Portable computer with latch assembly

A latch assembly including a lug, a rack, and a lever is provided for portable computer. The lug rotatably mounted on a cover case. A hook formed on the other end of lug protrudes through a hook opening of cover case in a closed position so as to be securely connected to hook holder of a main body case through a front opening of the main body case in a closed position and is securely located into inside of the cover case in the open position so as to avoid being broken and injuring an user. The rack slidably disposed within the cover case allows the lug to be projected through the cover case or to be located underneath the cover case. The lever disposed at an outer surface of the cover case is connected to the rack to causes the rack to slidably and linearly move and the lug to rotate and to protrude from and retract into the surface of the cover case. Protrusions formed on the lever contacts a pair of convex portion of the cover case so as to securely maintain the closed or open position.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to a latching device for a portable computer,
 and more particularly to a latch assembly suitable for a portable personal
 computer having a thin-layer cover.
 2. Related Art
 Latch devices have been used in portable computers including a cover case
 and a main body case. Typically, the cover case of the computer is
 connected to the main body case through a hinge which allows the cover
 case to rotate about an axis within the hinge to a closed position and an
 open position. A user opens the cover case upward from the main body case
 in the open position and then uses a key board and touch pad of the
 portable computer while viewing a screen of a display unit. When the cover
 case and the main body case are in the closed position, the latch device
 locks the cover case and the main body case so as to cover the main body
 case with the cover case, to protect the keyboard of the main body case
 and the display unit of the cover case, and to maintain the portable
 computer in the closed position. When the latch is manually released, the
 cover can be opened. The more compact in size and relatively light in
 weight the portable computer has continuously evolved, the more compact
 and precise the latch device suitable for a thin-layer cover case and a
 thin-layer main body case is needed to be.
 Efforts to lock the cover and the main body have spawned various types of
 latches. For example, U.S. Pat. No. 3,709,538 for a Latch for Receptacle
 issued to Seitz at al., U.S. Pat. No. 4,527,821 for a Sliding Spring Latch
 issued to Tanaka, and U.S. Pat. No. 4,790,579 for a Sliding Spring Latch
 issued to Maxwell at al. show a latch device attached to a door or cover,
 while U.S. Pat. No. 5,011,198 for a Handle Latch Assembly issued to
 Gruenberg et al. and U.S. Pat. No. 5,497,296 for an Electronic Apparatus
 With Hinged Display And Latch Mechanism For Releasably Latching Displays
 In Closed Position issued to Satou et. al. propose a latch assembly for a
 portable or laptop personal computer. We have found that the embodiments
 described by these references do not indicate that a latch claw protruding
 from a cover surface in a closed position can be retracted to the inside
 of the cover surface while in an open position.
 U.S. Pat. No. 4,984,833 for a Lock Hook issued to Knurr discloses a lock
 hook for a door of a computer cabinet. Although the lock hook pivots about
 a pivot axis and projects out of a main surface in a closed position and
 pivots complete into an opening in the main surface of the door in a open
 position, the lock hook assembly, however, rotates by a complicated
 combination of a push rod having an sectionally circular driver, an
 opening area accommodating the sectionally circular driver and a
 substantially positive rounded portion of the lock plate contacting the
 sectionally circular driver. We have noticed that this reference includes
 a complicated latch structure which does not fit a compact and small
 laptop or portable computer with a small thickness.
 SUMMARY OF THE INVENTION
 It is an object of the present invention to provide an improved latch
 apparatus able to position a cover case and a main body case of a portable
 computer to a closed position and an open position.
 It is another object to provide a latch apparatus able to protect a lug
 rotatably mounted on a cover case in the open position of the portable
 computer.
 It an yet another object to provide a latch apparatus able to securely
 maintain the lug located underneath of the surface of the cover case.
 It is still another object to provide a latch apparatus able to protect an
 user from being damaged by a look hook protruded from a surface of the
 cover case.
 It is a further object to provide a latch apparatus able to be installed in
 a compact portable computer having a cover case with a small thickness.
 It is also an object to provide a latch apparatus capable of securely
 maintain the closed position of the portable computer.
 It is also an object to provide a latch apparatus for automatically
 enforcing the cover case to be opened.
