US3643083A

US3643083A - Battery-operated devices

Info

Publication number: US3643083A
Application number: US864776A
Authority: US
Inventors: Helmut A Heine
Original assignee: Propper Manufacturing Co Inc; OPTOTECHNIK GmbH
Current assignee: Propper Manufacturing Co Inc; OPTOTECHNIK GmbH
Priority date: 1968-11-30
Filing date: 1969-10-08
Publication date: 1972-02-15
Anticipated expiration: 1989-02-15
Also published as: DE1811923B1; GB1260318A; DE1811923C2; FR2024964A1

Abstract

A battery-operated device such as a medical diagnostic unit requiring batteries for illumination purposes. The device has an elongated hollow grip which also acts to accommodate batteries in its interior, and a springy clip is carried by the grip at its exterior surface to enable the grip to be situated on the wall of a garment pocket or other enclosure with the grip situated within the enclosure and with an upper part of the wall thereof extending between the clip and the exterior surface of the grip. A movable switch member is guided for movement by the clip and situated in a position to be engaged by the upper edge of the wall of the enclosure and displaced thereby to a circuit-opening position whenever the grip is situated within the enclosure, so that in this way the circuit will be automatically opened when the device is not used and carried about in a garment pocket or placed in another enclosure which will operate in a similar manner to place the switch automatically in its open position.

Description

United States Patent Heine [54] BATTERY-OPERATED DEVICES [72] Inventor: Helmut A. Heine, Herrsching, Upper [21] Appl.No.: 864,776

301 Foreign Application Priority Data Nov. 30,1968 Germanym. ..Pl8ll923.8

[52] US. Cl. 340/1066, 240/646, 240/ 10.68, 240/ 10.6 CH

[51] Int. 2" 7/00 [58] FieldofSearch ..240/10.68, 10.6 R, 10.66, 10.5 F, 240/2 1, 10.6 CH, 6.46, 6.46 R, 6.4 CL; 320/2, 3,

Burgess ...240/ 10.68 Sherwood et al. ..240/ 10.68

[ 51 Feb. 15, 1972 3,005,090 10/ 1961 Moore ..240/ 10.6 R 3,261,973 7/1966 Kott ..320/2 X 3,316,396 4/1967 Trott et al ..240/ 10.68 X

Primary Examiner-Louis R. Prince Assistant Examiner-Daniel M. Ya'sich Attorney-Blum, Moscovitz, Friedman & Kaplan [57] ABSTRACT A battery-operated device such as a medical diagnostic unit requiring batteries for illumination purposes. The device has an elongated hollow grip which also acts to accommodate batteries in its interior, and a springy clip is carried by the grip at its exterior surface to enable the grip to be situated on the wall of a garment pocket or other enclosure with the grip situated within the enclosure and with an upper part of the wall thereof extending between the clip and the exterior surface of the grip. A movable switch member is guided for movement by the clip and situated in a position to be engaged by the upper edge of the wall of the enclosure and displaced thereby to a circuit-opening position whenever the grip is situated within the enclosure, so that in this way the circuit will be automatically opened when the device is not used and carried about in a garment pocket or placed in another enclosure which will operate in a similar manner to place the switch automatically in its open position.

7 Claims, 6 Drawing Figures PATENTEDFEB 15 1972 SHEET 1 OF 3 FIG.2

INH'INIOR. HELMUT A. HEINE PATENTEDFEB 1 5 m2 SHEET 2 [IF 3 "FIG. 4

FIG. 3

INVI') \"l'U/f. HELMUT A. HEINE PATENTEDFEB 15 ma 3, 643.083

INVICNIOR. HELMUT A. HEINE BATTERY-OPERATED DEVICES BACKGROUND OF THE INVENTION The present invention relates to battery-operated devices.

In particular, the present invention relates to devices such as medical diagnostic instruments which require illumination from batteries. Thus, for example, instruments such as otoscopes, ophthalmoscopes, illuminating devices for examining the human eye, and the like, are provided with lamps which must be energized to provide the required illumination.

Such lamps must receive their power either from a cable connected to the lines through a wall plug or from batteries. When a cable is used it is necessary to use also a transformer, while when batteries are used these are included in a chamber of the device itself.

Wherever it is possible, the use of batteries is preferred because an electrically conductive cable extending from the instrument is cumbersome and with the use of batteries any possible risks of defective operation as with a defective transformer, for example, are eliminated. Moreover, batteries are preferred because there often is no wall plug available to receive the cable.

