Abstract:
A communication system includes a voice-directed portable terminal with a voice user interface that is configured for being able to communicate with a computer system. The communication system includes a peripheral device having a cord coupled with the portable terminal and a connector adapted to disconnect from the portable terminal when a sufficient force is applied to the cord. This disengages the peripheral device from the portable terminal. The ability of the cord to break-away from the portable terminal prevents damage not only to the connector, but also to the cord, peripheral, and terminal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of application Ser. No. 10/185,300 filed on Jun. 27, 2002, the disclosure of which is hereby incorporated in its entirety by reference herein. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates generally to portable terminals and more specifically, to wearable, portable and/or mobile terminals and peripherals for wireless communication systems.  
       BACKGROUND OF THE INVENTION  
       [0003]     Wearable, portable and/or mobile terminals are used for a wide variety of tasks. Such terminals allow a worker using them to have mobility, while providing them with desirable computing and data-processing functions. Furthermore, various terminals provide a communication link to a larger, more centralized computer system. Such terminals are being implemented for an ever-increasing number of tasks.  
         [0004]     One illustrative example of a specific use for a wearable or portable terminal is inventory management. Computerized inventory management systems are used in inventory-driven industries for various tasks, such as food and retail product distribution, manufacturing, and quality control. An overall integrated inventory management system involves a combination of a central computer system for tracking and management, and the people who use and interface with the computer system in the form of order fillers, pickers and other workers. The workers handle the manual aspects of the integrated management system.  
         [0005]     To provide an interface between the central computer system and the workers, wearable or portable computers or terminals are used by the workers as they complete their numerous tasks. Such wearable terminals, for example, pull information directly from the central system and translate the information into voice or text commands for the workers. Through wireless radiofrequency (RF) networks, the commands to and responses from the workers are communicated between the system and the terminals. To communicate in a voice-driven system, for example, the worker wears a headset, which is coupled to their wearable terminal. Through the headset, the workers are able to receive voice instructions, ask questions, report the progress of their tasks, and report working conditions, such as inventory shortages, for example. Using such terminals, the work is done virtually hands-free without equipment to juggle or paperwork to carry around.  
         [0006]     In addition to headsets, other peripherals are often coupled to the terminals depending upon the tasks to be performed. For example, bar code readers and other scanners may be utilized alone or in combination with a headset to communicate back and forth with the system.  
         [0007]     An illustrative example of a job through a system utilizing wearable and/or portable terminals having voice capabilities may involve initially welcoming the worker to the system and defining a particular task or order, for example, a load to be filled for a certain truck to depart from a warehouse. The worker may then answer with a particular area (e.g., freezer) that they will be working in for that order. The system then vocally directs the worker to a particular aisle and bin to pick a particular quantity of an item. The worker then vocally confirms their location and the amount of items that are picked. The system may then direct them to a loading dock or bay for a particular truck to receive the order. As may be appreciated, various different scenarios might be played out through the system using a wearable terminal and attached peripherals.  
         [0008]     The peripherals, such as a headset, are attached to a terminal with a cord, which extends generally from the terminal (typically worn on a belt) to the head of the worker where the headset is located. As may be appreciated, the workers are moving rapidly around their work area and are often jumping on and off forklifts, pallet loaders, and other equipment. Therefore, there is a possibility for a cord to get caught on some object, such as a forklift. When this occurs, the cord will tend to want to separate either from the headset or from the terminal. Generally, the cords are permanently attached to a headset and each worker maintains their own headset (e.g. for individual responsibility and/or hygiene purposes). The cords are then plugged into the terminals, therefore the separation will generally occur at the terminal socket.  
         [0009]     Attempts have been made to appropriately handle a snagged cord and cord separation. However, there are competing issues that must be addressed. When the cord plug is strongly secured to the terminal socket, a snagged cord may pull the socket out of the terminal housing. This may render the terminal inoperable and require repair or replacement. However, strengthening the anchoring point of the socket in the terminal may lead to cords pulling away from their plug, thus rendering the headset unusable. Making the cord more securely attached with its plug, making the terminal socket securely anchored in the terminal housing, and then providing a secure coupling between the plug and the socket, however, may prevent separation but may leave the cord susceptible to catching on surrounding objects resulting in damage to the cord and/or the plug.  
         [0010]     Therefore, it is desirable to improve upon the conventional wearable terminals used in an environment where peripherals and their cords are susceptible to snagging. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.  
