Improvements in Key Combination-locks.
Year: 1898

page_text: Date of Application, 29th Nov., 1898--Accepted, 28th Jan., 1899
[Communicated from abroad by THE UNIVERSAL LOCK COMPANY, of Jersey City,
New Jersey, United States of America.]
Improvements in Key Combination-locks.
I, ARTHUR HENRY WALKER, of Gresham House, Old Broad Street, in the City
of London, Lawyer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement: —
This invention relates to improvements in key combination-locks of the type
known as locking-bar locks, wherein a series of independently movable tumblers
are arranged in combination with a locking-bar, in such manner that the
tumblers may be locked, through the co-operation of the locking-bar, in practically
as many combinations as there are different mathematical combinations possible
from a number of things equal to the total number of tumblers.
In such locks there may be as many different keys as there are possible lock-
ing combinations of tumblers, and only that key, which locked the tumblers, or
its exact duplicate, can open the lock. In such locks it is indispensable that the
locking combination shall not reveal itself to delicate feeling with a pick and shall
not permit an impression to be obtained of such combination, and it is the purpose
of this invention to prevent both, the picking of the lock and the obtaining of
an impression and also to allow the lock to be locked in both directions.
To safeguard the lock, it is necessary that every tumbler, whether locked or
unlocked shall have exactly the same degree and ease of motion, shall feel exactly
the same to a pick, and give the same impression on a blank as every other
tumbler. But heretofore these results have not been properly attained, because
pins have been heretofore employed to limit the motions of the tumblers, and
springs have been used to compel the tumblers and locking-bar to go to the full
limit of their throws. The result has been that, when some combination of
tumblers has been locked and an attempt has been made to feel out the combina-
tion, some of the tumblers would be moved up against the limiting pins and
others against the locking-bar, and a very delicate touch could sometimes detect
the difference and thus finally work out the combination. Or, if a blank were
inserted, it would sometimes be possible to get an impression of the locking com-
bination, owing to the different elasticity of the pins and locking-bar, aided by
the springs. It is also practically impossible, in manufacturing the locks, to
attain such perfection that the tumblers will bring up in the same manner on
two different parts, and the difference might be sufficient to permit "feeling
out" of the combination. The use of stop pins moreover prevents allowing the
tumblers to be moved from the neutral or unlocked position in locking in both
directions, and one of the especial advantages of the present invention is that it
does permit of constructing locks in which the tumblers can be locked in both
directions, such a double-locking lock being hereinafter shown and described.
Therefore, this invention consists broadly, in the combination of the locking-

page_text: bar and independently movable tumblers, so constructed and so arranged in co-
operation with each other, that the locking-bar equally limits the movement
of all the tumblers both in the locked and the unlocked positions, when the
effort is made to open the lock, and without any springs or pins. Thus, in an
attempt to open the lock with a pick every tumbler comes up against the same
locking-bar, and with the same degree and kind of motion, and no difference of
feeling is perceived, nor can an impression of the locking combination be
obtained, for both the locked and the unlocked tumblers are equally free to move
within the small limits imposed by the locking-bar, and all can be turned in-
differently a little this way or that, without any resistance of springs or other
parts.
Mechanically, the invention broadly consists in the combination of a rotatable
locking-bar and independently movable tumblers, each of which has an exactly
similar projection for rotating the locking-bar and other similar projections adapted
to engage on the locking-bar and limit the play of the tumblers.
The invention is applicable to any key combination-lock of the locking-bar
type, and I therefore show on the drawings and describe in the specification its
application to several locks. I also hereinafter fully describe in detail the co-
struction of one of said locks which includes several subsidiary improvements.
Referring to the drawings which accompany the specification, Fig. 1 is a
sectional elevation of the invention applied to a padlock, and showing the shackle
locked, Figure 2 is a horizontal section of the same as seen from below, and
Figure 3 is a similar section of the same parts but in the unlocked position.
