Locking device for substrate sockets

The locking device of the present invention is provided to constantly and reliably maintain the locked state even under severe environments of use, such as an application of an excessive amount of impact force, for example, and to drastically improve reliability. The locking device is equipped with a latch (2) comprising of a base end section (3), which is supported at the back side of the substrate B in a condition in which it is inserted into the substrate socket S; a base section (4) which projects out to the front side of the substrate B from this base end section (3), and a connecting section (5) having a primary connecting section (5a) and a secondary connecting section (5b) provided at the front end of this base section (4), with the primary connecting section (5a) connected to the recessed engaging section (Bh) formed at the substrate B and the secondary connecting section (5b) connected to the edge side section (Bs) of the substrate B in a locked state Mc which locks the substrate B, and the connection to the substrate B by the primary connecting section (5a) and the secondary connecting section (5b) canceled in the released state Mr in which the connecting section (5) is elastically displaced at the base end section (3) as the point of support.

BACKGROUND AND SUMMARY OF THE INVENTION
 This invention concerns a locking device for substrate sockets which locks
 a substrate (electronic circuitry substrate, for example) that is inserted
 into a substrate socket.
 Generally, electronic parts are mounted at a high density into portable
 personal computers, for example. The mother board that is stored inside is
 equipped with a substrate socket so that a memory substrate, for example,
 can be installed, and it can be optionally upgraded. The said substrate
 socket is also equipped with a locking device that locks so that the
 substrate that is inserted will not be removed through impact, for
 example.
 As a conventional locking device of this type, a locking device is already
 known which was proposed by this applicant in the official report for the
 Japanese Kokai Patent Application No. Hei 8[1996]-190958, and equipped in
 an electronic circuitry substrate socket. This locking device has a
 structure in which it is equipped with a latch consisting of: a base end
 section, which is supported in a freely rotatable manner at the back side
 of the substrate in a condition in which it is inserted into a substrate
 socket; a base section which projects out to the front side of the said
 substrate from this base end section; and a connecting section which is
 provided at the front end of this base section, and is also equipped with
 a spring section which presses down this latch, and in a locked condition
 where the substrate is locked, the connecting section is connected to a
 recessed engaging section formed at the substrate, and in a released
 condition in which the connecting section is elastically displaced at the
 base end section as the point of support, the connection to the substrate
 at the connecting section is canceled. Through this, the operational
 amount of displacement of the connecting section in the direction of the
 surface of the substrate decreases, and high density mounting while
 eliminating dead space surrounding the locking device can be attained.
 In the conventional locking device for a substrate socket described above,
 the connecting section, which is pressed down by the spring section, is
 connected to the substrate that is inserted into the substrate socket,
 locking the said substrate. Therefore, the locked state is reliably
 maintained in a general manner of use.
 However, because a portable personal computer, for example, is carried
 around and utilized, the risk of an excessive amount of impact force being
 applied to the locking device is great when it is dropped on the ground,
 for example. Therefore, the capability of constantly and reliably
 maintaining the locked state without canceling a locking is requested in
 this type of locking device even under severe environments of use, such as
 the application of an excessive amount of impact force, for example.
 This invention meets such a request in the conventional type, and its aim
 is to offer a locking device for a substrate socket which maintains a
 constant and reliable locked state under a severe condition of use, such
 as the application of an excessive amount of impact, for example, and the
 reliability can be drastically improved, while assuring the basic
 advantage of attaining high density mounting while eliminating dead space
 surrounding the locking device.
