is evident any possible combination of wards may set in position G or G against any attempt to pick the lock.

The arrangement of wards shown in Figs. 1, 2, and 3 will soon reveal to one tampering with the lock which are wards. Consequently I prefer usually to make the wards of the same shape on the side adjacent to the key-cylinder as the tumblers, and to place the wards and tumblers on the same axis as in Fig. 5. The wards G are formed of sheet metal, having the same curvature toward the key -cylinder F as the tumblers Q, and they have similar slots 8 t u and cams 0*, similarly placed to engage with the same locking-bar 0. Each ward also has recesses'v o for springs, similar to the tumblers. I may either arrange my wards in a group by themselves, as in Fig. 5, or I may distribute the wards among the tumblers, and I prefer to cut out the wards on the side toward the bolt, as shown in Fig. 5, so that the wards will not oppose the motion of the bolt'stump C,'and when the wards are arranged as in Fig. 5 I may shorten the boltstump, so that it will only reach across the tumblers Q, but not across the wards G.

The operation is as follows: The tumblers being in unlocked position and the wards in the position shown in Fig. 5, suppose the key Fig. 7 were used to lock and the key Fig. 8 were tried to unlock, then the shoulders 11 12 of said key Fig. 8 would engage false key-slots in a certain combination of wards which the first key Fig. 7 would have left with their cams 1" bearing on the fixed pin U, as seen in Fig. 1, and would tend to force said cams 0 against the said pins but said tumblers could not turn because of said pins and cams, and the key would be unable to reach the locked tumblers and open the lock. Conversely, suppose the key Fig. 8 had been used in looking, then its shoulders 11 12 would have rotated certain wards G simultaneously with certain tumblers to the position of the cams the locking-bar rotating as before described. Now the key Fig. 7 having slot 10 large enough to pass all the wards, its bits 7 S 9 will engage the locked combination of tumblers and begin to turn them to the unlocked position; but immedt diately the arm 1) of the locking-bar 0 will be brought down on the cams r of the certain wards, so that said locking-bar 0 may not retate to free the cams 1" of the locked tumblers. Consequently the keyFig. 7 will be unable to open the lock.

The foregoing description shows that 1 may give to the wards G also the functions of the 1 rue tumblers Q, thereby forming interchange able ward-tumblers by fashioning the wards G with a slot '10 for the stump O, and cams 00 to pass behind said stump, after the mannor of the said tumblers Q. Then I use a key having slots for such a combination of ward-tumblers as I wish to leave in the neutral position, and bits for the other tumblers. To unlock, it is necessary to use a key having similar slots to that which looked, otherwise the unlocking-key will be held from turning to engage with the locked tumblers by reason of the said neutrally-placed ward-tumblers. It is evident that I may also place all my wards on one axis and all my tumblers on another axis, producing an arrangement similar to that shown in my application filed February 8, 1889, Serial'No. 299,116, and now pending in the United States Patent Office. I may also distribute the wards among the tumblers on both axes.

I do not restrict myself to an y special form or arrangement of wards, my invention being the use in key locks of shiftable wards adapted to be set by the key so as to form at will variable obstructions to a false key; and my invention also is an interchangeable wardtumbler adapted to be set by the simple turning of the key for use either as a true tumbler or a true ward, the said wards being capable of as many combinations as are mathematically possible to the number of wards.

The ward principle hereinbefore set forth enables me to use the lock shown in Figs. 1 and 3 as a two-key lock in the following manner: One key may be of the form shown in Fig. 7, having tumbler-bits, but no ward-bits. The otherkey may have ward-bits, but no tumbler-bits. Insert the first key and throw the bolt and tumblersinto thelockedposition. Remove this key,ins ert the second key, and throw the wards into the position where their dogs bear onthe locking-bar O. The lock is now locked, and it is evident that it can only be opened by first using the ward-keyto throw the wards back to their original position. The

tumbler-key can then open the lock. Other arrangementsoftwokeyscanalsobeused. Thus the tumbler-key may have ward-bits as well as tumbler-bits. The ward-key will have the same ward-bits, but no tumbler-bits. The tumbler-key having first been used, the wardkey is turned in the reverse direction to draw the wards back to their original position. Then the lock can only be opened by first turning the ward-key to shift the wards to the position in which the tumbler-key before put them. Then the tumbler-key can open the lock.