Figure 4 is a view from below, but on large scale, showing certain tumblers and
the locking-bar in locked position. The shaded projections 5, 6 indicate the
tumblers which are in the locked position. Figure 5 is a similar view showing
all the tumblers and locking-bar in the unlocked position. Figure 6 is a diagram
illustrating the spacing of the projections of the tumblers. Figures 7 and 8 are
plan views of the lever which locks and releases the case through the agency of
the locking-bar, in the locked and unlocked positions respectively. Figure 9 is
a plan of a washer. Figures 10 and 11 illustrate two several keys. Figure 12
is a section, on large scale, of the invention applied to a cylinder lock, which is
arranged to lock in both directions, and showing the tumblers aud locking bar
in the unlocked position. Figure 13 is a similar section but showing the lock-
ing-bar and certain of the tumblers in a locked position. The shaded projection
indicates the locked tumblers. The stationary case in this figure is shown
slightly turned from the position in which it is shown in Figure 12. Figure 14
is a section on the line 14-14 of Figure 13, and showing the parts in the locked
position. Figure 15 is a diagrammatic plan and Figure 16 an edge view of
one of the tumblers, illustrating the spacing of the projections. Figure 17 is
a plan and Figure 18 an edge view of a washer. Figure 19 is a side view, partly
sectioned, of a lock equipped with sliding tumblers. The parts are in the un-
locked position. Figure 20 is a similar view, but showing the locking-bar and
certain of the tumblers in the locked position. The locked tumblers are indicated
by the shading. Figure 21 is a plan of a washer. Figure 22 shows certain
essential parts of a lock equipped with sliding tumblers which are adapted to lock
in both directions.
Referring to that form of lock shown in Figs. 1 to 8, A is the case of a pad-
lock adapted to be locked in one direction only, B, the shackle, 6 the socket
therein to be engaged by the bolt. The tumblers are assembled between the
bottom plate C and the top plate D, which are held at the proper distance apart
by the shield H, and fixed by rivets on said shield and by the axial pin f of the
tumblers F. E is the key barrel, which is a cylinder slotted for the passage of
the key, the slot being open on one side to permit the bits to project to engage
the tumblers in the manner hereinafter described. A longitudinal rib e² on said
barrel E serves to move the tumblers to the full limit of their throw both in locking
and unlocking. Said key barrel is the axis around which the tumbler-case rotates in
locking and unlocking, and is provided with necks e e¹ which have a working

page_text: fit through plates C D, and neck e comes flush with the outside of case A when
the lock is assembled, neck e¹ having a working fit and being movably held in a
socket in the top A', which carries the shackle B. The locking-bar G, pivoted
in plates C, D, is constructed and operates as hereinafter described. The bolt D'
is formed as a part of, or fixed on, said plate D, and in the locked position enters
socket of shackle B, thereby locking said shackle. As the lock unlocks, the
tumbler-case rotates to the position of Fig. 3, withdrawing bolt D₁ from socket b,
and permits the shackle to be raised and turned in the usual manner.
There may be any desired number of tumblers F, each capable of independent
rotation, and between each pair of tumblers is a stationary washer L. Each
washer is of thin metal, preferably shaped as shown in Fig. 9, and provided
with a hole 7, which fits on the pin f and with projections 1 on the end adjacent
to shield H, so that said washers are held stationary by engaging said shield.
Said projections are spaced so as to allow of the free sweep of the bits of the
key.
Each of said tumblers F is provided, on the side adjacent to said shield H,
with a true key slot 1, and false key slots 2, 3, each spaced on opposite sides of
said slot 1, an angular distance equal to the angular revolution of the tumblers.
On the side adjacent to the tumblers the said shield H is cut away sufficiently
for the ready insertion and sweep of the key in locking and unlocking, and there-
fore whatever tumblers are locked or unlocked there will always be two lines of
recesses at the open side of said shield H, and said recesses will not indicate what
tumblers are in either position. Said shield H will also prevent a pick from
reaching by to feel the third recess, and also from reaching the locking-bar G.
On the side opposite to said shield H and adjacent to said locking-bar G each
of said tumblers F is provided with projections 5, 6 and 7; projection 6 in par-
ticular serving to rotate the locking-bar G from the locked to the unlocked
position and the reverse, and also, in certain circumstances, serving like the
projections 5 and 7 to prevent rotation of the tumblers by engaging on the lock-
ing bar, as will be hereinafter explained. The surfaces 9, 10, 11 of said projec-
tions 5, 6, 7 respectively are preferably shaped on arcs of circles such that when
either projection is against the locking-bar, as in Figs. 4 and 5, said arcs are
parallel to the peripheral curve of said locking-bar G; that is to say, they then
coincide with arcs of circles struck from the axis of the said locking-bar as a
centre. Figure 5 makes this clear as to projections 6 and 7, and the same is true
of surface 9 of projection 5. The distance of projections 5 and 7 from projection 6
is such that if lines x y z (Fig. 6) are drawn from the axis of the tumbler to the
points where said arcs intersect the outer ends respectively of projections 5, 6, 7.
the angle between any two adjacent lines, as a y or yz, will be equal to the
angular movement of the tumbler in locking or unlocking, and the width of the
ends of projections 6 and is sufficient to interfere with said locking-bar G if an
attempt is made to surreptitiously open the lock.