 These and other objects may be achieved by providing a portable computer
 with a latch assembly including a lug rotatably mounted within a
 receptacle of a cover case, a rack slidably disposed within the receptacle
 of the cover case and allowing the lug to be projected through the cover
 case or to be located underneath the cover case, a lever disposed at an
 outer surface of the cover case, connected to the rack, causing the rack
 to slidably and linearly rotate the lug, and allowing the lug to protrude
 from and retract into the surface of the cover case, and protrusions
 formed on the lever, contacting a pair of convex portion of the cover
 case, securely maintaining a locking state in the closed position and a
 non-locking state of the open position.
 A pinion gear formed on one end of the lug contacts a rack gear formed on
 the rack. A hook formed on the other end of lug protrudes through a hook
 opening of cover case in closed position so as to be securely connected to
 hook holder of a main body case through a front opening of the main body
 case in a closed position and is securely located into the inside or
 underneath of the cover case in the open position so as to avoid being
 broken and injuring an user.
 The latching assembly further includes a first spring connected to an inner
 surface of the receptacle of the cover case and one end of the rack to
 securely maintain the closed position by holding the hook of the lug in a
 latch position when the cover case is positioned in the closed position, a
 locker disposed within the cover case and coupled to the other end of the
 rack to securely maintain the lug to be located underneath of the cover
 case when the cover case is positioned in the open position, and a second
 spring located to contact the locker and allow a protrusion of the locker
 to protrude from the surface of the cover case through a locker opening
 formed on the cover case so as to push out the front plate of the main
 body case when the cover moves from the closed position to the open
 position by the second spring.

DESCRIPTION OF THE PREFERRED EMBODIMENT
 Referring to FIG. 1, a portable computer 500 includes a main body case 510
 and a cover case 520 connected to main body case 520 in a closed position
 or an open position by means of a latch assembly 530 mounted on cover case
 520 and an opening 550 formed on the main body case 510. Cover case 520 is
 connected to main body case 510 through a hinge which allows cover case
 520 to rotate about an axis of the hinge to a closed position and an open
 position and to be opened upward from main body case 510 and a user to use
 a keyboard of main body case 510 and a display unit of cover case 520.
 Latch assembly 530 is usually located on a top side of cover case 520.
 When cover case 520 is locked by latch assembly 530 in the closed
 position, cover case 520 is fixed at main body case 510 of portable
 computer 500. A lug mounted on latch assembly 530 extends outwardly to be
 coupled to opening 550 of main body case 510. Since the lug 540 protrudes
 in the open position, user can be injured by the lug 540, and the lug 540
 can be broken or damaged.
 The main body case contains all of the essential circuitry of the computer
 such as the CPU, the power supply, data storage devices, and a keyboard
 attached to a front side of the main body case while the cover case
 holding a display unit covers keyboard. The display unit can be a video
 monitor, a liquid crystal display, or any other equivalent devices. The
 computer is often turned on when the cover case rotates upward. The cover
 case can protect both the display unit and keys of the main body case by
 covering the main body case for transportation.
 Referring to FIGS. 2 through 5, a portable personal computer 10 includes a
 main body 20 containing the internal electronic circuitry. A keyboard unit
 22 and a mouse pad 24 are attached to a front plate 25 of main body 20 and
 connected to the internal electronic circuitry. Keyboard unit 22 and mouse
 pad 24 allow an user to communicate with computer 10. A cover case 40
 including a display screen 42 is coupled to main body 20 by a hinge 21.
 Display screen 42 is located on display plate 44. A display screen 42 and
 a keyboard unit 22 are exposed when cover case 40 rotates about an axis of
 hinge 21 to an open position.
 A latch assembly 50 is attached to cover case 40 and is coupled to a hook
 holder 126 formed on front plate 25 of main body case 20 through a latch
 opening 62 formed on display plate 44 of cover case 40 and a front opening
 26 formed on front opening 25 of main body case 20. A latch receptacle 52
 is formed on inside of cover case 40 to accommodate a rack 90 and a lug 70
 while a lever receptacle 59 is formed on outer surface of side plate 63 in
 cover case 40 to accommodate a lever 100 connected to rack 90 through
 connecting holes 60A and 60B. Rack 90 is inserted into latch receptacle 52
 and slidably mounted on a bottom plate 56 of latch receptacle 52. While
 lever 100 is slidably mounted on a middle plate 58 of lever receptacle 59,
 extending pins 102A and 102B formed downwardly on lever 100 are inserted
 into holes 94A and 94B formed on rack 90 through connecting holes 60A and
 60B so as to couple lever 100 to rack 90.
