Memory stick having a lock device

A memory stick having a metal housing, a PC board, a tray carrying the PC board, a lock body, and a locking mechanism. The lock body includes a positioning block press-fitted into a top opening of the metal housing and a locating block engaged into a top notch of the metal housing and adapted for accommodating an upper part of the tray and a part of an IC package circuit of the PC board for enabling the USB interface circuit to be suspending in a bottom opening of the metal housing. The locking mechanism enabling the memory stick to be locked to an external object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a USB memory stick and more particularly, to a memory stick having a lock device, which is electrically connectable to a computer for data access, and facilitates carrying.

2. Description of the Related Art

A USB memory stick is a portable data storage device that is connectable to a computer for data access. As the data storage technology has developed, the storage capacity of typical USB memory sticks has been largely increased. The USB memory sticks are widely used in various fields.

A typical USB memory stick generally comprises a metal shell made of a metal sheet member by stamping, a plastic shell surrounding the metal shell, a PC board accommodated in the metal shell and having a data storage function and an insulative member stopping against the PC board in position. According to this conventional design, the fabrication of the metal shell by means of stamping technology has the advantage of rapid production and low manufacturing cost. However, there is a seam left in the metal shell to obstruct the sense of beauty after fabrication of the metal shell, and therefore the plastic shell is necessary to surround the metal shell and to keep the seam from sight.

Taiwan Patent Application Number 98115626 discloses a USB memory stick entitled “USB memory stick with a seamless metal housing”, which comprises a seamless metal housing made of an extruded rectangular metal tube, and an internal structure consisting of a PC board, a metal tray and an insulative upper block and inserted into the seamless metal housing. This design of the USB memory stick eliminates the drawback of the aforesaid conventional USB memory stick.

Further, adding a lock device to a USB memory stick facilitates carrying of the USB memory stick. This is another subject to be discussed in the present invention.

SUMMARY OF THE INVENTION

The main object of the present invention is to provide a memory stick having a lock device, which is equipped with a locking mechanism for easily fastening the memory stick to an object of corded or striped shape stably locking the memory stick to the object and preventing the memory stick from separating from the object to which the locking mechanism is locked. Another object of the present invention to provide a memory stick having a lock device, which facilitates quick assembling of the component parts and no rivet is used.

To achieve these and other objects of the present invention, the memory stick comprises a metal housing, a PC board, a tray, a lock body, a positioning block, a locating block, a locking mechanism, a spring member, and a slide. The metal housing is in the form of a seamless rectangular metal tube, which comprises a top opening and a bottom opening respectively located on opposing top and bottom sides thereof, a top notch transversely located on the top side around the top opening and a longitudinal top sliding slot vertically located on the top side remote from the top notch. The PC Board comprises a USB interface circuit and an IC package circuit having a memory function. The tray is made of a metal sheet member and is attached to the whole back side of the PC board. The lock body has an accommodation recess adapted for accommodating an upper part of the tray and a part of the IC package circuit of the PC board for enabling the USB interface circuit to be suspending in the bottom opening of the metal housing. The positioning block is disposed at the top side of the accommodation recess and press-fitted into the top opening of the metal housing. The locating block is engaged into the top notch of the metal housing and a notch disposed at one lateral side relative to the positioning block. The locking mechanism has a C-shaped shackle extended from the top side of the lock body and suspending above the notch of the lock body. The spring member is mounted in the notch of the lock body and the slide is supported on the spring member in a locking position where the slide closes the shackle. The slide is movable by an external force along the longitudinal top sliding slot of the metal housing from a locked position to an unlocked position where the slide is separated from the shackle. The slide has a press block suspending outside the longitudinal top sliding slot of the metal housing and a stub rod located on a top side thereof for engagement with the free end of the C-shaped shackle.

Further, the C-shaped shackle comprises a rounded recessed portion located on the free end thereof. Further, the slide of the locking mechanism comprises a rounded protrusion raised from the stub rod and adapted for being inserted into the rounded recessed portion of the shackle.

Further, the tray comprises a clip extending from the top side thereof for clamping the PC board, a spring leaf protruding from the clip and pressed on the IC package circuit to hold down the PC board in the tray, and a retaining lug obliquely upwardly extending from the front end of the clip for engagement with the lock body. Further, the lock body comprises a retaining groove disposed in the accommodation recess and adapted for receiving the retaining lug of the tray.

Further, the lock body comprises two side grooves respectively located on two opposite lateral sides thereof. Further, the metal housing comprises two oblique strips respectively engaging into the two side grooves of the lock body.

Further, the tray comprises a pair of ribs adapted for supporting the PC board in the tray at a high elevation.

Further, the top notch of the metal housing can be formed in the back wall of the metal housing and located on the top side of the metal housing. Alternatively, the top notch of the metal housing can be formed in the middle part of opposing front and back walls of the metal housing and located on the top side of the metal housing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIGS. 1 and 2, a memory stick in accordance with the present invention is shown comprising a metal housing1, a PC board2, a tray3, a lock body4and a locking mechanism5.

The metal housing1is a seamless rectangular metal tube, comprising a top opening11and a bottom opening12respectively located on the opposing top and bottom sides thereof, a top notch13transversely located on the top side around the top opening11, a longitudinal top sliding slot14vertically located on the top side and spaced apart from the top notch13, and two oblique strips15respectively extended from the two opposite lateral sides of the metal housing1.

