Abstract:
An improved hand-held sensor having a recessed LED array for indicating the location of an object behind a wall surface. The array displays in an arrow shaped format the location of the sensor relative to the object. The LED&#39;s can be offset both laterally and in depth from the surface of the sensor exterior case and are recessed from the surface. The sensor includes a soft feeling slip-resistant gripping surface for the user. One form of the sensor includes a slide switch actuator, which is retained in one wall of the sensor case to enable actuation of a switch mechanism without physical loading on the switch mechanism.

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to hand-held sensors, such as for sensing objects of varying density in or adjacent walls, and in particular to a sensor with improved handling, display, and actuation. 
     2. Description of Related Art 
     Hand-held sensors are generally well known, such as disclosed in U.S. Pat. Nos. 4,099,118 and 4,464,622, which are incorporated herein by reference. These sensors measure the change in capacitance sensed by the a sensor circuitry as the sensor is moved across a wall. Typically, the capacitance varies due to studs, metal objects, pipes or other structural differences such as electrical wiring. The sensors generally display, such as with one or more light emitting diodes (LED&#39;s) the presence of such a change in capacitance indicating the presence of a stud or other object. The circuitry can detect and indicate the presence of an alternating current (AC) source in or behind the wall. 
     The exterior cases of the hand-held sensors generally are formed from a hard thermoplastic material, which can include various types of ridges or other similar raised gripping surfaces. Nonetheless, such cases inherently are slippery and can become more slippery due to moisture, such as due to the user&#39;s perspiration or rain. Further, unlike most hand tools which are held in a single manner and position during utilization, the hand-held sensors are held in a multitude of positions at many different angles, such as for scanning ceilings or walls above or below a user&#39;s height. 
     The sensors include one or a plurality of LED&#39;s to indicate the sensed change in capacitance or for other functions, such as calibration and/or AC source sensing. The LED&#39;s generally are arranged in a vertical or horizontal row across the sensor case, although one display, model number EZ380B, made by National in Japan includes a somewhat arrow shaped orientation of LED&#39;s. These LED displays are either covered by a transparent cover, such as in the National display, or are exposed and can protrude beyond the casing wall of the sensor, such as the vertical aligned LED display in a sensor sold under the name “Intellisensor Stud Sensor” made by The Stanley Works in New Britain, Connecticut. The exposed LED&#39;s or transparent covers can be scratched, damaged or broken when being stored or transported, or if dropped. 
     The actuators, especially when designed as slide actuators, can be of a complicated design and can bear against the switch mechanism or the circuitry and can cause defects in the sensor. The actuators often are glued or adhered to the switch mechanism and hence are subject to breakage. 
     It would be desirable to provide a hand-held sensor which is easily gripped, does not have exposed LED&#39;s and has an actuator which is easily manufactured, not subject to breakage and does not load the switch mechanism or circuitry. 
     SUMMARY 
     An improved hand-held sensor having a recessed LED array for indicating the location of an object behind a wall or other surface. The array displays in an arrow shaped format the location of the sensor relative to the object. The LED&#39;s can be offset both laterally from one another and in depth from the surface of the sensor exterior case and are recessed from the surface in which the LED&#39;s are mounted. The sensor includes a soft feeling slip-resistant gripping surface for the user on a rear portion of the sensor. One form of the sensor includes a slide switch actuator, which is retained in one wall of the sensor case to enable actuation of a switch mechanism without physical loading on the switch mechanism. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 illustrates a partially exploded perspective view of one embodiment of the hand-held sensor of the present invention. 
     FIG. 2 is a perspective view of the sensor of FIG.  1 . 
     FIGS. 3A and 3B are respective top and side views of the sensor of FIG.  1 . 
     FIG. 4 is a perspective view of a display embodiment of the sensor of FIG.  1 . 
     FIG. 5 is a sectional view of the display taken along the line  5 — 5  of FIG.  4 . 
     FIGS. 6A-6D are partial sectional side views of an actuator which can be utilized in the sensor of the present invention. 
     FIG. 7 is a perspective view of a second embodiment of the hand-held sensor or device of the present invention. 
