Improvements in Locks or Fastening Devices.
Year: 1890

page_text: Date of Application, 26th Sept., 1890
Complete Specification Left, 22nd July, 1891-Accepted, 12th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in Locks or Fastening Devices.
I, FRANK OSBORNE BAIRD, residing at Murray Lodge, John Street, Porto-
bello, in the County of Midlothian, Civil Engineer, do hereby declare the nature of
this invention to be as follows:-
:-
The object of the invention is to produce an automatic lock, the parts whereof
are so arranged that great force may be applied to the locking-bar of the lock
without producing any appreciable strain on the parts of the apparatus to which
that bar is attached; and to mount the locking-bar in such a delicate manner as to
enable the unlocking to be effected by a very small application of force.
The means by which I accomplish this object will be understood by reference
to the annexed drawings:
In Fig. 1, a is the bar which it is required to lock, hereafter called the catch-bar.
This bar is here shown with a sloping head terminating in a notch or detent, but its
form may vary when applied to special cases. The catch-bar slides in a guide (not
shown) or has its course fixed by other means, but ultimately passes between b and c,
which are two pieces of metal, or other sufficiently hard material, of which the end
surfaces b and c c, hereafter called the bearing surfaces, lie accurately in one
plane.
d is the locking-bar turning round the axis e. The axis e is fixed to the axis f
which turns in bearings at the ends f, f. If the locking-bar be turned round the
axis e, but through a very small angle, and then released, it will be at once returned
by the spring g∙
The locking-bar is placed parallel to, but not touching, the bearing surfaces.
The distance between the locking-bar and the bearing surfaces is only sufficient to
allow the locking-bar to move freely in front of them.
If, now, the catch-bar be moved in the direction of the arrow, it is obvious that
it will push aside the locking-bar by causing the axis f to rotate; but, after the
catch-bar has been advanced a sufficient distance, the locking-bar falls into the
detent, and the catch-bar is thereby automatically locked-that is to say, the catch-
bar can no longer be moved in a direction contrary to the arrow.
The motion of
the catch-bar in the direction of the arrow is usually limited by a stop, so placed
that, when the catch-bar comes against the stop, the locking-bar, though within the
detent, is not in contact with any portion of the catch-bar. After the locking-bar
has fallen into the detent, if an attempt be made to move the catch bar in a
direction contrary to the arrow, the end of the detent will strike against the
locking-bar, which will turn round on the axis e; but, after turning through a very
small angle, the locking-bar will come in contact with the bearing surfaces, and,
before the catch-bar can be moved further in the same direction, either the catch-
bar or the locking-bar must break. It is obvious that whatever strain is brought
on the locking-bar is transmitted to and balanced by the reaction of the bearing
surfaces, and that the only strain on the axes e and is due to the reaction of the
weak spring g; consequently the axes e and ƒ may be mounted in a delicate manner
without fear of injury. The advantage of this will be seen at once by referring to
Fig. 2, where d is the locking-bar, e and f the axes round which it turns, and g the
returning spring. To the axis fis fixed the armature h of an electro-magnet. The
coils of the magnet are not shown, being of the usual type, but the lines i i indicate
the axes of the cores of the magnet. The catch-bar and bearing surfaces are also
not shown, being similar to those described in Fig. 1.
If wires be carried from the terminals of the electro-magnet, and a battery be

page_text: mcluded in the circuit, it is evident that on closing the circuit, one
be attracted, and, by causing the axis f to rotate, will throw the locking-bar out of
the locking position.
The rotation of the axis f is limited by a stop which is not shown in the drawing.
The weight j is to adjust the position of the centre of gravity.
I shall proceed to describe some forms assumed by the lock when applied to
special purposes.
Figs. 2 & 3 must now be regarded as forming parts of one lock, though shown as
two figures for the convenience of description. Fig. 3 represents a balance of
peculiar construction. It consists of a scale-pan k closed on three sides and open
at the front. The scale-pan is mounted on an arm l, fixed to and turning with an
axis m, and balanced by a weight or weights n, or in any other manner.
A wheel 0, of the form shown, is fixed spring-tight (and therefore adjustable) on
the axis m.