It is known to construct diagnostic instruments of this type in such a way that the batteries are housed within a hollow enclosure which at the same time acts as a grip for the instrument. It is important to provide particularly small and light battery-enclosing grips for instruments which a'physician carries about not only in his bag but also, for example, in a breast pocket of his jacket during visits to a hospital, so that'such an instrument is at all times readily available.

While it has been customary in the past to use for such purposes dry batteries (zinc-carbon batteries and the like), there are now available small rechargeable batteries, particularly in the form of nickel-cadmium battery cells. It is therefore desirable to construct a grip which serves as a battery housing in such a way that it is also possible to make use of cells of this latter type with the capability of recharging such cells without taking them out of the grip, since such operations would represent a highly significant inconvenience and disadvantage for a physician.

Inasmuch as the light source in diagnostic instruments of this type may be visible from the exterior and furthermore since the light provided by such a light source is in many cases not visible or only visible from a single direction, it frequently happens that the operator of the instrument forgets to turn the instrument off after it is used. The result is a useless discharge of the batteries and an early burning out of the short-lived lamps.

SUMMARY OF THE INVENTION It is in particular an object of the present invention to pro-.

vide a construction capable of automatically turning the device off when it is placed in the pocket of a jacket or when it is placed in a charging unit for recharging the batteries.

According to the invention the grip of the device is hollow so as to accommodate batteries in its interior. The grip has an exterior surface carrying a clip by means of which the grip with an instrument carried thereby may be mounted in a pocket or other enclosure with a wall of such an enclosure extending between the clip and the exterior surface of the grip. The electrical circuit includes a switch means which has a movable switch member movable between circuit-opening and circuit-closing positions, and the clip carries a guide means which guides the shiftable switch member for movement between these positions. The arrangement is such that the upper edge of the wall of the pocket or other enclosure will engage the shiftable switch member to displace it from its switch-closing to its switch-opening position when the grip is situated within the enclosure with wall thereof situated between the clip and the exterior surface of the grip, so that in this way an automatic opening of the circuit will take place even if the operator should forget to place the switch in its circuit-opening position.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a fragmentary sectional elevation of one embodiment of a structure according to the invention;-

FIG. 2 is a fragmentary sectional elevation of another embodiment of a structure according to the invention;

FIG. 3 is a fragmentary partly sectional illustration of detent structure for releasably maintaining a shiftable switch member in a selected one of a pair of positions;

FIG. 4 is a fragmentary partly sectional elevation of a further embodiment of a structure of the invention;

FIG. 5 is a fragmentary sectional elevation on an enlarged scale of the structure at the lower end region of FIG. 4; and

FIG. 6 is a schematic partly sectional perspective illustration of a recharging unit for recharging batteries within the grip.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, the embodiment of the invention which is illustrated therein is particularly suited to accommodate within the hollow grip particularly small dry batteries. The grip l is made of a suitable, advantageously light material, which preferably is plastic. Thus, the grip l is of an elongated tubular construction and has a wall which is not electrically conductive. In order to connect this grip or battery enclosure with a diagnostic instrument, the upper end of the tubular grip fixedly carries a threaded sleeve 7 made of metal. The instrument can be treated to this sleeve so as to be connected in this way to the grip 1. Of course, other types of connections can be used instead of a threaded connection. For example a bayonet connection can be used.

With this embodiment of the invention the lower end of the hollow grip l is closed, so that the insertion of the batteries into the hollow grip takes place upon removal of the instrument 9, which may simply be a hand lamp which can be focused, so that the interior of the hollow grip I becomes accessible through the threaded connecting ring 7. The lower end wall of the grip supports a spring 3 which urges the batteries 2 upwardly with the top pole of the upper battery 2 engaging a contact pin 10 which is electrically connected with the lamp of the instrument. In addition, the spring 3 is in electrical engagement with an elongated conductor 4 in the form of an electrically conductive strip which extends upwardly along the inner surface of the hollow grip l.

The grip carries a switch means which includes a stationary contact formed by the upper end of the conductor 4. This switch means includes a movable contact in the form of a springy member 5 capable of being displaced into and out of engagement with the stationary contact so as to close and open the circuit. The spring 5 will move away from the stationary contact due to the inherent resiliency of the spring 5. Since the top end of the conductor 4 is shaped to form the stationary contact, no special stationary contactor connection between the latter and the conductor 4 is required.

