Abstract: A modular snap-in keypad apparatus includes a planar frame member having a plurality of button accommodating apertures and a plurality of mounting posts extending therefrom. An elastomeric key button assembly has a planar surface containing a plurality of apertures which are positioned to receive each post. The button assembly comprises a plurality of raised elastomeric button structures which extend through an associated button accommodating aperture when said posts of said frame assembly accommodates the apertures in the button assembly. A planar switch assembly has a plurality of apertures which are congruently positioned with respect to the posts to enable the contact assembly to be positioned with respect to each button so that a conductive area of the button contacts the contact assembly when the button is depressed.

Abstract: A control body includes a circuit board, a housing having three engaging sets and a base having electric wire guiding grooves each of which includes three spaced radially arcuate platelets, a cover plate having three pairs of barbed legs respectively engaging with the three engaging sets, an end cover, a switch disk, a coupling piece, and a rotating disk so that the control body can be closed though a mechanically engaging style to have a water-proof effect.

Abstract: A printed circuit board mounted rotary electrical switch has a rotatable electrical contact carrier mounted for rotation within a cup-shaped housing and carrying indexing and rotation limiting devices cooperating with the housing. An electrical contact strip is carried by the rotatable carrier for selectively providing a direct electrically conductive bridge between pairs of a plurality of projecting electrical contacts attached to the circuit board and to corresponding printed wiring on the circuit board. The housing is attached to the circuit board by screws threaded into the circuit board through perforated ears projecting from respective sides of the housing. The carrier and the housing are made of an electrically non-conductive material to protect the strip and the contacts from extraneous electrical paths.

Abstract: Flexible membrane switchcores (100, 100a,100b) including a conductive first circuit (180) having first traces (171-178;194;196) and a conductive second circuit (185) having second traces (186-192;195;197), first contact elements (107a-162a) formed as nonbranched integral sections of the first traces (171-178;194;196), and second contact elements (107b-172b) formed as nonbranched integral sections of the second traces (186-192;195;197).

Abstract: A key switch assembly for direct mounting on a PCB or similar substrate. The key switch has a body with depending mounting pin having retainers thereon to secure the key switch at apertures in the substrate. The key switch body has a hinged key and includes a snappable dome moveable from a non-actuated position to an actuated position in direct contact with conductive elements in the substrate by manual depression of a key.

Abstract: A keyboard of a membrane contact type comprises a membrane contact unit having movable contacts, fixed contacts disposed respectively opposite to the movable contacts, and a printed wiring board having electronic circuit elements and provided with printed wiring lines. The membrane contact unit comprises a flexible, insulating, membranous substrate having movable contacts formed in a movable contact section and fixed contacts formed in a fixed contact section demarcated by a folding line, in the same surface as the movable contacts and arranged symmetrically about the folding line. First and second wiring lines connect the movable contacts and the fixed contacts respectively in a predetermined connecting pattern. A first terminal section having first terminals is connected respectively to the first wiring lines, and a second terminal section having second terminals is connected respectively to the second wiring lines. The first and second terminal sections are formed near the folding line.

Abstract: An open-contact membrane switch element (1,2) comprising a plastic film substrate (10) carrying a first conductive circuit (13), a dielectric coating (30) applied to cover the circuit (13) on the substrate (10) in a pattern defining uncoated zones (31,32,34) around each contact (14-17) of the circuit (13), and a second conductive circuit (35) applied on the dielectric coating (30) and having conductive tracks (36,37) electrically interconnected at the uncoated zones (31,32,34) to portions of the contacts (14-17) of the first conductive circuit (13).

Abstract: A DIP rotary code switch provided with a plurality of terminals arranged on a circuit board embedded in a base includes a rotor, conductive patterns disposed, on the bottom surface of the rotor the rotor being rotatably mounted in a cavity formed by a housing and a base, a contact member holder having a center boss on the upper surface thereof which rotatably supports the rotor and having slots extending therethrough and a contact member provided with an apex head fitted respectively into a slot extending through the contact member holder, the apex head intermittently contacting conductive patterns of the rotor when rotated and the contact member having two legs fitted respectively into slits extending in a the base to be electrically connected to conductive elements arranged on the surface of the circuit board embedded in the base.

