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.

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.

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.