Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to bolt mechanisms, and more
particularly is concerned with bolt mechanisms for safes, vaults, strong-
rooms and the like security enclosures.
It is common for the bolts on the door of a safe or the like
to be thrown into engagement with the body of the safe by means of a handle
on the outside of the door, and then to be locked in the thrown condition
by a separate key or combination lock. The throwing mechanism typically
comprises a cranX attached to a sp-indle turned directly or indirectly by
the handle. The crank-pin operates on the bolts via a scotch-yoke ~i.e.
the pin slides in a slot extending at right angles to the required direc-
tion of motion~ of a connecting bar attached to the bolt strap. The same
mechanism is also used to withdraw the boltwork from its thrown condition,
and moreover is liable to be used in an attack on the safe to put force
on the boltwork. Specifically, there is the disadvantage that force can
be applied through the handle in the sense t:o tend to withdraw the boltwork
from its thrown condition against the actiorl of the locking mechanism.
It is an aim of the invention to provide a form of bolt mech-
anism that may be used to overcome the above disadvantage, and accordingly
in one aspect the invention resides in a bolt mechanism for the door of a
security enclosure comprising a manually operable member accessible from
without the enclosure;
--2--
a crank arm rotatable in either sense by the manually
operable member and operatively connectable with a drive slot
in a linearly moveable. transmission member operatively
associated with the boltwork o the door whereby rotation of
the crank arm in either sense by the manually operable member
imparts linear motion to said transmission member in a
corresponding sense to throw or withdraw the boltwork, a lock
Eor selectively locking the boltwork when in its thrown
10 condition; and means for selectively disengaging the coupling
of the manually operable member to the boltwork when the
boltwork is in its thrown condition, at least in the sense of
force transmission from said member to the boltwork such as
to withdraw the boltwork, by disengaging said crank arm from
15 said drive slot.
Preferably the disengaging means are operatively associated
with said lock for selectively locking the boltwork when in
its thrown condition, whereby operation of the lock acts to
20 disengage the coupling oE the manually operable member to the
bo].twork as aforesaid. This need not necessaril.y be the
case, however, and it is also pose~ible, for example, for the
di6engaging means to be embodied as an independent key or
combination operated mechanism, separate ~rom any such lock.
--4--
The invention will now be more particularly described, by way
of example, with reference to the accompanying drawings, in
which:
Figure 1 illustrates a bolt mechanism in accordance with the
invention installed within a safe door, being shown in the
condition which pertains when the safe bolts are withdrawn;
Figure 2 illustrates the mechanism of Figure 1 in the
10 condition which pertains when the safe bolts are thrown and
the lock operated;
Figure 3 illustrates a modification to the mechanism oE
Figures 1 and 2, being shown in the condition which pertains
15 when the sa~e bolts are withdrawn; and
Fiyure 4 illustrates the mechanism of Figure 3 in -the
condition which pertains when the sa~e bolts are thrown and
the lock operated.
Referring to Figure 1, a handle (not shown) is mounted
externally oE the door 1 and has a spindle 2 that extends
through the door to be coupled to a crank arm 3. More
particularly the spindle 2 extends into a slot 4 in the arm 3
25 and is there fitted with a bush 5 that has flats 5A which
contact the opposite walls 6 of the slot 4. The arm 3
accordingly turns with the spindle 2 under torque applied to the
handle, but can slide transversely with re~pect to the rotational a~;is
of the spindle 2
The arm 3 carries a crank pin ~ to en~age in a drive slot 8 of a
s~otch-yoke coupling to a connecting bar 9. The connecting bar is
n~ounted to slide longitudinally and is Coupled to a strap 10 that
carries the safe bolts 11 ~only one of which is shown in part).
Turning of the spindle 2 accordingly turns the crank arm 3 and
moves the pin 7 up or down the slot 8. This movement oI the pin 7
drives the bar 9 to and fro and thereby throws the bolts 11 or
10 withdraws them in dependence upon the sense in which the external
han dl e i s r otat e d .
Referring now to Figure 2, when the bolts 11 have been thrown
into engagement with the body of the saie they are locked there in the
normal manner by key-ope~ration of a lock 12, the bolt 13 of the lock
15 being thrown to engage in a notch 14 in the bar 9. Such operation in
this case, however, also serves to disengage the co~pling of the
crank pin 7, and hence also of the external handle, to the boltwork in
the bolt-withdrawing sense. To this end a plate 15 is conrlected to
the lock bolt 13, and lies between the arm 3 and the connecting bar 9.
20 This plate has an arcuate slot 16 into which the crank pin 7 extends
and along which the pin runs during its norlnal operation when
throwing the safe bolts 11. When the bolts have been thrown but
before the lock 12 has been operated the crank pin is in the position
indicated in broken line in Figure 2. When the lock is then operated,
25 however, the plate 15 moves with the lock bolt 13 to carry the pin 7,
engaged in slot 16, to the position indicated in full line in Figure 2,
the arm 3 sliding on the spindle bush 5 to permit this operation. In
this condition the rotary colmection between the spindle 2 and arm 3
is still efective but, as will be appreciated from the Fi gure, the
30 crank pin 7 is now isolated from the flank 8A of the drive slot 8 so
force cannot be applied to the connecting bar 9 via the spirldle in the
sense to withdraw the safe bolts 11,
~5~
Preferably, provision is also made in the mechanisn~ lor
blocking rotational movement Or the crank pin in this disengaged
condition, such as by the inclusion of a fixed locking ~loc}; 17 v~hich
lies in the path of the pin (but being ol:fset :~rom the arm 3, pl~te 15
5 and bar 9). Also, il the opposing flanl; 8B of the drive slot 8 is
extended in comparison with :flank 8A, as shown in the Figure, so
that the pin 7 does not become isolated Irom this longer flank, the
blocking oI the rotational movement of the pin will provide an
additional positive locking action against the withdrawal of the sae
1 0 bolts .
The unlocking operation of the lock 12 withdraws the bolt 13 and
plate 15 so that the pin 7, still engaged in the slot 16, is pulled
towards the spindle 2 with the arm 3 sliding on the bush 5, to
re-establish coupling with the drive slot flank 8A. Turning of the
15 external handle in the appropriate sense will therefore now be
effective to withdraw the saie bolts 11.
It will be noted that a longitudinal slot 18 is provided in the plate
15 to clear the bush 5 as the plate moves to and fro with the lock bolt
13, and similarly a longitudinal slot 19 is provided in the connecting
20 bar 9 to clear the spindle 2 during its to and fro movement as the
safe bolts are thrown and withdrawn.
A modification to the mechanism is illustrated in Figures 3 and
4. In this there is an arm 3', pin 7', plate 15' and slot 16'
equivalent to the components identified by the same unprimed
;!5 reference numerals in Figures 1 and 2. In this case also there is a
flat-sided spindle 2l (or an equivalent bush) which engages between
the llats 6' of a slot 4' in the arm 3' to drive the latter in rotation
when the safe bolts are thrown or withdrawn, but the throw of the
lock bolt to which the plate 15' is connected is such that when the
30 plate is moved on operation of the lock the crank pin and arrn are
carried down into a position in which the spindle 2' lies in an end 4A'
of the slot 4' which is opened out to a diameter not less than the
--6--
greatest cross-sectional dimension of the spindle. Consequently, in this
condition the spindle and the external handle to which it is connected can
rotate without restraint, the thus free wheeling handle now being completely
isolated from the rest of the bolt-throwing mechanism. Only when the
spindle is correctly aligned by the external handle will it be possible to
unlock the safe bolts~ raising the plate 15' and crank arm 3' so that the
spindle re-engages between the flats 6'.
