Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a pistol a~paratus for
driving in tacks, small nails or the like (hereinaf-ter referred to
collectively as "tacks") ~articularly for decorating and/or la-
minatiny materials. The tacks may be used for furniture suit-
cases, or for ~ixing carpets and so on.
Numerous forms of pistol apparatus for driving tack~q i~-
to materials are known~ but these generally have the drawbacks of
not being able to protect the head o~ the tack sufficiently to
avoid de~ormation and of not being adapted to recei~e small tac~
of very diver~e dimenslons and ~hapes and of not permitting the
use of an elongated barrel; use of ~n elongated barrel is desirable
a~ it enables the placement of the tacks at points whlch are of
diffioult acces~
By way of example ln explanation o~ the known apparatus,
reference is made to a number of prior specifications. Thus,
German Specification laid open to inspection under ~o. 2245860 re-
lates to a pistol apparatus in which the small tacks are inserted
in a ribbon. In the act of cut-ting from the ribbon, two lateral
wings of plastic pro~ect from the tack, and these wings prevent
the correct operation and adver~ely affect the ae~thetic appeara~ce
of the inserted small nails~
In German Specification laid open to public in~peotion
under No 2163556 the small tacks are provided with casing~ and
are ~tuck onto a ribbon. In this ca~e, the small tacks which are
of a single, small tolerance measurement tend to become mutually
displaced and not fixed perpendicularly to the fi~ing surface.
In German Speciflcatlon laid open to public inapection
under No. 2211511 the small tacks are held by three ribbons and
not by casings allowing the receiving of variQus sizes of small
3o tacks having the ~ame outer measurement. In -this case, during the
adva~cing each ~mall tack does not remain supported and guided by
the ribbon with seriou~ resulting drawback of the possibility o~
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the tack jamming in the pistol apparatus.
In German Specification laid open to inspection
under No. 1478804 the carrier is hinged to one end of the grip
of a pistol.
A number of other known arrangements, less
relevant than those discu~sed above and disclosed in the following
published documents:
German Specification laid open to public inspection under No.
2348956;
German Specification laid open to public inspection under No.
1478897,
German Specificationlaid open to inspection uner No. 1957930;
German Gebrauchsmuster No. 7213327 and the German Gebrauchsmuster
No. 1929998.
According to the present invention there is
provided a pistol apparatus for driving in -tacks,comprising a
magazine adapted to receive at least one set of tacks arranged with
their stems parallel and attached to one another indirectly by
means of a strip of detachably interconnected cyl1ndrical casings
each holding a tack. The pistol comprises a barrel having a bore
which has the same internal diameter as the external diameter of
the casings, plunger means reciprocable in the barrel, means to
apply compressed air to the plungermeans to reciprocate the plunger
means relative to the barrel to detach a casing and its tack from
the set and to cause both to advance through the bore and to detach
the tack from the casing and to drive in the stem of the tack
into material to be tacked. Means provided on the plunger means
retract the empty casing to a position in line with the strip, and
means are provided to feed the strip into the path of the plunger
means whereby the advancing strip pushes the empty casing to a
position out of alignment with the barrel. A protuberance provided
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on the plun~er means contact and expel the empty casing of the
tack previously driven upon advance of the plunger means to drive
the next tack.
Preferably, the magazine contains at least two
sets of tacks attached to one another by their casings in plural
rows disposed side by side, the magazine being hingedly mounted
so as to be pivotable between positions of use in which respective
rows of tack can be driven in.
Unlike the known pistol apparatus~in the pistol
apparatusaccording to the invention, small tacks with heads of
different dimensions and shape can be held inside casings having
constant outer diameter or dimensions corresponding to the internal
diameter or dimensions of the barrel of the pistol apparatus. The
guiding of the small tacks is thus perfect even if the pistol
apparatus has a lony barrel; futhermore the s~ems of the small
tacks are always disposed axially with respect of the barrel.
An embodiment of the present invention will
now be described, by way of example, with reference to the accom-
panying drawing, wherein:
Figure 1 shows an elevation, partly in section,
of pistol apparatus according to the embodiment of the invention;
E'igure 2 shows the apparatus of Figure 1 in
front view;
Figure 3 shows a cross sectional elevation to
a larger scale of a casing containing a small tack,
Figure 4 is a view in plan showing a set of
casings joined together;
Figure 5 is a sectional view in plan of the
muzzle end of the apparatus of Figure l;
Figure 6 is a front view of one form of the
muzzle end of the apparatus of Figure l;
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Figure 7 is the front view of another form of
the muzzle end of the apparatus for use in the apparatus of Figure
1 in place of the detail of Figure 6; and
Figure 8 shows in front view, a modified form
of casing for an individual tack~
The pistol apparatus shown in Figure 1 is
pneumatically operated and consists of a body 1 provided with a
hand grip 2~
Inside the said body 1 is a cylindrical bore
1' in which is mounted an intermediate hollow cylindrical body 3
having a cylindrical cavity 3'. This body 3 has in its front part
a widened, conical portion 3". The outer periphery of
the body 3 is surrounded by chambers 6 and 6' which are independent
and watertight and communicate respectively with the said cylin-
drical cavity 3' by means of the bores 7, 7', and 8~ Within this
cylindrical cavity 3' slides a main piston ~, the rod 5 of which
is provided with a reduced diameter portion 5" and an enlarged
portion 5'. Against the rod side of the piston 4, is disposed a
washer or coating 9 of elastic material which serves the function
of shock absorber and partial return spring for piston 4 and rod 5.