Abstract: An electrical switch suitable for a miniature apparatus such as a wristwatch comprises a resilient contact plate which is mounted on a member capable of rotating about an axis. The contact plate has two arms which extend radially from a rigid or mounted central portion. The outer ends of the arms are supported on a contact member, the arms being elastically deformed by the action of the contact forces. The two arms have different lengths and they are weakened in a different manner by apertures at their mounting location. Consequently, it is possible to achieve ideal compensation for the couples produced by the contact forces. In addition, an ideal deformation of the arms of the contact plate is obtained, as well as a well-defined position for the bearing points of the contacts.

Abstract: A method for manufacturing a multiple wire brush contact includes the steps of stamping a continuous strip of material so as to define a series of spaced blanks, each including a cross bar and a base mounting plate, separating side carrier portions, welding and soldering contact wires onto the cross bar portions, cutting and forming the contact wiper. The multiple wire brush contact assembly thus includes a base mounting plate that is separate from the cross bar and wire spring and that is used to handle and mount the assembly in a cooperating receiving space in a rotor or other element.

Abstract: An electrical switch mounting structure includes a housing for the switch, terminals on the exterior of the housing, a substrate incorporating an opening into which the housing is inserted, conductive elements on the base which contact the terminals upon insertion of the housing, and elastic mounting members which both retain the housing in the base and assure contact between the terminals and the conductive elements.

Abstract: The present invention relates to an illuminated switch and in particular to one having a housing, switch contacts in the housing, an electrical device disposed in the housing and operatively associated with the switch contacts, a light transmissive colored filter mounted over a neon lamp of the electrical device, and a transparent member located over a cds photoresistor of the electrical device, whereby the neon lamp will light to provide indication of the switch location in darkness and will be extinguished when the switch is turned on.

Abstract: A key switch assembly for direct mounting on a PCB or similar substrate. The key switch has a body with depending mounting pin having retainers thereon to secure the key switch at apertures in the substrate. The key switch body includes a snappable dome moveable from a non-actuated position to an actuated position in direct contact with conductive elements in the substrate by manual depression of a key.

Abstract: Disclosed is a printed circuit board assembly including an integral metal stamping having a plurality of conductive circuit paths received in complementarily-shaped recesses of a dielectric substrate. The integral metallic stamping includes an improved snap action switch having an improved actuator mechanism, an improved rotary switch of the type making on/off contact during rotation thereof, and an upstanding plug-like connector member receivable in a mating female connector. Each of the switches mentioned above as well as the plug-like connector can be formed separately in different printed circuit board assemblies.

Abstract: The rotary electrical switch 1 which is mounted on a circuit plate 7 furnished with a printed circuit comprises a switch wheel 4 which is rotatably supported on the circuit plate 7 and whereat a contact bridge 48 is inserted into a pocket 46. On rotation of the rotary switch 1, said contact bridge 48 connects and/or disconnects at least two conducting paths of the printed circuit. Shaped at the switch wheel 4 is a pivot pin 17 which penetrates the circuit plate 7 and which is secured by a base member 5 to the circuit plate 7 on the said's bottom side opposite to the printed circuit. The switch wheel 4 includes catch-type recesses 42, with a resilient switching element 32 engaging into each one recess depending on the position of rotation of the switch wheel 4. The base member 5 urges via the switch wheel 4 the contact lugs 48 resiliently against the circuit plate 7, additionally forms the catch-type element 40 and simultaneously couples the switch wheel 4 and the circuit plate 7.

Abstract: To obtain a simple slidable switch structure of click operation type for changing over conductive patterns on a printed circuit board fixed in a card housing of a card module, the switch comprises three fixed through hole contacts formed in the board, and a movable contact formed with two convex contact portions. The movable contact is preferably coated with an insulating material except for the two convex portions and is directly disposed within the housing. When the movable contact is moved to and fro, the movable contact member deformably assembled within the insulation member is selectively and slidably brought into contact with two of the three fixed through hole contacts for changing-over operation.

Abstract: A rotary switch construction and method of making the same are provided, the switch construction comprising a surface unit having a substantially circular electrically conductive code pattern thereon, an electrically conductive wiper contact unit cooperating with the surface unit for making contact with a selected part of the pattern, and a rotary selector operatively associated with the units for selecting the desired part of the pattern that is to be contacted by the wiper contact unit, the wiper contact unit comprising a first pair of electrically connected wiper contacts disposed to respectively contact the pattern on a first substantially circular path thereof at points thereon that are disposed approximately 180.degree. from each other.

