1. A screw having a driving recess in a top face of its head, the recess comprising at least two recess-lobes evenly spaced around a longitudinal axis of the screw, and driving flanges joining adjacent lobes, wherein each flange in transverse section is an arc convex with respect to the longitudinal axis, has sides which are parallel said longitudinal axis and has a tangent which is radial with respect to said longitudinal axis, the floor of said recess-lobes being inwardly inclined from their junctions with said top face towards said longitudinal axis.
2. A screw as claimed in claim 1, in which said arc is substantially circular.
3. A screw as claimed in claim 2, in which the radius of each arc is between 60 and 80% of the radius of the lobes.
4. A screw as claimed in claim 3, in which the radius of each arc is between 66% and 68% of the radius of the lobes.
5. A screw as claimed in claim 1, in which said tangent is radial at a distance from where the arc meets each lobe.
6. A screw as claimed in claim 1, in which the lobes are part-circular in section at their junctions with said top face, centred on the longitudinal axis.
7. A screw as claimed in claim 1, in which the centre of each arc is on a circle that is centred on the longitudinal axis, the radius of which circle is the same as or greater than the radius of the lobes.
8. A screw as claimed in claim 1, in which there are three of said recess-lobes.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A disc player comprising:
a chassis;
a rotary tray mountable a plurality of discs arranged in a circumferential direction thereon;
a slide base supported on said chassis for supporting said rotary tray;
a rotary tray driving mechanism for rotating said rotary tray on said slide base;
a slide base driving mechanism for moving said slide base back and forth on said chassis between a disc exchanging position where the slide base is projected ahead of the chassis and a disc storing position where the slide base is substantially overlapped with the chassis; and
a player disposed backward within said chassis,
wherein said rotary tray driving mechanism includes a driving source provided on said slide base, and wiring for supplying an electric power and control signals to said driving source, and
wherein said wiring is connected to said driving source at one end thereof, and to said chassis at the other end, which is bent at a position ahead of the one end and the other end of said wiring when said slide base is positioned at the disc storing positoin.
2. The disc player according to claim 1, wherein the one and the other end of said wiring is connected to said driving source and said chassis, respectively, ahead of said player.
3. The disc player according to claim 1, said chassis is provided with a holding hook for preventing said wiring from separating from said chassis.
4. The disc player according to claim 1, wherein said driving source is positioned on said slide base in such a manner that a connecting portion between said driving source and said wiring remains within a casing of the disc player even when said slide base is moved to the disc exchanging position.
5. The disc player according to claim 1, further comprising:
a float base supported on said chassis; and
a bending piece mounted on said float base for folding said wiring at a given location in advance so as to allow said wiring to be accommodated at a predetermined position where a direction of the wiring is altered.
6. The disc player according to claim 5, wherein said bending piece comprises a lateral piece and a longitudinal piece, which are respectively formed with a certain clearance between themselves and an underside of said float base, and both outward ends of which are used for folding the wiring.
7. A disc player comprising:
a chassis;
a rotary tray mountable a plurality of discs arranged in a circumferential direction thereon;
a slide base supported on said chassis for supporting said rotary tray;
a rotary tray driving mechanism for rotating said rotary tray on said slide base;
a slide base driving mechanism for moving said slide base back and forth on said chassis between a disc exchanging position where the slide base is projected ahead of the chassis and a disc storing position where the slide base is substantially overlapped with the chassis;
a player disposed backward within said chassis;
a guide rail formed on each right and left side of said chassis in a moving direction of said slide base; and
a first guide piece and a second guide piece provided on each side of an underside of said slide base, said each side having the same width as that of guide rails, extending laterally, so as to allow said slide base to be slid along said guide rail,
wherein said first and second guide pieces are positioned upper than said guide rail so as to prevent said slide base from being lifted up during its back and forth movement.
8. The disc player according to claims 7, wherein said each guide rail has a recess for inserting said second guide piece so that said slide base can be slid along said guide rail of said chassis after inserting said second guide piece into the recess so as to assemble said slide base with said chassis.
9. The disc player according to claim 7, wherein said second guide piece has a lateral length shorter than that of said first guide piece so as to be easily inserted into said guide rail through said recess on the guide rail.
10. The disc player according to claim 7, further comprising:
a front end wall of said slide base having engagement holes,
wherein said each engagement hole is engaged with respective front distal ends of said guide rails to receive it when said slide base exists in the disc storing position, so that said slide base can be prevented from being lifted.