A releasable hold-down device is provided for use in a dockleveller wherein dock-raising springs are used to raise the dockboard. The hold-down device comprises a hydraulic cylinder assembly having the piston connected to the dockboard and the cylinder connected to the dockleveller frame. The cylinder assembly must thus expand and contract to permit the dockboard to be raised by the spring and lowered by the weight of a man standing on the dockboard. The cylinder assembly has fluid-filled stem a...

A sample and hold (S/H) circuit that produces an output signal having essentially zero offset voltage error is disclosed. The S/H circuit includes a pair of operational amplifiers (OA3 and OA4) that are connected in circuit during both the sample and the hold modes of operation. In the sample mode of operation one of the operational amplifiers (OA3) receives the incoming signal through a first resistor (R1) and in accordance therewith controls the magnitude of an inverted voltage stored on a sto...

There is disclosed a line circuit for establishing a hold condition on a communication line, extending between a switching machine and a key telephone station, during an open switching interval (OSI) when no current flows on the communication line. The control signal required to enable the hold circuit is arranged to be time dependent. For a fixed time interval, which bridges the OSI period, after the telephone station answers a ringing line a hold condition is enabled (402) exclusively by a con...

A single master unit hold circuit which can be utilized for a single or a group of telephone instruments connected to a common telephone line. A single latching circuit is coupled to the telephone line. The establishment of the hold condition may be affected in the off-hook state of the telephone instrument. Each of the telephones of the group has associated signaling capability. Each telephone can generate an actuating signal directly onto the telephone line, which is then detected by the latch...

A hold-in type of automotive relay which when actuated by a first switch controlled exciting current closes its normally open relay contacts and a second switch magnetically connected to said relay and the source of current. The contacts of the second switch remain closed even after the first switch is opened and until such time as the current passing through the second switch is interrupted.

A door hold-open mechanism including a door hinge member and a body bracket member pivotally interconnected by a hinge pin, a hinge sector secured to the hinge member and having at least four door stop detent slots or pockets formed therein, a directional cam pivotally mounted on the hinge pin and frictionally connected to the hinge sector and having a pair of seats and an intermediate cam slot formed thereon adjacent the detent slots, a torque-rod mounted on the bracket member, a roller mounted...

A releasable fastening for the ring portion of a tape tab to the body portion of the tab. The tab is a laminate of plastic and metal and is folded along its longitudinal edge to form a hem which not only increases the tensile strength of the tab and prevents tearing but, also, inverts the plastic, which is normally on the bottom of the tab, along opposite edges to provide plastic strips extending lengthwise of the tab. The ring portion is also hemmed and, in being folded onto the body portion, d...

A device is provided for holding and releasing a missile within a canister. The device includes a housing attached to the canister, a latch mechanism extending from the housing into the canister, a tension applier disposed in the housing to restrain the missile in the canister, a release mechanism disposed on the housing, an interface mechanism and a compression applier. The tension applier forces the latch mechanism against the housing to withdraw from the missile. The interface mechanism initi...

A horizontally rotatable and elevatable hold down arm that is adapted to engage and securely hold material that is being worked on, such as wood that is being sawed. The hold down arm is simply operated and positioned from the operator's position at the saw.

One or more elements in a telecommunications network (10, 10' and 10'') receive a call hold-initiating message when a first party places a second party to the call on hold, and in doing so, triggers a call hold event in the network. In response to the call hold-initiating message, the network element may take one or more actions, including releasing one or more network resources and/or providing a service to the second party during the period the call remains on hold. Upon resumption of the call...