Patent Publication Number: US-7896664-B1

Title: Articulated lever mechanism for retractable thumb drive

Description:
FIELD OF THE INVENTION 
     The present invention relates to a mechanism to extend and retract a thumb drive&#39;s connector. 
     BACKGROUND OF THE INVENTION 
     A number of mechanisms have been devised for protecting a USB connector in a thumb drive memory device. As discussed in U.S. Pat. No. 6,808,400 to Tu, the prior art solution used a removable cap that snapped over the USB connector. See Tu, at column 1, lines 30 through 40, and FIG. 1 (“Prior Art”). The Tu patent discloses a USB connector at the end of a printed circuit board (“PCB”) slidably disposed within a case. In one embodiment, a spring urges the PCB toward a position in which the USB connector extends beyond the case, and a “pushing button” with an arm having a “buckling piece” holds the PCB in a retracted position. Another embodiment disclosed in Tu reverses the spring and buckle arrangement to hold the PCB and USB connector in the extended position. Other embodiments of TU use a lipstick-style mechanism. The lipstick-style mechanism relies on a rotating knob that turns a threaded shaft which screws into a threaded bore connected to the PCB. When the knob is turned, the shaft causes the PCB to extend or retract. 
     A button mechanism is disclosed in U.S. Pat. No. 7,422,454 to Tang et al., relying on a “middle carrier” that is located within halves of a casing, whereby the carrier can be moved within the case, thereby extending or retracting a USB connector. 
     The present retractable thumb drive mechanisms relying on a button to extend and retract the USB connector provide no mechanical advantage. The lipstick-style mechanism provides some mechanical advantage, but requires two hands to operate and usually requires too many turns. 
     SUMMARY OF INVENTION 
     The present invention provides a retractable USB thumb drive mechanism that offers mechanical advantage for extending and retracting the USB connector. The present invention also provides a mechanism that can operated with one hand. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a three-quarter, cut-away view of the thumb drive mechanism of the present invention, showing the connector in the extended position. 
         FIG. 2  is a three-quarter, cut-away view of the thumb drive mechanism of the present invention, showing the connector in the retracted position. 
         FIG. 3  is a three-quarter, exterior view of the thumb drive mechanism of the present invention, showing the operating button of the operating lever in the extended position. 
         FIG. 4  is a three-quarter, exterior view of the thumb drive mechanism of the present invention, showing the operating button of the operating lever in the retracted position. 
         FIG. 5  is a three-quarter, detailed view of the lever mechanism of one embodiment of the invention, showing the mechanism in a fully extended position. 
         FIG. 6  is a detail view of the lever mechanism of one embodiment of the invention. 
         FIG. 7  is a three-quarter, detailed view of the lever mechanism of one embodiment of the invention, showing the mechanism in a fully retracted position. 
         FIG. 8  is a three-quarter, cut-away view of an alternative embodiment of a thumb drive mechanism of the present invention, showing the connector in the extended position. 
         FIG. 9  is a three-quarter, cut-away view of an alternative embodiment of a thumb drive mechanism of the present invention, showing the connector in the retracted position. 
         FIG. 10  is a three-quarter, exterior view of an alternative embodiment of a thumb drive mechanism of the present invention, showing the operating lever in the extended position. 
         FIG. 11  is a three-quarter, exterior view of an alternative embodiment of a thumb drive mechanism of the present invention, showing the operating lever in the retracted position. 
