Patent Publication Number: US-2009231805-A1

Title: System and Method for Information Handling System Chassis Impact Bumpers

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to the field of information handling system chassis, and more particularly to a system and method for information handling system chassis impact bumpers. 
     2. Description of the Related Art 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     Portable information handling systems have received wide acceptance among consumers because, in part, portable systems offer their end users convenience and flexibility. Portable information handling systems typically have an integrated power source, such as a rechargeable battery, and an integrated display, such as a liquid crystal display (LCD). For example, portable information handling systems are built into a chassis having a rotationally coupled lid. The chassis holds most of the processing components that cooperate to process information with a keyboard covering the processing components. The lid holds the LCD and rotates between a closed position in which the lid covers the keyboard and protects the display and an open position in which the keyboard and display are exposed for use. End users appreciate this “clamshell” configuration because portable information handling systems close to a convenient size for ease of transport and open to expose the keyboard and display for ease of use. 
     Portable information handling systems have recently evolved from the clamshell configuration to also have a tablet configuration. In the tablet configuration, the lid rotates about three axes so that the lid closes with the display exposed. For example, the lid rotates about a horizontal axis to an open position, about a vertical axis so the display faces away from keyboard and then about the horizontal axis so the display closes face up and exposed in a tablet position. In the tablet position, an end user makes inputs through a touchscreen associated with the display, such as with handwriting on the display or activating icons presented at the display. One difficulty with the tablet position is that the display typically must be locked in position so that it does not rotate about the vertical axis when the lid is closed. One way to prevent rotation about the vertical axis is by having bumpers extend from the chassis into a recess of the lid. The lid recesses are formed on both the front and rear of the lid so that rotation about the vertical axis is prevented in the closed position and the tablet position. Typically, the bumpers and the recesses are molded in plastic that forms the chassis and lid. The raised bumpers present a challenge in that ordinary use can sometimes damage or break off a bumper. Another difficulty is that the bumpers point of contact within a recess area provides poor shock absorption along both the vertical and horizontal axes. By molding bumpers within the chassis material, the bumpers can have well-supported thin shapes that extend a good distance into a recess of the lid. Although, the chassis material is typically rigid, which helps to withstand physical damage, the rigid material tends to damage mating parts and cosmetic surfaces when the lid is opened, closed and rotated to and from the tablet position. Further, rigid bumpers extending from chassis proximate to the keyboard palm rest tend to interfere with system use. 
     SUMMARY OF THE INVENTION 
     Therefore a need has arisen for a system and method which secures a tablet information handling system from rotation about a vertical axis with reduced risk of damage to the tablet information handling system. 
     In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for securing a tablet information handling system from rotation about a vertical axis. A bumper extends from a chassis aligned to enter a recess formed in an information handling system lid when the lid closes over top of the chassis. The bumper has a rigid material and a non-rigid material. The rigid material couples to the chassis and supports the non-rigid material exposed at the recess, which provides protection from scraping and a shock absorber for the lid relative to the chassis. 
     More specifically, an information handling system chassis has a rotationally coupled lid that rotates about a vertical and a horizontal axis between a closed position and a tablet position. The lid has recesses formed on a front side proximate an integrated display and a back side opposite the display. In the closed position, the recesses of the front side align with chassis bumpers extending from the chassis so that engagement of the chassis bumpers in the recess prevents the lid from rotation about the vertical axis. In the tablet position, the recesses of the back side align with the chassis bumpers so that engagement of the chassis bumpers in the recess prevents the lid from rotation about the vertical axis. The chassis bumpers are double shot injection molded so that a rigid material forms the inner portion of the bumper that couples to the chassis and a non-rigid material forms the outer portion of the bumper that engages the lid recess. The inner portion is, for example, made from a hard thermoplastic material that has heat stakes extending into the chassis to support heat staking of the bumper to the chassis. The outer portion is, for example, made from an elastomer material, such as a thermoplastic rubber, that absorbs impacts between the chassis and lid. Two shot injection molding creates a single component having rigid and non-rigid portions integrated with each other for ease of installation and for establishing a strong coupling with reduced risk of breaking. 
     The present invention provides a number of important technical advantages. One example of an important technical advantage is that a tablet information handling system is secured in closed and tablet positions by bumpers that are securely attached to the chassis yet have a non-rigid surface. The non-rigid surface helps to absorb shock transferred between the lid and chassis and presents less of a nuisance to an end user interacting with the chassis palm rest. The non-rigid surface reduces damage caused to other surfaces of the information handling system during movement of the lid relative to the chassis, such as for moving to and from the tablet configuration. Double shot molding of the bumper securely fixes the non-rigid portion to a rigid underlying portion that is permanently affixed to the chassis to reduce the risk that the bumper will detach from the chassis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element. 
         FIG. 1  depicts a front view of a tablet portable information handling system in an open position with chassis bumpers aligned to enter recesses formed in the lid proximate a display; 
         FIG. 2  depicts a front view of the tablet portable information handling system in an open position having the lid back side rotated towards the front to close to a tablet position with chassis bumpers aligned to enter recesses formed in the lid back side; 
         FIG. 3  depicts a side view of a portable information handling system having chassis bumpers entered into a lid recess; 
         FIG. 4  depicts an upper view of a chassis pocket having heat stake openings for accepting a bumper; 
         FIG. 5  depicts a side cutaway view of a chassis bumper installed in a chassis; and 
         FIG. 6  depicts a front cutaway view of a chassis bumper installed in a chassis. 
     
