An Improved Combination Lock.
Year: 1889

page_text: Date of Application, 5th Nov., 1889-Accepted, 18th Jan., 1890.
COMPLETE SPECIFICATION.
An Improved Combination Lock.
I EUGENE CHARLES SMITH, Mechanical Engineer of the City County and State of
New York United States of America 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 an improved combination lock which can be operated and
locked by any one of a series of keys that are arranged to be used with said lock but
which lock can only be opened by that key by which it was locked. Any number of
keys can be used for operating the lock and in the several keys the bits can be
arranged in different ways as to engage different combinations of tumblers thus
making it possible to provide a very great number of keys all of which can be used
on the same lock but in all cases the lock can only be unlocked by the same key by
which it was locked.
In the accompanying drawings Figure 1 is a vertical longitudinal sectional view of
the improved lock the bolt being thrown so as to engage the shackle.
Figures 2, 3, and 4 are side views of some of the different keys that can be used
with said lock.
Figure 5 is a horizontal sectional view of my improved lock on line - Figure 1
showing the arrangement of the sliding bolt the bolt being withdrawn.
Figure 6 is a similar view the bolt being thrown.
Figure 7 is a horizontal sectional view on the line y-y Figure 1 the bolt being
withdrawn.
Figure S is a detail view of the tumblers and locking bar.
Figure 9 is a side view of the locking bar.
Similar letters of reference indicate corresponding parts.
The lock mechanism is contained in the casing A provided with the cover or lock
base B in which the shackle C is mounted to turn said shackle having a long leg Cand
a short leg C² the long leg projecting through the base plate and being mounted to slide
and turn in the same and the short leg merely passing into an aperture in the top
of said base plate. The long leg has a notch C³ for receiving the end of the lock
bolt D and on its end is provided with a collar C or other projection to prevent with-
drawing said long leg entirely from the lock casing. The bolt D which slides on the
underside of the base plate B is provided with two longitudinal slots D' through
which the pins E E' pass which connect the end plate F of the lock mechanism with
the base plate B. The bolt is provided with two notches 1) for receiving the bent or
beveled end of a spring F¹ held by two pins E2 E3 which also serve to connect the
end plate F with the base plate of the lock. The bolt is provided in its inner edge
and at the end opposite the one that enters the notch in the shackle with a recess d
for receiving the end bits of the keys. On the pin G also connecting the base plate
with the end plate Fa series of tumblers H are mounted to turn each tumbler being
provided with a primary notch or recess a and with two auxiliary notches or recesses
arranged at the sides of the primary notch or recess a said auxiliary notches or
recesses bserving as blind recesses for aligning with the primary recesses a when
some of the tumblers have been shifted so as to prevent the feeling of the shifted
tumblers by means of a wire skeleton or blank key. If said auxiliary notches or
recesses were not provided a skeleton key wire or other implement could be inserted
until it meets the first tumbler shifted and then could be passed around the same to
the next and in this way it could be an easy matter to ascertain which tumblers had
been shifted. If the auxiliary notches are provided so as to align with the primary
notches a skeleton key or wire passed through the key guide will at all times pass

page_text: through a straight groove formed by the auxiliary recesses of those tumblers that
have been shifted and the primary recesses of the tumblers that have not been shifted
and it will thus be an impossibility to detect by means of a skeleton key or wire which
tumblers have been shifted. Each tumbler is provided in addition with two adjacent
V-shaped notches g and for receiving the V-shaped end of an accelerating and
retaining spring J of which one is provided for each tumbler said springs J being
held on pins E E³ as shown. In addition each tumbler is provided with a cam
projection K and with a shoulder or offset L. When the tumblers are thrown or
shifted the shoulders Lare adjacent to the pin E and when they are in their normal
positions the cams K are adjacent to the pin I also connecting the base of the lock
with the end plate F. The said pins M and E limit the movements of the tumblers in
one direction or the other. Between each tumbler an L-shaped guard plate N is
arranged one shank of each plate N being provided with a notch for receiving the
pin E and the other shank being provided with an aperture through which the pin G
passes. The several accelerating springs J of the tumblers are arranged between the
plates N. The bolt is provided with an offset or shoulder 0 against which the
Shank P of a retainer P can rest which retainer also has a shank 13 and is mounted
to swing on the pin M connecting the end plate F and base B. Said retainer is also
provided with a notch P for receiving a cam lug Q formed on one end of a locking
bar R provided with end pivots R' mounted in the end plate F and base B. The
locking bar is provided with two longitudinal cam surfaces S S¹ on which the curved
end of a spring T can rest which spring is held on a pin T projecting from the end
plate F the opposite end of the spring resting on the key guard V. Said spring T
not only serves for holding the locking bar R in different positions but also for
accelerating the movements of the same. Said locking bar R is provided with a
longitudinal groove W on one edge of which the bevel Wis formed for a purpose that
will be described hereinafter. The longitudinally slotted key cylinder V₁ is mounted
on its ends to turn in the base B and the bottom of the casing A and passes through
an aperture in the end plate F of the lock frame.
