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A locking device for a compact computer or a small computer, in particular, a personal data accessory or a palm data accessory (hereinafter referred to as PDA), is presented. The invention also includes a blocking device which is connected with the locking mechanism and is convertible between an unl

A locking device for a compact computer or a small computer, in particular, a personal data accessory or a palm data accessory (hereinafter referred to as PDA), is presented. The invention also includes a blocking device which is connected with the locking mechanism and is convertible between an unlocking position and a locking position, the blocking device is adapted to be locked and secured by the locking mechanism. The blocking device is adapted to be set to the locking position and resist against the incline surface of the stand so as to lock and secure the PDA with the stand.

대표청구항 ▼

A locking device for a compact computer or a small computer, in particular, a personal data accessory or a palm data accessory (hereinafter referred to as PDA), is presented. The invention also includes a blocking device which is connected with the locking mechanism and is convertible between an unl

A locking device for a compact computer or a small computer, in particular, a personal data accessory or a palm data accessory (hereinafter referred to as PDA), is presented. The invention also includes a blocking device which is connected with the locking mechanism and is convertible between an unlocking position and a locking position, the blocking device is adapted to be locked and secured by the locking mechanism. The blocking device is adapted to be set to the locking position and resist against the incline surface of the stand so as to lock and secure the PDA with the stand. orking cylinder; a switching valve for controlling supply and discharge of a hydraulic fluid with respect to a head-side port and a rod-side port of said working cylinder; a first pilot check valve which is disposed in a rod-side supply and discharge circuit for connecting said rod-side port of said working cylinder to said switching valve and whose pilot pressure is a pressure of a head-side supply and discharge circuit for connecting said head-side port of said working cylinder to said switching valve; a check-valve equipped sequence valve which is disposed in a connection circuit for connecting a drive chamber side of said pressure intensifying cylinder to a portion of said rod-side supply and discharge circuit closer to said switching valve than said first pilot check valve, and switches from a closed state to an open state with a rated pressure of a hydraulic pump for supplying said hydraulic fluid to said rod-side supply and discharge circuit via said switching valve; and a second pilot check valve whose pilot pressure is said pressure of said head-side supply and discharge circuit, said working cylinder, said pressure intensifying cylinder, said switching valve, said first pilot check valve, said check-valve equipped sequence valve and said second pilot check valve being connected in series in such a way as to satisfy K>PLb/Pp where K is a pressure intensifying ratio of said pressure intensifying cylinder, Pp is said rated pressure of said hydraulic pump and PLb is a pressure in said rod-side cylinder chamber when a maximum load occurring after Pp is balanced with a load acting on a piston rod of said working cylinder in a piston-rod reversing step of said working cylinder is applied, and ΔV=(PLb-Pp)×Vb×β where ΔV is a maximum discharge volume of said pressure intensifying chamber of said pressure intensifying cylinder, Vb is a volume of said rod-side cylinder chamber when balance is held and β is a compressibility of said hydraulic fluid. 3. A pressure intensifying apparatus for a hydraulic cylinder comprising: a working cylinder; a pressure intensifying cylinder for allowing a pressure intensifying chamber to communicate with a head-side cylinder chamber of said working cylinder; a switching valve for controlling supply and discharge of a hydraulic fluid with respect to a head-side port and a rod-side port of said working cylinder; a pilot check valve which is disposed in a head-side supply and discharge circuit for connecting said head-side port of said working cylinder to said switching valve and whose pilot pressure is a pressure of a rod-side supply and discharge circuit for connecting said rod-side port of said working cylinder to said switching valve; a pressure sensor for detecting a pressure in said head-side cylinder chamber of said working cylinder; and pressure intensification control means for controlling supply and discharge of said hydraulic fluid to and from a drive chamber of said pressure intensifying cylinder using a detection signal from said pressure sensor in a