Abstract: The assembly comprises a casing and a PC-Board in sheet form arranged therein, having a comb-spring and projecting freely into a recess of the wall of the casing. The lower face of the PC-board is furnished with a set of conductive pathways leading to microchips to be connected to an independent electric system by bending the PC-board sheet so as to make contact with a second set of homologous conductive pathways belonging to said system. This bending is obtained by displacing a shoe pushing a cylindrical bar freely engaged in a slot of the wall of the casing in communication with the recess, the bar lying on the structure formed by the combining and the PC-board sheet.The electrical contact between both sets of conductive pathways can be interrupted by moving the shoe axially in a first direction corresponding to the bending of the PC-board sheet; a motion of the shoe in a second opposite direction re-establishes the electrical contact conditions of both sets of pathways.

Abstract: An electrical rotary switch includes a single support housing (18) for rotation about a base (12). The base (12) is a circuit board which includes an opening (16) through which the housing (18) is secured to the base. A pair of contact pads (14) extend radially away from the opening (16) on the base (12). The housing (18) includes a cavity (34) facing the base (12). A conductive roller (38) is located in the cavity (34) for rolling over the pair of contact pads (14) to establish an electrical connection. The switch is characterized by a fulcrum ridge (40) extending from the housing (18) into the cavity (34) for allowing the roller (38) to rock in case a bump is incurred in the contact pads (14) to ensure an electrical connection.

Abstract: An electrical connector for selectively connecting various electrical circuits of a first vehicle to corresponding electrical circuits of a second vehicle. The connector includes variably positionable switches whereby no rewiring of either vehicle is necessary. The housing for the connector is parallelepipedonal in form and the switches project from a major surface of the housing.

Abstract: Rotary electrical signal generator includes fixed electric contacts and slider contacts which engage the fixed contacts. To enhance the abrasion resistance and the corrosion resistance, the surface of printed electrodes is coated with an amorphous Ni-P plated layer containing from 15 to 25 atom % of P.

Abstract: A key operated switch for keyboards having an improved layer type construction comprising a key carrier and key return spring supporting printed circuit conductors and contacts so arranged as to facilitate fully automatic production of keyboards. The simple formation of a leaf spring, a key guide and the key stem comprising the switch enables these parts also to be assembled by machine, making the manufacture of a keyboard simple and inexpensive.

Abstract: A cam activated electrical switching means for an elastic multicircuit printed circuit board (PCB). A plurality of PCB reeds with disattached portions at one end nearest the edge of the PCB are cut out in the generally central portion of the PCB, and an electrical board, positioned adjacent to but separated from the PCB, made of elastic PCB-type material has the same number of plurality of flexible reeds cutout therefrom in its central portion. The PCB reeds and electrical board flexible reeds have electrical leads etched on the back sides thereof with the PCB reeds having an electrical contact pin on the front of the disattached end portion facing the etched electrical lead on the back of the disattached end of the flexible reed. An embossed mechanical rider is positioned on the front of the disattached end of the flexible reeds. The electrical etched lead on the back of the flexible reed may be connected to some electrical source on the electrical board.

Abstract: An electrical connector containing a switch which makes or breaks an electrical connection when the connector is plugged into or unplugged from a mating connector. The switch is located in an aperture in the electrical connector. It is capable of limited reciprocal motion parallel to the longitudinal axis of the aperture. The switch includes at one end a pair of normally touching contacts and a dielectric finger. Electrical connection is broken when the switch reciprocates so that the dielectric finger is interposed between the normally touching fingers and, likewise, electrical contact is made when the reciprocation movement of the switch removes the finger.

Abstract: Compressible metal spring washers are mounted around the shank portions of terminal rivets and are clamped against thin conductor laminae of a flexible printed circuit having a resilient resinous plastic base lamina, clamped by the rivets against a relatively rigid plastic terminal supporting member. Each washer has a central dished portion, a reversely dished peripheral portion, and a smoothly rounded annular bulging portion therebetween for engaging one of the thin conductor laminae, without cutting into the laminae. The spring washers obviate any looseness of the terminal rivets due to dimensional variations, shrinkage with age, and temperature variations.