 Two pairs of lever protrusions 66A and 66B as a first locking member formed
 on lever 100 contact a pair of convex portions as a second locking member
 formed on lever receptacle 59 of side plate 43 respectively while lever
 100 slides in lever receptacle 59. Lever protrusions 66A and 66B may have
 a concave shape to accomodate one of convex portions 64A and 64B formed on
 lever receptacle 59 of side plate 43 respectively. When convex portions
 64A and 64B arc located between the pair of lever protrusions 66A and 66B
 respectively, lever 100 held at a latching position causes latch assembly
 350 to maintain cover case 40 and main body case 20 in the closed position
 or in the open position. One of lever protrusions 66A or 66B formed on
 lever 100 engages one of convex portions 64A or 64B formed on cover 40 to
 lock lug 70 to maintain in the lock state so as to hold lug 70 to project
 through latch opening 62 in the closed position or to be positioned within
 latch receptacle 52 without projecting through opening 62. One of convex
 portions 64A or 64B as the second locking member may be formed between
 lever protrusions 66A or 66B of lever 100. Once one of convex portions 64A
 or 64B is located between lever protrusions 66B, advertent releasing of
 cover 40 from the main body 20 is prevented by firmly locking lever
 protrusions and convex portions. Moreover, lug 70 positioned within latch
 receptacle 52 in the opening position is prevented from advertently
 projecting through latch opening 62 by firmly locking first and second
 locking members. In order to unlock first and second locking members, the
 user has to force lever 100 to slide. Before the user slide lever 100, the
 locking state of first and second locking members is firmly maintained.
 Lug 70 includes a pinion gear which is coupled to a rack gear 92 formed on
 rack 90. A pin as a shaft is inserted into a hole formed on a center
 portion of pinion gear 72 and mounted on between a bottom plate 56 and
 middle plate 58. Lug 70 rotatable around pin 80 rotates about an axis of
 pin 80 while lever 100 and rack 90 move linearly and pinion gear 72 of lug
 70 engages rack gear 92 of rack 90. A hook 71 formed on one end of lug 70
 protrudes through and retracts from a latch opening 62 formed on display
 plate 44 of cover case 40 during the rotation of lug 70 and the linear
 movement of rack 90 and lever 100.
 FIGS. 4 and 5 show a non-latching state and a latching state of latch
 assembly 50 in the locking apparatus. When cover case 40 has moved to the
 closed position, the user slides lever 100 in the direction of an arrow C
 and moves to a latching position shown in FIG. 4. Lug 70 rotates around
 pin 80 depending on the movement of lever 100 and rack 90 and moves from
 the non-locking state to the lock state described in dotted lines A and B.
 Hook 71 of lug 70 protrudes and passes through latch opening 62 of cover
 case 40 and front opening 26 of main body case 20 and latches main body
 case 20 and cover case 40 by holding hook holder 21 formed on front plate
 25 in main body case 20 as shown in a dotted line B of FIG. 4. The pair of
 convex portions 64A and 64B are located between the pairs of lever
 protrusions 66A and 66B respectively.
 Lever protrusions 66A or 66B formed on lever 100 engages said one of convex
 portions 64A or 64B formed on cover 40 to lock lug 70 to maintain in the
 lock state so as to hold lug 70 to project through latch opening 62 in the
 closed position or to be positioned within latch receptacle 52 without
 projecting through latch opening 62. One of convex portion 64A or 64B as
 the second locking member may be formed between a set of lever protrusions
 66A or 66B as the first locking member while the other one of convex
 portions 64A or 64B is formed between the other set of said protrusions
 66A or 66B in FIG. 4. Once each convex portions 64A or 64B is located
 between lever protrusions 66B in the open position, the advertent
 projection of lug 70 through latch opening 62 is prevented by firmly
 locking first and second lock members. In order to unlock first and second
 lock members and project lug 70 through latch opening 62 for latching
 state, the user has to slide lever 100 to disengage first and second
 locking member. Before the user slide lever 100, the locking state of
 first and second lock members is firmly maintained.
 One of convex portions 64A or 64B as first locking member formed on lever
 100 engages lever protrusion 66A or 66B as second lock member formed on
 cover 40 to hold the lug 70 to maintain in the latching state so as to
 project the lug 70 through both latch openings 62 and front 26. Once the
 other one of convex portions 64A or 64B is located between lever
 protrusions 66B as shown in FIG. 5, lug 70 is prevented from unlatching by
 firmly locking first and second lock members. In order to unlock first and
 second lock members, the user has to slide lever 100 to disengage first
 and second locking member. Therefore, the movement of lever 100 and rack
 90 is prevented, and lug 70 is maintained to securely hold hook holder 21
 of main body case 20. Before the user slide lever 100, latch assembly 50
 latches main body case 20 and cover case 40 in the closed position.
