IMPROVEMENTS IN LOCKS
Year: 1876

page_text: LETTERS PATENT to Carl Pieper, of Dresden, Saxony, for the Invention of
"IMPROVEMENTS IN LOCKS." A communication from August W. O. Kleinau,
residing at Hamburg, Germany.
Sealed the 2nd March 1877, and dated the 19th December 1876.
COMPLETE SPECIFICATION filed by the said Carl Pieper at the Office of the
Commissioners of Patents on the 19th December 1876.
CARL PIEPER, of Dresden, Saxony. "IMPROVEMENTS IN LOCKS." A communi-
cation from August W. O. Kleinau, a person resident at Hamburg, Germany.
This Invention relates to the construction of an improved door lock, which, how-
ever, in a modified form may also be used for other purposes.
The lock, as adapted for doors, is represented in its simplest form on the annexed
Sheet 1 of Drawings.
Fig. Ia is a view of the same with one of the side plates of the lock case
removed.
.
Fig. Ib is a cross section through the centre of the tumbler 1, the latter being in
its lower position.
Fig. I. is a section with the key introduced and tumbler lifted.
Fig. II.a shows the bolt pushed fully out.
Fig. IIb is the cross section corresponding to this position; and Fig. III. repre-
sents the key in different views.
It has to be considered a main peculiarity of this lock that the "latch" and the
"bolt" of the common lock are united in one piece 7, which henceforth may simply
be termed "bolt." In the position of Fig. I. this pieco serves as latch. f is a spiral
spring fastened at one end to the lock case, whilst the straightened wire at the
other end passes through a part of the bolt, and terminates in a loop; the spring
thereby draws the bolt forward, when the latter serves as latch. The spring,
however, is prevented from shifting the bolt as long as the tumbler & remains in its
lower position within the recess el of the bolt, but by one of the knobs k the bolt
may be moved back from either side of the door, so that the door having only been
latched may thereby be opened. When the knob is released the spring draws the
•

page_text: bolt forward again as far as the tumbler permits. The bolt is bevelled at its
forward end, as usual with the latch.
If the bolt is to be pushed further out for the purpose of locking the door the
tumbler must first be lifted. From the inside of the room or the house this may
be done by the small knob s². The bolt r can then be pushed out by one of the
knobs k as far as the slott and the studs permit, whereupon the tumbler drops into
the recess e³, and fixes the bolt in this position, see Fig. II.a. The unlocking may
be done from the interior in a corresponding manner.
For locking the door from the outside the bolt has also to be shifted by the
knob k, but previously the tumbler must be raised by the key s¹. This key in its
simplest shape consists of a flat piece of iron bevelled at the forward end, as shown
in Figures I and III. The same, after having been introduced into the key guide
fixed in the wood of the door, is pushed with its bevelled end under the tumbler,
whereby the latter is lifted. To facilitate this the lower edge of the tumbler is rounded.
As soon as the tumbler is out of the recess e¹ the spring of shifts the bolt slightly
forward, ie., as much as the recess e² of the bolt (which is made somewhat wider
than the thickness of the key) permits. In consequence the tumbler cannot now
drop again into the recess e¹ after the key has been withdrawn, but it rests on the
top edge of the recess, and the bolt may be pushed out by the knob k, as before.
The tumbler then drops into the recess e³, and the bolt is again arrested.
For the purpose of unlocking the door from the outside the key is again intro-
duced, and the tumbler thereby lifted; after this the key, being pushed in a little
further, acts by a sloped shoulder j (see Fig. III.) against the back (or right-hand side)
of the recess e, and shifts the bolt so far back as to prevent the tumbler from
dropping again into the recess es after the key has been drawn out; the bolt may
then be drawn back by the knob, as before.
To prevent the spring f from hindering the locking of the bolt, the lower
projection of the latter has a slit through which the straight tail of the spring
passes.
If an objection should be raised against the described arrangement, which requires
the knobs to be pulled sideward for unlatching the door, the bolt r may be pro-
vided with teeth forming a rack into which a pinion gears, as shown in Fig. XIII.,
Sheet 2, the axis of this pinion having knobs on the outside. In this case the
spring has to be placed somewhat lower, so as to keep it clear of the said
pinion.
A small slide v arranged in front of the keyhole, and serving to keep out dust,
&c., is lifted by the key in the same manner as the tumbler.