Abstract: An input device of the tablet type comprising opposed planar resistance bodies with a plurality of dot spacers interposed therebetween, plate-like insulating bodies made of soft and elastic material and provided respectively and integrally on the outsides of the planar resistance bodies, and a fixed plate for securing and supporting one of the plate-like insulating bodies, and characterized in that a plurality of cavities are formed in an abutment area between the one plate-like insulating body and the fixed plate by which each dot spacer portion can sink when a force is applied, whereby entry of information relating to the dot spacer portion also is allowed.

Abstract: A printed wiring board comprising a supporting frame, a resilient sheet supported by the supporting frame and having a wiring pattern formed thereon, and a tongue member made of the resilient sheet and providing the wiring pattern formed thereon; the supporting frame having a escape space formed therein corresponding to the tongue member; the terminal of an electronic device being pressed against the wiring pattern of the tongue member in such a manner that the restoring force of the tongue member completes the electrical connection between the wiring pattern and the terminal of the electronic device.

Abstract: An electronic device capable of removably mounting a memory card used as an external memory to a printed circuit board having a circuit pattern formed thereon comprises a memory card holder, a guide member which pivots the holder and has a biasing force imparted toward the circuit pattern of the printed circuit board, and locking means for locking the guide member when the guide member is spaced from the circuit pattern of the printed circuit board.

Abstract: An improved multiple circuit keypad switch of the type in which a rigid key having a shorting puck on its underside is supported over exposed traces of a printed circuit card by a flexible membrane so that the puck shorts designated exposed traces to close all circuits when the key is depressed, the improvement arising from the layout of the exposed traces in which individual circuits are arranged in concentric rings and the shorting puck contains shorting elements arranged in corresponding concentric rings.

Abstract: A rotary encoder comprises a case containing a rotary brush setting plate and an idler gear which is associated with an inside gear formed on the brush setting plate and a reduction gear contained in the case and connected to a driving shaft penetrating the case. Brushes on the rotary brush setting plate rotatingly slide on the plural pulse producing conductive patterns formed on inside surface of the case, thereby to effect switching in plural modes as the shaft revolves.

Abstract: A circuit pattern on a circuit board, as used in telecommunications systems and other electrical apparatus, often has contact positions for switches, such as pushbutton switches, and for other purposes. The normal copper circuit pattern is covered at the contact positions to give improved contact conditions. Carbon ink has been proposed by obtaining the necessary high level of alignment of carbon ink with the copper pattern at contact positions is difficult as such contact positions have very close members. The invention proposes contact positions having closely spaced inter-digital contact members, in which the circuit pattern extends to and stops at the peripheral region of a contact position, the contact members being of carbon ink and overlapping conductors of the circuit pattern at the peripheral region.

Abstract: A cable terminal which connects two woven ribbon cables and has a terminal connector which is capable of engaging standard device connectors. A switch mounted in the cable terminal provides selective interconnection of the woven ribbon cables in the cable terminal which allows the channel to be fed back when the cable terminal is unplugged. The cable terminal can be employed in a tag cable for computer applications. The cable terminal utilizes a housing which can be disassembled for repair of conductive connections within the cable terminal. The cable terminal employs a PC board which provides two-sided termination with a separate connector for each signal wire to reduce termination time. Additionally, mass ground terminators are also provided to reduce termination time. Teeth are incorporated within the structure of the housing to engage the woven ribbon cable so as to provide strain relief between the woven ribbon cable and the PC board.

Abstract: A membrane switch comprises an insulating substrate on the surface of which thin-film-like electrodes are formed with a connecting lug section provided integrally at one end of the substrate. Thin-film-like conductive layers continuing from the electrodes are extending up to the connecting lug section and the extended end portions of the conductive layers compose a connecting terminal section.

Abstract: A laminate switch assembly comprising dual dome switchplates providing improved tactile sensation good balance characteristics and able to maintain a low dynamic resistance throughout its life expectancy. Both tensioned domes are aligned with electrical contact areas part of which is formed on the underside of one dome and the other on a printed circuit board or backplate, which in response to depression are placed in contact with each other to provide a switch closure to a connected or associated electrical device.

Abstract: A combination latch/switch mechanism is operative to lock a circuit board into a support housing and enable and disable selected circuits during the insertion process. A lever of the mechanism includes a notch to engage the support housing and a contact arrangement engaging and disengaging circuit paths as the circuit board is inserted into the housing.

