Apparatus for cooling and retarding an increase in the temperature of a liquid contained in a vessel. The apparatus includes a base for substantially occupying the lower interior of liquid containing vessel and a cooling body for upward projection from the base so that when the base is placed in the vessel the cooling body projects upwardly therefrom for submersion in the liquid. The cooling body comprises a sealed container substantially filled with a slow-to-freeze, slow-to-thaw gelatinous mat...

The invention concerns a maintaining, positioning or clamping device comprising at least a housing (18) containing a moving element (17) mobile in translation by the action of actuating means including an electric motor (11). The device comprises means for controlling and powering the electric motor (11), arranged to avoid powering the electric motor in a jamming position with risk of overheating and damaging the electric motor (11). The device is particularly useful for maintaining, positioning...

Optical isolators for use in fiber optic networks utilizing a birefringent wedge set with a Faraday rotator disposed between the birefringent wedges. In a first embodiment a polarization maintaining optical isolator is disclosed which will maintain the polarization of the light which passes through it in a forward direction and block light in the reverse direction. In a second embodiment a single polarization optical isolator is disclosed which will pass only a single linear polarization of the ...

An apparatus for maintaining hair in a braid is describe which includes of an elongate body having a top surface, a first end and a second end. A comb is transversely positioned at the first end. A plurality of pegs extend upwardly from the top surface of the body. The pegs are spaced at intervals between the first end and the second end to define a plurality of hair receiving spaces. Strands of hair are interwoven by being laid in a zig-zag fashion into the spaces between the pegs. The interwov...

A tool for connection in a wellbore drill string for maintaining penetration of a drilling bit attached to the drill string when the drill string becomes stuck or hung up during drilling operations. The tool has a telescoping outer member and inner member which form an annular chamber between them which contains a plurality of springs that are selected to provide a desired amount of contraction of the tool when a predetermined axial compressive load is applied through the tool to the drilling bi...

In an apparatus for making plastic bags or the like from a continuous film of material comprising a sealing drum having at least one seal bar for imparting transverse seals to the film at regularly spaced intervals and a perforator having a rotatable perforator blade for imparting transverse perforations to the film at regularly spaced intervals, the film comprising print marks appearing thereon at regularly spaced intervals, an apparatus and method are disclosed for tracking the positions of ea...

A slip joint connects coaxially oriented tubular members in a manner to allow axial slippage while maintaining concentricity without generating large axial loads. The joint comprises a first tubular member having a smaller outside diameter than an inside diameter of a second member whereby the first member is slidable into the second member. A pair of spaced lands circumscribe the first member and define a groove therebetween. The slip joint has a seal ring position in the groove. The lands have...

In an apparatus for making plastic bags or the like from a continuous film of material comprising a sealing drum having at least one seal bar for imparting transverse seals to the film at regularly spaced intervals and a perforator having a rotatable perforator blade for imparting transverse perforations to the film at regularly spaced intervals, the film comprising print marks appearing thereon at regularly spaced intervals, an apparatus and method are disclosed for tracking the positions of ea...

A waking degree maintaining apparatus of this invention estimates a waking degree of a person on the basis of a correlation between brain waves and the reaction time or between the blinking frequency and the reaction time, and discriminates a drop in waking degree on the basis of the obtained waking degree. A stimulus according to the waking degree is presented to maintain the person in a waking state of a predetermined level. The waking degree of a person is recovered to a normal state, not onl...

A method and apparatus for maintaining consistency in databases among data processors of a computer network involves an improved epidemic protocol involving the generation of database version vectors for database replicas. Overhead of the protocol grows linearly with the number of data items being copied during an update propagation, not with the number of data items as in typical epidemic protocols. Since this number is less than the total number of data items in the database, the present proto...