 This invention for the construction of a locking device for a substrate
 socket S, which locks a substrate B that is inserted into a substrate
 socket S, has the characteristic of being equipped with a latch (2)
 consisting of a base end section (3), which is supported at the back side
 of the substrate B in a condition in which it is inserted into the
 substrate socket S; a base section (4), which projects out to the front
 side of the said substrate B from this base end section (3); and a
 connecting section (5), which is provided at the front end of this base
 section (4) and has a primary connecting section (5a) and a secondary
 connecting section (5b), in a locked state Mc in which the substrate B is
 locked, the primary connecting section (5a) is connected to the recessed
 engaging section Bh formed at the substrate B, and the secondary
 connecting section (5b) is also connected to the end section Bs of the
 substrate B, and in a released state Mr in which the connecting section
 (5) is elastically displaced at the base end section (3) as the point of
 support, the connection to the substrate B by the primary connecting
 section (5a) and the secondary connecting section (5b) is canceled.
 In this case, in a satisfactory manner of implementation, the base end
 section (3) is positioned between the primary connecting section (5) and
 the secondary connecting section (5b) in the direction of the surface of
 the substrate B and in the direction of the displacement of the connecting
 section (5). Also, the base end section (3) of the latch (2) is supported
 in a freely rotatable manner, and the base section (4) is pressed into the
 locking direction by a spring section (6), and the position is also
 controlled at a constant position in the locking direction. On the other
 hand, the base section (4) engages with the inside of the recessed
 engaging section Bh in the locked state Mc, and controls the position of
 the substrate B in the direction of the surface. Also, inclined faces
 (5as) and (5bs), which allow the substrate B to pass by escaping when the
 said substrate B inserted hits the substrate socket S, and a controlling
 knob (7) are respectively provided to the engaging section (5).
 Through this, the locking device (1) is pressed in a direction in which the
 base section (4) locks by the spring section (6) in a natural state, and
 the position is controlled at the constant position in the locking
 direction as well. Accordingly, the connecting section (5) escapes by the
 inclined faces (5as) and (5bs) when the substrate B is directly inserted
 into the substrate socket S, and the substrate B can be installed into the
 substrate socket S. Through this, the locking device (1) has the locked
 state Mc, the primary connecting section (5a) of the connecting section
 (5), which is pressed by the spring section (6), is connected to the
 recessed connecting section Bh formed at the substrate B, and the
 secondary connecting section (5b) is connected to the edge side section Bs
 of the substrate B, and the substrate B is locked. In the locked state Mc,
 because the base end section (3) is positioned between the primary
 connecting section (5a) and the secondary connecting section (5b) in the
 direction of the surface of the substrate B and in the direction of
 displacement of the connecting section (5), the connecting section (5)
 cannot be displaced at the base end section (3) as the point of support
 even if the substrate B attempts to escape from the substrate socket S
 when an external force interacts in the orthogonal direction to the
 substrate B. Accordingly, the locked state Mc is always and reliably
 maintained even under severe environments of use, such as the application
 of an excessive amount of impact force, for example. On the other hand,
 when removing the substrate B from the substrate socket S, the locking
 device (1) will have a released state Mr by elastically displacing the
 connecting section (5) with the base substrate (3) as the point of
 support, the connection to the substrate B by the primary connecting
 section (5a) and the secondary connecting section (5b) will be canceled,
 and the substrate B can be removed.

DETAILED DESCRIPTION OF THE DRAWINGS
 Next, a satisfactory application example for this invention will be given,
 and it will be explained in detail based on the figures.
 First, an abstract of a substrate socket S equipped with a locking device
 (1) in this application example will be explained while referring to FIGS.
 8 and 9.
 In FIG. 8, (50) and S respectively show a mother board that is built within
 a portable personal computer, for example, and a substrate socket that is
 mounted over the said mother board (50). The substrate socket S is formed
 into the shape of the letter `c`, has a contacting section Sc, into which
 a connecting end Ba of the substrate B is inserted and connected at the
 middle section, and has holding arm sections Sa and Sb which extend out
 from both sides of this contacting section Sc in an orthogonal direction
 and hold both sides of the substrate B. These holding arm sections Sa and
 Sb have substrate supporting sections Sas and Sbs, onto which the back
 surface of the substrate B is mounted, and base controlling sections Saw
 and Sbw which control the edge sections to the left and right of the
 substrate B. Then, locking devices (1) and (1) are respectively provided
 at the front ends of each of the holding arm sections Sa and Sb.