Abstract: In a pulse generator with a rotor (7) provided with a conductive pattern and fixed contact springs wiping over the pattern, the latter is formed by a central continuous slip ring (15) which is concentric with the drive shaft (3) of the rotor (7) and has inwardly and outwardly projecting teeth (16; 17), the number of internal teeth (16) being equal to the number of external teeth (17), and the internal and external teeth having the same angular spacing (.alpha.).

Abstract: An apparatus and method is disclosed for providing a rotor switch. The rotor switch consists of a rotor device positioned between a pair of printed circuit boards. One printed circuit board having conductive pads, coupled to the output of the switch, and the other board having a conductive strip, coupled to the input of the switch. A conductive spring, or similar conductor, is disposed through the rotor to couple one of the conductive pads to the conductive strip. A housing having a retainer that fits into exterior notches located in the printed circuit boards and the rotor acts to secure the rotor in place when rotational forces are exerted on the switch.

Abstract: A switch device comprises a chassis with a number of key-tops, a switch unit, and a support board, piled up in that order and coupled at their centers by one screw. Plural screws pass through elongated screw holes bored in the support board and oriented radially around the center and are threaded to bosses of the chassis. The bosses pass loosely thru-holes bored in the switch unit.

Abstract: Electric switches whose fixed contacts (3) are formed by the conductors on a printed circuit board (1), which are coated with a layer of noble metal, the connections between the fixed contacts provided on a contact path (2) and electrically connected among each other, extend outside the contact paths (2) of the movable contacts. Prior to the application of the layer of noble metal the connecting lines are covered and, therefore, a considerable saving of noble metal results.

Abstract: A key operated security switch has a housing containing a fixed contact. The housing has a slider provided with contact means movable therewith for slidable, non-rotary movement in the housing. A plurality of locking pins are slidably mounted in recesses formed in the housing and are spring-urged partly into the housing and partly into said slider so as to lock the slider relative to the housing. A plurality of plungers engage at one end with the adjacent ends of said locking pins and at the other end are engageable by the stepped edge of a key inserted into the slot of a barrel rotatably mounted in the housing. The stepped edge of the key projects through the slot of the barrel but does not engage the plungers during insertion or withdrawal.

Abstract: A miniature rotary multi-position switch capable of being mounted on a printed circuit board (2). The housing (1) and the rotor (8) of the rotary switch, are each provided with a throughgoing bore (33, 16). The rotating control shaft (17) is inserted into the bore (16) of the rotor (8), so that the shaft projects on one of the sides (3, 18) of the housing (1). This permits the rotary switch to be actuated from any optional side of the printed circuit board (2). Therefore, the printed circuit board (2) can be installed with one of its two plane sides facing the actuating side of an equipment unit, and the rotary switch can be nevertheless actuated in that the control shaft (17) is fitted accordingly. The rotary switch is mounted to the printed circuit board (2) by snap locks (5) and the rotor (8) is held inside the housing (1) with the aid of detent elements (10).

Abstract: A simplified electric switch construction is disclosed. The switch construction comprises at least a pair of confronting first and second terminals each having a bridge portion, a conductive resilient plate having one end shaped as a polygonal pyramid disposed in confronting relation to the bridge portion of the first terminal and an opposite end connected to the bridge portion of the second terminal, a presser for depressing an intermediate portion of the resilient plate to bring the tapered end into contact with the bridge portion of the first terminal, and a driver for depressing the presser. The switch construction may contain a printed-circuit board with an electric circuit thereon.

Abstract: A pressure-sensitive electrical switch is provided with a diaphragm which can be displaced against the action of a spring and which defines together with a supporting housing a pressure chamber. There is at least one outwardly projecting connection contact in the form of a contact pin. For mechanically mounting the housing of the switch there is provided at least one latching element comprising a latch for engagement in a receiving opening of a supporting board or print board or the like, the electric contact with the conductor paths of the printed circuit board being established by an electrically conductive pressure spring superimposed upon the pin-like outwardly projecting connection contact which spring in the latched position of the at least one latching element is urged into contact with the associated electric conductor path.