The spring pis insulated from the other parts of the balance by
means of insulating material q. The spring presses against the end of the axis m
to insure good electrical connection between this axis and the framework of the
balance. The wires shown, proceeding from the balance, are carried to the
terminals of the electro-magnet in Fig. 2, and a battery (not shown) is included in
the circuit.
When the arm of the balance is in the position shown in the figure, the electric
circuit is broken by the wheel o not being in contact with the spring p; but on
sufficient weight being put into the scale-pan to turn the arm of the balance, the
scale-pan descends, the wheel o is brought into contact with the spring p and the
circuit is closed, thereby causing the electro-magnet to attract the armature and
throw the locking-bar out of the locking position.
After the arm of the balance has turned through a certain angle, the contents
of the scale-pan are discharged and the arm returns to its original position; but
on, or during, the return of the arm, the wheel o ceases to make contact with the
spring p, and the circuit being thus broken, the armature is no longer attracted
and the locking bar falls, or is automatically made to fall, into the locking
position.
By adjusting the size or position of the weights n, the arm of the balance can,
obviously, be made to turn when any specified weight is put into the scale-pan;
and if the lock were applied to what are commonly known as " automatic
machines," that is to say, machines for the automatic sale of articles of commerce,
the weight put into the scale-pan would be in the form of coins.
Fig. 4 illustrates another form of lock, in which the use of electricity is dispensed
with, and Fig. 5 is a back elevation of the same with scale-pan and balancing
weights removed.
The balance here shown is, as far as regards the scale-pan, arm, axis, and
balancing weights, similar to the one already described. The arm l, however,
carries the locking-bar with its attachments which are similar, and similarly
lettered, to the corresponding parts in Fig. 1, except that in Fig. 1 the locking-bar
is controlled by one spring, whereas in Fig. 4 two light springs g are used.
The catch-bar, in place of sliding, is, for diversity of illustration, shown fixed
to, and turning with, an axis s (Fig. 5).
The catch-bar a is shown in plan in Fig. 6, and it will be noticed that, in this
case, no detent is required.
to is a weight movable on the rod to which it is attached, and used for adjusting
the position of the centre of gravity, but this weight is not always necessary.
C,
By an inspection of the figure, it will be readily understood that on the scale-
pan being caused to descend, the locking-bar is carried past the bearing surfaces b
and consequently ceases to obstruct the motion of the catch-bar in the direction of
the arrow. On the scale-pan rising, the locking-bar is again brought opposite to
the bearing surfaces, that is, it resumes the locking position.
To prevent the locking-bar returning too quickly to the locking position, which
in some practical applications of the lock would be objectionable, I have shown,

page_text: in Figs. 4 & 5, a method of automatically fixing the arm of the balance in any
position desired, and of keeping it fixed until automatically released.
fixed
A wheel t is spring-tight on the end of the axis m, and into this wheel
a pinu (Fig. 5). A small head v, of the form shown, is fixed to a light pin or
rod turning on a centre attached to the bar w. The head and pin are held in
position by a very light spring a. The wheel can be adjusted, so that the pin 16
shall strike the small head when the arm of the balance has turned through
any required angle; and on the sloping side of the head being struck by the pin,
the head is thrown back, and, after allowing the pin to pass, is at once returned by
the spring
On the arm of the balance tending to return to the locking position,
the pin u comes against the flat surface of the head and the turning of the arm
is arrested.
I.
The catch-bar is now free to move past the lock, and on being turned into the
dotted position (Fig. 5) strikes against the bar w, which, being hinged at the base,
is forced back and carries with it the head v. The head being thus freed
from contact with the pin u, the arm of the balance returns to the locking
position. On the bar wo being released from the pressure of the catch-bar, it is
brought back to its normal position by means of a spring y..
Fig. 7 represents a very compact form of lock, of which Fig. 8 is a back
elevation with the scale-pan removed.
As the action of this lock is precisely similar to the one just described, and the
drawings similarly lettered, it is only necessary to explain that the balancing weight,
in place of being on the arm of the balance, consists of a weight, or receptacle
capable of holding shot, sand or other substance, as shown at n. This weight or
receptacle is suspended by a cord of silk or other suitable material, which cord
passes over a grooved wheel and is attached to a point in the circumference. The
scale-pan is shown mounted on an axis at the front and held in position by a spring
at the back. This construction gives to the scale-pan a certain elasticity which
facilitates the discharging of its contents.
