U.S. patent number 3,648,715 [Application Number 05/049,827] was granted by the patent office on 1972-03-14 for cold temperature water drain for locomotives.
This patent grant is currently assigned to Farr Company. Invention is credited to Clyde O. Boothe.
United States Patent |
3,648,715 |
Boothe |
March 14, 1972 |
COLD TEMPERATURE WATER DRAIN FOR LOCOMOTIVES
Abstract
A water drain for locomotives in which an explosive squib
adjacent a drain plug creates a pressure surge sufficient to force
the drain plug free so that the water can drain from the water
cooling system; the squib being actuated by a thermistor which
triggers a firing circuit when the temperature drops to a
preselected level.
Inventors: |
Boothe; Clyde O. (Rolling Hills
Estates, CA) |
Assignee: |
Farr Company (El Segundo,
CA)
|
Family
ID: |
21961959 |
Appl.
No.: |
05/049,827 |
Filed: |
June 25, 1970 |
Current U.S.
Class: |
137/62;
137/68.13; 137/68.23; 219/499; 219/501; 307/117 |
Current CPC
Class: |
F16K
13/06 (20130101); F16K 17/40 (20130101); Y10T
137/1353 (20150401); Y10T 137/1714 (20150401); Y10T
137/1647 (20150401) |
Current International
Class: |
F16K
17/00 (20060101); F16K 17/40 (20060101); F16k
013/06 () |
Field of
Search: |
;137/59-62,68-71
;123/41.14 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nelson; M. Cary
Assistant Examiner: Gerard; Richard
Claims
I claim:
1. The combination with a water system subject to freezing
temperatures, of an automatic cold temperature water drainage
means, comprising, means forming a drain opening for the water
system, a closure for the drain opening in contact with the water
in the water system and adapted to open in response to a
predetermined transitional pressure surge therein, an explosive
squib adjacent the closure and also in contact with the water in
the water system for producing said pressure surge in the water
system, at least in that portion of the water system between the
squib and closure sufficient to drive the closure from the drain
opening and means sensitive to a predetermined cold temperature for
activating the pressure surge producing means.
2. A drainage means as defined in claim 1 wherein, the cold
sensitive activating means includes a bridge having a thermistor,
an amplifier normally biased by the bridge to its off condition and
responsive to predetermined change in the resistance of the
thermistor to cause completion of a circuit through the squib.
3. The combination with a water system subject to freezing
temperatures, of an automatic cold temperature water drainage
means, comprising, a fitting adapted to be connected to a low point
in the water system and having a drain bore, a plug closing the
lower end of the bore and in contact with the water in the bore,
the plug adapted to be driven from the bore at a predetermined
surge pressure to permit drainage of water from the water system
through the bore, an explosive squib having a rupturable wall in
contact with the water in the bore, the explosive squib on ignition
producing a pressure surge in the water within the bore sufficient
to drive the plug therefrom, and means sensitive to a predetermined
cold temperature for activating the pressure surge producing
means.
4. A drainage means as defined in claim 3, wherein, the cold
temperature activating means includes an electric power source and
condenser adapted to ignite the squib, a bridge having a thermistor
for sensing temperature change, an amplifier normally biased to an
off condition by the bridge and responsive to a predetermined
change in the resistance of the thermistor to cause completion of a
circuit through the power source, condenser and squib.
Description
It is often necessary that a railroad locomotive be left idle on a
siding for a few hours or days. This may be due to the need for
repair outside the skill or training of the operating crew; or due
to traffic conditions or other reasons. Should this occur during
freezing weather, it is necessary that the water be drained from
the water cooling system, for should the water freeze, great damage
to the engine may occur.
The present invention is directed to a means whereby should
freezing conditions develop, the water is automatically drained
from the locomotive.
A primary object is to provide a cold temperature water drain for
locomotives which utilizes an explosive squib located adjacent a
drain plug which, when fired, produces a pressure surge in the
water sufficient to blow the drain plug free; the squib being fired
when a temperature sensing means triggers a firing circuit.
A further object is to provide an automatic water drain for
locomotives which is inexpensive, and of greater importance, is
highly dependable, the device being capable of remaining dormant
for months, even years, before operation.
A further object is to provide a device of this class, which after
operation or for test, may be removed and another device
substituted merely by separation of one electrical connector.
Still other objects and advantages of the cold temperature water
drain for locomotives of this invention will appear from the
following description and the accompanying drawings, wherein:
FIG. 1 is a partial sectional, partial side view of the cold
temperature water drain for locomotives, and showing fragmentarily
a drain pipe depending from the water system of the locomotive.
FIG. 2 is a wiring diagram, illustrating the circuit which controls
the explosive squib.
The cold temperature water drain for locomotives includes a housing
1, having a vertical bore 2 screw-threaded at its upper end for
attachment to a drain line 3 depending from the water system of the
locomotive. The lower end of the bore 2 is normally closed by a
drain plug 4, in the form of a concave closure disk pressed into a
rudimentary counterbore 5.
The housing includes a chamber 6, located at one side of the bore 2
and provided with a cover 7 as well as a screw-threaded tubular
boss 8. Mounted in the wall between the bore 2 and the side chamber
6 is an explosive squib 9.
Mounted within the side chamber is a control unit 10 involving a
circuit shown within broken lines in FIG. 2. The control circuit as
well as the end of the squib protruding into the side chamber is
encased in a suitable potting resin 11.
The control circuit 10 includes a bridge 12, having fixed resistors
13 in two arms; the third arm is provided with an adjustable
potentiometer 14, and the fourth arm is coupled to a thermistor 15.
The thermistor need not be located in the side chamber but may be
at a remote location in the locomotive engine's cooling water
system, the connecting wires extending through suitable conduit,
not shown, screw-threaded to the boss 8.
The bridge output goes to an integrated circuit amplifier 16,
operating in open loop mode and preferably having a gain of about
60,000. The output of the amplifier 16 triggers a two-stage
transistor amplifier 17, which when activated, short circuits a
battery 18 and a large capacitor 19 through the squib so as to
produce a voltage and current surge sufficient to fire the
squib.
The battery may be maintained at full potential by trickle charger
components such as a diode rectifier 20 and current limiting
resistor 21 connected across the battery. An external power source
from the locomotive is connected to leads 22 and 23.
Operation of the cold temperature water drain for locomotives is as
follows:
Normally, that is, at temperatures above a critical low
temperature, the resistance of the thermistor is such that the
bridge output biases the amplifier 16 to cut off. When the
temperature is lowered past the present critical point, determined
by the potentiometer 14, the bridge output reverses polarity
actuating the amplifiers 16 and 17, triggering the circuit through
the squib 9, battery 18 and capacitor 19. Ignition of the squib
produces a pressure surge in the water contained in the bore 2
sufficient to drive the drain plug 4 from the lower end of the bore
2 so that water may drain from the locomotive water system.
Thus by this invention I provide a novel cold temperature water
drain which although primarily intended for locomotives, is also
applicable to any closed water system which might be subjected to
damage should water freeze therein. This is possible with the form
of my invention herein disclosed but it is to be understood that
additional embodiments and forms of cold temperature water drains
may come within my invention defined by the appended claims.
* * * * *