         FIG. 12  is a three-quarter, detailed view of the lever mechanism of an alternate embodiment of the present invention, showing the mechanism in a partially extended position. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
       FIG. 1  shows a flash memory thumb drive  10  with the USB connector  11  in the extended position. In the embodiment shown in  FIG. 1 , the USB connector  11  is electrically connected to the memory device  13 , which together form a support structure  12 . The USB connector  11  and the memory device  13  may be mounted on a printed circuit board assembly (“PCBA”) and together form the support structure  12 . It is not necessary that the USB connector  11  and memory device  13  be fixed on a PCBA to form a unitary structure, but, if the memory device  13  is separate from the support structure  12 , then alternative electrical connections between the connector  11  and the memory device  13  must be provided. Persons in the art will appreciate that such connections can be provided by wires, contact strips, or other arrangements. The support structure  12  is mounted in a carriage  15  which is slidably received between the bottom  14  and top  25  (shown in  FIG. 3 ) halves of the complete flash memory thumb drive  10  casing. The USB connector  11  is at one end of the support structure  12 . The opposite end (where the line for reference number “ 15 ” is directed in the drawings) of the carriage  15  is connected by a shaft  19  to a first lever  16 . First lever  16  is pivotably connected at a pivot end  20  to the proximal end of an operating lever  17 . Operating lever  17  pivots on a shaft  18  located in the middle of the lever  17 . The distal end of the operating lever  17  is the operating end  21  of the mechanism. The operating end  21  of the operating lever  17  swivels about a 90-degree arced wall  22  from position A to position B (as shown in  FIG. 2 ). In position A, operating lever  17  and first lever  16  are aligned from end  21  to end  19 , so that the support structure  12  is extended to its maximum travel and the USB connector  11  extends out of the casing of the thumb drive  10 . When operating end  21  is moved to position B, as shown in  FIG. 2 , operating lever  17  swivels about pivot shaft  18  and comes to a stop at a right angle to the length of the thumb drive  10 . In position B, the first lever  16  is pulled by the pivot end  20  and the shaft  19  in turn pulls the carriage  15  into a retracted position, which brings the USB connector  11  within the casing of the thumb drive  10 . 
       FIGS. 3 and 4  show the thumb drive  10  with the top half  25  of the casing in place. In  FIG. 3 , the operating end  21  of the operating lever  17  (not seen in  FIG. 3 ), is in position A on the arced wall  22 , so that the USB connector  11  is extended out of the thumb drive  10  casing. In  FIG. 4 , the operating end  21  of the operating lever  17  (not seen in  FIG. 4 ), is in position B on the arced wall  22 , so that the USB connector  11  (not seen in  FIG. 4 ) is retracted within the thumb drive  10  casing. 
       FIGS. 5 through 7  provide detail of the lever mechanisms.  FIG. 5  shows the mechanism in position A, which pushes the carriage  15  forward to extend the USB connector  11  out of the thumb drive  10  casing (as shown in  FIG. 1 ). The opposite end of the carriage  15  has the shaft  19  to which the first lever  16  is pivotably connected. When first lever  16  is pushed or pulled by the operating lever  17 , shaft  19  pushes or pulls the carriage  15 . At the pivot end  20 , the first lever  16  is pivotably connected to the operating lever  17  by a shaft  29 . Operating lever  17  pivots on a rocker shaft  18 . At the distal end of the operating lever  17  is the operating end  21 , which can have a grooved surface (as shown), to provide more grip to the user.  FIG. 5  shows the operating end  21  in position A, where the operating lever  17  and first lever  16  are aligned and the carriage  15  is pushed to its extended position.  FIG. 5  provides detail of the operating end  21  of the operating lever  17  in position A and  FIG. 7  shows it in position B.  FIG. 6  is a detail, cross section view of the operating end  21  of the operating lever  17 . At the base of wall  22  is a channel  27  into which a guide portion  30  of the operating end  21  is trapped. Guide portion  30  extends down below the bottom of operating end  21  into channel  27 . At positions A and B, indents  28  and  26  (as shown in  FIGS. 6 and 7 ) provide a notch into which the guide portion  30  is releaseably latched. Operating end  21  is flexible, so that when the user pushes on the operating end  21 , the guide portion  30  is released from the indent ( 28  or  26 ) and the operating lever  17  can be swivelled about the arced wall  22 . 