The fixing appliance, described in connection with Figs. 4 & 5, is equally
applicable to this form of lock, as also to the electrical lock shown in Figs. 2 & 3,
and it can be applied as easily to a sliding as to a revolving catch-bar.
Throughout the foregoing descriptions, I have referred only to the prevention of
motion in one direction; but if the lock were required to prevent motion in two
directions, it would then be necessary to have two pairs of bearing surfaces and
the locking-bar placed between them.
Dated this 25th day of September 1890.
COMPLETE SPECIFICATION.
Improvements in Locks or Fastening Devices.
1, FRANK OSBORNE BAIRD, of Murray Lodge, John Street, Portobello, in
the County of Midlothian, Civil Engineer, 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 automatic locks and its object is to produce an
automatic lock the parts whereof are so arranged that great force may be applied
to the locking bar of the lock without producing any appreciable strain on the parts
of the apparatus to which that bar is attached, and to mount the locking bar in
such a delicate manner as to enable the unlocking to be effected by a very small
force.
The means by which I accomplish this object will be understood by reference to
the drawings which I filed with my Provisional Specification, and in which
Figure is a perspective view of parts of an automatic lock constructed
according to my invention, and

page_text: Figures 2, 3, 7 and 8 show certain forms of my improved lock adapted to
special purposes.
Like letters of reference relate to the same parts throughout the drawings.
In Figure 1 a is the bar which it is required to lock, hereafter called the catch-
bar. This bar is here shown with a sloping head terminating in a notch or
detent but its form may vary when applied to special cases.
The said catch bar
slides in a guide (not shown) or has its course fixed by other means, but ultimately
passes between two strips or pieces b, c which are made of metal or other
sufficiently hard material and of which the front edges hereafter called the
bearing surfaces lie accurately in one plane.
d is the locking bar which is mounted so as to be capable of turning round
an axis e. The said axis e is fixed to an axis which is preferably at right
angles or thereabouts to the plane of the bearing surfaces and which turns in
bearings at its ends.
9 is a light spring so arranged that it tends to retain the
locking bar in a certain position and to return the bar to that position should it be
moved the efrom.
The locking bar has a position of rest close to but not touching the bearing
surfaces. It is thus enabled to move freely in front of the said surfaces.
If the catch bar be moved in the direction of the arrow from the position shown,
it is obvious that it will push aside the locking bar by causing the axis to rotate.
When the catch bar has been advanced sufficiently to bring its detent or notch
opposite the locking bar the latter falls into the said detent or is pressed therein by
a spring or weight and the catch bar is thereby automatically locked, that is to say,
the catch bar can no longer be withdrawn. The motion of the catch-bar in the
direction of the arrow is preferably limited by a stop so placed that, when the catch
bar comes against the stop, the locking bar though within the detent is not in
contact with any portion of the catch bar.
Any attempt to withdraw the catch bar after it is locked will cause the end of
the detent to strike against the locking bar which will turn round on the axis e,
but after turning through a very small angle the locking bar will come in contact
with the bearing surfaces and before the catch bar can be moved further in the
same direction either the catch bar or the locking bar must break. It is obvious
that whatever strain is brought on the locking bar is transmitted to and balanced
by the reaction of the bearing surfaces, and that the only strain on the axes e and f
is due to the reaction of the weak spring y. Consequently the axes e and ƒ may be
mounted in a delicate manner without fear of injury.
In Figure 2, d is the locking bar; e.and the axes ronnd which the said bar
turns; and g the returning spring. To the axis is fixed the armature h of an
electro-magnet. The coils of the magnet are not shown being of the usual type,
but the lines ii indicate the axes of the cores of the magnet. The catch bar and
bearing surfaces are also not shown, being similar to those shown in Figure 1. If
wires be carried from the terminals of the electro magnet and a battery be included
in the circuit it is evident that on closing the circuit the armature will be
attracted and by causing the axis to rotate, will withdraw the locking bar from
the locking position. The rotation of the axis f may be limited by a stop not shown
in the drawing. j is an adjustable weight for the purpose of adjusting the
position of the centre of gravity of the locking bar and its supporting arm about
the axis.