The switch means includes a shiftable switch member 6 which is guided for movement in a corresponding groove formed in the exterior surface of the grip I. When the shiftable switch member 6 is in its upper end position, displaced toward the instrument 9, the contact 5 situates itself away from the stationary contact, so that in its upper end position the switch member 6 is in its circuit-opening position. When, however, the shiftable switch member 6 is displaced downwardly away from the instrument 9, this switch member 6 will cam the movable contact 5 into engagement with the stationary contact at the top end of the conductor 4, so that the circuit will be closed. Thus, the lower position of the shiftable switch member 6 represents the circuit-closing position thereof.

Inasmuch as battery grips of this type will conveniently be carried about by a physician, for example, in a garment pocket, such a battery grip is provided, in accordance with the invention, with a springy clip 8 capable of releasably holding the grip 1 within the pocket or other enclosure with the wall of the latter situated between the springy clip 8 and the exterior surface of the grip 1. Thus, the clip 8 has a lower free end resiliently urging itself toward the exterior surface of the grip I so as to clamp the grip releasably in a pocket engaging the wall thereof. The top end of the clip 8 is fixed directly to the exterior surface of the grip 1.

At the region of its upper end the clip 8 is formed with an elongated opening acting as a guide means in that the clip 8 has opposed side edges slidably engaging the shiftable switch member 6 so as to guide the latter for movement between its upper circuit-opening and lower circuit-closing positions. The shiftable switch member 6 extends outwardly beyond the front surface of the clip 8 through a distance sufficient to provide for convenient manipulation of the switch member 6 in order to turn the device on and off. At the same time the shiftable switch member 6 does not extend beyond the clip 8 to such an extent that accidental shifting of themember 6 will take place, and thus the structure reliably prevents unintentional turning of the device on'and off by accidental engagement of the switch member 6 with an exterior projection.

It is clear, therefore, that the shiftable switch member 6 extends across the gap between the exterior surface of the grip l and the clip 8. Therefore, when the grip l is placed in a pocket or other enclosure, the upper wall portion of the latter will have its upper edge situated in the region of the shiftable member 6 between the exterior surface of grip l and the clip 8. If it should happen that the shiftable switch member 6 is in its lower circuit-closing position, then this upper edge of the wall of the pocket or other enclosure will engage the switch member 6 and automatically displacev it upwardly to its circuitopening position during insertion of the device into the pocket or other enclosure. In this way there is an assurance that the instrument will reliably be turned off even in the case where the operator unintentionally leaves the instrument turned on, this automatic turning off of the instrument taking place during insertion thereof into a pocket in the above-described manner. In this way one of the important advantages of the structure of the invention is achieved.

In order to make certain that the shiftable switch member 6 does not become displaced between its circuit-opening and circuit-closing positions without actuation of a certain minimum actuating force, a detent means is provided for releasably holding the shiftable switch member 6 in one or the other of its positions. Thus, as may be seen from FIG. 3, the shiftable switch member 6 is provided with a transverse bore accommodating at its end regions a pair of detent ball members 26 which are urged apart from each other by a 7 spring 27 situated within the bore 25. The elongated opening of the clip 8 has at its opposed side edges which guide the switch member 6 detent recesses 28 and 29. Thus, the detent recesses 28 are situated to receive the detent ball members 26 when the shiftable switch member 6 is in its upper circuitopening position, while the pair of detent recesses 29 are situated to receive the ball members 26 when the shiftable switch member 6 is in its lower circuit-closing position. With the position of the part shown in FIG. 3 the detent balls 26 are in the upper recesses 28 thus releasably holding the member 6 in its circuit-opening position.

FIG. 2 of the drawings illustrates another embodiment of the invention. According to this embodiment the elongated tubular grip II. is designed to accommodate somewhat larger batteries 12 and has at its bottom end a removable cap which is removably connected with the tubular wall of the grip II. After this cap is removed it is possible to remove and replace batteries through the bottom end of the hollow grip. In this way it is possible to place in the hollow grip of this embodiment batteries whose diameters are greater than the diameter of the connecting element by which the instrument on top of the grip is releasably connected thereto. In the illustrated example the instrument is, as indicated at the upper part of FIG. 2, an ophthalmoscope 19.

