Abstract: A crossbow includes a barrel, a fixing member and a limb. The barrel includes a recess defined between the first and second ends of the barrel. The fixing member is engaged with the recess. A pin extends through the barrel and the fixing member to restrict the fixing member from disengaging from the recess. The pin includes a head and a shank which has a groove, a first notch and a second notch. The groove is located between the first and second notches. A positioning unit positions the pin to the barrel. A string is connected between two ends of the limb. The fixing member is able to quickly engaged with or disengaged from the recess of the barrel to quickly assemble or dis-assemble the limb relative to the barrel.

Abstract: A crossbow includes a body and an activator. The body has a shooting device, a first safety device and a string connected thereto. The shooting device has a trigger. The activator is located at the rear end of the body and has an extension. A second safety device is located between the extension and the body, and includes a rod and contact member. When the activator is operated, the activator is removed from the rod which pivots the contact member, and the contact member contacts the first safety device to restrict the trigger from being pulled. When the activator is not operated and positioned at the body, the rod is pushed by the activator and pivots the contact member, and the first safety device is released so that the trigger can be pulled.

Abstract: A spanning device of a crossbow includes a barrel, an action unit and an spanning unit. A space is defined in the barrel. A limb is connected close to the front end of the barrel. A string is connected between two ends of the limb. The action unit slidably located in the space and has a portion exposed from the space. The action unit has a slide, a restriction member, a safety member, a hook member and a trigger. The restriction member, the safety member, the hook member and the trigger are connected to the slide which is slidably engaged with the space. The spanning unit has a pull rod, a pivotal rod and a first link. The spanning unit drives the action unit to move in the space, so that when the hook member hooks the string, the string is easily pulled with less effort.

Abstract: A compound bow structure includes a riser having a grip and a recess is defined in the inside of the grip. A first cam and a second cam are respectively connected to the two limbs and a string is connected between the first and second cams. Two cables each have a first end connected to the first/second cam corresponding thereto. The two cables each have a second end which has two split sub-cables. The sub-cables of the two cables are respectively connected to two sides of the first/second cam corresponding thereto. A protector is connected to the inside of the grip and located to cover the recess of the grip. The string bounces toward the protector along a plane that passes through the rear side of the protector. A gap is formed between the grip and the protector to accommodate the user's hand.

Abstract: A compound bow structure includes a riser having a grip and a recess is defined in the inside of the grip. A first cam and a second cam are respectively connected to the two limbs and a string is connected between the first and second cams. Two cables each have a first end connected to the first/second cam corresponding thereto. The two cables each have a second end which has two split sub-cables. The sub-cables of the two cables are respectively connected to two sides of the first/second cam corresponding thereto. A protector is connected to the inside of the grip and located to cover the recess of the grip. A gap is formed between the grip and the protector to accommodate the user's hand. The distance between the lowest point of the recess and the string is smaller than ? of the length of the string.

Abstract: A quick-release device for a crossbow stock assembly includes a main body having a fixing member which is threadedly connected to the extension of the stock. An axial groove is defined in the outside of the threaded section of the extension. A locking member is pivotably connected to the fixing member and positioned between a locked position and a release position. The locking member has an engaging end and a press end. The engaging end is engaged with the axial groove when the locking member is located at the locked position, and the engaging end is separated from the axial groove when the locking member is located at the release position. A collar is threadedly connected to the threaded section to keep the locking member at the locked position. The stock is quickly installed to or removed from the main body of the crossbow.

Abstract: A quick-release device for a crossbow stock assembly includes a main body having a fixing member which is threadedly connected to the extension of the stock. An axial groove is defined in the outside of the threaded section of the extension. A locking member is pivotably connected to the fixing member and positioned between a locked position and a release position. The locking member has an engaging end and a press end. The engaging end is engaged with the axial groove when the locking member is located at the locked position, and the engaging end is separated from the axial groove when the locking member is located at the release position. A collar is threadedly connected to the threaded section to keep the locking member at the locked position. The stock is quickly installed to or removed from the main body of the crossbow.

