U.S. patent number 3,756,356 [Application Number 05/207,892] was granted by the patent office on 1973-09-04 for brake for manually operated rotary file.
This patent grant is currently assigned to Acme Visible Records, Inc.. Invention is credited to Samuel Aston Loyd, Jr..
United States Patent |
3,756,356 |
Loyd, Jr. |
September 4, 1973 |
BRAKE FOR MANUALLY OPERATED ROTARY FILE
Abstract
A circular file is rotatably mounted on a base that includes an
annular electromagnet secured against rotation but movable toward
and away from the base of the file. The magnet may be electrically
energized via one or more switches positioned at various locations
around the file in order to cause the electromagnet to frictionally
engage and stop rotation of the file at any desired position.
Inventors: |
Loyd, Jr.; Samuel Aston
(Waynesboro, VA) |
Assignee: |
Acme Visible Records, Inc.
(Crozet, VA)
|
Family
ID: |
22772402 |
Appl.
No.: |
05/207,892 |
Filed: |
December 14, 1971 |
Current U.S.
Class: |
188/164;
40/378 |
Current CPC
Class: |
G06K
17/0009 (20130101); F16D 55/00 (20130101); F16D
2121/20 (20130101) |
Current International
Class: |
F16D
55/00 (20060101); G06K 17/00 (20060101); F16D
65/14 (20060101); F16d 065/34 () |
Field of
Search: |
;40/68,68.4,68.6
;188/164 ;312/183,186 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reger; Duane A.
Claims
Having thus described the invention, what is claimed is:
1. A rotary file comprising a circular filing wheel, a base, a
fixed vertical shaft secured in said base and extending upwardly
therefrom, bearing and support means between said filing wheel and
said base for rotatably mounting said wheel around said shaft above
said base at a substantially fixed vertical distance therefrom, a
magnetic plate secured to the bottom of said wheel, support means
secured in said base around said shaft, a plurality of studs
projecting upward from said support means, an annular electromagnet
disposed around said shaft and normally resting on said support
means, said electromagnet having apertures therein in which
respective studs are received, whereby said electromagnet is
limited in movement to a vertical direction toward and away from
said magnetic plate, and means for providing electrical energy to
said electromagnet to activate the same, said electromagnet, upon
activation, being attracted to and frictionally engageable with
said magnetic plate, such that friction between said electromagnet
and said plate brakes rotary movement of said wheel.
2. The rotary file of claim 1 wherein said means for providing
electrical energy to said electromagnet comprises an electrical
circuit connected thereto, and a plurality of switches connected in
parallel in said circuit, said switches being provided at spaced
locations around said wheel to allow braking of said wheel from
each of said locations.
3. The rotary file of claim 2 wherein control means are provided in
said circuit for regulating current through said electromagnet,
said control means comprising a triac connected in said series in
said circuit, a source of voltage connected to the gate of said
triac, and means for regulating the voltage to said gate.
4. A rotary file comprising a filing wheel, a base beneath said
wheel, means for rotatably mounting said wheel over said base,
brake means supported upon said base and movable into engagement
with said wheel, said brake means comprising an electromagnet
having an upwardly facing pole face and means on said base for
confining movement of said electromagnet to a direction toward and
away from said wheel, a plate composed of a magnetic material is
mounted on the bottom of said wheel and is engageable by said
electromagnet, and means for energizing said electromagnet from
various positions around said wheel.
5. The rotary file of claim 4 whprein means are provided for
adjusting the flow of current through said electromagnet for
regulating the degree of braking force applied thereby.
Description
BACKGROUND OF THE INVENTION
This invention relates to a rotary filing system and more
particularly to an apparatus adapted to carry large volumes of
indexed filing data, which are retrievable by a plurality of
persons located at control stations spaced around the
apparatus.
A typical rotary filing system includes a wheel member which is
rotatable about a vertical axis, with the wheel being adapted to
carry a multiplicity of spaced indexing or divider elements that
contain file data such as cards, books and the like. Rotary filing
systems are expecially suitable and convenient for the handling of
large volumes of reference data within a relatively confined space
by one or several people stationed at fixed locations around the
outer periphery of the wheel. The wheel is simply rotated until the
desired information is reached, and the wheel is then stopped to
allow access to the information.