The elongated tubular hollow grip I1 is advantageously made of plastic so that the economically favorable manufacturing methods may be used to construct the device and in order to give the device the smallest possible weight. It is required to provide a connection between the lower pole of the lower battery and the switch means. For this purpose the closure cap can either be manufactured entirely of metal or, as indicated in FIG. 2, the cap may have a bottom wall 2] made of an insulated material and a metallic threaded ring 22 which is connected with an extends upwardly from the wall 21. This ring 22 has an electrically conductive connection with the contact spring 13 which in addition serves to urge the batteries upwardly against the upper contact 20 of the diagnostic instrument. The lower end of the grip ll fixedly carries a metal ring 23 onto which the ring 22 is threaded. This ring 23 is in contact with the elongated conductor 14 which forms a contact strip extending upwardly along the interior of the grip and terminating at its top end in the stationary contact 24 with which the movable contact 15 coacts in the manner described above. Thus, with this embodiment also the hollow tubular grip 11 carries at its upper end region the springy clip 18 which has the guide means for the shiftable switch member 16 which coacts with the movable contact 15 to displace the latter into engagement with the stationary contact 24 when the member 16 is shifted downwardly while the member 15 will displace itself away from the contact 24 when the member 16 is displaced upwardly, as pointed out above in connection with FIG. 1. Thus, the embodiment of FIG. 2 will achieve the same results as that of FIG. 1 with respect to the automatic turning off of the instrument when it is placed in the pocket or other enclosure in the manner described above.

FIGS. 4 and 5 of the drawings illustrate an embodiment of the invention which may optionally be used with rechargeable batteries, particularly gastight nickel-cadmium cells, while it desired it is also possible to use dry batteries. It is required to provide the possibility for charging the cells without removing them from the hollow tubular grip. In this embodiment also there is a lower closure 50 removably connected with the bottom end of the hollowtubular grip so as to enable insertion and removal of batteries through the bottom end of the grip to be carried out either initially when new batteries are placed in or whenever batteries are to be changed.

Inasmuch as the charging of the batteries must be capable of taking place while the latter are in the hollow grip, without removing the instrument 39 from the top of the grip, it is required to provide suitable contacts by means of which the exterior source for the charging current may be connected with the batteries. In one embodiment of this inventive concept this result is achieved by placing one pole of the charging voltage through a corresponding opening 46 in the lower electrically nonconductive wall 41 of the closure in engagement with the contact portion 47 of a' support which carries the spring 33. The second pole for the charging voltage is placed in engagement with the outer metal ring 42 of the closure 50. This ring 42 is connected with the insulating wall 41 in any suitable way such as by gluing or the like.

In order to provide, when the closure 50 is in its closing position, an electrical connection between the outer ring 42 and the upper battery pole, a springy contact plate 45 is situated at the upper end region of the hollow grip 31 engaging the upper poleof the upper battery and also engaged by the connecting contact of the unit 39 which consumes the energy.

This contact plate 45 is electrically connected through an elongated conductor 44, in the form of a contact strip, with the metallic, electrically conductive ring 43 which is fixed to the electrically nonconductive wall of the grip 31 and onto which the outer ring 42 of the closure 50 is threaded. Thus, as is particularly apparent from the lower left region of FIG. 5, the conductor 44 is electrically connected with the ring 43 onto which the ring 42 is threaded so that in this way the ring 42 and the contact plate 45 are electrically connected with each other.

The electrically conductive portion 47 of the support for the spring 33 provides the electrical connection to the other pole of the battery. Thus the spring 33 provides the electrical connection to the opposite pole of the lower battery while at the same time pressing the top pole of the upper battery against the contact plate 45. Moreover through the spring 33 the electrical connection is made with the spring supporting structure which is electrically conductive and which is insulated from the ring 42 by a layer of insulation 48. Thus, the charging voltage can now be applied between the contact portion 47 and the ring 42 of the grip.