piston-rod advancing step of said working cylinder, wherein K>PLa/Pp is satisfied where K is a pressure intensifying ratio of said pressure intensifying cylinder, Pp is a rated pressure of a hydraulic pump and PLa is a pressure in said head-side cylinder chamber when a maximum load occurring after Pp is balanced with a load acting on a piston rod of said working cylinder in a piston-rod advancing step of said working cylinder is applied, and ΔV≥(PLa-Pp)×Va×β where ΔV is a maximum discharge volume of said pressure intensifying chamber of said pressure intensifying cylinder, Va is a volume of said head-side cylinder chamber when balance is held and β is a compressibility of said hydraulic fluid, and said pressure intensification control means supplies said hydraulic fluid to said drive chamber of said pressure intensifying cylinder when Sr>Ss≥Sp where Ss is a level of said detection signal from said pressure senso r, Sp is a level of an output signal corresponding to Pp and Sr is a level of an output signal corresponding to PLa, and discharges said hydraulic fluid from said drive chamber of said pressure intensifying cylinder when Ss>Sr. 4. A pressure intensifying apparatus for a hydraulic cylinder comprising: a working cylinder; a pressure intensifying cylinder for allowing a pressure intensifying chamber to communicate with a rod-side cylinder chamber of said working cylinder; a switching valve for controlling supply and discharge of a hydraulic fluid with respect to a head-side port and a rod-side port of said working cylinder; a pilot check valve which is disposed in a rod-side supply and discharge circuit for connecting said rod-side port of said working cylinder to said switching valve and whose pilot pressure is a pressure of a head-side supply and discharge circuit for connecting said head-side port of said working cylinder to said switching valve; a pressure sensor for detecting a pressure in said rod-side cylinder chamber of said working cylinder; and pressure intensification control means for controlling supply and discharge of said hydraulic fluid to and from a drive chamber of said pressure intensifying cylinder using a detection signal from said pressure sensor in a piston-rod reversing step of said working cylinder, wherein K>PLb/Pp is satisfied where K is a pressure intensifying ratio of said pressure intensifying cylinder, Pp is a rated pressure of a hydraulic pump and PLb is a pressure in said rod-side cylinder chamber when a maximum load occurring after Pp is balanced with a load acting on a piston rod of said working cylinder in a piston-rod reversing step of said working cylinder is applied, and ΔV>(PLb-Pp)×Vb×β where ΔV is a maximum discharge volume of said pressure intensifying chamber of said pressure intensifying cylinder, Vb is a volume of said rod-side cylinder chamber when balance is held and β is a compressibility of said hydraulic fluid, and said pressure intensification control means supplies said hydraulic fluid to said drive chamber of said pressure intensifying cylinder when Sr>Ss≥Sp where Ss is a level of said detection signal from said pressure sensor, Sp is a level of an output signal corresponding to Pp and Sr is a level of an output signal corresponding to PLb, and discharges said hydraulic fluid from said drive chamber of said pressure intensifying cylinder when Ss>Sr. 5. A pressure intensifying apparatus for a hydraulic cylinder comprising: a working cylinder; a pressure intensifying cylinder for allowing a pressure intensifying chamber to communicate with a head-side cylinder chamber of said working cylinder; a switching valve for controlling supply and discharge of a hydraulic fluid with respect to a head-side port and a rod-side port of said working cylinder; a pilot check valve which is disposed in a head-side supply and discharge circuit for connecting said head-side port of said working cylinder to said switching valve and whose pilot pressure is a pressure of a rod-side supply and discharge circuit for connecting said rod-side port of said working cylinder to said switching valve; position detection means for detecting when a piston rod of said working cylinder reaches a known position of said piston rod where a rated pressure of a hydraulic pump is balanced with a load acting on said piston rod of said working cylinder in a piston-rod advancing step of said working cylinder; and pressure intensification control means for starting supplying said hydraulic fluid to a drive chamber of said pressure intensifying cylinder based on a detection signal from said position detection means in said piston-rod advancing step of said working cylinder, wherein K>PLa/Pp is satisfied where K is a pressure intensifying ratio of said pressure intensifying cylinder, Pp is said rated pressure of said hydraulic pump and PLa is a pressure in said head-side cylinder chamber when a max