 On the other hand, the substrate B is in a rectangular shape, and 4 IC (51)
 . . . are mounted over the surface of the substrate shown as an example.
 Also, the front edge section of the substrate B has the aforementioned
 connecting end Ba, and recessed engaging sections Bh and Bh, which are
 cut-off in a semi-circular shape, are formed at the left and right edge
 sections.
 Next, the structure of the locking device (1) in this application example
 will be explained while referring to FIGS. 1-7. This application example
 shows a case in which a pair of locking devices (1) and (1) are provided
 at both the left and right sides. In this case, each of the locking
 devices (1) and (1) has the same structure except that they are
 symmetrical to the left and right. Accordingly, only the locking device
 (1) at one side will be explained below.
 First, the locking device (1), as shown in FIGS. 6 and 7, is equipped with
 a latch (2), which is integrally formed of a synthetic resin. This latch
 (2) roughly consists of: a base end section (3) which is formed into the
 shape of a round bar; a base section (4) which projects out from the
 middle position of this base end section (3); and a connecting section (5)
 which is provided at the front end of this base section (4).
 The base section (3) is supported in a freely rotatable manner at the back
 side of the substrate B in a condition in which it is inserted into the
 substrate socket S. In other words, one side of the base end section (3)
 is inserted into a bearing (30), which is provided to the holding arm
 section Sa in a lateral hole style, the other side of the base end section
 (3) is prevented from escaping by a controlling section (21s), which is
 the front end of a controlling plate section (21) projecting out from the
 substrate controlling section Saw, and is bent at a right angle. In this
 case, a hooking section (21sf), which is bent at a right angle, is
 provided at the front end of the controlling section (21s), and this
 hooking section (21sf) latches into a latching hole (31), which is
 provided at the substrate supporting section Sas (refer to FIGS. 2 and 5).
 Also, a spring plate section (22) projects out from the substrate
 controlling section Saw. A spring section (6) is formed at the front end
 side of the spring plate section (22), and the front end of this spring
 section (6) makes pressure contact with the back section of the base
 section (4). Through this, the base section (4) is pressed into the
 locking direction by the spring section (6). In this case, the base
 section (4) is controlled by a positional controlling section (32), which
 is provided at the substrate supporting section Sas, and stops at a
 constant standing up position in the orthogonal direction of the surface
 of the substrate B in a natural state (refer to FIG. 4). Accordingly, the
 latch (2) can be elastically displaced in the direction of separating from
 the substrate B at the base end section (3) as the point of support. Also,
 the base section (4) projects out to the surface side of the substrate B
 in a state in which it is inserted into the substrate socket S, and during
 this, it has the function of engaging with the inside of the recessed
 engaging section Bh of the substrate B and controlling the position in the
 direction of the surface of the substrate B.
 On the other hand, the connecting section (5) has a primary connecting
 section (5a) and a secondary connecting section (5b) which project out to
 one side in the displacement direction during a rotational displacement at
 the base end section (3) as the point of support. The front end of the
 primary connecting section (5a) is projectively formed into a
 semi-circular shape that is smaller than the curvature of the recessed
 engaging section Bh formed at the substrate B, and is connected to the
 recessed engaging section Bh when the latch (2) is positioned at a
 constant position. The secondary connecting section (5b) is extensionally
 provided next to the primary connecting section (5a), and is connected to
 the edge side section Bs, which is adjacent to the recessed engaging
 section Bh, when the latch (2) is positioned at a constant position (refer
 to FIG. 2).
 The significant point in this case is that the base end section (3) is
 positioned between the primary connecting section (5a) and the secondary
 connecting section (5b) in the direction of the surface of the substrate 9
 and in the direction of the displacement of the connecting section (5).
