US3705424A - Electrical switching apparatus utilizing conductivity of the human skin - Google Patents

Abstract

Apparatus whereby selective closing of a plurality of electrical circuits may be accomplished by slight movement of a human body member, thereby establishing a conductive path through or along the surface of such member. In one embodiment, a plurality of circuit contacts are disposed in circumferential fashion around an annular opening into which an individual''s finger is receivable. A slight sidewise movement of the finger in a radial direction effects the closing of a particular one of a plurality of circuits depending on the direction in which the radial movement occurs. Since the individual''s hand remains essentially stationary, extremely rapid sequential switching is possible, as only a sidewise movement of one finger is required instead of a complete displacement of this member as in known arrangements. The invention is particularly adapted for use with keyboards, control panels or display devices of any nature where manual manipulation forms an essential part.

Description

United States Patent [151 3,705,424 Harvey, Jr. [451 Dec. 5,1972

[54] ELECTRICAL SWITCHING Primgry Eramineh-Donald J. Yusko APPARATUS UTILIZING Assistant Examiner-Robert .1. Mooney CONDUCTIVITY OF THE HUMAN SKIN I Inventor: Richard P. Harvey, Jr., 4074 Hitch Blvd., Moorpark, Calif. 93021 Filed: March 29, 1971 Appl. No.: 129,083

References Cited UNITED STATES PATENTS Seibel et al. ..l97/l9 Kafafian ..l97/ 19 OConnor 197/98 Johnson "340/365 Attorney-Richard S. Sciascia, Q. Baxter Warner and Howard J. Murray, Jr.

[57] ABSTRACT Apparatus whereby selective closing of a plurality of electrical circuits may be accomplished by slight movement of a human body member, thereby establishing a conductive path through or along the surface of such member. In one embodiment, a plurality of circuit contacts are disposed in circumferential fashion around an annular opening into which an individuals finger is receivable. A slight sidewise movement of the finger in a radial direction effects the closing of a particular one of a plurality of circuits depending on the direction in which the radial movement occurs. Since the individuals hand remains essentially stationary, extremely rapid sequential switching is possible, as only a sidewise movement of one finger is required instead of a complete displacement of this member as in known arrangements. The invention is particularly adapted for use with keyboards, control panels or display devices of any nature where'manual manipulation forms an essential part.

3 C a s, 0. Draw n Figures PATENIEU DEC 5 m2 SHEET 1 [IF 2 FIG. I

FIG. 4

JR. INVENTOR Y E V R A H P D R A H m R GENT ATTORN Y PATENTEDHEB 19 2 3.705.424

' sum 2 BF 2 sou-mom 4o FIG 6 FIG. 7

KEYBOARD FIG 9 48 DISPLAY DATA PRO- CESSOR 4 4 HG. l0

FOOT SWITCHES g 52 COMMON J CI C2 C3 60 58 CONDUCTOR ELECTRICAL SWITCHING APPARATUS UTILIZING CONDUCTIVITY OF THE HUMAN SKIN STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION I It is known that the surface of the human skin is electrically conductive. This property has been made use of in designing so-called touch-sensitive circuits wherein some body member such as a finger or thumb can selectively interconnect or bridge a pair of contacts so as to establish a current path therebetween. Arrangements of this type have found favor in many systems where rapid switching is involved, since no moving parts are present in the device itself. This results in high reliability of operation and low maintenance requirements.

At the present time, however, such equipment is designed so that a single body member (for example, a finger or digit) is employed to selectively close a particular circuit by being placed across a gap or break in a single electrical conductor so as to establish a continuous current path. This is adequate where the system is of relatively simple design, but where a large number of such circuits are involved, the number of possible combinations using this technique is obviously limited. Also, when a human body member is rapidly moved from one set of switch contacts to another, the accuracy of the results obtained depends upon the dexterity and skill of the individual carrying out the program, much as in the operation of a standard typewriter. When a body member is required to undergo rapid positional displacements of any substantial magnitude, the possibility of error is increased in direct proportion to the speed at which the action takes place. Any expedient which simplifies such a process is therefore highly desirable.

SUMMARY OF THE INVENTION hand as in known arrangements. A much higher switching rate is thus obtainable.

STATEMENT OF THE OBJECTS OF THE INVENTION One object of the present invention, therefore, is to provide means whereby a portion of the human body is selectively and/or sequentially interposed into a plurality of electrical circuits so as to close a current path therethrough.

Another object of the invention is to provide means for sequentially establishing a current path through a plurality of electrical circuits by a slight shifting motion of some part of the human body.

A further object of the invention is to employ such means to secure a given region against unauthorized access.