         [0012]      FIG. 1  is an illustration of a wearable terminal incorporating the present invention;  
         [0013]      FIG. 1A  is a schematic block diagram of a system incorporating the present invention;  
         [0014]      FIG. 2  is an enlarged, exploded view of the encircled area  2  of  FIG. 1 , depicting an embodiment of the present invention;  
         [0015]      FIG. 3  is a cross-sectional view taken generally along lines  3 A- 3 A and  3 B- 3 B of  FIG. 2 ;  
         [0016]      FIG. 4  is a cross-sectional view of the connector of  FIG. 3 , showing the plug and terminal portions just prior to coupling;  
         [0017]      FIG. 5  is a cross-sectional view of the connector of  FIG. 3 , depicting the plug and terminal portions coupled together; and  
         [0018]      FIG. 6  is a view showing detail of the terminal housing in cross-section and the lever arm and engagement claws in elevation. 
     
    
     DETAILED DESCRIPTION  
       [0019]     Although the invention will be described next in relation to certain embodiments, the invention is not limited to practice in any one specific type of portable or wearable terminal. It is contemplated that the principles of the invention can be used with a variety of electronic devices, including but not limited to wearable, portable and/or mobile terminals for use with inventory systems. The description of the invention is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims. In particular, those skilled in the art will recognize that the components of the invention described herein could be arranged in multiple different ways.  
         [0020]     Referring to  FIGS. 1 and 1 A, a portable or wearable terminal  10  may be worn by a worker on a belt  14  and is connected to a peripheral device  16 , such as a voice headset, by a cord  18  that is coupled to the terminal  10  by a break-away connector  12 . Such wearable terminals  10  may be used in inventory management environments where workers  11 , each using one of the wearable terminals  10 , are required to retrieve various items within the warehouse. The wearable terminal  10  and peripheral  16  may permit the worker  11  to communicate bi-directionally, such as with a wireless link  19 , with a central computer system  13  ( FIG. 1A ), or other information system, to send and receive information regarding the activities performed by the worker  11  and the inventory being managed. One suitable wearable terminal  10  for incorporating the invention is the TALKMAN® product available from Vocollect, Inc. of Pittsburgh, Pa.  
         [0021]     The peripheral device  16  is adapted with a transducer that generates a signal in response to a suitable input, such as voice input, from the worker  11  and the cord  18  electrically couples the peripheral device  16  with the wearable terminal  10  for transferring the signal from peripheral device  16  to the wearable terminal  10 . The central computer system  13  constitutes part of a larger system for sending and receiving information regarding the activities and tasks to be performed by the worker  11 . The central computer system  13  may run one or more system software packages for handling a particular task, such as inventory and warehouse management. The peripheral device  16  may also include another transducer that translates information received from the computer system  13  into a format understood aurally by the worker  11 .  
         [0022]     In a certain environments in which inventories are managed, the cord  18  connecting the peripheral  16  with the terminal  10  may become snagged or entangled, such as on shelving structures or equipment, for example, used to transport the items collected from the inventory. Therefore, it is desirable to have connector  12  which provides a secure electrical connection between cord  18  and terminal  10 , but which will break away at a specified break-away force whereby the connector  12  becomes uncoupled or disconnected from the terminal  10  to prevent damage to the terminal  10 , peripheral  16  or cord  18 .  
         [0023]      FIG. 2  shows detail of the exemplary connector  12  comprising two portions, a plug portion  20  and a terminal portion or socket portion  22 . The portions  20 ,  22  are shown uncoupled in  FIG. 2  for clarity. Advantageously, plug portion  20  may be coupled to terminal portion  22  to provide an electric connection between a peripheral device  16  and the wearable terminal  10  via contacts  32 , such as pins, on the plug portion  20  and corresponding contacts  74  on the terminal portion  22 . The wearable terminal  10  may have a terminal portion for a single connector  12 , or may be provided with multiple terminal portions  22  for the coupling of multiple plug portions  20 , as depicted in  FIG. 2 . When multiple connectors  12  are used, the plug and terminal portions  20 ,  22  may be provided with keys  60  and corresponding keyways or key slots  62 , respectively, to ensure that the appropriate plug portion  20  is coupled to its respective terminal portion  22 .  