In a lock of the simple arrangement, shown by the Figures I and II., the
tumbler might be lifted by a strip of sheet iron or other similar means; for making
this operation difficult a slot is cut into the tumbler, which is but little narrower
than the key. The latter, instead of having the plain shape of Fig. III., may be
modified in various ways. A few of the possible different forms of sectional area
of such keys are shown in Fig. IV. The keyholes for the same have of course to
be corresponding.
A modification of this lock, which presents greater security than the one described,
is represented in Figures V. and V.b. The same contains three tumblers, which
have to be lifted at different heights, the key being shaped accordingly, as will be
.seen from Fig. VII. The tumblers and have each one slot for the purpose
already stated; has two such slots, the tongue between them being the point on
which the lower step of the key acts. The two small projections and of the
key pass through the slots of, and then one of them lifts the third tumbler."
The second or middle tumbler remaining in a lower position than the two others a
corresponding slot has to be cut into the top of the bolt at g, as otherwise it could
not move. If one of the tumblers is lifted too high by a wrong key or other
instrument it acts on the lever h, and the slide i being thereby depressed behind
the bolt prevents the latter from being pushed back; a weight at the other end of
the lever gives this end a tendency to descend. To the said weight the slide i¹ is

page_text: attached, the object of which is to prevent the tumblers from being lifted one after
the other by means of a hook or other instrument. To carry out such lifting the
bolt must be pressed gently against the tumblers, so as to support those which have
beon lifted, and to find out by the resistance against the introduced instrument
which of them has to be lifted next. Supposing now the slide i to be so arranged
that having dropped into the recess e¹ it will first of all receive the pressure of the
bolt; it is then impossible to press the tumblers against their guides for the purpose
of lifting them successively by the hook. They will ever fall back again as soon
as the hook is withdrawn. Whilst the bolt serves as latch the slide ¹ remains
supported by the top of the bolt.
Another important modification of this lock is represented in Figures VIII., IX,
X., and XI. Each of the three tumblers is here cut, as it were, into two parts 11, 1º,
and being the upper, m², m², and m³ the lower parts.
Fig. VIII. shows the bolt drawn back into the position in which it serves as
latch; the lower tumbler parts m always remain in the appropriate recess of the bolt,
and move with the same.
Fig. VIIIb shows the bolt locked; and the Figures VIII & VIIId are the
sections respectively corresponding to VIII. and VIIÏ.b The tumblers have to bo
lifted to such a height that the top of the parts m be even with the top of the bolt.
If any one of the pairs of tumblers is lifted insufficiently the upper part of this
pair prevents the bolt from being moved; and, on the other hand, if it is lifted
too high the lower part m acts in the same manner.
In the lock represented there is yet arranged a device for the purpose of greater
security, to which I attach special importance. As will be seen from Fig. XI. the
key is made very thin at the acting part, and it has a slit v, whilst the bolt, shown
detached from the lock in part in Fig. IX., has a tongue u¹. The key, when pushed
into the lock lifts the tumblers, and its slit v comes into a position opposite to the
tongue u¹. The bolt not being held any more by the tumblers may be moved to
a certain amount, the tongue passing through the slit v of the key. After this the
key can and must be withdrawn through the slit u, whereupon the bolt may be
fully pushed back.
If the piece m, Fig. X., is substituted for the tumbler part m², the key after
being introduced for the purpose of unlocking cannot be drawn out again before
the bolt is partly moved back, as the small tongue x in the piece m dropping
into the slit of the key prevents this. The key being consequently, as it were,
trapped I have called this lock "trap lock." A counterfeit key, in which the slit
is not cut properly, or which in other respects deviates but slightly from the correct
shape, cannot be drawn out of the lock again without destroying one part or another
of the latter.
To prevent the lock from being opened by successively lifting the tumblers by
means of hooks, pins, etc., the upper parts of the tumblers have a square notch at
their lower left-hand corner. Supposing even that all the tumblers / have been
lifted by hooks to the proper height the bolt may then be shifted until the tongue u¹
begins to close the keyhole, and presses on the books, whereupon the latter have
to be withdrawn. As soon as this is done the tumblers drop back into the recess of
the bolt to an amount equal to the height of the aforesaid notch. If the tumblers
had no such notch the least shifting of the bolt would suffice to keep the tumblers
out of action after once being lifted.
