U.S. patent number 3,663,772 [Application Number 05/062,973] was granted by the patent office on 1972-05-16 for foot control for switching of an electric drive.
This patent grant is currently assigned to Grundig E.M.V. Elektro-Mechanische Versuchsanstalt IHA, Max Grundig. Invention is credited to Ulrich Grabel, Peter Michaelis.
United States Patent |
3,663,772 |
Grabel , et al. |
May 16, 1972 |
FOOT CONTROL FOR SWITCHING OF AN ELECTRIC DRIVE
Abstract
A foot control particularly for a dictating apparatus. The
electric drive the dictating apparatus is to be switched between an
inoperative mode, a forward mode and a reverse mode and the
switching between these modes is to be sequential. A housing
includes an upwardly open lower shell section and a superimposed
downwardly open shell section having two spaced marginal portions.
The sections are connected with bayonet-type closures permitting
the upper section to move upwardly and downwardly with reference to
the lower section. A leaf spring is located in the housing and has
a first end portion fixed to the lower shell section and urges the
upward shell section upwardly with its remote second end portion. A
spherical element is interposed between the second end portion and
the upper shell sections so that the latter rocks about the
spherical element with reference to the lower shell section when
downward pressure is applied on one of two spaced marginal portions
of the upper shell section. Pressure on one of these marginal
portions causes the upper shell section to be rocked downwardly to
a first position in which the drive is switched from inoperative to
forward mode, and pressure on the other marginal portion causes the
upper shell section to be rocked downwardly to a second position in
which the drive is switched sequentially past the forward mode to a
reverse mode.
Inventors: |
Grabel; Ulrich (Nuernberg,
DT), Michaelis; Peter (Nuernberg, DT) |
Assignee: |
Grundig E.M.V. Elektro-Mechanische
Versuchsanstalt IHA, Max Grundig (Fuerth/Bay,
DT)
|
Family
ID: |
5743360 |
Appl.
No.: |
05/062,973 |
Filed: |
August 11, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Aug 21, 1969 [DT] |
|
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P 19 42 495.4 |
|
Current U.S.
Class: |
200/86.5; 74/512;
G9B/15.013 |
Current CPC
Class: |
G11B
15/10 (20130101); G05G 1/30 (20130101); H01H
13/16 (20130101); Y10T 74/20528 (20150115); H01H
21/26 (20130101) |
Current International
Class: |
H01H
13/16 (20060101); G11B 15/10 (20060101); H01H
21/00 (20060101); H01H 21/26 (20060101); H01h
003/14 () |
Field of
Search: |
;200/6A,59B,61.29,86.5
;74/512 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scott; J. R.
Claims
What is claimed as new and desired to be protected by Letters
Patent is set forth in the appended:
1. A foot control, particularly for use with a dictating machine,
for effecting sequential switching of an electric drive between an
inoperative mode, a forward mode and a backspace mode, comprising a
housing including an upwardly open lower shell section and a
superimposed downwardly open upper shell section having two spaced
marginal portions; connecting means configurated as bayonet
couplings and connecting said upper shell section to said lower
shell section with limited freedom of movement towards and away
from the latter; a leaf spring in said housing and having a first
end portion fixed to said lower shell section and a free second end
portion urging said upper shell section upwardly away from said
lower shell section; and rocker bearing means interposed between
said second end portion and said upper shell section so that the
latter, in response to downward pressure on one of said marginal
portions, rock relative to said lower shell section to a first
position in which said electric drive is switched from inoperative
mode to forward mode, and in response to additional downward
pressure on the other of said marginal portions rocks to a second
position in which said electric drive is switched past said forward
mode to said backspace mode.
2. A foot control as defined in claim 1; further comprising a first
and a second set of cooperating abutments on said upper and lower
shell sections, respectively, the abutments of said first set being
engageable in response to rocking of said upper shell section to
said first position and the abutments of said second set being
engageable in response to rocking of said upper shell section to
said second position.
3. A foot control as defined in claim 1; further comprising a first
switch in said housing connectable with said drive and
displaceable, in response to movement of said upper shell section
to said first position, from a normal inactive position to an
active position initiating said forward mode of said drive; and a
second switch in said housing also connectable with said drive and
displaceable, in response to movement of said upper shell section
to said second position, from a normal rest position to an
operating position initiating said backspace mode of said
drive.
4. A foot control as defined in claim 1, said rocker bearing means
comprising a rocker bearing element of roundish configuration
interposed between and in contact with said upper shell section and
said second end portion of said leafspring.
5. A foot control as defined in claim 4, said rocker bearing
element being of spherical configuration.
6. A foot control as defined in claim 5, said second end portion
having a recess dimensioned to partly accommodate said spherical
rocker bearing element, and the latter being partly accommodated in
said recess.
