An insert-and-twist building block structure includes a connection bar and a connection terminal unit. The connection bar has an end from which a combination projection section extends and has a conic shape. The combination projection section has an external circumferential surface formed with a bead ring including multiple raised beads intermittently arranged in a ring configuration. The connection terminal unit includes a connection terminal having an end inward recessed to form a combination cavity in a conic shape. The combination cavity has an internal circumferential surface formed with a groove ring including multiple recessed grooves intermittently arranged in a ring configuration. The recessed grooves each a middle portion forming a deep trough section and two ends each forming a shallow trough section, and a depth is decreased from the deep trough section toward the shallow trough sections.

A fastener structure includes a head portion, rod member and fitting member. The head portion has a lateral holding portion and vertical receiving portion. The rod member has a lateral attaching portion and engaging member. The rod member is penetratingly disposed at the receiving portion to allow the attaching portion to correspond in position to the holding portion. The fitting member is penetratingly disposed at the attaching portion and the holding portion to fit the head portion and the rod member together. To couple two objects together, the head portion drives an engaging portion of the rod member, such that the engaging portion penetrates one object before being fastened to the other object. To unfasten the objects, the head portion is moved reversely to remove the engaging portion from the other object, effecting separation of the objects, so as to achieve quick coupling and easy unfastening.

A fastener structure includes a head portion, rod member and fitting member. The head portion has a lateral holding portion and vertical receiving portion. The rod member has a lateral attaching portion and engaging member. The rod member is penetratingly disposed at the receiving portion to allow the attaching portion to correspond in position to the holding portion. The fitting member is penetratingly disposed at the attaching portion and the holding portion to fit the head portion and the rod member together. To couple two objects together, the head portion drives an engaging portion of the rod member, such that the engaging portion penetrates one object before being fastened to the other object. To unfasten the objects, the head portion is moved reversely to remove the engaging portion from the other object, effecting separation of the objects, so as to achieve quick coupling and easy unfastening.

A device for securing a first unit to a second unit includes a first component having a body and a head. The body is configured to be inserted in at least one of a first orifice of the first unit and a second orifice of the second unit. The first component includes a retainer at a lower longitudinal end of the body. A second component is configured to couple to the first component. At least one of the first and second components includes at least one cam surface and the other of the first and second components includes at least one follower configured to cooperate with the at least one cam surface, and to transform a rotational movement of the first component into a longitudinal translation movement of the first component in relation to the second component so that the retainer bears on the lower surface of the second unit.

A device for securing a first unit to a second unit includes a first component having a body and a head. The body is configured to be inserted in at least one of a first orifice of the first unit and a second orifice of the second unit. The first component includes a retainer at a lower longitudinal end of the body. A second component is configured to couple to the first component. At least one of the first and second components includes at least one cam surface and the other of the first and second components includes at least one follower configured to cooperate with the at least one cam surface, and to transform a rotational movement of the first component into a longitudinal translation movement of the first component in relation to the second component so that the retainer bears on the lower surface of the second unit.

A connecting device may be provided comprising a positive connecting element and a negative connecting element, wherein the positive connecting element has an elevation arranged on a base surface and the negative connecting element has a depression introduced into a contact surface, into which the elevation of the positive connecting element can be introduced, wherein the positive and the negative connecting element may be connected to one another by rotation relative to one another.

A fastening bracket is provided. The fastening bracket is adapted to be affixed to a mounting surface and connected to an object. The fastening bracket includes a base and a connection unit. The base is for being affixed to the mounting surface. The connection unit is connected to the base, wherein the connection unit includes a unit inclined surface and at least one unit abutting portion. The object includes at least one object abutting portion. When the object is in a separated state, the object abutting portion is separated from the unit abutting portion, and when the object is in a connected state, the object abutting portion abuts the unit abutting portion. While the object is being moved from the separated state to the connected state, the object abuts the unit inclined surface and slides relative to the unit inclined surface.

A fastening bracket is provided. The fastening bracket is adapted to be affixed to a mounting surface and connected to an object. The fastening bracket includes a base and a connection unit. The base is for being affixed to the mounting surface. The connection unit is connected to the base, wherein the connection unit includes a unit inclined surface and at least one unit abutting portion. The object includes at least one object abutting portion. When the object is in a separated state, the object abutting portion is separated from the unit abutting portion, and when the object is in a connected state, the object abutting portion abuts the unit abutting portion. While the object is being moved from the separated state to the connected state, the object abuts the unit inclined surface and slides relative to the unit inclined surface.

A fastener-less valve cover plate assembly that can be used to enclose a pressure chamber, such as a valve chamber of a relay valve. Installation of the components of the fastener-less valve cover plate assembly is simplified as compared to prior art cover plates utilizing fasteners, while still providing suitable performance. In addition, the fastener-less valve cover plate assembly is not readily disassembled with common tools thereby discouraging tampering.

Provided is a lock, comprising a locking module and a driving module, wherein the locking module comprises a latch mounted on a first main body, a oblique pin ring gear mounted on a second main body and adapted to the latch; the radial thickness of the oblique pin ring gear changes continuously; a first slot is arranged on the latch, and wherein the driving module is used for driving the oblique pin ring gear to move in a circular motion, such that on the latch in a closed position the oblique pin ring gear clips to or separates from the first slot. The lock mechanism can realize inward or outward arcuate connection and planar connecting without finishing.