The combinations of wards and tumblers.- In combination key-locks, the combinations of the tumblers have hitherto been formed on the principle of variable motion and constant numberthat is, each locking combination has been formed by moving each tumbler through a different space from some other tumblers of the same combination, and all the tumblers have been brought into every combination,and the principle of the change from one combination to another has been the varying of the spaces through which some tumblers are moved from the spaces through which the same tumblers are moved in the other combinations. This, as before said, is defined as the principle of variable motion and constant number, and its use in keylocks is attended with great complication of mechanism, several sets of tumblers being required to prevent differences in the position of those tumblers which are accessible from the key-hole from giving an immediate indication of the amount of motion of every tumbler in the combination, and resulting in the opening of the look by false keys, and appliances being necessary to hold some set of tumblers in their diiierent positions during the time the mechanism is locked. are found in the United States Patents of R. Nowell, (18M and subsequent years) the British Patent of Victor Newton, (1855,) and the United States Patents of \V. R. Doremus, Nos. 370,183, 374,170, 378,784., (1887.) The reason for the adoption of theabove-referredto principle was that so long as lock-makers knew of no simple means of fixing the locked tumblers against being severally moved by a pick to the unlocked position the greater the number of tumblers in each combination the greater the security, since the chance of the surreptitious discovery of the proper mo tions of a large number of tumblers is much less in the case of a small number. Therefore the greatest possible number of tumblersviz., all in the lock-were brought into each combination. I have, however, discovered a new principle of combination for key-locks-- via, the principle of constant motion and variable number-that is, each combination is formed of a number of tumblers less than the whole set in locked position by the key, and each tumbler in the combination is moved through equal spaces. The change of combination is effected by changing the number of Examples tumblers or their groups in the different combinations according to the mathematical law governing the combinations possible from a given number of things. The application of this principle to looks has important practical results in simplicity and security, for all the tumblers throughout thewhole range of the combinations having equal motions, it is possible, by the simple expedient of false and true key-slots, as hereinbefore described, to avoid any indication of the position of any tumbler or group of tumblers. I have also devised a means of carrying this principle into successful operation-via, a locking-bar to hold the tumblers of the locked combination against any attempt of a pick to bring them severally back to the unlocked position.

I apply my principle of combination in looks as follows: I form a key Fig. 7 of shape, size, and position of bits, as hereinafter described, suitable to enter the lock and shiftable bolt and tumblers. The said key has a bolt-bit z, tumbler-bits 7 8 9, and a ward-slot 10. Now if such key be inserted in the unlocked lock and all the tumblers therein being in neutral position the bits 7 8 9 will act on corresponding tumblers and rotate said tumblers to the locked position, as hereinbefore described, and will leave all the other tumblers at rest in the neutral position. During the motion of the tumblers the locking-bar O rotates, as hereinbefore described, and fixes the combination of tumblers corresponding to the bits 7 8 9 aforesaid in the locked position, as hereinbefore explained, and also holds the unlocked tumblers in their neutral position. Thus by the action of the key Fig. 7 one certain locked combination of tumblers has been formed,which combination is by means of the locking-bar isolated from the unlocked tumblers and made to constitute a locking unit until the combination is dissolved by the same key and the locked combination of tumblers again brought back to the neutral position. A change of combination is affected by looking with a key having a different arrangement of bits, as Fig. 9. The bits of said key will bring a different combination of tumblers into the locked position, where they are isolated as another locking unit by means of the locking-bar. So other suitable keys will produce other combinations of tumblers; but all the bits of all the keys are of equal length, as shown in the drawings, whereby equal motion is given to everylocking-tumbler throughout the whole range of combinations. I may of course throw all the tumblers into one of the possible combinations; but the principle is the mathematical law governing the number of possible combinations from a given number of things, which I make applicable to looks by means of combinations of tumblers less than the whole number set in locked position by the key. WVhen I use wards distinct from tumblers, I apply the same principle of combination to the wards Gr by means of a locking-bar and keys having ward-bits of equal length, as will be evident from the description hereinbefore given of the operation of the shiftable wards.

The Zccy.The form of the key to operate my locking-bar is a necessary mathematical result of the operation of a locking-bar lock with rotary tumblers, and is determined as follows:

Fig. 10 is a diagrammatic representation of a tumbler locking-bar, key-cylinder, and key, A being a rotary tumbler, having its center of rotation at S; B, a locking-bar, having its center of rotation at S; G, the key-cylinder, having its center of rotation at O; D D, the place of the cams in locked and unlocked position, respectively, and the straight lines 0 E O E representing the positions of the key as it just engages and just releases the tumbler in its motion from unlocked to locked position. The angle D S D, struck: through the center S and the middle of the cams D D, is the angle of rotation of the tumbler A while the cam is moving from D to D. Now, since the locking-bar B is straight longitudinally and of uniform cross-section, as hereinbefore explained, it follows that for the cams D of all the tumblers to properly engage with the said locking-bar as the tumblers rotate the angular motion of every cam must be equal to the angle D S D of the cam D of tumbler A; but every other point on the tumblers must have the same angular motion as the cams D, consequently the key-slots must have the same angular motion as the cams D. Now let E and E represent the two positions of the key-slot of tumbler A, and the angle E S E equal to angle D S D represent the angular motion of the key-slot of tumbler A. Then the angular motion of the key-slots of all the tumblers will be equal to the angle E S E. From 0, the center of the key-cylinder G, draw 0 E and O E to represent the two positions of the key. Then the angle E O E will be the angular movement of a bit E of said key, and as every point on said key has equal angular motion with the bit E the other bits will all have angular motion equal to E O E; but it is easily demonstrated mathematically that this equality each to each of all the angles D S D and all the angles E C E can only be attained when the ends of all the bits of the key are equally distant from the axis of rotation C of said key, and that no key having bits of appreciably unequal lengths will properly operate my locking-bar lock, and any considerable difference of length of said bits will prevent the key from turning the tumblers. By length of bits I mean the distance from the axis of rotation O of the key to the outer edge of the bits. Having discovered this principle governing the form of the key,I

may apply it as follows:

Thepossible combinations of a number of things equal to the number of tumblers in the lock are calculated. For convenience I invention.

may indicate the tumblers in their order by letters of the alphabet, as a b c, or by figures. Then the calculation just before referred to determines what and how many tumblers are in each combination, and also the grouping of the contiguous tumblers. 'For example, in a twelve-tumbler lock one combination may be a, (Z c,j it Z-that is, the combination will consist of three groups of tumblers, arranged one in a group a, two in a group (1 c, and three in a group of contiguous tumblers j 7; 7. The tumblers not in the combination determine the spaces which separate the groups in the combination, and also the spaces between the bits of the key. Thus tumblers b c d etermine one space and tumblers f g 71. '2' another space between the bits of a keyadapted to operate the combination of tumblers aforesaid. To determine the width of the bits of the key, I measure the thickness of each group of contiguous tumblers in the combination, allow ing for the washers and also for easy play of the key. By width of the bits I mean the extension of the bits in a direction parallel to the axis Y Y, hereinbefore referred to. Itis apparent that as I change the combinations of the tumblers so I change the Width of the bits of the key, or rather of the solid groups of bits corresponding to each combination of tumblers. This arrangement of the bits in solid groups of a width equal to the thickness of the groups of contiguous tumblers which are in the locking combination is an essential feature of my key and a part of my The width of the spaces between the bits is similarly determined by measuring the thickness of the groups of contiguous tumblers which are notin the locking combination. It will be apparent without further explanation that the ward-bits and ward-slots are determined in the manner herein described as to the tumblcrbits and slots. IIaving thus determined the arrangement of bits and slots for any combination, I take a flat strip of metal of a thickness suitable for the slot in the key-cylindcr G, Fig. 10, and mark on it a straight line y 7 Fig. 7, to represent the axis of rotation of thekey. Then having determined the radius S E of the tumbler A, Fig. 10, the angular movement E S E of said tumbler and the centers S and C of rotation of the tumblers A and key-cylinder G, respectively, I measure the distance 0 E, which will be the distance of the ends of all the groups of bits from the axis of rotation of the key. A line Z Z is then drawn parallel to y y and at a distance therefrom equal to U E. ()n

this line Z Z, or a little within it, for easy play, will lie the ends of all the groups of bits. 011 the space between the lines Y Y and Z Z and in the positions and of the width determined by the combinations of tumblers, as hereinbefore said, are marked the groups of bits corresponding to the certain combination of that key. The position of the bolt-bit is determined by reference to the place of the bolt-talon in the lock, and then the spaces between the bi ts are removed by a punch or by cutting. The width of the key-blank behind the axis 9 y is determined, so as to fit the slot in the key-cylinder, and the bow of the key is formed in any usual manner. The ward-bits and ward-slots are formed in a manner similar to that above described for the tumbler bits and slots.

I claim- 1. In a combination tumbler-lock, a series of severally-shiftable wards adapted to be actuated by the bits of a key independent of the bits which actuate the tumblers, each ward having a shoulder, and a stop fixed in the lock for the purpose of limiting the motion ot-the wards, as herein described.

2. In a combination tumbler-lock, a series of severally-shiftable wards adapted to be actuated by the bits of a key independent of the bits which actuate the tun'iblers each ward having a shoulder and a projection, in combination with an axially-rotatin g lockin gbar having arms adapted to engage with the aforesaid projections on the wards, as herein described.

In a lock, a series of severally-shiftable interchangeable ward-tumblers, each having a shoulder, and a stop fixed in the lock to limit the motion of the aforesaid interchangeable ward-tumblers, as herein described.

.4. In a combination-lock having a series of sevcrally-shiftable tumblers, a group of such tumblers less than the whole number of tumblers set in locked position by a key, as herein described.

5. In a combination-lock having a series of scverally-shiftable tumblers, a group of such tumblers less than the whole number of tumblcrs set in locked position by a key, each tumbler of the said group of tumblers having a projection, in combination with an axially-rotating locking-bar having an arm engaging with the aforesaid projections, as herein described.

6. The combination, in a lock, of a series of severally-shiftable tumblers each having a projection, an axially-rotating locking-bar having arms adapted to engage the said projections, and a key having bits arranged in solid groups of a width equal to the thickness of the groups of contiguous tumblers which are in the locking combination, and the said key having the ends of all the groups of bits equally distant from the axis of rotation of the key, as herein described.

In witness whereof I have hereunto set my hand this id day of March, 1889.

EUGENE 0. SMITH.

Witnesses:

0. I FROTHINGHAM, ALEX. D. ANDERSON.

IIS