Abstract: A computerized interactive learning system includes a display device and a compatible input device. The display device provides work items to a learner. The input device detects input activities from the learner in response to the work item. The system analyzes the input activities at two or more tiered levels of granularity. The display device provides conditional feedback to the learner based on the analysis. The input device and the display device can be incorporated into an integrated touchscreen.

Abstract: A riser of a compound bow includes a lower section and an upper section. The upper section has an end section and a connection section which is connected to the lower section by engagement of pins and pin holes of the two respective connection ends. The connection is further reinforced by way of welding. The end section is further connected with the connection section by engagement of pins and pin holes of the two respective connection ends. The connection is further reinforced by way of welding. The riser is strong and saves material.

Abstract: A riser of a compound bow includes a lower section and an upper section. The upper section has an end section and a connection section which is connected to the lower section by engagement of pins and pin holes of the two respective connection ends. The connection is further reinforced by way of welding. The end section is further connected with the connection section by engagement of pins and pin holes of the two respective connection ends. The connection is further reinforced by way of welding. The riser is strong and saves material.

Abstract: Method implementing a generic computer human input device using key event signal coding compliant to the standard protocols so as to expand its application range without losing plug-and-play property. Applications of the present invention include audience response, gaming, legacy system support and cross-platform system integration, for example.

Abstract: System integrating one or more touchscreen devices into a general-purpose non-session based computing system for greater usability and productivity is provided. Methods for operating such system are also provided. A handheld multi-mode input device supporting the methods and the system to achieve the objects is also provided.

Abstract: An improved ink cartridge structure comprises a cartridge body, and a first panel and a second panel disposed to two sides of the cartridge body to seal the cartridge body. An ink throttle layer is disposed in the cartridge body. A containing tank is formed at a side of the ink throttle layer. An ink supply passage having bend channels is disposed to another side of the ink throttle layer. An ink inlet is disposed to an end of the ink supply passage. The ink inlet has two air holes that communicate with the containing tank. Another end of the ink supply passage is engaged with a filter port. The filter port is engaged with an ink outlet storing chamber. The ink outlet storing chamber is connected to an ink outlet. With the ink supply passage and the two air holes, pressure can be reduced, and ink flow can be regulated.

Abstract: A pivot cover can incorporate with an ink cartridge to close an ink refill opening of the ink cartridge. The pivot cover has a cover body having a leaning portion, and a push member is extended from an end of the cover body while a fastening member is extended from another end of the cover body. The fastening member has a pivot hole. A pushing portion is disposed to an upper end of the push member while an embedding portion is disposed to a lower end of the push member, and the embedding portion protrudes the leaning portion. While pushing the pushing portion, the push member takes the pivot hole as an axle core to allow the pivot cover to rotably perform opening and closing motion so that the embedding portion can be positioned to allow the leaning portion to close the ink refill opening of the ink cartridge.

Abstract: A method makes it possible to establish PTT connections among mobile communication devices that belong to different service groups of different servers. The mobile communication devices are capable of directly transmitting signals and data to each other in a peer-to-peer manner according to session initiation protocol (SIP). The permission to speak is transferred among the mobile communication devices by transmitting specific signals according to predetermined paths of signal delivery.

Abstract: A laser gun for recreation has a body, a laser device, an air start system and a firing device. The body has a barrel with a bottom and a handle is formed at the bottom. The laser device is mounted in the body and has a laser generator that produces and emits a laser beam through a muzzle of the barrel when a laser switch is closed. The air start system provides the compressed air to switch the laser switch on when a trigger of the firing device is squeezed. The compressed air escaping through exhaust holes generates a gunshot like sound and a movement to the laser gun when the laser gun is fired to simulate a real gun.

Abstract: An audio-visual system includes a signal source, a distributor, a control box, a control panel, and a sound reproducing unit. The signal source provides at least an audio source signal. The distributor includes a pre-amplifier coupled electrically to the signal source for amplifying the audio source signal therefrom, and an impedance matching circuit coupled electrically to the pre-amplifier for matching load impedance associated with an amplified audio source signal from the pre-amplifier to that of the signal source. The control box is coupled electrically to the distributor for processing and amplifying an impedance-matched signal received therefrom. The control panel is coupled electrically to the control box for receiving output of the control box. The sound reproducing unit is coupled electrically to the control panel for audio reproduction.