7. A foot control as defined in claim 3, said first and second
switches being rocker switches.
8. A foot control as defined in claim 1, said bayonet-couplings
each comprising cooperating male and female connecting portions
provided on said shell sections.
9. A foot control as defined in claim 8, said upper and lower shell
sections having respective juxtaposed side walls, and said
connecting portions being provided on said side walls.
10. A foot control as defined in claim 1, said upper and lower
shell sections being of polygonal outline.
11. A foot control as defined in claim 1, said upper and lower
shell sections being of quadratic outline.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a foot control, and more
particularly to a foot control for an electric drive. Still more
particularly the invention relates to a foot control which is
especially but not exclusively useful for controlling dictating
apparatus and which serves for effecting sequential switching of an
electric drive in dictating or other apparatus between an
inoperative mode, a forward mode and a reverse mode.
The invention will hereafter be described with respect to its use
in conjunction with a dictating apparatus, particularly a dictating
apparatus utilizing magnetic tape. However, it is understood that
its operation would be analogous where other drives in other
devices are to be controlled in the same sense.
In dictating apparatus it is usually desired to provide the foot
control with switching means permitting the drive of the apparatus
to be stopped entirely, permitting the drive of the apparatus to be
switched to a forward mode of operation and permitting the drive of
the apparatus to be switched to a temporary reverse or backspace
mode of operation so that the user may briefly reverse the magnetic
tape. One known type of foot control for this purpose utilizes
pressure variations wherein a single switch is depressed lightly to
switch the drive from inoperative mode to forward mode, with a
stronger pressure being required to switch the drive from forward
mode to reverse mode of operation. It is known, for instance, to so
construct foot controls of this type that 0 kp pressure is required
for the switching of the device to inoperative mode, that between
0.5 and 1 kp pressure is required for switching the device from
inoperative to forward mode, and that 2 kp pressure is required for
switching the device to reverse mode of operation. Thus, if for
instance a pressure of 2.5 kp is exerted on such a known foot
control when the same is in a position in which the drive is
inoperative, then reverse mode of operation is immediately selected
thereby without the possibility of erroneously selecting the
forward mode of operation. However, it follows from this that in
this type of construction the increasing pressure required for
switching the drive to reverse mode of operation makes for a slight
difficulty in operating the foot control, and that operation of the
foot control in the varying conditions of use requires the exertion
of variable pressure. This is tiring to the person utilizing the
foot control and an attempt has been made to avoid this difficulty
by constructing another type of foot control utilizing two separate
control pedals or the like which, however, must have an arresting
device in order to assure the necessary and desired switching
sequence, for instance "reverse mode," "forward mode" and
"inoperative mode;" unless such sequence is maintained, damage to
the recording carrier, for instance the magnetic tape, will result.
This second type of construction, however, also is not particularly
well liked by persons utilizing such controls because it requires a
constant shifting in the position of the foot of the operator which
not only is time-consuming and tiring but also is detrimental to
maintaining proper concentration on the actual work.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to provide
an improved foot control for the purposes set forth above.
More particularly it is an object of the invention to provide an
improved foot control of the type under discussion which is simple
in its construction and inexpensive to produce and to sell.
An additional object of the invention is to provide such an
improved foot control which is easy to operate and is not tiring to
the operator, and which also operates reliably and provides for a
reliable error-free sequential selection of the desired operational
modes of the drive which it controls.
In pursuance of the above objects, and others which will become
apparent hereafter, one feature of the invention resides in a foot
control, particularly for use with a dictating machine, for
effecting sequential shifting of an electric drive between an
inoperative mode, a forward mode and a reverse mode which briefly
stated comprises a housing including an upwardly open lower shell
section and a superimposed downwardly upper shell section having
two spaced marginal portions. Connecting means connects the upper
shell section to the lower shell section with limited freedom of
movement towards and away from the latter. A leaf spring is
provided in the housing and has a first end portion fixed to the
lower shell section and a free second end portion urging the upper
shell section upwardly away from the lower shell section. Rocker
bearing means is interposed between the second end portion and the
upper shell section so that the latter, in response to downward
pressure on one of the marginal portions, rocks relative to the
lower shell section to a first position in which the electric drive
is switched from inoperative mode to forward mode and in response
to downward pressure on the other of the marginal portions rocks to
a second position in which the electric drive is switched passed
the forward mode to reverse or backspace mode.
According to another advantageous embodiment the rocker bearing
means may be in form of an element interposed between the second
end portion of the leaf spring and the upper shell section, and
this element will have a roundish configuration, preferably but not
necessarily a sphere. The displacement in the position of the upper
shell section takes place with reference to the center of the upper
shell section and as a result the foot control can be operated
equally well from all sides, including the backside, that is the
side which normally faces away from the operator when the foot
control is positioned on the ground ready for use. This makes it
possible to utilize the novel foot control in any position relative
to the foot of the operator, because it now no longer requires a
predetermined position of the foot control with reference to the
foot of the operator as has always been the case in the
constructions known from the prior art.