 More precisely, when the primary connecting section (5a) and the secondary
 connecting section (5b) are connected to the substrate B, as shown in
 FIGS. 5 and 6, the positional relationship of each of the sections is set
 in a manner so that the connecting position Xi of the primary connecting
 section (5a) with the substrate. B is offset only by the distance Li from
 the position Xm of the base end section (3) in the direction of the
 surface of the substrate B and in the direction of the displacement of the
 connecting section (5), and the connecting position Xo of the secondary
 connecting section (5b) with the substrate B is offset only by the
 distance Lo from the position Xm of the base end section (3) in the
 direction of the surface of the substrate B, which is the direction of the
 displacement of the connecting section (5), which is in an opposite
 direction from the said connecting position Xi. Also, the connecting
 position Xo can be matched with the position Xm of the base end section
 (3). Through this, in a state in which the primary connecting section (5a)
 and the secondary connecting section (5b) are connected to the substrate
 B, the connecting section (5) cannot be displaced at the base end section
 (3) as the point of support even if an external force interacts in the
 orthogonal direction of the surface of the substrate B when the substrate
 B attempts to separate from the substrate socket S, and the locked state
 Mc will be constantly and reliably maintained under severe environments of
 use, such as an application of an excessive amount of impact force, for
 example.
 Furthermore, inclined faces (5as) and (5bs), which allow the substrate B to
 pass by escaping when the said substrate B that is inserted into the
 substrate socket S hits, are provided at the primary connecting section
 (5a) and the secondary connecting section (5b) of the connecting section
 (5), and a controlling knob section (7), which projects out into the
 opposite direction of the primary connecting section (5a) and the
 secondary connecting section (5b) and is formed into the shape of a strip,
 is integrally provided at the front end of the base section (4).
 Next, the method of use as well as the function of the locking device (1)
 in this application example will be explained while referring to each of
 the figures.
 First, a case in which the substrate B is installed into the substrate
 socket S will be explained. As described above, the latch (2) stops at the
 constant position of standing up in the orthogonal direction to the
 surface of the substrate B in a natural state. Accordingly, when
 installing the substrate B to the substrate socket S, as shown in FIG. 8,
 the connecting end Ba of the substrate B is inserted diagonally from above
 the contacting section Sc of the substrate socket S, and the back edge of
 the substrate B is simultaneously lowered, and the substrate B can be
 mounted onto the substrate supporting sections Sas and Sbs. During this,
 the substrate B hits the primary connecting section (5a) and the secondary
 connecting section (5b) of the latch (2), but they respectively have the
 inclined faces (5as) and (5bs), and they escape from the elasticity of the
 spring section (6), and the substrate B will be allowed to pass. On the
 other hand, when the substrate B is completely mounted over the substrate
 supporting sections Sas and Sbs, the primary connecting section (5a) and
 the secondary connecting section (5b) will be positioned over the
 substrate B and they return by the elasticity of the spring section (6).
 Through this, the primary connecting section (5a) is connected to the
 recessed engaging section Bh, which is formed at the substrate B, and the
 secondary connecting section (5b) is connected to the edge section Bs of
 the substrate B. This state becomes the locked state Mc which locks the
 substrate B, which is basically the same position as the natural state
 (refer to FIG. 4).
 Also, because the primary connecting section (5a) and the secondary
 connecting section (5b) are connected to the substrate B in the locked
 state Mc, the connecting section (5) cannot be displaced at the base end
 section (3) as the point of support even though an external force
 interacts in the orthogonal direction of the surface of the substrate B
 when the substrate B attempts to separate from the substrate socket S.
 Accordingly, the locked state Mc will be constantly and reliably
 maintained even under severe environments for use, such as an application
 of an excessive amount of impact force, for example, and the reliability
 will be drastically improved.
