Abstract: A book holder includes a bracket rotatably and adjustably secured to a base with one or more fasteners and/or with a serrated surface or a number of teeth. A casing includes a pedestal secured to the bracket, to allow the casing to be adjustably secured to the base at selected angular position by the bracket, and to support documents at the selected angular position relative to the base and to the readers. The base may include one or more weights to increase a stability of the base. The casing includes two end fences each having a number of apertures to rotatably receive pins of plates, and to rotatably secure the plates to the casing.

Abstract: A clamping device includes two jaws each having a hinge end pivotally secured together with a pivot shaft. One of the jaws includes a distal attachment end having a number of teeth, and the other jaw includes a distal attachment end having a pivotal pawl which has a catch biased to engage with either of the teeth of the jaw, and to detachably or openably secure the attachment ends of the jaws together. A spring may bias the catch of the pawl to engage with either of the teeth. A housing may further be secured to the jaw to shield the teeth or the pawl, and to prevent the pawl from being disengaged from the teeth inadvertently.

Abstract: A manually operated corner cutter includes a base, a support and guide device, a blade post, multiple cutting tools, a press and control handle, and a press plate. The support and guide device includes an upright support post and a slide seat each secured on the base. Thus, the manually operated corner cutter may be operated easily, rapidly and conveniently. In addition, the cutting tool may be replaced easily and conveniently, thereby facilitating replacement of the cutting tool.

Abstract: A number lock device, comprising a lock housing, a lock core, a cable, a cover, a movable member, a driving member, a locking plate, and a locking pin. Thus, the number lock device can be operated by the user's one hand only, thereby facilitating the user operating the number lock device. In addition, the correct numbers of the number rings of the lock core of the number lock device can be changed easily and conveniently.

Abstract: A manually operated corner cutter includes a base, a support and guide device, a blade post, multiple cutting tools, a press and control handle, and a press plate. The support and guide device includes an upright support post and a slide seat each secured on the base. Thus, the manually operated corner cutter may be operated easily, rapidly and conveniently. In addition, the cutting tool may be replaced easily and conveniently, thereby facilitating replacement of the cutting tool.

Abstract: A quick holder includes a bottom housing, a cover, two clamping members, and a tensile spring. The tensile spring is urged between the retaining posts of the two clamping members conveniently, so that the two opposite clamping members may be used to clamp the paper by a single tensile spring, thereby simplifying the whole structure, and thereby decreasing the difficulty of assembly.

Abstract: A security device is provided wherein spindle is engaged with a lock pin and the spindle is engaged with an abutment plate such that a locking/unlocking of the security device is effected by simply using one hand to rotate the spindle to cause the lock pin to rotate together. This device can inhibit the theft of small but expensive pieces such as a computer or the like.

Abstract: A rack includes a front and lower horizontal board, and a rear and upper vertical panel, and two or more plates coupled between the horizontal board and the vertical panel. The books, the documents or the files received in the rack may be engaged with the horizontal board to force and support the rack in the erect working position. Two or more racks may be stacked together to form a compact packing or packaging configuration for storing and transportation purposes. A stand is engaged with the rack for supporting the rack in the erect working position.

Abstract: A pencil sharpener includes a casing secured in a housing and having a groove for receiving a pencil to be sharpened and having a cutter blade for sharpening the pencil. A device has a slide slidably received in the housing and has an extension extended from a resilient arm and engaged into the groove of the casing for determining the engagement of the pencil into the groove of the casing and for controlling the sharpening operation of the pencil. The slide may be adjusted relative to the housing for adjusting the engagement of the extension into the casing.

Abstract: A rack includes a front and lower horizontal board, and a rear and upper vertical panel, and two or more plates coupled between the horizontal board and the vertical panel. The books, the documents or the files received in the rack may be engaged with the horizontal board to force and support the rack in the erect working position. Two or more racks may be stacked together to form a compact packing or packaging configuration for storing and transportation purposes. A stand is engaged with the rack for supporting the rack in the erect working position.