The ring 43 which is fixed to the grip 31 and the outer ring 42 of the closure can be interconnected by threads so that the closure can be threaded onto or off from the grip. However, other types of connections such as bayonet connections may be provided, if desired. 7

The lower support member of the closure, which isinsulated from the ring 42 by the layer 48, and which carries the spring 33 and has the electrically conductive portion 47 which is accessible through the opening 46, is in electrical engagement with an inner ring which is fixed to the hollow grip 31 and which is in electrically conductive engagement with an elongated conductor 34 in the form of an elongated strip extending upwardly along the interior of the hollow grip 31 and situated opposite the conductor 44. This conductor 34 terminates at its top end in the stationary contact of the switch means, and this stationary contact coacts with the movable springy contact 35. The upper portion of FIG. 4 shows the internally threaded ring 37 which is fixed to the grip and serves to connect the diagnostic instrument 39 to the grip. The springy contact 35 of the switch means is displaced into and out of engagement with the stationary contact of the switch means formed by the top end of the conductor 34 by vertical displacement of the shiftable switch member 36 guided by the guide means at the upper end region of the spring clip 38 which is connected at its top end to the exterior surface of the grip 31. Thus, this embodiment will produce the results set forth above with respect to automatic opening of the circuit whenever the device is situated in a pocket or other enclosure where a wall of the enclosure extends between the clip 38 and the exterior surface of the grip 31 to displace the switch member 36 upwardly to its circuit-opening position in the automatic manner referred to above.

In order to charge the batteries, a separate charging unit is provided, as indicated in FIG. 6. This charging unit has, in a known way, a transformer 52 which steps the line voltage down to the required lower voltage of only a few volts, and the unit also includes a rectifier 53 in order to achieve the required direct voltage for the charging of the batteries Furthermore, it is possible to situate in the charging circuit protective resistors which limit the charging current to an acceptable maximum value.

The charging unit is provided with an enclosure for receiving the battery grip which contains the batteries which are to be charged. This enclosure is in the form of a tubular sleeve 57 into which the hollow grip 31 is placed in the manner illustrated in FIG. 6. Thus, the hollow tubular enclosure 57 receives the grip, and this enclosure or guide sleeve 57 may be made of metal or insulating material. Coaxially arranged beneath the enclosure 57 is a sleeve 58 of insulating material. This sleeve 58 accommodates the required contact devices to bring about the electrical connection between the grip and the charging structure. In the construction shown in FIG. 6 the contact structure includes a ball member 55 which is pressed by a spring 56 against the outer metal ring 42 of the closure 50 of the grip. In addition the structure includes a metal contact pin 54 supported in a yieldable springy manner for movement through the opening 46 in the closure wall 41 into engagement with the conductive element 47. These contacts are brought about automatically upon introduction of the grip into the enclosure 57.

Of course, before the battery grip is inserted into the charging unit the device should be turned off by movement of the shiftable switch member 36 to its upper circuit-opening position. In this way the instrument 39 will not be operating during charging and at the same time the batteries will not be discharging simultaneously with the charging thereof, so that, in other words, energy is not taken from the batteries by the consumer 39 during charging of the batteries. However. inasmuch as the operator may frequently forget to turn the device off, the wall of the enclosure 57 has dimensions enabling this wall to become situated between the springy clip 38 and the exterior surface of the grip 31 in such a way that when the device is inserted into the charging unit the upper edge region of the enclosure 57 will engage the shiftable switch member 36 and automatically displace the latter to its upper circuit-opening position so that the circuit is automatically opened. In this way even if the operator should unintentionally forget to turn the device off, it will automatically be turned off and will not undesirably discharge as long as the device is mounted in the charging unit.

What is claimed is:

1. In a device which operates with electric illumination, an elongated hollow grip which also functions as a battery housing, said grip having an exterior surface, a springy clip carried by said grip at said exterior surface thereof for clipping the grip onto an upper edge region of an enclosure such as a garment pocket with the grip situated in the latter, said clip having a bottom free end and a top end fixed to said grip and said clip defining an elongated gap with said exterior surface of said grip, so that the enclosure wall can pass between the grip and the bottom free end of the clip toward the top end of the latter into and along said gap, and switch means carried by said grip for closing and opening an electrical circuit, said switch means including a shiftable switch member bridging said gap and movable between a lower circuit-closing position and an upper circuit-opening position, and said clip carrying a guide means which guides said switch member for movement between said positions with said switch member when in its lower position situated in alignment with the enclosure wall to be engaged by an edge of the latter for automatic displacement upwardly to said circuit-opening position when the grip is situated within the enclosure withthe upper wall portion thereof extending along said gap between the clip and the exterior surface of the grip.

2. The combination of claim 1 and wherein said guide means includes an elongated portion of said clip which is formed with an opening through which part of said shiftable switch member extends with edges of said clip which defines said opening thereof engaging and guiding said shiftable switch member for movement between said positions thereof.