 Next, a case in which the substrate B is removed from the substrate socket
 S will be explained. In this case, the controlling knob section (7) is
 pressed by a finger, and the latch (2) may be displaced by rotational
 movement. More precisely, the connecting section (5) may be elastically
 displaced at the base end section (3) as the point of support to a
 position where the connection with the substrate B by the primary
 connecting section (5a) and the secondary connecting section (5b) is
 canceled. This state becomes the released state Mr (refer to FIG. 5).
 Through this, locking of the substrate B by the locking device (1) is
 canceled, and the substrate B can be directly removed.
 The point that should receive attention in this case is that the substrate
 B can be removed only by operating the locking device (1) at one side.
 More precisely, in the conventional locking method which is generally used
 and in which the latch is moved parallel to the direction of the surface
 of the substrate, it is necessary to simultaneously operate the locking
 devices as a pair that are provided at both the left and right sides.
 However, because the latch (2) in the locking device (1) in this invention
 is a rotational type, when the locking of the locking device (1) at one
 side is canceled, and one side of the substrate B is lifted up, the latch
 (2) of the locking device (1) on the other side follows the inclination of
 the substrate B and is rotationally displaced. Accordingly, the substrate
 B can be very easily and smoothly removed by operating the locking device
 (1) with one hand, and removing the substrate B with the other hand, for
 example. Also, the latch (2) uses a rotational type, and the basic effect
 of attaining high density mounting while eliminating dead space
 surrounding the locking device (1) can also be received.
 The application example was explained in detail above, but this invention
 should not be limited by such an application example, and the structures,
 shapes, materials, and quantities, for example, of detailed sections can
 be optionally altered, added, and eliminated within a range that does not
 deviate from the substance of this invention. For example, the locking
 devices (1) were provided as a part of the substrate socket S, but they
 may be separately constructed from the substrate socket S. Also, a pair of
 locking devices (1) and (1) were provided at both the left and right sides
 in the example, but one locking device (1) may be provided. When there is
 only one locking device (1), a structure may be adopted which is connected
 at the center of the back edge side section of the substrate B. In such a
 case, a structure may be adopted in which the locking device (1) in
 particular is separate from the substrate socket S. Also, the latch (2) is
 pressed by the separate spring section (6) in the example shown, but the
 base section (4) itself may be formed of a spring material (elastic
 material), for example. In such a case, the separate spring section (6)
 becomes unnecessary, and the base end section (3) may be fixed because a
 rotation is not necessary. Connecting in this invention does not
 necessarily require making contact.
 In this manner, the locking device of this invention has a structure which
 is equipped with a latch consisting of the base end section, which is
 supported at the back side of the substrate in a condition in which it is
 inserted into the substrate socket; a base section which projects out to
 the front side of the substrate from this base end section, and a
 connecting section having a primary connecting section and a secondary
 connecting section provided at the front end of this base section. The
 primary connecting section is connected to the recessed engaging section
 formed at the substrate, and the secondary connecting section is connected
 to the edge side section of the substrate in a locked state which locks
 the substrate. The connection of the substrate by the primary connecting
 section and the secondary connecting section is canceled in the released
 state in which the connecting section is elastically displaced at the base
 end section as the point of support. Therefore, it displays a prominent
 effect in which the locked state is constantly and reliably maintained,
 and moreover, reliability is drastically improved, even under severe
 conditions of use, such as an application of an excessive amount of impact
 force, for example, while assuring the basic advantage of attaining high
 density mounting while eliminating dead space surrounding the locking
 device.
 Explanation of symbols
 1. Locking device, 2. Latch, 3. Base end section, 4, Base section, 5.
 Connecting section, 5a. Primary connecting section, 5b. Secondary
 connecting section, 5as. Inclined face, 5bs. Inclined face, 6. Spring
 section, 7. Controlling knob section, S. Substrate socket, B. Substrate,
 Bh. Recessed connecting section, Bs. End side section, Mc. Locked state,
 and Mr. Released state.