       FIGS. 8 through 12  show alternate embodiments of the present invention.  FIGS. 8 and 9  show the thumb drive  10  with the top half of the casing  25  in ghost, so that the mechanism may be seen as it rests on the bottom half of the casing  14 . The opposite end of the carriage  15  is connected by shaft  19  to first lever  16 . The operating lever  17 , described above, is divided into two portions, a proximal portion  34  and a distal portion  31 . First lever  16  is pivotably connected at pivot end  20  to the proximal portion  34 . The proximal  34  and distal  31  portions form a lever that pivots  35  in the middle. The distal portion  31  is the operating end  32  of the mechanism. The operating end  32  swivels 90-degrees on an arced surface  33  from position C to position D (as shown in  FIG. 9 ). In position C, the proximal  34  and distal  31  portions of the lever are aligned with lever  16  from end  32  to end  19 , so that the carriage  15  is extended to its maximum travel and the USB connector  11  extends out of the casing of the thumb drive  10 . When operating end  32  is moved to position D, as shown in  FIG. 9 , distal portion  31  swivels about pivot shaft  35  and comes to a stop at a right angle to the length of the thumb drive  10 . In position D, the first lever  16  is pulled by the pivot end  20  and the shaft  19  in turn pulls the carriage  15  into a retracted position, which brings the USB connector  11  within the casing of the thumb drive  10 . 
       FIGS. 10 and 11  show the thumb drive  10  with the top half  25  of the casing in place. In  FIG. 10 , the operating end  32  of the distal portion  31  (shown in  FIG. 8 ), is in position C on the arced surface  33 , so that the USB connector  11  is extended out of the thumb drive  10  casing. In  FIG. 11 , the operating end  32  of the distal portion  31  (shown in  FIG. 9 ), is in position D on the arced surface  33 , so that the USB connector  11  (shown in  FIG. 9 ) is retracted within the thumb drive  10  casing. 
       FIG. 12  provides a closer detail view of the lever mechanism shown in  FIGS. 8 through 11 . In  FIG. 12 , the top half  25  of the casing of the thumb drive  10  is drawn in ghost to reveal the latching mechanism described below. The opposite end of the carriage  15  has the shaft  19  to which the first lever  16  is pivotably connected. When first lever  16  is pushed or pulled by operating lever  17 , shaft  19  pushes or pulls the carriage  15 . At the pivot end  20 , the first lever  16  is pivotably connected to the proximal portion  34  at  20 . Distal portion  31  pivots at  35 . Proximal portion  34  is located under the top casing  25 , but distal portion  31  is located outside the top casing  25  on the arced surface  33 . The proximal  34  and distal  31  portions of the lever are joined at the pivot  35 . Thus, the distal portion  31  operates as an arcing lever.  FIG. 12  shows the operating end  32  in position C, mid-way between the fully extended (C) and fully retracted (D) positions. 
       FIG. 12  also shows an alternative latching mechanism to hold the carriage  15  in the extended (C) or retracted (D) positions. The shaft  19  extends upward and is trapped by a pair of downwardly directed guide rails  36  formed as part of the inner surface of top casing  25 . The pair of guide rails  36  form a guide channel. Protrusions  37  in the guide rails  36  trap the shaft  19  when it is in the fully extended (C) or fully retracted (D) position. The shaft  19 , top casing  25 , guide rails  36 , and protrusions  37  are made of deformable material, such as plastic, so that when shaft  19  is pushed by the lever mechanism against protrusions  37 , the shaft  19  will overcome the resistance of the protrusions  37  and be forced past them. But, the protrusions  37  will provide enough resistance to hold the support structure  12  in the extended (C) or retracted (D) position. 
     The drawings and description set forth here represent only some embodiments of the invention. After considering these, skilled persons will understand that there are many ways to make a lever mechanism for a retractable thumb drive according to the principles disclosed. The inventors contemplate that the use of alternative structures, materials, or manufacturing techniques, which result in a lever mechanism for a retractable thumb drive according to the principles disclosed, will be within the scope of the invention.