I will now proceed to describe some forms assumed by the lock when applied to
special purposes.
Figures 2 and 3 must now be regarded as forming parts of one lock, though
shown as two figures for the convenience of description. Figure 3 represents
a balance of peculiar construction. It comprises a scale pan k closed on three
sides and open at the front. The said scale pan is mounted on an arm / which is
fixed to and turns with an axis m, and is balanced by an adjustable weight or
weights n or in any other suitable manner. The said axis is mounted in suitable
standards or bearings. A segment disc o is fixed spring-tight (and therefore

page_text: adjustable) on the axis m, and a spring p insulated from the other parts of the
balance by means of insulating material q is so arranged as to make contact with
the segment disc o in certain positions of the latter.
A spring presses against the end of the axis m to ensure good electrical
connection between this axis and the framework of the balance. The wires shown
proceeding from the balance are carried to the terminals of the electro magnet in
Figure 2 and an electric battery (not shown) is included in the circuit. One of
the said wires is in electrical connection with the segmental disc o and the other
with the spring p.
When the arm of the balance is in the position shown in the figure, the
electric circuit is broken by reason of the disc o not being in contact with the
spring p, but on sufficient weight being put into the scale pan to turn the arm of
the balance, the scale pan descends, and the disc o is brought into contact with the
spring p and the electric circuit is closed, thereby causing the electro magnet to
attract the armature and throw the locking bar out of the locking position. After
the arm of the balance has turned through a certain angle, the contents of the
scale pan are discharged and the arm then returns to its original position; but on
or during the return of the arm, the disc o ceases to make contact with the
spring, and the circuit being thus broken, the armature is no longer attracted;
and the locking bar falls, or is automatically caused to fall, into the locking
position.
By adjusting the size or position of the weights n the arm of the balance can
obviously be made to turn when any specified weight is put into the scale pan, and
if the lock were applied to what are commonly known as "automatic machines,"
that is to say machines for the automatic sale of articles of commerce, the weight
put into the scale pan would usually be in the form of coins.
Figure 7 represents in side elevation a portion of a very compact form of
automatic lock, of which Figure 8 is a back elevation with the scale pan removed.
In this lock the axis e of the locking bar d is rigidly connected to and rotates with
the axis of the arm that carries the scale pan, and the said bar is mechanically
withdrawn from the locking position when the scale pan is depressed. 9, are
light springs that perform the same function as the single spring g in Figure 1.
The balance weight n of the scale arm consists of a weight or receptacle capable
of holding shot, sand or other material, as shown at n. This weight or receptacle
is suspended by a cord of silk or other suitable material, which cord passes over a
grooved wheel carried by the scale pan axle and is attached to a point in the
circumference. The scale pan is shown mounted on an axis at the front, and held
in position by a spring at the back. This construction gives to the scale pan a
certain elasticity which facilitates the discharging of its contents.
When desired, I may by means similar to those described in my former Specifi-
cation No. 12976 of A.D. 1890 prevent the immediate return of the locking bar to
the locking position after it has been removed therefrom. For example I may
provide a catch that engages with the locking bar or parts connected therewith
when the said bar is withdrawn and holds the same in the unlocked position. This
catch is moved to release the locking bar when the catch bar of the main lock is
re-inserted.
Throughout the foregoing description I have referred only to the prevention of
motion in one direction; but, if the lock were required to prevent motion in two
directions it would then be necessary to have two pairs of bearing surfaces, and the
locking bar placed between them.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
First. A lock capable of withstanding great force while having a delicately
mounted locking bar which is capable of turning about two axes and which is

page_text: actuated when required to be moved to the unlocked position, by an electro-magnet
substantially as set forth.
Second. An automatic lock wherein the locking bar is capable of turning about
two axes and tends always to move to the locked position, and which is adapted to
be unlocked by an electro-magnet substantially as set forth.
Third. An automatic lock constructed substantially as described with reference
to Figures 1, 2 and 3 or to Figures 7 and 8 of the accompanying drawings and
operating as specified.
D
01
T. 1001
FRANK O. BAIRD.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.