A still further object of the invention is to provide means whereby both the manual and pedal extremities of an individual may be cooperatively employed to produce data for transmission to a processing or display device.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a preferred form of electrical switching unit designed in accordance with one embodiment of the present invention;

FIG. la is a sectional view of FIG. 1 along the line la-la;

FIG. 2 shows another form of the invention;

FIG. 3 is a schematic view illustrating the manner in which a switching unit such as shown in FIGS. I and la may be employed with each finger and thumb of an operator's hands;

FIGS. 4 and 5 illustrate how hand supports may be used to facilitate the operation of switches such as shown in FIGS. 1 and la;

FIG. 6 is a schematic view illustrating how the principles of the present concept may be utilized for security purposes;

FIG. 7 is a schematic view of one form of the invention in which both the hands and feet of an operator are utilized for the selective generation of. data ,to be displayed;

FIG. 8 is a schematic view showing the principle employed in the foot switches of FIG. 7;

FIG. 9 is a top view of an alternative multiple-switch arrangement utilizing the principles of the invention; and

FIG. 10 is a sectional view of FIG. 9 taken along the line 10-10.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 1a of the drawings is illustrated one embodiment of the invention in which a slight shifting motion of a single digit can selectively and sequentially effect the closing of a plurality of electrical circuits by the establishment-of a current path through such digit or along the surface thereof. In this embodiment, a complete displacement or re-location of the digit is unnecessary, only the tip portion thereof undergoing motion during the switching operation while the main body of the hand remains essentially stationary.

As shown, an annular member 10 of electrically conductive material has embedded therein a plurality of contacts l2, 14, 16, 18, 20 and 22, each contact being electrically insulated from member 10 by any suitable means, such as a non-conductive coating on all common surface portions. Each of these contacts leads to an external circuit (not shown), while member 10 is grounded. Consequently, the establishment of a curmemo nnmr rent path from member I to any one of the contacts 12-22 energizes that particular circuit of which the selected contact forms a part.

The open central region 24 of member is adapted to receive some member of an individuals body, such as a digit or thumb. Preferably, it will be the tip of a persons finger, represented in FIGS. land 1a by the reference numeral 26. The diameter of opening 24 is such that, when centrally positioned, the fingertip 26 is out of contact with any surface portion of member 10 and also out of engagement with any of the contacts 12-22.

The diameter of opening 24 is also selected so that, when the fingertip 26 shifts radially from its neutral or centrally located position of FIG. 1, it may engage one of the contacts 12-22. Also, the cross-sectional diameter of the fingertip 26 is sufficiently great as to concurrently engage one or both portions of the surface of member 10 lying on opposite sides of the particular one of contacts 12-22 to which the fingertip has moved. In FIG. 1, the broken line 26a represents a bridging of elements l0 and by the surface or skin of the fingertip 26, thereby establishing a current flow in that particular electrical circuit of which contact 20 forms a part.

The multiple-contact assembly of FIGS. 1 and 1a is of course designed for association with a single digit such as represented by the reference numeral 26. If a greater number of circuits are present, a plurality of units such as illustrated in FIGS. 1 and la may be so arranged that each finger and thumb of an individual is associated with its own switch assembly. This is schematically illustrated in FIG. 3, where the reference numerals 28 each designate a switching unit of the type described above. A very large number of separate electrical circuits may thus be controlled by one individual.

In FIG. 2 is shown one manner in which the digit 26 may selectively inter-connect two contacts located in a recessed portion 27a of a planar base member 27b formed of insulating material. In the position shown, digit 26 bridges the two contacts 27d and 27e. By moving forward, contacts 27d and 270 are bridged. Any number of contacts may lie in a single such recess.

For ease of operation of the various switching units, one or more hand supports 30 may be provided. In FIG. 4, one such support is located beneath the wrist of the operator. In FIG. 5, the support is so placed that the palm of the hand rests thereon.

The present concept is ideally suited for the purpose of securing a given region against unauthorized access. In FIG. 6 of the drawings is set forth one possible arrangement for securing a door 32 so that it may be opened only by an individual 34 who has knowledge of the location of two sets of spaced-apart contacts 36 and 38. These contacts form part of a series circuit including a battery 39 and a solenoid 40 controlling an extendable plunger 42 which normally precludes door 32 from opening when extended. However, when individual 34 touches both sets of contacts 36 and 38 so as to bridge the spaced-apart elements thereof with his fingers, the circuit is closed and plunger 42 is withdrawn to permit door 32 to be opened. Obviously,

the contacts 36 and 38 may be concealed from view so 6 that an unauthorized person is unaware of where to position his hands to effect the door opening.

' In FIGS. 7 and 8 is shown an embodiment of the invention where both the hands and feet of an individual are utilized in determining the nature of the information to be supplied to a data processor 44. An individual 46 operating a keyboard 48 with his hands and a pair of foot switches 50 and 52 (FIG. 8) with his feet, can generate information which is supplied to a processor or computer 44 and then displayed on a panel 54. The switches on keyboard 48 may be of the type illustrated in FIGS. 1 or 2, or of any other design which embody the principles of the present concept. The foot switches 50 and 52 are schematically set forth in FIG. 8, each switch being of the four-position type. A pair of planar pedal members 56 pivot about a central point 58 so as to selectively close one of the contacts 60 effectively spaced apart, depending on the direction of the pressure applied by each foot of the operator 46.

