Automatic Age

14
T h e A u t o m a t ic A ge
SOM E PRINCIPLES
OF SLUGPROOF
M E C H A N ISM S
B y H. E . W U R Z B A C H
Research Engineer, Selector Corp.
Slugs — slugs — slugs! Everybody
has a crack at them and probably
some of the things said would not
bear printing. W e have been study­
ing the slug detecting problem for the
past five years, during which time
we conducted many hundred experi­
ments and expended considerable
money and energy in an attempt to
discover the best and most practical
means for ridding the coin controlled
machine of the slug nuisance.
It has been said that a 100 per cent
slug proof mechanism is a physical
impossibility, which, taken literally,
may be true, because a slug may be
made from the identical metal alloy
used in coin manufacture and also the
details of construction, such as knurl­
ed edge, diameter, average impression
on either side with the correct thick­
ness, etc., would of course operate an
otherwise slug proof mechanism.
However, to manufacture slugs with
the above detail would require me­
chanical skill, machinery and the use
of valuable metals that would reduce
the profits between the manufacturer
and the user to proportions that
would be attractive to neither, in
which case there would be little in­
centive to take the risk of public criti­
cism or possible prosecution for con­
tributing to a fraudulent practice.
Such perfection in slug detection may
never be required in merchandising
machines, but will likely be necessary
© International Arcade Museum
on change making machines above the
10 cent denomination in case of their
extensive use in places void of attend­
ance. A slug detecting mechanism
such as the above can be made and
may become necessary at some future
date, but would hardly warrant ex­
tensive production at this time, in
view of the fact that there are thou­
sands of merchandising machines
now in operation or perfected that
must have immediate protection
against slugs to preserve their ex­
istence.
In considering the field of merchan­
dise machines, we have the 5 cent
merchandise and play machines in
first place, the 10 and 25 cent ma­
chines in second place, and the 50 cent
machines in third place, with the
$1.00 machine in the future.
It is obvious that the most economic
application of slug detection lies in
the selecting of the best possible se­
lector for the particular application;
that is, a 25 cent machine would likely
require better protection than a 5
cent machine. Adequate slug protec­
tion does not necessarily mean that
100 per cent perfection is necessary
or economical, because the 100 per
cent machine would necessarily be
more expensive in first cost and have
greater maintenance costs.
The trouble with practically all
coin operated machines in service to­
day is not due to the fact that they
http://www.arcade-m useum .com /