As described in U.S. Pat. Nos. 3,056,506, 3,084,007, 3,120,824,
3,124,398 and 3,383,147, the wheel of the filing system may be
rotatably mounted on a base and driven by a motor. Stopping of the
rotating wheel driven by a motor presents no difficulties, since
the continuous engagement of the motor drive with the wheel
provides a braking effect when the motor is shut down.
In contrast to the aforesaid driven systems, the present invention
is particularly suitable for use with a manually rotated file that
is rotatably mounted on bearings on a support. Because the circular
file may be substantially great in diameter and may carry
considerable weight, the inertia developed by the rotating file may
be of such a magnitude that stopping of the file at a precise
location is difficult or impossible. Thus, although the wheel may
be easily rotated by hand, the problem of accurately stopping the
wheel has presented a deterrent to the widespread use of such
manually operated systems.
SUMMARY OF THE INVENTION
The foregoing problems are solved by the provision of an
electromagnetic brake positioned between the wheel and its support.
Preferably, the wheel is mounted on a vertical shaft extending
upwardly from the support. An annular electromagnet is mounted on
the top of the support around the shaft and has a pole facing
upward. The electromagnet is mounted so as to be non-rotatable but
movable toward and away from a metallic base plate on the wheel. A
variable rectified DC circuit is provided to activate the
electromagnet from a plurality of stations by means of a switch
located at each station. The annular electromagnet, upon
activation, frictionally engage the metallic base plate on the
wheel and immediately brings the wheel to a complete stop. Upon
deactivation, the magnet immediately falls away from the base plate
to allow unrestricted rotation of the wheel. The power through the
electromagnet may be varied to increase or decrease the degree of
braking force applied on the wheel.
THE DRAWINGS
FIG. 1 is a perspective view, shown partly in outline, of a rotary
file assembly, the wheel thereof being dissociated from the
base;
FIG. 2 is an enlarged fragmentary perspective view of the base of
the assembly, looking downward from the top thereof and
illustrating features of the presently described invention;
FIG. 3 is a vertical sectional view of the rotary file assembly
that incorporates features of the presently described invention,
with the wheel of said assembly being omitted for the sake of
clarity;
FIG. 4 is a plan view of the base of the assembly, taken
substantially along line 4--4 of FIG. 3;
FIG. 5 is a sectional view taken along line 5--5 of FIG. 3; and
FIG. 6 is a schematic of the circuit employed in connection with
the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, the rotary filing system generally comprises a
circular file wheel 10 adapted to carry file data in any suitable
manner well known to those skilled in the art. Thus, the wheel 10
may comprise a disc-shaped base 12 having a plurality of upstanding
and radially arranged partitions 14 at the outer periphery thereof
between which books or other articles of data may be stored. The
wheel 10 is adapted to be rotatably mounted around a vertical shaft
16 secured in an underlying base 18 and extending upwardly
therefrom.
As shown in FIGS. 1, 2 and 3, the base 18 supports the wheel 10 and
includes a rectangular unitary framework comprising four vertical
legs 20 having respective threadably adjustable feet 22 to permit
leveling of the base. Respective pairs of transverse beams 24 and
25 are secured between the respective tops and an intermediate
portion of opposed pairs of legs 20. In addition, respective upper
and lower pairs of closely spaced cross beams 26 and 28 are secured
medially between the transverse beams 24 to complete the basic
framework. The framework may be surrounded by a cylindrical
enclosure 30 which extends slightly above the level of the internal
framework.
As best shown in FIGS. 2, 3 and 5, the lower portion of the shaft
16 is supported centrally within the base between the pairs of
cross beams 26 and 28. The bottom of the shaft 16 is received in a
socket 32 mounted upon a base plate 34 secured at its corners (FIG.
5) by bolts 36 or the like to and between the lower pair of cross
beams 28, in order to stabilize the lower end of the shaft and to
vertically secure the shaft at a fixed level. The socket 32 may
include a set screw 38 engaging and preventing rotation of the
shaft. The shaft 16 is also held in position at the top of the
framework by means of a top plate 40 secured at its corners (FIG.
4) to and between the upper cross beams 26 by means of bolts 42 or
the like, said top plate having a circular aperture 44 that snugly
receives and supports an intermediate portion of the shaft.