The keys m for the lock are provided with bits n so arranged that they can act on
the tumblers said bits passing through and into the primary notches a of said
tumblers. Figures 2, 3 and 4 show different arrangements of the bits so as to engage
the different tumblers. Figure 4 shows a larger bit which serves to engage two
adjacent tumblers. It is evident that the width of the bits can be increased so that
the same can engage a greater number of tumblers than two if desired.
The operation is as follows
When the lock is open that is to say when the bolt is not thrown the several
tumblers all have the position shown in Figure-7 the primary notches or recesses a of
the several tumblers being in line. If a key is inserted into the key cylinder V₁ and
turned in the direction of the arrow Figure 7 the end bit n of the key passes into
the notch d of the bolt and pushes said bolt in the direction of the arrow Figure 7
and the head of the bolt is passed into the notch of the shackle Jeg C as shown in
Figure 6. Then after the bolt has been shifted in this manner and the key is turned
further in the direction of the arrow Figure 7 the bits n on the key which are in
the primary noteles a of some of the tumblers turn said tumblers in the direction of
the arrow Figure 7 whereby the shifted tumblers are brought into the position
shown by that tumbler Figure 8 not provided with the surface shading. As the
tumblers pass from the position shown in Figure 7 into the position shown in
Figure 8 the cams K of those tumblers that are shifted pass into the longitudinal
groove W of the locking bar R whereby said locking bar is turned in the direction of
the arrow Figure 7 and is brought from the position shown in Figure 7 into the
position shown in Figure 8 in which position it is held by the tumblers the movement
of said locking bar being accelerated by the spring T. By turning the locking bar R
in the direction of the arrow the cam Q on that end of the same adjacent to the
underside of the base R is also moved in the same direction and acting on the
shank P of the said retainer P swings said shank against the shoulder O of the bolt

page_text: thereby keeping said bolt in thrown position. If now a false key wire or analogous
instrument is passed through the key cylinder it will meet with no obstructions as the
primary notches a of those tumblers that have not been shifted register with the
auxiliary notches b of the tumblers that have been shifted.
If a blank key covered with wax or an analogous substance is inserted in the lock
in order to ascertain which tumblers have been shifted and said key is turned one of
its sides will be pressed against the sides of the primary recesses of the tumblers that
have not been shifted and against the sides of the auxiliary recesses of the tumblers
that have been shifted.
The tumblers that have not been shifted can give in the direction of the arrow ²
and can give slightly in the inverse direction of the arrow as the cams K are a
short distance from the pin M. The tumblers that have been shifted can be turr ed
by this blank key slightly in the direction of the arrow as the shoulders L are a
short distance from the pin E and they can be turned slightly in the inverse
direction.
The impressions thus made on the waxed key will be alike for all the tumblers
whether they have been shifted or not and the said key can give no clue whatever as
to which tumblers have been shifted.