The PC board2comprises a USB interface circuit21and an IC package circuit22with memory function, as shown inFIG. 1B.

The tray3is made of a metal sheet member by stamping and attached to the whole back side of the PC board2. The tray3comprises a clip31extending from the top side thereof over the front side of the PC board2, as shown inFIG. 1B, a spring leaf32protruding from the clip31and pressing on the surface of the IC package circuit22to hold down the PC board2in the tray3, a retaining lug33obliquely upwardly extending from the front end of the clip31for engagement with the lock body4, a pair of ribs34for supporting the PC board2in the tray3at a high elevation to facilitate quick heat dissipation and positive electric contact upon insertion of the memory stick into a USB port, and an end flange35perpendicularly disposed at the bottom side thereof and spaced apart from the clip31for stopping the PC board2in the tray3to keep the USB interface circuit21in alignment with the bottom opening12of the metal housing1and to prevent the PC board2from falling out of the tray3, as shown inFIG. 4.

The lock body4comprises an accommodation recess41adapted for accommodating the upper part of the tray3and a part of the IC package circuit22of the PC board2and for working as a track during installation so that the surface of the USB interface circuit21can suspend in the bottom opening12of the metal housing1, as shown inFIGS. 3 and 4, a positioning block42disposed at the top side of the accommodation recess41and press-fitted into the top opening11of the metal housing1to enhance installation stability, a locating block43located in the top notch13of the metal housing1to avoid vibration upon insertion of the bottom opening12of the metal housing1into a USB socket, as shown inFIG. 2, a notch44disposed at one lateral side relative to the positioning block42, a retaining groove45disposed in the accommodation recess41for receiving the retaining lug33of the tray3, as shown inFIG. 4, and two side grooves46respectively located on two opposite lateral sides thereof for receiving the oblique strips15of the metal housing1respectively to enhance connection stability between the lock body4and the metal housing1, as shown inFIG. 3.

The locking mechanism5comprises a C-shaped shackle51, a spring member52and a slide53. The C-shaped shackle51extends from the top side of the lock body4to the top side of the notch44of the lock body4. The spring member52supports the slide53in the notch44, allowing movement of the slide53along the longitudinal top sliding slot14. The slide53provides the locking and unlocking actions of the locking mechanism5, comprising a press block531suspending outside the longitudinal top sliding slot14of the metal housing1and a stub rod532located on the top side thereof for engagement with the free end of the C-shaped shackle51. As shown inFIG. 5, the spring member52supports the slide53in the top side of the notch44of the lock body4, as indicated by the imaginary line, pressing the stub rod532out of the top opening11of the metal housing1to engage the free end of the shackle51. When the press block531is pressed downwards to the solid line shown inFIG. 5, the stub rod532is moved backwardly (downwardly) away from the free end of the C-shaped shackle51to a position below the top opening11of the metal housing1and the slide53is lowered to compress the spring member52, and therefore the locking mechanism5is unlocked. Further the C-shaped shackle51comprises a rounded recessed portion511located on the free end thereof. Further, the stub rod532comprises a rounded protrusion533, which is inserted into the rounded recessed portion511when the locking mechanism5is locked, enhancing locking stability.

During the assembly process, as shown inFIG. 6, the PC board2is inserted into the tray3, and then the tray3is inserted into the accommodation recess41of the lock body4in the direction as indicated by the arrowhead sign G1, and then position the metal housing1around the PC board2, the tray3and the lock body4by moving the metal housing1in the direction as indicated by the arrowhead sign G2, and forming the configuration as indicated inFIG. 2. When replacing the PC board2, disengage the oblique strips15of the metal housing1from the two side grooves46of the lock body4, and then remove the PC board2, the tray3and the lock body4from the metal housing1for replacement of the PC board2.

It is to be noted that the design of full space engagement between the top notch13of the metal housing1and the locating block43of the lock body4avoids vibration of component parts of the memory stick upon insertion of the bottom opening12of the metal housing1into a USB socket, assuring positive contact between the USB interface circuit21and the internal circuit of the USB socket for positive signal transmission.

InFIGS. 1 and 2, the top notch13of the metal housing1is located on the back wall of the metal housing1. Alternatively, as shown inFIG. 7, the top notch13is located on the middle of the front and back walls of the metal housing1at the top, and the locating block43of the lock body4is also located on the middle for positive engagement with the top notch13.

Further, the design of the rounded protrusion533of the stub rod532of the slide53of the locking mechanism5for engagement with the rounded recessed portion511of the C-shaped shackle51assures a high level of locking stability. Thus, when the locking mechanism5is fastened to a thin object, the thin object will not separate from the memory stick.

In conclusion, the invention provides a USB memory stick having a lock device, which has the advantages as follows:

1. The memory stick is equipped with a locking mechanism for fastening to a cord-like or strip-like object.

2. When the shackle of the locking mechanism is closed by the slide, the rounded protrusion of the stub rod of the slide is engaged into the rounded recessed portion of the shackle, assuring a high level of locking stability and avoiding falling of the memory stick from the object to which the locking mechanism is locked.

3. The spring leaf engagement design facilitates quick assembling of the component parts without riveting.

Further, as shown inFIG. 8, a rectangular shackle51′ may be used to substitute for the aforesaid C-shaped shackle51.