     Utilization of the same reference numerals in different FIGS. indicates similar or identical elements, structurally and/or functionally. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In accordance with one embodiment of the present invention, a hand-held sensor or device is designated generally by the reference numeral  10  in FIGS. 1-3. The sensor  10  includes a casing or housing  12 , which conveniently can be formed in an upper casing portion  14  and a lower casing portion  16 . The portions  14  and  16  can be formed to snap fit together or can be removably secured together by screws or other conventional securing devices to form the assembled casing  12 . 
     One of the problems presented with the hand-held sensor  10  is the material from which the housing  12  is manufactured. The housing  12  generally is formed from a hard impact resistant, preferably moldable material such as a hard thermoplastic material such as ABS or polystyrene. These hard materials inherently are slippery and easily can become more slippery when greasy or wet and prior art sensors have included pebbling or roughening of the surface and/or adding raised protrusions to assist in gripping of the sensors. The use of soft or low durometer thermoplastic elastomers is becoming popular to improve the grip and feel of hand held devices and tools. 
     The hand-held sensor  10  includes a pair of grips  18 ,  20 , on a rear end portion  21 , with each grip  18 ,  20  formed in mating half portions  22 ,  24  and  26 ,  28  respectively. The portions  22 ,  24 ,  26 ,  28  are adhered or overmolded to the respective upper and lower casing portions  14 , 16 . The grips  18 ,  20  can be formed from any of the so-called “soft-touch” elastomer materials, such as those sold under the tradenames “Santoprene”, “Kraton” and “Monprene”. The grips  18 ,  20  preferably include a plurality of indentations or scallops  30  which provide finger-holds for a user and again assist in resisting slippage or dropping of the hand-held sensor  10 . This is especially important for the hand-held sensor  10 , since the sensor  10  is held and manipulated in a wide variety of positions and angles, while required to be maintained flat against the surface being scanned. 
     The electronic circuitry (not illustrated) such as that disclosed in the referenced U.S. Pat. Nos. 4,099,118 and 4,464,622, can provide a multiplicity of functions. The hand-held sensor  10  generally includes an on/off actuator or switch  32  (FIG.  3 B), which can be a push-button type actuator. The sensor  10  has a multi-modal operation, selected by the position of a slide activator  34 . The structure of the actuator  34  will be more fully described with respect to FIG.  6 . 
     The actuator  34  is illustrated in a center position, which corresponds with the illumination of an LED  36  in an aperture  38 . Each LED of the sensor  10  is mounted in or below a like aperture, which will be described in more detail with respect to FIG.  5 . In each case, however, the LED can be seen through the aperture, but is mounted such that the top of the LED will not extend above the surface in which the aperture is formed. Thus the LED&#39;s are physically protected without the use of any additional shielding members. 
     The actuator  34  has another first end position  40 , which corresponds with the illumination of an LED  42 . The actuator  34  has an opposite end position  44 , which corresponds with the illumination of an LED  46 . The three operational positions, as indicated by the respective illumination of one of the LED&#39;s  36 ,  42  and  46  can correspond to: 
     (1) Metal sensing. 
     (2) Deep scan (high sensitivity). 
     (3) Normal (stud scan). 
     The operational positions are not critical and the functions can be designated for any one of the positions of the actuator  34  as desired. 
     The hand-held sensor  10  preferably includes an AC scanning mechanism (not illustrated), which can be located in a front portion  48  of the sensor  10 . The actuating of the AC scanner indicating an AC source, in or behind a wall, can be indicated by illumination of an LED  50 . An audio signal also can be emitted, such as from a speaker area  52 . A final LED  54  can be illuminated when the hand-held sensor has completed a calibration mode, as initiated by the user, typically through operation of the push button actuator  32 . 
     A key element of the hand-held device  10  of the present invention is an arrow or wing-shaped LED display array  56 , as best illustrated in FIGS. 3A,  4  and  5 . The display  56  includes a plurality of arrow-shaped segments formed in operative pairs  58 ,  60  and  62  and a center arrow segment  64 . Each of the segments is offset from one another, both laterally and in depth from a top surface  66  of the housing  12 . The segments  58 ,  60  and  62  are offset or stepped below the surface  66 , while the arrow segment  64  is even with the surface  66  (FIG. 5) or preferably raised above the surface  66  (FIGS. 1,  2 ,  3 A, and  4 ). 