In Figures XII.a, b, o, and d, on Sheet 2, a lock is represented which in the main
points agrees with the foregoing, but the bolt of the saine has three tongues, the
middle one u¹ pointing downward, the other two v and v¹ directed upward. By
these tongues the keyhole is closed completely at a certain point in the course of
the bolt, so that the possibility of keeping the tumblers (especially the third one ³)
lifted by foreign instruments is here precluded altogether. The key, Fig. XII., has
to be provided with one slit from the top, and two slits v₁ from the bottom, cor-
responding with the tongues. The lock is designed with two pairs of tumblers;

page_text: the lower part of one pair has a tongue ¤, by which this lock becomes a trap lOCK
like the foregoing.
The advantage presented by the closing of the keyhole can even be made
available without the application of several or of the double (ie., upper and lower)
tumblers. If a single tumbler (in the present case ) is made with a step, so that
the lower end lies behind the middle tongue u¹ of the bolt, then also the tumbler
cannot be kept lifted by any other instrument than the proper key.
I consider it an advantage of the described locks that the mechanism for the
very purpose of locking has been simplified by the non-application of springs.
The spiral spring f comes into action only when the bolt is turned into use as
latch.
With regard to other locks to be opened by the simple introduction of the key
(without turning it) my lock presents the advantage amongst others that it can
be opened by the key from either side, and that therefore it may be used as door
lock.
If the lock is to be applied to portable cash boxes it is necessary to arrange the
same so as to prevent a releasing of the bolt by turning the box upside down. For
this purpose three small tubes w¹, w, and w³, Fig. XIII., have been screwed into
the side plates of the lock case, in each of which a pin fits loosely. The pins are
prevented from falling out of the tubes by small screws, as shown by the Drawing,
but the pins may partly enter into the interior of the lock. The tubes are all
inclined downward, so that in the upright position of the lock the pins will all lie
in the tubes. In every other position in which the tumblers may drop out of the
bolt one of the pins falls into a notch or hole of the bolt, or behind the same, and
prevents it from moving. Three tubes with pius are required, two of which on one
side are inclined downward and laterally towards tho left and the right, and one on
the other side inclined downward only, so that in all undue positions of the lock at
least one of the pins comes into action.
The modified lock represented in Figures XIV.a, b, &, and XV., & b,
Sheet 2, although generally applicable, is especially intended for boxes, drawers,
trunks, etc., and it may also be used as padlock; the same presents a complete
security against being opened by any other means than the proper key.
In this lock, as shown by the Drawing, seven tumblers have been applied, of which
cach is divided into two parts, and m, as in the lock Fig. IV.; the lock being
designed to be opened from either side, the tumblers, & 1, 12, & 1º, 13, & 1³, havo
to be alike, so as to allow the key to act in the same manner from both sides ;
the key being introduced into the keyhole for the purpose of locking, mainly lifts
the tumblers and , these only having a sharp corner below on the right-hand
side, by which the bolt is detained; the tumblers from 12 to 1 are bevelled at the
corresponding corner so that they will slide along and upward on the incline of the
bolt at y, without being previously lifted.
The slot in the bolt through which the key passes is somewhat wider than the
latter so that the spiral spring f will shift the bolt slightly forward when the tumblers
1, and 17, are lifted; the key having been withdrawn, the bolt may be pushed for-
ward completely by one of the knobs k, as "formerly, whereupon the tumblers 7,
dropping into the after recess, detain the bolt in its place; the relative positions
which the tumblers occupy at the time are shown by Fig. XV. It will be seen
that for the purpose of unlocking the tumblers and have to be lifted first of all;
the key being introduced into the lock raises m¹ and m7, Fig. XV.b, and conse-
quently and high enough to allow the bolt of being partly moved back. The
tumbler parts from to le do not prevent this moving as they have a notch at their
left hand lower corner; the parts m³ to me now touch the teeth, respectively, the
bottom of the slits of the key by their bevelled tongues a, so that they slide up and
on the key by the motion of the bolt, thereby also lifting the tumblers to ; as soon
as the tongues have passed the key the tumbler parts m drop back again, and the
key, which so long had to remain in its place, must now be withdrawn. Besides,
there was so far no possibility of drawing the key out again, as the tumbler parts

page_text: m³ and m³ prevented this in a similar manner as in the "trap lock" described
above. Before the dropping of all the tumbler parts m, the bolt has been shifted
back far enough that the parts I find a resting point on the top of the bolt at y', and
therefore no more prevent the bolt from being pushed back fully. In case one of
the tumbler parts m should have been lifted too high by a wrong key, it cannot
the stops, whereby unlocking is prevented.
pass
In this lock there is no special guide for the key as in the former locks, as the
key is completely guided by the keyholes in the lock case, and the escutcheons on
the outside of the door, etc. The described arrangement yet presents the advantage
that a larger number of tumblers may be placed into a narrower space than in the
other described locks, because the inclined edges by means of which the tumblers
are lifted are not placed on the key, but on the tumbler parts m; the inclines on
the key necessarily require the same to be longer and the tumblers to be thicker.