         [0024]      FIGS. 3-5  show cross-sectional views of the plug and terminal portions  20 ,  22  of an exemplary electrical connector  12  of  FIG. 2 . The plug portion  20  includes a plug housing  24  which is configured to be attached to an end of a multi-conductor cord or cable  18 . A strain relief  28  provided at one end of the plug housing  24  helps to retain the multi-conductor cord  18  and participates in preventing damage to individual conductors  30  within the cord  18  which may be caused by tension applied to the cord  18 .  
         [0025]     Individual conductors  30  of the multi-conductor cord  18  are separated within the plug housing  24  and are electrically coupled with respective electrical contacts  32 . In the exemplary plug portion  20  shown, the electrical contacts  32  are retractable contacts, such as pogo pin contacts. The contacts  32  protrude through apertures  34  provided in a mating surface  36  of the plug portion  20 . The contacts  32  have respective biasing members or springs  38  that bias the pins  32  in a direction toward the mating surface  36 , and which also permit the contacts  32  to be displaced such that they are substantially flush with the mating surface  36  when the plug portion  20  couples with the terminal portion.  
         [0026]     Each contact  32  is provided with an insert  42 , such as a solder cup, that is press-fit into a corresponding cavity  41  provided in the plug housing  24 . Each spring  38  is compressed between the insert  42  and a frustoconical portion  43  of the respective contact  32 . The insert  42  also electrically couples each conductor  30  of the multi-conductor cord  18  with a corresponding one of the electrical contacts  32 . The insert  42  operates to seal off the junction between each conductor  30  and the corresponding contact  32  from moisture infiltrating about the contact  32  into the associated cavity  41 .  
         [0027]     When the wearable terminal  10  is used in alternatingly warm, humid environments, such as a warehouse or the outdoors, and cold, dry environments, such as a storage freezer, there may be a tendency for the condensation which develops on the connector  12  to freeze, potentially interfering with the electrical contacts. Advantageously, the spring force of the springs  38  on contacts  32  may be selected such that the spring force will break off any ice which may have formed over the contacts  32 , when the connector portions are uncoupled and the contacts  32  are moved toward their extended positions by springs  38 .  
         [0028]     With continued reference to  FIGS. 3-5 , the plug portion  20  further includes first and second engagement claws  44 ,  46  which are used to secure the plug portion  20  to the terminal portion  22  in a break-away fashion in accordance with the principles of the present invention. The first engagement claw  44  is provided on one part of the plug housing  24  such as by being formed with the housing, for example. The second engagement claw  46  is provided on a lever arm  48  which is pivotally mounted by a pin  50  to another part of the plug housing  24 , such that the second engagement claw  46  is positioned substantially opposite the first engagement claw  44  on the housing  24 . A biasing member or spring  52  disposed between the lever arm  48  and the plug housing  24  biases the arm  48  in one direction toward a first position for engaging the terminal portion  22  of connector  12  when coupled thereto. The lever arm  48  may be pivoted in the opposite direction toward a second position for coupling and uncoupling the plug and terminal portions  20 ,  22  by rotating the lever arm  48  about the pin  50  against the force of spring  52 . A protrusion  54  formed into one end of the lever arm  48  helps to retain the spring  52  in position on the plug housing  24  along with a cavity  53  in the housing.  
         [0029]     The first and second engagement claws  44 ,  46  have angled surfaces  56 ,  58 , respectively, which facilitate coupling the plug portion  20  with the terminal portion  22 . The second engagement claw  46  on lever arm  48  has a leading edge  60  which is angled to facilitate coupling the plug portion  20  with the terminal portion  22 , whereby contact between leading edge  60  and the second engagement lip  78  urges lever arm  48  from the first position toward the second position, against the opposing bias force created by spring  52 . In an exemplary embodiment, leading edge  60  is angled approximately 111° from a surface parallel to the angled surface  58  of second engagement claw  46 , as depicted in  FIG. 6 . The angled surfaces  56 ,  58  also permit the plug portion  20  to become uncoupled from the terminal portion  22  when a specified force is applied to the plug portion  20 , as will be described more fully below.  