 FIG. 6 shows a second embodiment of the locking apparatus according to the
 principle of the present invention. FIGS. 7 and 8 illustrate a locking
 state and a non-locking state of the locking apparatus of FIG. 6. One end
 of a first spring 110 formed with the coil type is connected to a link
 portion 98 formed on first end of rack 90, the other end of first spring
 110 is connected a side wall 51 of latch receptacle 52. A second spring
 130 formed with the plate type is disposed within latch receptacle 52 of
 cover case 40. One end of second spring 130 contacts a back plate of latch
 receptacle 52, the other end of second spring 130 contacts a surface 124
 of a locker 120 to give an elastic force to locker 120 and to push locker
 120 outside of cover case through locker opening 27 formed on display
 plate 44. A locker holder 126 formed on locker 120 is connected to a rack
 holder 96 formed on rack 90 in the closed position and disconnected from
 rack holder 96 in the open position.
 When the cover case 40 and main body case 20 are in the closed position,
 front plate 25 pushes locker 120 into inside of cover case 40 through
 locker opening 27, and then locker holder 126 of locker 120 is
 disconnected from rack holder 96. The disconnection between locker holder
 126 and rack holder 96 causes first spring 110 to pull rack 90 and lug 70
 to maintain the latching position. When the user slides lever 100 to open
 cover case 40 from main body case 20, rack holder 96 becomes connected to
 locker holder 126. Extended portion 122 of locker 120 pushes front plate
 25 to open cover case 40 from main body case 20 in response to the elastic
 force of second spring 130 during the connection between locker holder 126
 and rack holder 96. Hook 71 of lug 70 is retracted from the latching
 position to the inside of cover case 40. The connection between locker
 holder 126 and rack holder 96 causes lug 70 to be located inside of cover
 case 40 in the open position.
 When cover case 40 is located in the open position shown in FIG. 8,
 extended portion of locker 120 partially protrudes from display plate 44
 of cover case 20 due to the elastic force of second spring 130. Locker
 holder 126 of locker 120 is coupled to rack holder 96. In this state, rack
 90 is securely fixed to maintain the closed position by coupling rack 90
 and locker 120. As cover case 20 is closed, locker 120 is pressed by front
 plate 25 of main body case 20, and locker holder 126 is released from rack
 holder 96. The connection causes rack 90 to move to the direction of the
 arrow C for the latching position B by the elastic force of first spring
 110 and results to the rotation of lug 70 shown in FIG. 7 and a dotted
 line B of FIG. 8. Lug 70 rotates through hook opening 62 and front opening
 26 as shown in FIG. 7 and a dotted line A of FIG. 8. Because of the
 elastic force of the first spring 110, the latching position of the lug 70
 is securely maintained.
 As described above, according to the principle of the present invention, a
 latch assembly including a lug rotatably mounted on a cover case securely
 maintains the lug not only to the latching state in the closed position
 but also to non-locking state for fully hiding lug in the inside of the
 cover case in the open position by using both a convex portion of the
 lever receptacle formed on the cover case and a protrusion formed on a
 lever connected to the lug through the rack. By using a pinion gear formed
 on one end of the lug and a rack gear formed on the rack and engaging the
 pinion gear of the lug, the latching state and non-lock state is securely
 maintained and become more accurate in closed and open positions. By using
 a first spring connected between the rack and the latch receptacle, a
 locker connected to and disconnected from the rack, the latch assembly
 securely maintains the latching state in the closed position and the
 non-lock state in the open position. The connection between the rack and
 the locker prevents the locker from protruding from the cover case and
 allows the locker to extend by a predetermined length. A second spring
 disposed between the locker and the latch receptacle causes the locker to
 push the front plate of the main body case during moving from the closed
 position to the open position and to help the user to open the cover case.
 The invention has been described using exemplary preferred embodiments.
 However, it is to be understood that the scope of the invention is not
 limited to the disclosed embodiments. On the contrary, it is intended to
 cover various modifications and similar arrangements. The scope of the
 claims, therefore, should be accorded the broadest interpretation so as to
 encompass all such modifications and similar arrangements.