    
    
     DETAILED DESCRIPTION 
     Chassis bumpers extending from a tablet portable information handling system into a lid recess with the lid in the closed or tablet configuration prevents rotation of lid about a vertical axis. For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     Referring now to  FIG. 1 , a front view depicts a tablet portable information handling system  10  in an open position with chassis bumpers  12  aligned to enter recesses  14  formed in the lid  16  proximate a display  18 . Information handling system  10  is built into a chassis  20  which supports a plurality of processing components that cooperate to process information, such as a CPU  22 , a hard disk drive  24 , RAM  26  and a chipset  28 . A keyboard  30  placed over the processing components accepts inputs from an end user. Lid  16  is rotationally coupled to chassis  20  with a hinge  32  that allows rotation about a horizontal axis  34  and a vertical axis  36 .  FIG. 1  depicts information handling system  10  in an open configuration with keyboard  30  accessible for inputs by an end user and display  18  visible and facing keyboard  30  for presenting visual displays to an end user. Lid  16  rotates about horizontal axis  34  to a closed position in which display  18  closes over top of keyboard  30  so that bumpers  12  enter into bumper recesses  14 . Once bumpers  12  enter into recesses  14 , lid  16  is constrained from rotation about vertical axis  36  as long as lid  16  is held proximate to chassis  20   
     Referring now to  FIG. 2 , a front view depicts tablet portable information handling system  10  in an open position having lid  16  back side  38  rotated towards the front to close to a tablet position with chassis bumpers  12  aligned to enter recesses  14  formed in lid back side  38 . Once lid  16  rotates about horizontal axis  34  so that lid back side  38  closes over keyboard  30 , display  18  is exposed for use as a tablet. Engagement of chassis bumpers  12  into bumper recesses  14  formed in lid backside  38  constrains lid  16  from rotation about vertical axis  36  as long as lid  16  is held proximate to keyboard  30 , such as by a latch. 
     Referring now to  FIG. 3 , a side view depicts a portable information handling system  10  having chassis bumpers  12  entered into a lid recess  14 . Chassis bumper  12  extends outward from chassis  20  towards lid  16  by a distance sufficient to maintain engagement in recess  14  when lid  16  is latched closed to chassis  20 . By having recesses formed on both the front and back of lid  16 , bumpers  12  prevent rotation in both the closed and tablet positions. Bumpers  12  are built to have a non-rigid material on the outer surface exposed at chassis  20  so that lid components coming in contact with bumpers  12  are not subjected to damaging impacts and so that end user interaction with bumpers  12  will not injure the end user. Bumpers  12  are built with a rigid material where the inner surface contacts chassis  20  to ensure good coupling and to reduce the risk of a bumper  12  breaking off. 
     Referring now to  FIG. 4 , an upper view depicts a chassis pocket  40  having heat stake openings  42  for accepting a bumper  12 . During manufacture of information handling system  10 , chassis pocket  40  is formed in chassis  20  to accept a bumper  12 . In the example depicted by  FIG. 4 , three heat stake openings  42  are formed to accept heat stakes of the bumper for heat staking the bumper to chassis  20 . Chassis pocket  40  has dimensions so that the rigid material of the bumper fits with in pocket  40  and substantially only the non-rigid portion of the bumper is exposed after the bumper couples to chassis  20 . Although heat staking provides a method for secure attachment of the bumper, other types of securing techniques might be employed to ensure adequate attachment of the bumper to chassis  20 . 
     Referring now to  FIG. 5 , a side cutaway view depicts a chassis bumper  12  installed in a chassis  20 . Chassis bumper  12  has a rigid material  44  that couples proximate to chassis  20  and a non-rigid material  46  that covers rigid material  44  where bumper  12  is exposed from chassis  20  proximate to lid  16 . For example, rigid material  44  is a hard thermoplastic and non-rigid material  46  is a rubber or other elastomer thermoplastic. Rigid material  44  and non-rigid material  46  are cast together as a single component, such as with two shot injection molding. Rigid material  44  is cast to include heat stakes  48  that extend into heat stake openings  42  formed in chassis  20 . During manufacture, an adhesive  50  holds bumper  12  in place while the heat stake process is performed to couple rigid material  44  to chassis  20 . 
     Referring now to  FIG. 6 , a front cutaway view depicts a chassis bumper  12  installed in a chassis  20 . In the example embodiment depicted by  FIG. 6 , chassis bumper  12  has a total thickness of approximately 2 mm with non-rigid material  46  having a thickness of approximately 0.5 mm enclosing rigid material having a width of approximately 1 mm. Chassis  20  forms a molded wall to accept bumper  12 , with the thickness c of the molded wall approximately 0.6 mm to help retain bumper  12  within chassis  20 . Total thickness of heat stake  48  is approximately 1 mm to retain bumper  12  in chassis  20  with reduced risk of breaking. The height b of the heat stake within chassis  20  is approximately 1 mm to retain heat stake  48  within chassis  20 . 
     Although the present invention has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.