         [0030]     With continued reference to  FIGS. 3-5 , the terminal portion  22  of the electrical connector  12  includes a terminal housing  70  which is configured to mate with the plug housing  24 . The terminal housing  70  may be connected to, or formed integrally with the housing of a device, such as wearable terminal  10 , with which the electrical connector  12  is used. One or more conductors  72  are routed to the terminal portion  22  and are attached to electrical contacts  74  which are configured to mate with corresponding electrical contacts  32  of the plug portion  20 . Therefore, the contacts  74  are arranged generally in the same fashion as the contacts  32  as seen in  FIG. 2 . In the exemplary electrical connector  12  shown, the electrical contacts  74  have flat ends which protrude just above, but generally flush with, a mating surface  75  of the terminal portion  22  (as opposed to the upraised pins  32 ) which is configured to interface with the mating surface  36  of the plug portion  20 .  
         [0031]     As shown in  FIGS. 4 and 5 , the terminal contacts  74  are configured to mate with the contacts  32  of the plug portion  20  when the plug portion  20  is coupled to the terminal portion  22 . An O-ring  68  positioned inside the terminal housing  70  seals the interior of the housing  70  to protect the conductor-contact interface against moisture infiltration. While the contacts  32 ,  74  shown in the exemplary embodiment are pogo pins and flat contacts configured to mate with the pogo pins, it will be understood that the contacts  32 ,  74  may be of various other configurations as are known in the art.  
         [0032]     As shown in  FIGS. 3-5 , the terminal housing  70  includes first and second engagement lips  76 ,  78  which are configured to mate with the first and second engagement claws  44 ,  46  of the plug portion  20  when the plug portion  20  is coupled to the terminal portion  22 . The first and second engagement lips  76 ,  78  have angled surfaces  80 ,  82  which correspond to the angled surfaces  56 ,  58  of the first and second engagement claws  44 ,  46 , respectively, whereby the contact between the first and second engagement claws  44 ,  46  and first and second engagement lips  76 ,  78  retains the plug portion  20  on the terminal portion  20 , as shown in  FIG. 5 . When the plug portion  20  and the terminal portion  22  are coupled together, the mating surfaces  36 ,  75  of the plug and terminal portions  20 ,  22  interface with one another such that the contacts  32  on the plug portion  20  and the contacts  74  on the terminal portion  22  are in full contact.  
         [0033]     Advantageously, the angled surfaces  56 ,  58 ,  80 ,  82  on the first and second engagement claws  44 ,  46  and on the corresponding first and second engagement lips  76 ,  78  act in cooperation with the spring  52  on the plug portion  20  to allow the plug portion  20  to break away from the terminal portion  22  when force of a specific magnitude is applied to the plug portion  20 . This force may be applied to the plug portion  20  through the cord  18  connected to the plug housing  24 , such as when the cord  18  becomes snagged on an object or machine. Accordingly, the angled surfaces  56 ,  58 ,  80 ,  82  on the first and second engagement claws  44 ,  46  and the first and second engagement lips  76 ,  78  may be selected, in conjunction with a given spring constant of the spring  52  on the plug housing  24  to permit the plug portion  20  to break away from the terminal portion  22  at a predetermined break-away force. This break-away force may be applied to the plug portion  20  in any direction, such as normal to the mating surface  36 , tangential to the mating surface  36 , or generally any angular direction therebetween.  
         [0034]     When the force applied to plug portion  20  reaches the predetermined break-away force value, lever arm  48  is caused to rotate about pin  50  toward the second position, whereby plug portion  20  may become uncoupled from terminal portion  22 . The relationship between the angled surfaces  58 ,  82  is such that the relative length dimensions of corresponding surfaces  58  and  82  determine the amount of rotation of lever arm  48  about pin  50  against the force created by the accompanying compression of spring  52 .  
         [0035]     Advantageously, the break-away force may be specified such that the plug connector portion  20  will remain coupled to the terminal portion  22  during normal operation of the terminal  10 , but permits the plug portion  20  to uncouple from the terminal portion  22  when the force applied to the plug portion  20  through the cord  18  reaches the specified break-away force to thereby prevent damage to the electrical connector  12 , or to prevent hindering the user of terminal  10 . For example, the orientation of the angled surfaces  56 ,  58 ,  80 ,  82  and the spring constant of spring  52  may be selected such that the break-away force is approximately equal to a force at which cord  18  has been rated to operate without sustaining damage, multiplied by a design factor.  