The file wheel or tier 10 is freely rotatably mounted on the shaft
16 in a fixed vertical position above the base 18. A central
vertical opening 46 is provided in the bottom of the wheel and is
fitted with a collar 48 surrounding the upper portion of the shaft
16 and spaced therefrom. The collar 48 has a downwardly facing
shoulder 50 abutting the outer race 52 of a bearing 54 extending
from the collar and secured around the shaft. The outer race 52 is
supported upon a large disc-shaped base plate 56 secured centrally
to the bottom surface of the wheel base 12 and having a central
aperture 58 therein for accommodating the shaft 16. A sleeve 60 is
provided around the shaft 18 and extends between the top plate 40
and the inner race 62 of the bearing 54, thereby maintaining a
vertically fixed distance relationship between the top plate 40 of
the base and the base plate 56 of the wheel.
The brake assembly, as best shown in FIGS. 2 and 3 generally
includes an electromagnetic member 64 secured in the base against
rotation but movable vertically into and out of frictional
engagement with the base of the wheel to provide the required
braking effect. The electromagnet 64 is preferably annular in shape
and contains a coil connected between leads 66 and 68 (FIG. 2) and
embedded in magnetizable material between respective inner and
outer concentric upstanding bands 70 and 72 mounted on an annular
base 74 (FIG. 2). The electromagnet is thus designed to have an
upwardly facing pole face that may be attracted to the base plate
40 of the wheel, said base plate being formed of a ferrous or other
magnetic material.
As shown in FIGS. 2 and 4, the electromagnet 64 is normally
supported on top of the plate 40 and is retained thereon by means
of two or more opposed upstanding studs 76 received in respective
aligned apertures 78 in the annular base 74 of said electromagnet.
In this manner, the electromagnet 64 is movable axially or
vertically toward and away from the stationary plate 40 on the
studs 76 but is positively restrained against rotation about its
vertical axis or against other movement by virtue of said studs.
Upon activation, the electromagnet 64 moves upward by its magnetic
attraction toward the base plate 56 of the wheel and thereby
frictionally engages said base plate to quickly retard rotary
movement of the wheel.
FIG. 6 illustrates a schematic of a circuit which may be employed
to controllably energize the magnet and which utilizes 115 V AC
current. A conventional bridge rectifier 80 is connected in series
to the AC line 82 which may include a fuse 84. The rectifier,
utilizing four semi-conducting devices, supplies full wave
rectified current between the leads 66 and 68 of the electromagnet
64 which are connected at the positive and negative sides of the
rectifier.
A control circuit is also provided in the AC line to regulate the
current available to the rectifier 80. For this purpose, a bridge
86 is provided in the AC line, one side of which is connected to
the anode of a triac or its equivalent, which is a bi-directional
silicon thyristor 88 capable of conducting current when switched
from a high impedance state to a low impedance state. The other
side of the bridge 86 comprises the gating circuit for the triac
and contains a variable resistor 90 and a charging capacitor 92
connected in series and a diac 94 connected between said resistor
and capacitor to the gate of the triac 88. The diac 94 is also a
bi-directional component and serves to controllably switch the
triac 88 to a conductive state when power is applied in the
circuit. The resistor 90 may thus be conveniently adjusted to vary
the power available to the coil of the electromagnet 64 and hence
to vary the degree of available braking force to be applied.
In order to close the circuit, a relay 96 is connected across the
AC input, an isolation coil is connected to a plurality of normally
open push button switches 98, which when closed, shorts out the
remote control winding and closes the main circuit. In this manner,
one switch may be provided at each of the various operator
locations around the wheel.
In operation, the wheel 10 is turned and rotated by one of a
plurality of operators desirous of locating a file. When the
desired location is reached, the operator pushes a switch 98, which
closes the main circuit, thereby energizing the electromagnet to
perform the braking function. As long as the operator maintains the
stop button in a closed position, the brake remains in engagement
and prevents rotation of the wheel by other operators. The variable
resistor 90 may be conveniently adjusted to control the braking
force, depending on the weight and size of the wheel.
It will be apparent to those skilled in the art that various
modifications and changes in design may be made to the invention
described herein without departing from the scope of the appended
claims.
* * * * *