The novel features which are considered as characteristic for the
invention are set forth in particular in the appended claims. The
invention itself, however, both as to its construction and its
method of operation, together with additional objects and
advantages thereof, will be best understood from the following
description of specific embodiments when read in connection with
the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partly broken-away top-plan view of a foot control
according to the present invention;
FIG. 2 is a side-elevational section of the embodiment shown in
FIG. 1, depicting the foot control in a position in which it
controls the inoperative mode of the drive;
FIG. 3 is a view similar to FIG. 2 but depicting the foot control
of FIG. 1 in a position in which it controls the drive for forward
mode of operation;
FIG. 4 is a view also similar to FIG. 2 but depicting the foot
control in a position in which it controls the drive for reverse
mode of operation;
FIG. 5 is a view similar to FIG. 2 illustrating a further detail of
the embodiment shown in FIG. 1; and
FIG. 6 is a top-plan view of FIG. 5, partly broken away, to
illustrate the detail of FIG. 5 in top-plan view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Discussing now the drawing in detail it will be seen that the foot
control according to the present invention is provided with a
housing which preferably is quadratic in outline, but which may be
generally polygonal. The housing is composed of two shell sections,
a lower upwardly open shell section 2 and an upper superimposed
downwardly open shell section 1. Located in the interior of the
space or chamber thus enclosed are two rocker switches 14 and 15 of
known construction which are positioned in the manner illustrated
in FIG. 1 in particular.
As FIGS. 2-4 show most clearly, a shell-like insert 25 of
preferably sheet metal--which may be formed by stamping--is located
in the interior of the upper shell section 1 and is at its outer
side surrounded by a tightly fitting similarly configurated shell
portion 29 of a suitable synthetic plastic material, preferably
Caprolan (trademark) or on Caprolan basis. The lower shell section
2 advantageously is composed of metal, for instance pressure-cast
zinc or the like. Any recesses which are required (compare for
instance FIGS. 1 and 2) are formed in the lower shell section 2 at
the time the latter is shaped.
As the drawing shows, the shell sections 1 and 2 are connected by
four bayonet-type connecting arrangements cooperating between the
juxtaposed side walls 5 and 6 of the shell sections 1 and 2. Thus,
the upper shell section 1 is movable upwardly and downwardly with
reference to the lower shell section 2 to the limited extent made
possible by the bayonet-type connecting means or closures. Each of
these bayonet closures comprises, as the drawing clearly shows
(particularly FIG. 1), a projecting male pin 3 provided on the
inside of the upper shell section 1 and a corresponding or
cooperating recess 4 provided on the lower shell section 2. The
configuration of the recesses 4 is such that the pin 3 is inserted
into a throat 4' of the recess 4 when the upper shell section 1 is
placed in superimposed relationship upon the lower shell section 2,
whereupon the upper shell section 1 is pressed down and moved
towards the left as seen in the drawing, so that the pin 3 then
slides from the throat 4' into the main portion of the recess 4 as
the upper shell section is lifted upwardly again. This lifting
occurs automatically as a result of the upwardly directed biasing
action of a leaf spring 7 one end portion of which is connected to
the lower shell section 2 by means of screws or similar connecting
means 7a. The other free end portion of the leaf spring 7 urges the
upper shell section 1 upwardly away from the lower shell section
2.
A rocker bearing means, here illustrated as a spherical element 8,
is interposed between the free end portion of the leaf spring 7 and
the upper shell section 1. The free end portion of the leaf spring
7 is provided with a recess or aperture 9 in which the spherical
element 8 is partly accommodated so as to be fixed in its position,
and a similar recess or aperture 9' is provided in the shell-like
portion 25 of the upper shell section 1. Thus, the upper shell
section 1 rocks or tumbles with reference to the lower shell
section 2 when downward pressure is exerted on any one of its
marginal portions, regardless of which one of them. This is true
even if the pressure is exerted on the marginal portion at the back
or reverse rear side of the upper shell section 1, that is the one
which normally would face away from the operator and where the
electrical conductor 21 enters the foot control.
Two slots 27 are provided in the lower shell section 2 at that side
which would normally face the operator, and two projecting pins 26
of the portion 25 of the upper shell section 1 extend into these
slots 27. Two grooves 28 are provided at the side of the lower
shell section 2 which is opposite the slots 27, and when the upper
shell section 1 is placed upon the lower shell section 2, two
arresting projections 23 of an arresting member 22 can pass into
these grooves 28. This will be discussed in more detail
subsequently.