Said locking-bar G, is sufficiently long to extend across the edge of all the
assembled tumblers (Fig. 1), and is preferably shaped in cross section as shown.
Said locking-bar is provided with arms or ribs 15, 16, separated by a slot or
groove 17, which extends the whole length of said locking bar, and in which the
projection 6 works somewhat like the tooth of a gear, the co-action of the tumblers
and locking-bar resembling that of a gear and pinion. Said arm 15 of the lock-
ing bar is preferably hammer-shaped in cross section as shown.
On the end of locking-bar G adjacent to the cap A¹ is a cam 20, (Fig. 7) which
engages in a recess or talon 21 of a plate lever 22, pivoted on the pin f. Said
lever 22 is provided with a hook 24, adapted to engage on the end of said cam 20
when locking-bar G is in the locked position (Fig. 2), and prevent the said lock-
ing-bar from turning too far, and is also provided with a hook 26, which is bent
at right angles to the plane of said plate lever 22 and works in a curved slot 27
in the cap A At the end of said slot 27, adjacent to the position of hook 26
when the lock is locked, is a recess 28, into which the said hook 26 is moved by

page_text: the locking-bar to prevent turning the tumbler case to the unlocked position,
until the lock is unlocked.
The lock is operated as follows: Suppose it to be unlocked, all the tumblers F
and the locking-bar G being in the positions of Fig. 5, the tumbler-case C, D
in the position of Fig. 3, and the bolt 1) withdrawn from the socket in shackle B.
Now a
key K, having a combination of bits 30, 31, 32, corresponding to some
combination of tumblers is inserted and turned in the direction of the arrow 4,
Fig. 5. Said bits 30, 31, 32, engaging in the true key recesses 1 of the said
tumblers, the tumbler case turns to the position of Fig. 2, wherein bolt D¹ enters
socket 6 in shackle B, and, further motion of the tumbler case as a whole being
prevented by said hook 26, the key turns said tumblers to the locked position of
Figs. 2 and 4. While so turning the projections of each of the tumblers in the
locking combination have engaged on the locking arm 15 of locking-bar G, and
turned said locking-bar to the locked position of Figs. 2 and 4, wherein said
arm 15 just clears the projection 6 of said locking tumblers, the rounded periphery
of said locking-bar meantime sweeping freely by the surfaces 10 and 11 of the
projections and 7 of the tumblers which were not moved by the key. As the
locking-bar turns, its cam 20 turns lever 22 so that the hook 26 comes into
the recess 28, and prevents turning back the works to withdraw the bolt from the
shackle, and hook 24 prevents turning the locking-bar too far.
As the tumblers come to the limit of their movement, which is determined by
projections 5 coming against the periphery of the locking-bar, the bits of the
key pass out of the recesses in said tumblers and the key continues turning, the
ribe of barrel E entering the recesses 3 of such tumblers as were locked and the
recesses 1 of such as remained unlocked, and lining all up just as the key turns
to the full end of its motion. The lock is now locked and the key may be with-
drawn.
To unlock, the same key as locked, or the exact duplicate thereof, is inserted
and turned in the reverse direction to that of locking. Its bits, engaging the
slots 1 of such tumblers as were locked, turn same back to the unlocked position,
the projections 6 of such tumblers engaging arm 16 of locking-bar G and turning
it back to the unlocked position. As the locking-bar turns its cam 20, engaging
lever 22, moves hook 26 out of recess 28, and the continued pressure on the key
rotates the tumbler case as a whole back to the unlocked position, hook 26 now
moving freely back through slot 27. At the final movement of the key, rib e²
on barrel E, engaging in slots 2 of all the tumblers lines all up. The lock is
now unlocked._
Suppose, when the lock is locked, an effort is made to open the lock with a
false key having some bits, among others, which will engage some of the un-
locked tumblers, then the projections 7 of such tumblers will move so as to be
engaged by arm 15 of locking-bar and prevent same from turning back to the un-
locked position.