The slight play between the shoulders L and pin E and the cams K and pin Mis
thus requisite to prevent obtaining a wax impression of the shifted tumblers.
In case in some way or other an implement is inserted by means of which one of
the shifted tumblers could be turned in the inverse direction of the arrow Figure 7
the cam K of said tumbler would turn the locking bar R in the inverse direction of
the arrow Figure 7 and the sides of the groovo in said locking bar acting on the
cams K of the remaining unshifted tumblers would also turn said remaining tumblers
in the inverse direction of the arrow ³ Figure 7.
If one single tumbler is pressed in the inverse direction of the arrow ² it turns the
locking bar R in the inverse direction of the arrow 3 and thereby the bevel W¹ is
brought in such a position that it abuts against the ends of the cams K of the
remaining shifted tumblers as shown in Figure 8 thus preventing said locking bar
from being turned in the inverse direction of the arrow and from moving into such
a position as to permit of withdrawing the bolt. It thus follows that it is impossible
to change the positions of the shifted tumblers by turning the locking bar R and that
said tumblers can only be shifted by means of the bits of a key.
In order to move the bolt after the same has been thrown precisely the same key
must be inserted that was used for throwing the bolt for the reason that this correct
key has its bit so arranged that when the key is inserted into the key cylinder the
bits will pass into the auxiliary notches of the tumblers that have been shifted while
throwing the bolt and there will be no bits in the primary notches of those tumblers
that have not been shifted. If this correct key is turned in the inverse direction of
the arrow it will turn the tumblers that have been shifted in throwing the bolt in
the inverse direction of the arrow 2 whereby all the primary notches of the several
tumblers will be in line again. The cams K turn the locking bar R in the inverse
direction of the arrow and the cam lug acting on the shank P³ of the retainer P
swings the shank P₁ away from the shoulder O of the bolt thus permitting the end of
the key to withdraw the bolt..
While it is true that the same key is required for withdrawing the bolt that was
required for throwing it, it is nevertheless possible to use a very great number of keys
in this lock, but on each key the bits must be arranged in a different manner so as to
act on different combinations of tumblers. For example the bits may be arranged as
shown in Figures 2 and 3 where two bits are close to each other and the third a
greater distance away or as shown in Figure 4 where one bit is arranged to throw
one tumbler and the larger bit is arranged to throw two. As the number of tumblers
arranged in the lock is increased the number of keys or combinations of bits that can
be used with this lock increases.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a lock a series of severally shiftable interchangeable tumblers each having a
shoulder or offset and a stop fixed in the lock to limit the motion of the aforesaid
.tumblers as herein described.
2. In a combination lock the combination with a series of severally shiftable
tumblers each having a cam projection and offset or shoulder and stops against which
said shoulders and cam projections can strike substantially as set forth.
3. In a combination lock the combination with a series of severally shiftable
tumblers of which each has a cam projection and an axially rotating locking bar
adapted to engage said cams as herein described.
4. In a combination lock the combination with a series of severally shiftable
tumblers of which each has a cam projection an axially rotating locking bar adapted
to engage said cams and a bolt retainer operated by said locking bar substantially as
:set forth.
5. In a combination lock the combination with a series of severally shiftable
tumblers each having a cam projection a primary key recess and an auxiliary recess
at each side of the primary recess and an axially rotating locking bar adapted to
eng. "In
the cam projections of the tumblers as herein described.
a combination lock the combination with a series of severally shiftable
tumblers of retaining and accelerating springs acting on the tumblers intermediate
fixed plates between the several tumblers and an axially rotating locking bar adapted
to engage said tumblers as herein described.
7. In a combination lock the combination with a series of severally shiftable
tumblers of an axially rotating locking bar adapted to be engaged by said tumblers
said locking bar having a cam at one end and of a bolt retainer which is moved by
said cam on the locking bar as herein described.
8. In a combination lock the combination with a series of severally shiftable
tumblers of an axially rotating locking bar having a longitudinal groove provided
with a bevel as herein described.
Dated this 5th day of November 1889
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.