The rod 5 is slidably mounted axially in a hollow cylindrical
sleeve 32 which has in its rear part an enlarged portion 32' pro-
vided with a bore 32" lying radially with respect to the axis of
the said sleeve. Portion 32'has an internal diameter less than the
external diameter of portion 5. Inside the bore 32", which opens
into the bore of the sleeve 32 and which in the position shown
is in alignment with the reduced diameter portion 5" of rod 5, are
two balls 30 and 30' placed one above the other. These are supported
by being trapped between the reduced diameter portion 5" of the
rod 5 and the inner wall of the cylindrical body 3. On the front
part of the hollow cylindrical body 32 is mounted a member 34
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coaxial with.sleeve 32 and provided with. two lateral wings 35
and 35' (Figure 5), that extend inwards at their front ends and
a protuberance 36 in the upper part (Figures 1 and 5). The wings
35 and 35' and the protuberance 36 are adapted to slide in the
radial grooves 39, 39' and 39" respe~ively of the barrel 38
~figures 1 and 2). The rod 5 and the hollow cylindrical sleeve 32
are capable of moving axially through the front end 37 of the body
1. On the hollow sleeve 32 is mounted sliclably and axially a body
31 of elastic material, which serves the function o~ a shock absor-
ber and return spring for portion 32' and sleeve 32.
Against the free end of the barrel 38 is fixed
an interchangeable fitting 16 (Figures 1 and 6) having a bore
concentric with the axis of the said barrel and an inner diameter
adapted to that of the head of the respective small tack to be
driven by the apparatus. This part also has radial grooves 16'
(Figures 1 and 6) to ensure perfect alignment be-tween the heads
22 of the individual small tacks by supporting the end of the
groove 16' on head 22' of the small tack, previously inserted, as
shown in Figure 6.
Where the spacing between the tacks driven
in is to be greater, the arrangement shown in Figure 7 may be used.
The fitting 43 is used instead of fitting 16, and it will be seen
that this fitting 43 has a radial tongue 43' having a concave end
43" matched to the shape of the tack head.
Under the barrel 38 of this pistol apparatus
there is mounted a carrier or magazine 24 which is perpendicular
to the lo.ngitudinal axis of the barrel. The magazine is carried
on the plate 44 and has a slidable body 46 (Figure 2) which is
urged by a spring tnot shown) to cause the associated set of small
tacks to be advanced towards the body 32. The tacks are shown
connected to one another with the stems parallel and equidistant,
and with each head held in its own casing 21. The casings 21
(Figure 4) have circular cross sections and are attachecl to one
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another tanqentially. In addition, the carrier 24 contains two
or more sets of small tacks contained respectively in casings 21
attached to one another. After the exhaustion of one set of tacks,
the second set of tacks can be presented for use by la-teral dis-
placement of the carrier 24 about an axis of rotation defined by
connecting stud 49 (Figure 1) and the tacks of the second set can
be used immediately. As seen in Fig. 2, this movement to switch
from the first set of tacks to the second, is shown as a swinging
movement of the upper end of carrier 24 in the direction of the
arrow 24'.
The said casings 21 are made of elastic or
flexible material, in particular thermo~plastics ma~eria:L. The
head 22' of each of the small tacks is of more or less spherical
shape and is held by the pressure of a continuous inner and
elastic annular edge 21' " (Figure 3) which pushes it against the
front continuous annular edge 21"", the latter having an inner
diameterslightly less than the outer diameter of the head 22'
of the said small tack. It is obvious that whatever the shape
of these casings they will have a bore 21" to permit the passage
therethrough of the rod 5 of the piston 4.
In Figure 8 there is shown a casing 21 having
notched edging 21". The barrel 38 of the pistol apparatus will
have an inner bore of diameter substantially equal to that of the
individual casings. It is also possible, although less practical,
to make the bore of the barrel 38 of square or rectangular section
and to give the casings 21 the same outer shape, to ensure a more
secure connection in a set between casings. One of the main ad-
vantages of the pistol apparatus described is that it permits of
driving in small tacks in places of difficult access such as in
complete articles of furniture, since it is possible to make the
barrel very long and the small tack is guided by the casing as far
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1 03765~
as the end of the barre~. This is not possible with the pistol
apparatus of most known typel in which the small tacks are not
provided with casings.
Other important advantages of the pistol appa-
- ratus described consist in that in the act of driving in o~ the
stem of the small tack, the stem in kept accurately perpendicular
in relation to the fixing plane, and in that the head of the
small tack is efficiently freed from the casing.
