An improved manually operated flip dog mountable ceiling speaker enclosure, for ceiling or other panel installation, has a biased sliding ratchet block that can be latched in place by an extension from a T-handle of an integral actuator rod. The ratchet block is controlled in its sliding motion by alignment rods extending from a vertical portion of a base and slidingly received in alignment bores of the ratchet block. A face of the ratchet block has downward pointing ratchet teeth that engage upward pointing ratchet teeth on a barrel of a flip dog to hold the flip dog in a clamped position. Over time, the biasing springs may lose their strength, but the latching of the ratchet block obviates this problem.

A rotation-adjustable hanging device includes a pivot seat, a hanging arm body and a limiting unit. The hanging arm body includes a pivot end connected pivotally to the pivot seat about a first pivot axis. The limiting unit includes a main body, two limiting arms and two limit ends. The main body is disposed on the pivot seat and defines a second axis. The limiting arms are directed toward the pivot end to extend the limit ends to the arm body such that the limit ends are disposed at two opposite sides of a first line that passes through the first and second pivot axes and such that the limit ends is able to stop rotation of the arm body.

A support structure provides two or more axes of intelligent locomotion for a movable object on the support structure. The support structure can include a track system made up of a plurality of identically configured track modules that are connected end-to-end. Each track module can include an elongated body defining a longitudinal axis and having two ends. Each end can include at least one beveled edge and at least one track surface extending longitudinally along the elongated body. The track modules can be connected to a power source and include electrical contacts that provide electricity to movable objects that travel along the track system.

A rotary joint which, in order to limit the mutual rotation of the outer bearing ring (2) with respect to the inner bearing ring (2), is provided with a raceway (11), which is limited by one or two stops (14) and in which a projection connected to the outer bearing ring engages. In order to ensure that a rotation greater than 360° is possible, the raceway is of helical design.

A projector is attached to an opening provided in an installation surface and projects an image to one side with respect to the installation surface. The projector includes: an exterior panel exposed on the one side; a projection section that projects image light from a projection port formed in the exterior panel to the one side; and a rotation adjustment mechanism and an inclination adjustment mechanism that adjust a posture of the projection section with respect to the installation surface.

An equipment boom and methods of installation are provided. The equipment boom includes a base member and at least one extension slidably received by the base member. A fixing arrangement is also provided which allows for fixing the axial length of the equipment boom.

A support assembly for a fan includes a hanging member, an elongate support member, a resilient interface member, and a fastener member. The hanging member has a support surface and an inner circumferential surface defining a central passage. The elongate support member includes a first end portion and a second end portion, the first end portion extending into the central passage and defining a first fastener aperture and a second fastener aperture. The resilient interface member is interposed between the elongate support member and the central passage, includes a first plurality of outwardly extending ribs configured to engage the inner circumferential surface in the central passage, and defines a third fastener aperture substantially aligned with the first fastener aperture and a fourth fastener aperture substantially aligned with the second fastener aperture. The fastener member extends through the fastener apertures and is supported by the support surface.

A mounting bracket having a base plate with a first set of apertures and a second set of apertures formed therein. A mounting plate couplable with one of the first set of apertures and the second set of apertures formed in the base plate. A bracket housing couplable with the base plate and having an inner surface and an outer surface. A retainer assembly coupled with the base plate and adjacent to and abuttingly engaged with the bracket housing.

Devices for mounting objects on space frame truss or other structural members are provided.

In a dropped ceiling assembly system elements are provided which include an elongate planar shelf held below an elongate spine. The shelf has lateral edges which can support edges of a ceiling tile resting thereon. This spine is configured to be held in position either adjacent to spines of other elements within a dropped ceiling or from above, such as by suspension wires passing through suspension holes in the spine. A compartment is provided on an underside of the shelf which is sized and shaped to receive and hold at least a portion of a loudspeaker therein. The loudspeaker mounting system is thus integrated into the shelf which also acts to hold ceiling tiles within a dropped ceiling.