If this lock is to be applied to portable boxes, etc., the tumblers must be prevented
from dropping out of the bolt in case the box is turned upside down. In deviation
from the former arrangements a spring, f, has been introduced in this case, which
presses the tumblers against the bolt so as to keep them in their place.
The modification of the tumblers of this lock shown in Figures XVI.a & b, yet
materially enhances its security against being opened by hooks or other instruments.
There is a remote possibility of opening the lock of Fig. XIV. in the following
manner: First of all, the tumblers and are lifted by hooks, the bolt is than
pushed back so that its corner 31 bears against the corresponding corner of the
tumblers to ", which are then lifted one after the other under continued pressure
of the bolt against them. For the purpose of making this mode of opening the lock
impossible, the tumblers and the bolt may be arranged as shown in Figure XVI.A.
The bolt has a small notch y, and the tumblers have corresponding projections
or toes which enter into the notch y² if the bolt is pushed back before the
tumblers 2 to 10 have been completely raised. A successive lifting of the tumblers
without the pressure of the bolt against them is impossible, and as by the described
arrangement the very pressure of the bolt serves to keep the tumblers down, there
is no possibility whatever of lifting then successively by hooks or other similar
instruments.
In Fig. XVI.b the bolt is provided at y with inclined teeth to which similar
teeth on the tumblers to 1 correspond. The object of these teeth is the same
as that of the notch y¹ of the bolt and the toes 2 on the tumblers in Fig. XVI..
This arrangement may also be applied to my other locks with several tumblers.
Having now described the nature and the object of this Invention and how it
may be carried out in practice, I declare that I claim as new and essential features
of the same:-
1. In a lock the combination of the bolt provided with the recesses e¹, c², e³,
and e, the spiral spring fhaving its straight end passed through a part of the
bolt and one or more tumblers l, the bolt being provided with the knobs kas in
Fig. Io, or with rack and pinion as in Fig. XIII.a for moving the same, all
arranged to operate substantially as and for the purpose described.
2. In a lock having one or more.tumblers falling into recesses in the bolt, I claim
the key provided with an inclined shoulder j on one or on both sides, to operate on
the bolt, substantially as herein set forth.
3. The lever hand slides i & in combination with a recessed bolt and one or
more tumblers, as and for the purpose specified.
4. The combination of the bolt r provided with recesses c¹ and e³ and slot g,
the tumblers 2 and 3 having each one slot, the tumbler two slots, and the key
having projections n, n², as shown by Figures V., b, VI. & VII., all substantially
as and for the purpose herein set forth.
5. In a lock I claim the combination of the bolt having recesses e¹ and e³, and a
series of tumblers made each in two parts and m, the lower parts m moving with
the bolt as shown by Figures VIIIa-d, and IX, as and for the purpose described.
6. The tongue u¹ in the bolt of Fig. VIII.ad, and Fig. IX., or the combination of

page_text: the tongue u¹ with the tongues vand v¹ in the bolt, Fig. XII. e, the key having
one slit o, Fig. XI., or the slits o and o', Fig. XII, as and for the purpose specified.
7. The tongue in the tumblers m², Fig. X., and m², Fig. XII.º, as and for the
purpose set forth.
8. In combination with a lock having gravitating tumblers I claim the inclined
tubes w¹, w, ws, Fig. XIII.a, b, with loose pins inside, for the purpose stated.
9. In combination with the bolt r, Fig. XIV, and XV., 6, the tumbler parts m
having bevelled tongues x, for the purpose described.
10. In the bolt of a lock the notch y², Fig. XVI.a, together with the toes or
projections on the tumbler parts 1, 1, or the inclined teeth y, Fig. XVI.b, on the
bolt r, and the corresponding teeth on the tumbler parts 13, 16, as and for the
purpose specified.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand
and seal, this Fourteenth day of December, in the year of our Lord One
thousand eight hundred and seventy-six.
CURT DINDED
זסו
CARL
DIEDED
MYRTOTT TATT
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