A further advantage of the apparatus is shown
by the fact that the dimensions of the inner seating of the casings
may be varied, keeping their outer diameter, and thereby it is
possible to accomodate in respective cases small tacks and orna-
mental tacks of considerably different configuration as regards
shape, diameter, height and carvature of the head 22', and length
and section of the stem 22" '. These can all be driven in using
the same pistol apparatus which is not possible with the pistol
apparatus of known type
The pistol apparatus described operates as
follows:
The pistol apparatus is connected to a source
of compressed air through pipe 54. Pressing the trigger 25 causes
the compressed air from pipe 54 to pass through the bore 26 of the
grip 2 and the bore 8 of the cylindrical body 3, driving the pistol
4 forwards. Pushed by the compressed air, the piston 4 shoots
forward, displacing in its course stem 5 and in consequence the
balls 30 and 30' which are trapped in the reduced part 5" of the
stem 5 and against the hollow sleeve 3 and so the sleeve 32 moves
with the piston 4. Advancing of the cylindrical sleeve 32 moves
sleeve 34 and the lateralwings of sleeve 34 (Figure 5)
into registry with a casing 21 provided with a small tack (Figure
5). This casing 21 and its tack are thus foreibly torn off and
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separated form the set arranged in the carrier or magazine 24. The
casing and its tack are thus pushed, until sleeve 32 reaches the
end of its stroke. The point 22 of the small tack will then pro-
trude by about a couple of millimeters beyond the outer face of
the interchangeable spoke 16. At this point, the balls 30 and 30',
which, during the advancing described, slide contained between
the inner wall of the cylindrical body 3 and the reduced portion
5" of the stem 5 preventing the said stem 5 from sliding freely
relative to the hollow cyllnder 32, arrive at the location of the
widened portion 3" of the cylindrical body 3" of the cylindrical
body 3. On reaching this position, the balls 30, 30' are now
free to move radially outwardly and do so due to the reaction
resulting from the compressed air thrust on piston 4 thereby
enabling the piston 4 and its stem 5 to move f.reely forward
relative to the body 3 and sleeve 32. Thus the stem 5, which is
always under the action of the piston 4, is pushed onto the head
of the small tack through the cylindrical bore 21" (Figure 3) of
the casing and drives the tack from the casing into the material,
whilst the said casing remains held from further advancement by
the inwardly ben~ ends-of wings 35 and 35' (Figure 5) of ~he
member 34.
During its advance, piston 4 forces air out
of cavity 3' through bores 7 and 7' and out into the peripheral
chamber 6. Furthermore, the piston 4 moves, during its advance,
beyond the bore 7' in the cylindrical body 3, permitting the com-
pressed air to pass out into the peripheral chamber 6 where it
is accumulated for the return movement of the piston. sy releasing
the trigger 25, the air pressure driving the piston is instantaneous-
ly vented to atmosphere through the bore 26 and the valve(not shown)
In this forwardmost position of the parts, in
which the tack has been fully driven, the bodies 9 and 31 of
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elastic material are compressed and the air in chamber 6 is also
compressed. Body 9 forces the piston 4 back relative to the
sleeve 32, thus closing bore 7' and shutting cavity 3' and chamber
6 off from communication with each other. When piston 4 is moved
sufficiently to the rear relative to sleeve 32 to permit reduced
portion 5" of rod 5 to register with the bore 32', the enlarged
portion 5' of rod 5 will contact the enlarged portion 32' with
its relatively small internal diameter, which will drag sleeve 32
to the rear. The balls 30 and 30' are now forced to move back
into reduced portion 5" of rod 5 by the tapered orconvergent inner
surface of enlarged portion 3", which acts like a cam to force them
into reduced portion 5". Thus the balls 3~' are positively
cammed back into reduced portion 5", after which piston 4 and
sleeve 32 with portion 32' are locked toyether to move to the
right to return to the Figure 1 position of the parts. The air
to the rear of piston 4 is vented through bore 26 and the valve
(not shown~ upon release of the trigger 25 so as not to impede
this return movement, the return movement of piston 4 being not
only under the spring action of the bodies 9 and 31, but more
particularly under the influence of the air compressed in chamber
6, which flows back through bores 7 and 7' for this purpose.
Automatically, the casing 21, now empty, and
located between the curved wings 35 and 35' of the member 34 is
brought back into its initial position in alignment with the
carrier or magazine 25. Under the action of the thrust of the
slide 46, the empty casing held between the curved wings of the
member 34 is struck radially by the next Eull casinCJ of the set
located in the carrier 24, and is compelled to slide towards the
top until it touches the projecting body 60, whilst the full casing
which has so pushed it enters between the wings 35 and 35'
of the cylindrical body. On re-operating the trigger 25, the
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advance of the piston 4, of the stem 5, of the hollow cylindrical
body 32 and of the cylindrical body 34 already described, will
recur. Whilst the lower part of the member 34 separates the casing
containing a small nail held between the two wings of the set lo-
cated in the carrier 24, the protuberance 36 (Figures 1 and 5) of
the member 34 will expect the empty casiny thrusting it
and pushing it forward through the opposite opening 61 (Figures 1
and 2) made in the barrel 38.
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