Improvements in and connected with Drawing-pins.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with Drawing-pins.
I, KARL MÜLLER of Eberswalde, in the Province of Brandenburg, Kingdom of
Prussia, German Empire, Manufacturer, do hereby declare the nature of my said
invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
My invention relates to the well-known drawing-pins used for fastening drawing-
paper to drawing-boards, and composed of the pin proper and of a head-plate fixed
thereto, and my improvements in such pins relate, briefly declared beforehand, in
making the same in two separate parts, each of a special formation, and in
connecting these two parts but in the very moment of use by means of an apparatus
especially made for that purpose.
Drawing-pins as made hitherto are sold in a finished state, i.e. the pin proper
and the head-plate rigidly connected. When pressing such pin into the wood, it
often happens, that both parts disconnect when a certain depth and a certain
resistance is reached, and that, in consequence thereof, the head-plate alone is
moved down onto the board, whilst the upper part of the pin penetrates into the
finger of the operator, thus causing there a very inconvenient and, perhaps,
dangerous wound. When, further, on driving the drawing-pin home, the pressure
does not act perfectly axially, but somewhat sideways, it very easily occurs, that
the pin proper is bent, so that the whole drawing-pin, irrespective of the uninjured
head-plate, must be thrown away.
All these drawbacks shall be avoided by the new drawing-pin shown in Figs. 1
and 2, in which a is the pin proper and 6 the head-plate, the former having a
hemispherical head a¹, and the plate having a corresponding cavity b', in the centre
of which latter a hole for the pin is provided. This hole is somewhat larger than
the diameter of the pin shortly below its head a', so that both parts, i.e. pin a and
plate 6, when loosely put together, may move against each other without decrease
in their surface of contact, on account of the hemispherical shape of the parts a¹
and ¹.
The head-plate may be of plano-convex section, as in Fig. 1, or of double-
convex section, as in Fig. 2, in which latter case a hemispherical cavity is provided
on each side.
Drawing-pins constructed according to my invention are driven into the board
not by hand, but by a special auxiliary-device, as for instance by that shown
in Fig. 3.
The said device consists of a small casing c having in its bottom a cavity c¹ for
the reception of the head-plate b, and a vertical guide-channel e² for receiving the
pin proper a and a piston d. The latter has a knob d', by means of which the
piston may be pressed onto the pin, so as to drive the latter down into the wood,
and to fasten thereby the head-plate, too. Casing c and kuob d¹ may be connected
by a cord or chain e.
In order to simplify the connection and fastening of a larger number of the new
drawing-pins, and to render the said operations more convenient, the apparatus
shown in Figs. 4-9 may advantageously be employed.
The casing e, in this case, contains besides channel c², Fig. 5, a compartment i
for the reception of a greater number of the head-plates b. The upper part 3 of
channel is enlarged and contains a correspondingly enlarged part of the
piston d. To this part d² is fixed a horizontal rod g connected with the former
through the slit e, Fig. 7.
Casing e has at its under part a projecting ring within which is arranged a
rotatable disk (Figs. 4, 5, 6 and 9) held by a screw-cap i. This disk has at its
rear side a number of oblique radial slits h', and at its front-side a corresponding

page_text: number of projections h². The pins a are put into the said oblique slits through
an inlet-piece k, Figs. 4 & 8, and the disk h is, for this purpose, intermittently
rotated by hand by means of the projections h². As soon as all slits are filled, the
two signs o o, Fig. 4, on the casing and on the disk will coincide, thus indicating
that no more pins a should be inserted.
All the slits may be brought into communication with the channel by an
inclined channel c, Figs. 5 & 6. As soon as the highest slit coincides with the
channel, the pin contained within said slit will slide down into the channel c, and
will be held then in the position shown in Fig. 5 by aid of two adjustable springs 1,
Fig. 7.
The head-plates contained within compartment f are singly transported into
the enlargement c¹ below channel c by means of a slide m, Figs. 4, 5 & 8. This
slide is held by a strong spring n, over the upper end of which extends the
bent end g of the horizontal rod g. Thus, when knob d' is pressed down, the
slide m is pushed forward by the influence of nose g' on spring n, and the lowest
plate bis brought below the piu a (Fig. 5) before the latter has been touched by
the piston. The latter coming down now on the pin presses the same down into
the wood or board so as to fasten thereby the head-plate b, too.
In order to turn the disk h automatically in intervals corresponding to the
movements of the slide m, a pawl p (Fig. 4) is suspended from the front-
end of bar g by means of a flat steel-spring r. When moving bar 9 downwards,
the pawl comes under the next of the projections 2, and when going upwards
again, catches the said next projection and draws it upwards, so as to turn thereby
the whole disk, and to bring another slit h' with a pin before the entrance to the
inclined channel e. This pin will glide then down into the channel c², and will be
held again by the springs 1, as in Fig. 7.
A second pawl p², Fig. 4, held by a flat steel-spring is arranged opposite to
pawl p, and catches between two neighbouring projections 92 so as to prevent any
undue rotation of the disk whilst pawl p is moved downwards.
I have shown disk h to be provided with twelve slits h', but I wish it to be
understood, that I have chosen this small number but on account of distinctness.
The number of slits is, in practice, far greater, and corresponds to the number
of head-plates, which may be placed into the compartment f.
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. A drawing-pin, consisting of the pin proper a and a head-plate b, pin a having
a head a', and plate 6 having a cavity of corresponding shape, the plate being
loosely connected with the pin by driving the latter home, for the purpose as
described.
2. A drawing-pin, consisting of the pin proper a and a head-plate b, pin a having
a hemispherical head a', and plate having a cavity b' of corresponding shape,
the plate being loosely connected with the pin by driving the latter home, for
the purpose as described.
3. A drawing-pin, consisting of the pin proper a and a head-plate b, pin a having
a hemispherical head a¹ the circular base of which is on the upper side, and
plate having a cavity b' of corresponding shape and position, the plate being
of plano-convex or double-convex formation, and being loosely connected with
the pin by driving the latter home, for the purpose as described.
4. A device for connecting the parts of the drawing-pin claimed under 1, 2
or 3, consisting of a casing c having cavity c¹ and channel c³, the latter containing
a piston d, for the purpose as described.
5. An apparatus for connecting a number of the drawing-pins, claimed under 1,
2 or 3, consisting of a casing chaving the fixed compartment f for the head-
plates, and the movable compartment for the pins, means for bringing both
parts of the drawing-pin together, for the purpose as described.

page_text: 6. An apparatus for connecting a number of the drawing-pins claimed under 1,
2 or 3, consisting of a casing having the fixed compartment f for the head-
plates, and the movable compartment h for the pins, the head-plates being
pushed into cavity c¹ of the casing by a slide m, the pins gliding onto the plate
in said cavity through a channel c connecting the highest of the oblique slits h
of the rotatable disk with channel c³ of the casing, for the purpose as described.
7. An apparatus for connecting a number of the drawing-pins claimed under 1, 2
or 3, consisting of the essential means shown in Figs. 4, 5 and 6, substantially as
described.
Dated this 21st dor of Avonst 1802
By Geo. H. Rayner,
KARL MÜLLER,
37, Chancery Lane, London, W.C., Agent for the Applicant.