The foot control is shown in FIG. 2 in a position in which the
drive which it controls is in inoperative position. When pressure
is exerted on one marginal portion of the upper shell section 1 in
the direction of the arrow 10 (see FIG. 3) this marginal portion is
downwardly displaced with reference to the lower shell section 2
until the surface 17 of the upper shell section 1 abuts against an
upper free edge 11 of the lower shell section 2; when this takes
place, the switch 14 energizing the drive for forward operation has
been actuated. Pressure on an opposite marginal portion of the
upper shell section 1 in the direction of the arrow 12 (see FIG. 4)
again displaces the upper shell section 1 in a rocking or tumbling
movement about the element 8 in downward direction with reference
to the lower shell section 2, until the surface 17 of the upper
shell section 1 abuts against an upper edge face 13 of the lower
shell section 2, at which time the switch 15 has been energized in
a sense switching the drive controlled by the foot control to
reverse or backspace mode of operation.
It will be appreciated that the rather broad leaf spring 7 which
advantageously consists of sheet steel, constitutes a lever which
can be displaced stepwise and via which the two rocking switches 14
and 15--which are of entirely conventional construction--are
actuated. It is immaterial upon which marginal portion of the upper
shell section 1 the pressure is exerted, because the upper shell
section 1 will always be first displaced from the position shown in
FIG. 2 through one stage to the position shown in FIG. 3 in which
it energizes the switch 14. Only after abutment has taken place
between the surface portions 11 and 17 will additional displacement
to the second stage take place by further displacement of the upper
shell section 1 to the position shown in FIG. 4, caused simply by a
slight rocking of the foot of the operator. Assuming that the
device is positioned as shown in the drawing, with the right-hand
(as seen in the drawing) edge facing the operator and the left-hand
edge facing away from the operator and assuming that the device is
in the position shown in FIG. 4 to which it is brought simply by
pressing down with the tip of the foot, then the device is returned
to the position of FIG. 3 simply by lifting the tip of the foot
lightly whereby the edge 19 of the shell section 1 snaps upwardly
under the urging of the leaf spring 7 with the left-hand pins 3
thus moving upwardly into abutment with the upper edges of the
corresponding openings 4 to delimit the maximum upward movement. As
this takes place, the contact spring of the rocker switch 15 snaps
downwardly again into the open position illustrated in FIG. 2 and
the reverse mode switching is thereby terminated. If the foot is
lifted further, thereby terminating pressure upon the edge 20 of
the upper shell section 1, then this edge also snaps to the upper
or rest position shown in FIG. 2 from the position in FIG. 3, and
the switch 14 also returns to circuit-interrupting position,
thereby switching the drive from forward mode to inoperative mode.
Thus, the desired switching sequence in operative mode, forward
mode and reverse mode can be reliably maintained in sequence, both
starting with inoperative mode and starting with reverse mode,
which is to say that the sequence is maintained irrespective of
whether the operation of the control begins with the drive in
inoperative mode or whether it begins with the drive in reverse
mode.
To prevent undesired opening of the housing, that is separation of
the shell sections 1 and 2, a longitudinally shiftable and
preferably arrestable arresting member 22 is provided in the
interior of the upper shell section 1. This is most clearly shown
in FIGS. 5 and 6 where it will also be seen that the member 22 has
two arresting projections 23. A projection or bead 30 on the member
22 snaps into corresponding openings 31 in the portion 25 of the
upper shell section 1 in the two end positions of the member 22.
This member 22 may be displaced from the broken-line open or arrest
position to the full-line arresting position (see FIG. 6) in
suitable manner, for instance by inserting a screw driver or
similar member through a cut-out 24 in the lower shell section 2
and exerting a requisite force upon the member 22. In the full-line
position the projections 23 may abut against the adjacent outer
side wall of the lower shell section 2 and thus prevent the
opposite projection 26 of the upper shell section 1 from being
withdrawn out of the slots 27 of the shell section 2. On the other
hand, when the member 22 is in the open position illustrated in
FIG. 6 in broken lines, the projections 26 can be withdrawn from
the slots 27 because the projections 23 can in this position enter
into the corresponding grooves 23 provided in the side wall of the
lower shell section 2.
It will be understood that each of the elements described above, or
two or more together, may also find a useful application in other
types of constructions differing from the types described
above.
While the invention has been illustrated and described as embodied
in a foot control, it is not intended to be limited to the details
shown, since various modifications and structural changes may be
made without departing in any way from the spirit of the present
invention.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can by applying current
knowledge readily adapt it for various applications without
omitting features that, from the standpoint of prior art, fairly
constitute essential characteristics of the generic or specific
aspects of this invention and, therefore, such adaptations should
and are intended to be comprehended within the meaning and range of
equivalence of the following claims.
* * * * *