In some circumstances, a switch design such as illustrated in FIGS. 9 and 10 may be desirable. In this arrangement, a plurality of contacts C1, C2-C7 are embedded in, but insulated from, a common planar conductor C8. A slight sidewise shifting of a single digit to cover one of the insulated areas will electrically connect one of the contacts C1-C7 to the common conductor C8 and close the circuit of which the selected contact forms a part. In this design it is only necessary that the contacts Cl-C7 have sufficient spacing therebetween that the digit carrying out the switching operation not bridge more than one contact at a time.

It will be recognized that, if desired, a thimble-like conductive fingertip shield may be attached to the digital portion of each finger. Different combinations of circuits may then be achieved by running wires between thimble elements located on selected fingers. Electrical conductivity can also be established by covering the skin of each finger with a suitable material such as aluminum paint or a metallic-based plastic. Any of the body members, such as the toes, can be so treated if the operating requirements so dictate.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. In a data processing system in which information as to the data so processed is presented on a display panel, and in which an operator manipulates a keyboard to generate data to be so processed, the combination of:

a plurality of devices on said keyboard, said devices being of the type for enabling rapid electrical switching to be accomplished by means of a limited movement of one or more of an individuals body members through or along which a conductive path is established, said devices comprising:

an annular member of electrically conductive material adapted to have a body member centrally placed therewithin but out of contact therewith; and

a plurality of electrical contacts spaced apart in circumferential fashion around the inner surface of said annular member but electrically insulated therefrom,

whereby a radial movement in a particular direction of said body member from a central position at least one foot switch actuatable by said operator,

the data acquired from manipulation of said keyboard and/or from actuation of said foot switch being presented on said display panel.

The combination of claim 1 in which said foot switch comprises a planar pedal member pivoted at its center, and a plurality of contacts selectively closable by a tilting in a particular direction of said pedal member from a neutral position by the operators foot.

In a data processing system in which information as to the data so processed is presented on a display panel, and in which an operator manipulates a keyboard to generate data to be so processed, the combination of:

a plurality of devices on said keyboard, said devices being comprised of; an essentially planar member composed of insulating material and having a recess formed therein capable of receiving a human digit, and a plurality of spaced apart electrical contacts located in sad recess, said contacts being so disposed that any chosen two thereof are bridged by the entry of said digit into said recess with a particular positional orientation, such a bridging of said chosen two contacts establishing an electrical path therebetween through or along said digit; and at least one foot switch actuatable by said operator, the data acquired from manipulation of said keyboard and/or actuation of said foot switch being presented on said display panel.

Claims (3)

1. In a data processing system in which information as to the data so processed is presented on a display panel, and in which an operator manipulates a keyboard to generate data to be so processed, the combination of: a plurality of devices on said keyboard, said devices being of the type for enabling rapid electrical switching to be accomplished by means of a limited movement of one or more of an individual''s body members through or along which a conductive path is established, said devices comprising: an annular member of electrically conductive material adapted to have a body member centrally placed therewithin but out of contact therewith; and a plurality of electrical contacts spaced apart in circumferential fashion around the inner surface of said annular member but electrically insulated therefrom, whereby a radial movement in a particular direction of said body member from a central position within said annular member to engage both said annular member and one of said plurality of contacts will result in the establishment of an electrically conductive path through or along such body member, thus closing an electrical circuit which includes said annular member and said one contact, the particular contact thus engaged depending on the direction of radial movement undergone by said body member; and at least one foot switch actuatable by said operator, the data acquired from manipulation of said keyboard and/or from actuation of said foot switch being presented on said display panel.

2. The combination of claim 1 in which said foot switch comprises a planar pedal member pivoted at its center, and a plurality of contacts selectively closable by a tilting in a particular direction of said pedal member from a neutral position by the operator''s foot.

3. In a data processing system in which information as to the data so processed is presented on a display panel, and in which an operator manipulates a keyboard to generate data to be so processed, the combination of: a plurality of devices on said keyboard, said devices being comprised of; an essentially planar member composed of insulating material and having a recess formed therein capable of receiving a human digit, and a plurality of spaced apart electrical contacts located in sad recess, said contacts being so disposed that any chosen two thereof are bridged by the entry of said digit into said recess with a particular positional orientation, such a bridging of said chosen two contacts establishing an electrical path therebetween through or along said digit; and at least one foot switch actuatable by said operator, The data acquired from manipulation of said keyboard and/or actuation of said foot switch being presented on said display panel.

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