Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to a method of and
apparatus for printing of identification data on a structural
component.
In motor vehicle construction it is necessary to
provide the body with a chassis number and the engine with
an engine number which numbers normally provide information
in code form concerning that component.
To apply the relevant data to the components in as
permanent a manner as possible, the various sequences of
symbols, letters, and numerals are at present read from a
data carrier, reference card or punched card, thereafter com-
posed by manual selection of thelvarious punches, and then
stamped manually.
` This manner of operation has serious drawbacks. ;
- With manual selection there is always the risk of human error,
and by manual stamping the resulting impression is frequently
irregular, possibly with deformation of the body metal. ~;
In order to mitigate such disadvantages, the
practice is known of manually selecting the group of charac-
ters, inserting these in a roll punch, whereupon the complete
` reference group is stamped in a roll process. Here, however,
it is necessary to provide an under-support for the surface
to be stamped. In this way it is possible to produce a
better quality of inscription, without risk of deformation of
the body metal, but it is still not possible to e7iminate the
frequent cases oE human error.
An object of the present invention is to provide a
method of the kind described initially in which the human
selection error is completely eliminated and a uniform im-
print is obtained without the necessity of providing under-
supports for the structural component~
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According to the present invention there is pro-
vided a method of printing on structural components charac-
ters forming a group according to which method the various
characters are imprinted by a series of percussions, said
method including the steps of
(a~ placing a percussion machine having a percussion
pin upon the surface of the component on which
; the group of characters is to be printed,
(b) feeding the characters in the required sequence
into a computer unit connected to the percussion
machine,
(c) converting the charact~rs into consecutive inter-
related co-ordinate movements,
(d) moving the percussion pin in accordance with said ~;
inter-related co-ordinate movements at a constant,
preselectable vibration rate approximately verti-
cally to the surface of the component and at the
same time parallel to the surface of the component
so that the consecutive indentations produced by
the tip of the percussion pin produce the desired
sequence of characters.
By the method according to the present invention
it is possible to obtain fully automatic imprinting of
characters such as letters, numerals and other symbols upon
structural components. Particularly in the case of the
series production of motor vehicles and like machines which
are required to carry commission numbers or the like it
frequently occurs that the characters are inaccurately or
wrongly applied. This leads later to serious difficulties,
especially in the case of motor vehicles where the relevant
reference numerals require also to be entered in the vehicle
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documents. When discrepancies occur between the number
carried on the body and that on the vehicle documents, this
has serious consequences not only for the owner of the
vehicle but also for the authority responsible for register- -
ing the vehicle. By the method according to the present in-
vention such not uncommon difficulties are almost completely
obviated. For example, the particulars of a given vehicle
can be fed by way of a data-input apparatus into a computer
which is programmed to produce therefrom the engine number
and chassis number. The two numbers can correspond in one
set of numerals but differ definitively in another. The com-
puter may control one or more percussion machines connected
thereto so that the correct sequence of characters is im-
printed on the relevant component. Misreading of characters,
transposition of numerals and other errors arising in the
manual application of identification references is thus
eliminated.
Further according to the present invention there is
; provided a percussion machine for imprinting characters on
structural components, said machine including a percussion
tool support which is mounted within an open-ended housing
so as to be displaceable by a guide system and wherein said
guide system includes controllable electric motors coupled to
move said support selectively along two mutually perpendicu-
lar axes and the support carries a percussion tool having a
percussion pin which is caused to vibrate at a preselectable
and constant speed along a third axis which is approximately
at right angles to the said two axes.
Such a machine is placed upon the surface to be
printed so that the tip o~ the percussion pin lies directly
above or in contact with the surface. The percussion pin is ,
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, then set in operation and at the same time is controlled by
` the guide system so that its tip follows the contours o the
characters to be printed. The control of these co-ordinate
movements is provided by separate drive means.
This machine produces an invariably high quality
of in~cription. The vehicle body is not dented or in any
other way damaged when the tool is applied even to enamelled
surfaces. The printing operation is smooth and free from
stress. `
The percussion machine is preferably pneumatically ~-
driven and the housiny is preferably provided with suction
cups connected to a vacuum source.
The machine according to the invention possesses
the advantage that almost any type of character can be repro~
duced since no letter punches are required for the individual
letters which are imprinted by closely spaced indentations
produced by the tip of the percussion pin of the machine. ~-
By suitable programming of the computer unit, the type of
character can be simply adjusted and can be varied as desired.
Moreovert the present method produces a very uniform impres- -sion due to the multiple indentations produced by the tip of
' the percussion pin~ It is difficult to alter the characters
thus produced, whereas, in the case of the straightforward
letter punches, falsification is quite possible.
Since the indentations caused by the tip of the
percussion pin follow each other closely but quite separately,
undersupport provision for the structural component is un-
necessary. ''"!
In the case of vehicle engines it has been found
that it is no longer necessary to prepare the surface of the
component by milling. The imprint produced by the tip of the
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percussion pin on the skin of the cast engine block is per-
fectly legible. Thus, in the case of castings there is
economy in the elimination of mil:Ling preparation of the
surface.
An embodiment of the invention will no~ b~ des-
cribed by way of example with reference to the accompanying
drawings in which:
Figure 1 shows in diagrammatic form how the
method according to the invention may be
applied to motor vehicle construction; and
Figure 2 lllustrates a percussion printing
machine according to the present invention.
Figure 1 is intended to illustrate the sequence of
operations in the method according to the present invention.