         [0036]     Generally, the force for which the cord  18  is rated to operate without sustaining damage is specified by the manufacturer of the cord. The design factor generally has a value less than 1 and is applied to the rated force to account for variations in material properties, the number of loadings which may be experienced by the cord, the durability of the cord over time, and other considerations which add uncertainty to the determination of a proper rating for the cord. In an exemplary embodiment, cord  18  is rated for about 40 pounds and the design factor is selected to range from about 0.25 to about 0.33, whereby the desired break-away force is about 10 pounds.  
         [0037]     With reference to  FIG. 6  and in an exemplary embodiment, the first engagement claw  44  has an angled surface  56  oriented approximately 46° from the mating surface  36  of the plug portion  20  and the second engagement claw  46  has an angled surface  58  oriented approximately 24° from the mating surface  36  of the plug portion  20  when the lever arm  48  is in the first position, as depicted by phantom lines in  FIG. 6 . In the exemplary embodiment, the 24° angle of the surface  58  of second engagement claw  46  corresponds to an angle of approximately 122° from a surface which is parallel to a longitudinal axis of lever arm  48 , as shown in  FIG. 6 . The terminal portion  22  of the exemplary embodiment has first and second engagement lips  76 ,  78  with angled surfaces  80 ,  82  oriented at approximately 46° and 24°, respectively, from a plane containing the mating surface  75  of the terminal portion  22 . When the spring constant of the spring  52  is 81.5 lb/in., the break-away force of the exemplary electrical connector  12  is in the range of approximately 8 to 12 pounds. Of course, other selected break-away force ranges may be used, such as by varying the spring force of spring  52  or the angles of the respective angled surfaces on the engagement claws  44 ,  46  and lips  76 ,  78 . Generally, the break-away force may range from about 3 pounds to about 15 pounds without departing from the spirit and scope of the invention.  
         [0038]     The plug housing  24 , terminal housing  70 , and arm  48  may be formed from polymeric material. In an exemplary embodiment, the plug housing  24 , terminal housing  70 , and arm  48  are formed from XENOY®, a thermoplastic resin available from GE Plastics, Seven Hills, Ohio. This polymer has good low temperature characteristics useful when the connector  12  is exposed to low temperatures.  
         [0039]     With reference to  FIGS. 3-5 , coupling of the plug portion  20  with the terminal portion  22  will be described. In use, the connector  12  of the present invention may be used to couple a peripheral device  16 , such as a headset, to a wearable terminal  10  or other device. The worker depresses lever arm  48  on the plug portion  20  to move the arm  48  toward the second position and brings the first engagement claw  44  on the plug portion  20  into engagement with the first engagement lip  76  on the terminal portion  22 . The corresponding keys  60  and keyways  62  will ensure that the proper plug portion  20  is coupled with the proper terminal portion  22 . The worker then urges the second engagement claw  46  into engagement with second engagement lip  78 , whereby the angled leading edge  60  of the second engagement claw  46  facilitates engagement of the claw  46  with second engagement lip  78 . Mating surfaces  36 ,  75  are brought into substantially abutting relation and contacts  32 ,  74  are in full contact with one another. The plug portion  20  and terminal portion  22  are fully coupled and the worker may then release lever arm  48 . Advantageously, the connector  12  securely couples peripheral  16  to wearable terminal  10  during normal activities of the worker. However, if a cord  18  between peripheral  16  and plug portion  20  should become snagged on an object, the plug portion  20  will become uncoupled from terminal portion  22  when the force applied to plug portion  20  through cord  18  reaches the specific break-away force to thereby prevent damage to terminal  10 , connector  12  or cord  18  while allowing a clean beak-away for the worker. The connector  12  may then be easily coupled or re-secured with the terminal  10  for further use.  
         [0040]     While described herein with regard to a wearable terminal  10 , it will be appreciated that the exemplary connector  12  is applicable to other wearable, portable and mobile electronic devices connected by a wire or cord to a peripheral device. Moreover, while an exemplary embodiment is disclosed herein with respect to a voice headset, other peripherals  16  may also be utilized equally with the present invention. For example, bar code readers, scanners, printers and other peripherals which might be coupled to terminal  10  through cord  18  will also benefit from the aspects of the present invention. Furthermore, while an exemplary embodiment is described with respect to use of the invention and a portable terminal  10  in an inventory management environment, the principles of the invention will have equal applicability to other terminals or electronic devices, and other operating environments.  
         [0041]     While the present invention has been illustrated by the description of the various embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants&#39; general inventive concept.