3. The combination of claim 2 and wherein a detent means coacts with said shiftable switch member and said clip for releasably holding said switch member in one or the other of said positions thereof.

4. The combination of claim 3 and wherein said detent means includes a part of said shiftable switch member which is formed with a transverse bore, a spring situated in the latter bore, a pair of ball members urged apart from each other by said spring, and one pair of recesses formed in said clip and receiving said ball members when said switch member is in one of its positions while said clip is formed with a second pair of recesses receiving said ball members when said switch member is in the other of said positions thereof.

5. The combination of claim 1 and wherein said switch means includes a stationary contact carried by said grip and a movable contact displaced by said switch member into engagement with said stationary contact when said switch member is moved to said switch-closing position thereof while said movable contact assumes a position displaced from said stationary contact when said switch member is moved to said circuit-opening position thereof, said grip having an upper end adapted to be connected to an instrument and a lower end provided with a removable end wall which may be removed for inserting batteries into and removing batteries from the interior of the grip, said grip having an elongated tubular wall of electrically nonconductive material providing the grip with its exterior surface and carrying at the region of said lower end a circular ring of electrically conductive material, said removable end wall having a conductive portion engaging said ring and carrying a spring engaging a battery to provide part of an electrical circuit from the battery through the spring to the ring carried by said wall of said grip, and an elongated conductor extending from said ring along said wall of said grip to said stationary contact of said switch means.

6. The combination of claim 1 and wherein said hollow grip is adapted to accommodate rechargeable batteries in its interior, said grip being made up of an elongated tubular wall of electrically nonconductive material and carrying in an inner upper end region an electrically conductive plate engaging one pole of a battery as well as a contact of an electrical instrument mounted on the grip, said grip having a lower end carrying a removable closure and in the region of said closure a threaded ring fixed to said grip and made of an electrically conductive metal, an elongated conductor extending along said grip in the interior thereof and electrically connecting said ring to said plate, said closure having an outer electrically conductive ring threaded onto said ring carried by said grip, and said closure having a bottom end wall of insulating material carried by said outer ring thereof, an inner electrically conductive support situated within said closure and carried by said outer ring thereof with a layer of insulation situated between said support and outer ring to prevent said support and outer ring from being in electrical communication with each other, a spring carried by said support and engaging a pole of a battery within said grip to connect the battery electrically to said support, said electrically nonconductive bottom wall of said closure being formed with an opening and said support carrying an electrically conductive portion accessible through said opening, and said switch means having a stationary contact carried by said grip and a movable contact displaced by said shiftable switch member into and out of engagement with said stationary contact, and an elongated conductor extending along said grip from said stationary contact to said support of said closure and being electrically connected to the latter, whereby said closure may be removed and replaced for removing and inserting batteries into said grip while with batteries still in said grip a pair of contacts of a recharging unit can respectively be placed on and engagement with said portion of said support through said opening of said bottom wall and the other in engagement with said outer ring of said closure to provide for a recharging circuit enabling batteries to be recharged while they remain within said grip.

7. The combination of claim 6 and wherein a charging unit is provided for recharging the batteries in the said grip, said charging unit having a guide sleeve for receiving said grip, and said sleeve being received between the exterior surface of said grip and said clip and having a top edge which engages said shiftable switch member to move the latter upwardly to its circuit-opening position when the grip is mounted on the charging unit, so that the circuit is automatically opened when recharging of the batteries takes place.

Claims

1. In a device which operates with electric illumination, an elongated hollow grip which also functions as a battery housing, said grip having an exterior surface, a springy clip carried by said grip at said exterior surface thereof for clipping the grip onto an upper edge region of an enclosure such as a garment pocket with the grip situated in the latter, said clip having a bottom free end and a top end fixed to said grip and said clip defining an elongated gap with said exterior surface of said grip, so that the enclosure wall can pass between the grip and the bottom free end of the clip toward the top end of the latter into and along said gap, and switch means carried by said grip for closing and opening an electrical circuit, said switch means including a shiftable switch member bridging said gap and movable between a lower circuit-closing position and an upper circuitopening position, and said clip carrying a guide means which guides said switch member for movement between said positions with said switch member when in its lower position situated in alignment with the enclosure wall to be engaged by an edge of the latter for automatic displacement upwardly to said circuitopening position when the grip is situated within the enclosure with the upper wall portion thereof extending along said gap between the clip and the exterior surface of the grip.