A component, in the present case a vehicle body 1 and inter-
nal combustion engine 2, is required by law to carry at
specified points of the surface identification particulars 3
; usually in the form of a series of characters. For this pur-
pose with reference to a data carrier 4 attached to the body !'
1~ a punched card 5 is wlthdrawn from a punched card index.
The particulars in question already appear on the punched
card in mechanically readable form. The punched card 5 is
simply fed into a punched card reader 6 which passes the ~;
information to a computer unit 7 which processes the opera-
ting instructions for a percussion printing machine 8 and is
connected thereto by way of a cable 9.
As soon as the percussion machine 8 (Figure 2) with
housing 10 and resilient Erame 11 is placed upon the appro-
priate surface of the component 1 or 2 and is adjusted, a
starter button 12 is pressed whereupon suction cups 13 are
placed under vacuum so that the percussion machine 8 is held
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securely by suction to the surface of the component 1 or 2.
It is, of course, possible to employ two percussion
machines at the same time, one fox the body 1 and one for the
~; engine 2, so that it is possible to apply both series of
characters simultaneously, both being controlled by the com-
puter unit 7.
The percussion machine shown in Figure 2 comprises
the housing 10 in which a percussion tool 19 is slidably
; mountedD The lower surface of the housing 10 is at least
10 partly cut away and carries the resilient frame 11 which can
be applied firmly to the component to form a tight seal.
Alternatively, in place of the unitary resilient frame, a
plurality of suction cups or compartments may be provided.
. The percussion tool 19 is clamped to the horizontal
limb of an L-shaped bracket 22 the vertical limb of which has
a U-shaped slide member 23. An internally-threaded bore
passes through the bracket 22 at the base of the vertical
limb and threadedly engages a worm spindle 24 which is jour- ;-
nalled in the two end walls of the housing 10 and driven by
an electric motor 17 by way of a worm drive 25. When the
worm spindle rotates, the percussion tool 19 and its pin 20 :~
are displaced following the X-axis indicated in Figure 20
Motion following the Y-axis indicated in Figure 2 ~.
'I is produced by tilting the percussion tool 19 around the
axis of the worm spindle 24. For this purpose a swivel
mounting 15 is provided which is in the form of an inverted U,
~ the base of the U lying parallel to the worm spindle 24. At
the extremities of the limbs of the U there are bearings 26
which are carried on the worm spindle 24.
On the base of the U of the swivel mounting 15 and
disposed in a plane at right angles thereto there is provided :~
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a rack segment 16 which meshes with a pinion 27 driven from
an electric motor 18 by way o~ a gear system 28. As the
pinion 27 rotates, the mounting 15 is swivelled around the
axis o~ the worm spindle 24, so that the percussion tool
support 22 is also swivelled. Although the percussion tool
19 also swivels around the spindle 24, the impression o~ the
characters remains of an approximately constant depth over
their entire length. The tool limits the vibratory motion
of the tip 21 parallel to the Z-axis. A particular advan-
tage o~ the described percussion printing machine is that itcan produce characters even on curved surfaces since the
amplitude o~ the percussion pin is essentially determined by
the distance of the surface to be printed and the depth of
indentation is largely governed by this distance.
It is also possible to secure the percussion tool
19 to a slide which is caused to move parallel to the co-
ordinates of a right angle co-ordinate system. This would,
however, involve larger dimensions in the machine 8.
In order to affix the housing of the percussion
machine firmly by suction to the component to be printed,
suction compartments 13 are provid~d which are con~ected to
a ring suction tube 32 from which branch pipes connect to the
various compartments.
From the foregoin~ it will be evident that the
electric motor 17 controls the motion of the percussion tip
21 in the X-direction, whilst the electric motor 18 controls
its motion in the Y-direction. The conversion of characters
into suitable co~ordinate motions employing an electronic
calculator is known and may be carried out with conventional
programming methodsO
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The percussion tool 19 is known per se and there-
fore does not require to be described here in detail. The
tip 21 of the downwardly projecting percussion pin 20 vi-
brates in longitudinal direction ~with refexence to the tool
19 and engages the surface of the component. At the comple-
tion of any single character the percussion pin 20 may be
halted in the upper or rest position.
When the housing 10 has been affixed to the com- ;~
ponent, the computer unit 7 sets the percussion tool support
22 in motion; the support is moved to the initial position
; for the first character by means of the two programmed elec-
tric motors 17 and 18. The percussion tool 19 is now caused
to vibrate vertically and the support 22 guides the percussion
pin 20 so that its tip 21 follows the contours of the parti-
cular character required. The motion of the percussion pin
20 may of course be halted in the upper rest position at the
completion of each individual character. There are, however, ~
various possible methods of arranging the intervals between ,
characters.
In the case of components made of ferrous metals,
a frame with magnetized edges may be employed in place of the
resilient frame with suction cups.
When dealing with components in which the inscrip-
tion area may contain unevennesses, the housing of the per-
cussion machine may be provided with mechanical clamping mem-
bers co-operating with edges or projections on the component.
In the case of the inscribing of vehicle bodies and
engine blocks a percussion pin is recommended which has a tip
with a conical angle of approximately 20, terminating in a
spherical calotte of approximately D = 0.4 mm.
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As the percussion device 19 a percussion riveter
may be employed such as that marketed by Gartner, Denver
and called "Micro-riveter Type 43R - IR". The percussion
. rate lies preferably between 6,000~and 9,000 percussions per
minute. The working stroke is preferably in the region of
12 mm.
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