Suppose an effort is made to feel out the combination with a pick, then, since
all the tumblers, whether locked or unlocked, have their motions limited by
the locking-bar G, and the free play of all is equal in all directions, there is no
indication of what tumblers are locked or unlocked. Also if the pick moves any
unlocked tumbler as far as it will go toward the unlocking position, its projec-
tion 7 will prevent said locking-bar from turning to the unlocked position.
If an effort is made to obtain an impression of the combination, all the tumblers
being equally free to move, all will make the same impression in the blank, and
no indication of the combination will be given.
Referring to Figs. 12 to 16, which show the principal features of the invention
applied to a cylinder-lock capable of being locked in both directions, S is the
external fixed ease, T the internal rotatable cylinder or tumbler case, the
annular tumblers, and G¹ the locking-bar. Said tumblers and locking-bar are
now shown constructed and arranged to lock in both directions, but I do not show
or describe all the minor details of construction, since said figures are shown

page_text: only to indicate how the principle of arranging the locking-bar and tumblers so
that the locking-bar shall limit the motion of the tumblers without requiring any
stop pins or springs is applied to cylinder locks.
Each of said tumblers Fis provided with two projections 40, 41, which are
adapted to rotate the locking-bar in locking and unlocking in one or the other
direction, and with two surfaces, 42, 43, which are also in effect projections and
are adapted to limit the motion of the tumblers, when in the locked position, by
engaging with the locking-bar. As shown, said tumblers are practically circles,
with the spaces between said surfaces 42, 43 and projections 40, 41, cut away,
the ends of said projections being on the same are as the general periphery of the
tumblers. The surfaces 45, 46, 47, 48 of said projections are preferably shaped
on arcs of circles, in the manner described in connection with the tumblers of
the padlock. Said tumblers centre and turn easily within the tumbler case T,
and around the central orifice of each tumbler is a number of recesses, 50, 51, 52,
53, 54, 55, 56, 57, all spaced an angular distance apart equal to the angular
rotation of the tumblers. Slot 50 serves as the true key slot, and the others to
conceal the relative position of the tumblers, since, whether any tumbler is locked
or unlocked there is always presented to the key hole the same number of lines of
slots.
Said locking-bar G¹ is now provided with three arms, 60, 61, 62. Said arm 60
has two hammer-shaped surfaces as shown, one of which will just clear said pro-
jection 40 in one locked position, and the other of which will just clear said pro-
jection 41 in the other locked position. The back, 64, of said locking-bar is pre-
ferably shaped on an arc struck from the axis of the tumbler case T as a centre
and is so situated that, when the locking-bar is unlocked, it will pass freely by
the inner wall of the fixed case S, but that, when the locking-bar is locked one
of its edges will enter one or the other recess 68, 69, in the said case S, and
thereby prevent turning the tumbler case T, which latter will be operatively con-
nected with a bolt in any suitable manner.
Between each pair of tumblers is an annular washer 70 of thin metal, pre-
ferably circular in shape, with projections 71, 72, which enter recesses 74, 75, in
case T, and hold the washers stationary. The orifice in the centre of each washer
is large enough to permit of the free insertion and sweep of the key X'.
A key barrel can of course be used, but I prefer dispensing with it, and using
a key which has a cylindrical shank 76, equipped with the desired combination
of bits on one side.
A stop pin 78, (or equivalent device) working in a circular groove in the tumbler
case T, limits the motion of said case.
In operation, the parts being in the unlocked position of Fig. 12, the desired
key being inserted engages in the key recesses 50 of some combination of
tumblers. As the key turns to the locked position of Fig. 13 it first revolves the
tumbler case T until the locking-bar G¹ comes opposite recess 68, and then the
projections 41 of the locking tumblers engaging on the corresponding surface of
arm 60, of locking-bar G¹ rotate said locking bar to the locked position, in which
one edge thereof enters said recess 68, and the ends of said projections 40 of the
locking tumblers prevent the locking-bar from turning out of said recess 68,
to free case T, until the same key or its exact duplicate, has been inserted in the
lock and turned in the reverse direction, restoring the parts to the unlocked
position.
Similarly, if, the works being unlocked, the key has been turned in the other
direction, it would have locked the tumbler-case in that direction, the other edge
of the locking-bar turning up into recess 69.