Abstract: A combination keyboard including a first set of switches closed by depressing discrete keys (b 21) and a second set of switches closed by depressing selected areas (69) of a flexible overlay (49) is disclosed. The first set of switches includes a printed wire board (pwb) (23) having switch terminals (31) on one surface. Overlying the switch terminals are switch closing elements, which may take the form of caged metal domes (29). Overlying the closing elements are the discrete keys (21). The second set of switches also includes a pwb (41) having switch terminals (51) on one surface and overlying switch closing elements, which may also take the form of caged metal domes (59). The flexible overlay (49) is positioned atop the switch closing elements. Further, the pwb and flexible overlay include aligned apertures (57, 71) through which the discrete keys (21) pass. Thus, both the discrete keys (21) and the flexible overlay (49) lie in substantially the same actuation plane.

Abstract: A custom prototype membrane switch panel, kit, and method for construction. Two membranes, an insulative spacer for use therebetween, and a plurality of conductive elements disposable between each membrane and spacer are provided. Spacer apertures in registry with the elements permit electrical contact therebetween upon displacement of one membrane toward the other. The elements are comprised of conductive ink bonded to an insulated backing in any desired geometric shape or shapes, and may be provided individually or plurally in sheet form separable therefrom for disposition between the spacer and membranes. Elements of different colors facilitate tracing different conductive paths created thereby in the resultant switch panel, and the backing automatically electrically insulates crossovers between the elements.

Abstract: A keyboard switch includes a lower-electrode insulating sheet provided with an electrode pattern formed by arranging lower electrodes at given distances, each of the lower electrodes being composed of a pair of electrodes having interfitted teeth; and an upper-electrode insulating sheet provided with an electrode pattern formed by arranging a plurality of lines of rectangular upper electrodes so that each of the rectangular upper electrodes crosses the corresponding pair of teeth of the electrodes of the lower electrodes at right angles.

Abstract: A membrane panel including at least one electrical component. The panel includes a rigid support member having substantially planar top and bottom surfaces. At least one void region, or hole, extends from the bottom surface of that support member. A flexible top member including at least one flexible layer, overlies the support member. A flexible bottom member including at least one flexible layer underlies the support member. The bottom member has its upper surface affixed to the bottom surface of the support member. Further, the bottom member includes an integral flexible tail. The bottom member includes at least one electrical component affixed to its upper surface with that component underlying and extending into an associated one of the void regions of the support member. An electrically conductive pattern is affixed to the upper surface of the bottom member and that pattern is electrically coupled to the component to permit its operation in an electrical network.

Abstract: An illumination type push button switch wherein a switch mechanism and an illuminant such as a light emitting diode are provided interiorly of a casing, a pair of external terminals adapted to supply power to the illuminant to light the same are supported on a base plate detatchably supported on said casing. An electronic circuit is formed on the base plate so that the circuit may be interposed in the electric connection between the illuminant and the external terminals, thereby rendering miniaturization of the switch possible and facilitating handling of the same.

Abstract: A reduced size pushbutton (6) switch having a plurality of contact pairs (40, 42, 44, 46) arranged angularly for radial actuation by normally-open cams (34c) or normally-closed cams (34d) on a vertically reciprocated actuator block (34) by a snap-action mechansim (30c, 30d, 36, 38 or 66, 68a). The contact pairs are electrically connected to a control circuitry PC board (52) which provides an output control as well as controlling a multi-character alpha-numeric display mounted within the pushbutton. This display includes a light source (22), a display (24) and movable (14) and stationary (12) contacts connecting the light source to a display drive PC board (10) which may be connected to the control circuitry PC board to afford control of the display by some of the contact pairs. A seal (8) between the front panel and the display PC board hugs the pushbutton to prevent dirt from entering the switch base (54).

Abstract: A pushbutton switch assembly, for a keyboard, comprises a plurality of switch units each having at least a pair of superposed switch contacts, one of which is movable by an actuator to make or break contact. Each actuator is a hingedly mounted cantilever having a pushbutton at its free end. When the pushbutton is depressed an intermediate part of the cantilever actuates the movable switch contact. The cantilever is dimensioned so that the operating force needed at the pushbutton is only a fraction of that required to operate the switch contact directly. Also the pushbutton travel is correspondingly longer. Accordingly the assembly may use a relatively stiff, small travel type of switch unit, for example a snap-action spring plate or flexible membrane, yet provide at the pushbutton the "soft" action and long travel preferred by so many users.