     Each of the segments  58 ,  60  and  62  includes an LED aperture  38  (FIG.  5 ), with the segment  64  including a pair of the apertures  38 . Respective pairs of LED&#39;s  68 ,  70 ,  72 , and  74  are mounted into the respective apertures  38 . As illustrated in FIG. 5, the LED&#39;s  68 ,  70 ,  72 , and  74  are mounted on a stepped frame  76  and a circuit board or base  78 , such that the respective LED&#39;s  68 ,  70 ,  72  and  74  are mounted to shine through the apertures  38 , but are physically located below the surrounding surface area. Thus the LED&#39;s  68 ,  70 ,  72  and  74  are easily visible to the user, but are recessed into the housing  12  to physically protect the LED&#39;s without utilizing a separate cover member. 
     In operation as the hand-held sensor  10  is scanned over a wall (not illustrated) as an object, such as a stud, is sensed the outer pair of LED&#39;s  68  are illuminated, without regard to which side of the sensor  10  the stud is located adjacent to. As the sensor  10  is scanned closer to the object, the next pair of LED&#39;s  70  then is illuminated and typically the LED&#39;s  68  are turned off. Next the LED&#39;s  72  are illuminated and when the sensor  10  is over a first edge of the object the LED&#39;s  74  in the center arrow segment  64  are illuminated. The LED&#39;S  74  remain illuminated until the sensor  10  is moved past the object&#39;s opposite edge, thus clearly locating the two edges of the object, such as a stud or double stud. The center arrow segment  64  and the LED&#39;s  74  preferably are aligned also with a line or groove  80 . The aligned LED&#39;s  74  , along with the raised arrow segment  64  and the groove  80  form a definitive visual alignment. 
     The slide actuator  34  is best illustrated in FIGS. 6A-6D. The actuator  34  includes a slide member  82 , which includes a slide button  84 , mounted on or formed with and on top of a planar slide member  86 . The housing portion  14  includes a slide slot  88  into which the slide member  82  can be mounted. 
     The length of the slot  88  and length “A” are chosen, such that the slide member  82  can be inserted into the slot  88  from the top or outside of the housing  12  as indicated in FIG.  6 A. The housing  14  includes a pair of elongated L-shaped support arm flanges (only one of which is illustrated)  90  on opposite sides of the slot  88 . The flanges  90  are spaced from a bottom surface  92  of the housing  14  and the end of the slot  88 , such that the slide member  82  can be pivoted and slideably engage the flanges  90 , as illustrated in FIG.  6 B. 
     The bottom of the slide member  82  preferably includes a recess (not illustrated) in an area  94  between a pair of prongs  96 . The prongs  96  preferably are beveled and have a width to fit in a slot (not illustrated) formed between the edges of the support arm flanges  90 . A three way switch  98 , for example, also can be mounted into the base  78  or another surface as desired. The switch  98  includes a slideable lever or post  100 . 
     The post  100 .s sized to fit between the prongs  96  and into the recess which form a capture structure for the post  100  and the slide member  82 , as illustrated in the center position of the actuator  34  in FIG.  6 B. The two opposite end actuator positions are illustrated in FIGS. 6C and 6D, with the post  100  seated in the recess, between the prongs  96 . As illustrated in FIGS. 6C and 6D, the travel of the switch post  100  determines the length “A” of the slide member  82 , such that the slide member  82  is retained in the slot  88  and so that the slide member  82  covers the slot opening  88 . This prevents any exposure of the circuitry of the sensor  10 . The actuator  34  provides a slide mechanism which can be mounted from the top of the housing  14 , but then is retained therein by the switch  98 , when the casing portions  14  and  16  are secured together. 
     Referring to FIG. 7, another hand-held sensor embodiment of the present invention is designated by the reference numeral  110 . The sensor  110  is essentially the same as the sensor  10  in physical construction, except the sensor  110  can be physically smaller, since the actuator  34  and attendant structure and function has been removed from the sensor  110 . The on/off switch  32  can provide some of the features such as high sensitivity, allowing the sensor  110  to operate either in the normal stud scan or high sensitivity mode. 
     Although the present invention has been described with reference to particular embodiments, the described embodiments are examples of the present invention and should not be taken as limitations. Although the LED array  56  is stepped in separate segments  58 ,  60 , and  62 , it also could be of the same depth or formed in one inclined surface. As will be appreciated by those skilled in the art, various other adaptations and combinations of the embodiments described herein are within the scope of the present invention as defined by the attached claims.