Referring to Figs. 19, 20 and 21, U is the tumbler case, which will be placed
in an outer case, not shown. F are the sliding tumblers, G2 the locking bar,
which is similar to that shown in connection with the padlock. But, as will
be understood by those versed in the art, a locking-bar similar to that shown in
Figs. 12 and 13, and arranged to lock both ways, can be used with the sliding

page_text: tumblers, by providing the proper arrangement of projections on said tumblers,
and such a locking-bar G3, in combination with sliding tumblers is shown in
Fig. 22. True key recesses 80, and false key recesses 81, 82 are provided in the
outer edges of each tumbler. and spaced equally apart a distance equal to the
throw of the tumblers; 83 being a shield around the key. On the edge adjacent
to locking-bar G2 each tumbler has a projection 85, adapted to rotate the said
locking-bar, and also has surfaces 86, 87 which are practically projections on
opposite sides of said projection 85 and at a distance therefrom equal to the throw
of the tumblers. The surfaces 88, 89, 90 of said projections are preferably
shaped on arcs of circles, as herein before described in connection with the rotating
tumblers. Between each pair of tumblers is a washer 92, preferably shaped as
shown and of thin metal, and provided with projections 93, 94 which enter
spaces 96, 97, in case U and hold the washers stationary, said washers also being
cut out on the opposite side, as at 98, to permit of insertion and the free sweep
of the key.
Supposing the parts unlocked and in the position of Fig. 19, a key being in-
serted and turned will shift some combination of tumblers to the position of
Fig. 20, rotating the locking-bar G2 to that position in which it locks the
tumblers, as hereinbefore described, only the key which locked or its exact dupli-
cate being able to open the lock.
Referring to the aforesaid Fig. 22, the locking-bar G³ is similar in shape
and construction to the locking-bar G of Figs. 12 and 13. The tumblers F3,
shaped as shown, are provided with projections 104, 105 adapted to engage with
an arm 110 on the locking-bar to move the said locking-bar in one or the other
direction, and with the projections 106, 107 to limit the extreme motions of the
tumblers by bringing up on the locking-bar. True key slots 100, 101, and false
key slots 102, 103 are formed in the other edge of the tumblers, so that what-
ever may be the positions of the tumblers, two straight lines of slots will be
accessible from the key-hole, and no indication of the position of any tumbler will
be given.
The projections of the sliding tumblers, as well as those of the cylinder lock,
in combination with the locking-bar, permit of dispensing with all springs and
stop pins, and ensure the security and other advantages hereinbefore enumerated.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
First. A key combination-lock so constructed that the locking-bar can be
turned to effect the locking by means of any of a series of independently movable
tumblers and can then be unlocked only by the tumblers that were used for
locking it, and the movements of the said tumblers are limited by the said lock-
ing-bar without the aid of springs or stop-pins, substantially as hereinbefore
describel.
Second. The combination of independently movable tumblers, a rotatable lock-
ing-bar engaging therewith, and a lever adapted to be moved by the said lock-
ing-bar, the said tumblers, locking-bar and lever being so formed and arranged
as to limit the motions of the tumblers and locking-bar without springs or pins,
substantially as described.
Third. The combination of a rotatable locking-bar, a series of independently
movable tumblers each having a projection adapted to rotate the said locking-bar
and other projections adapted to engage with the said locking-bar and limit
the motion of the said tumblers, and a key-barrel having a projection adapted to
move the said tumblers to the extreme limit of their throw, substantially as
described.
Fourth. The combination of an oscillating tumbler-case carrying a locking-
bolt and equipped with a rotatable locking-bar and independently movable
tumblers adapted to engage with the said locking-bar, and a lever adapted to be

page_text: engaged by the said locking-bar and in one position to lock the said tumbler-
case and in the other position to release the same, substantially as described.
Fifth. The combination of a rotatable locking-bar, a series of independently
rotatable tumblers adapted to engage with the said locking-bar and provided
with true and false key-slots equally spaced, a shield adjacent to and open to-
ward the said tumblers, and a key-barrel provided with a projection adapted to
bring all the tumblers up to the limit of their throw, substantially as described.
Sixth. The improved key combination-lock constructed substantially as de-
scribed with reference to either of the forms or modifications illustrated in the
accompanying drawings and operating as, and for the purposes, above specified.
Dated this 29th day of November 1898.
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.