Ribbon hub and spool assembly
A ribbon hub and spool assembly includes a hub having at least two cantilever beams having a smooth, tapered, and curved crown, and a spool having curved and tapered splines. The cantilever beams balance the forces when inserting the hub into the spool, and the shape of the crowns of the hub and splines of the spool enable easy insertion and alignment of the hub and spool assembly.
1 . A ribbon hub and spool assembly, comprising:
a hub, comprising:
a cylindrical body having at least two recessed portions;
at least two flexible beams, each beam having a first end attached to a bottom portion of the cylindrical body and a second end attached to a curved and tapered crown, wherein the beams are radially movable within the recessed portions; and
a top portion; and
a ribbon spool, comprising:
opposing flat discs;
a cylindrical ring connecting the two flat discs, wherein the cylindrical ring has an inner surface and an outer surface; and
a plurality of splines along the inner surface of the ring, wherein the splines have at least one curved and tapered end.
2 . The assembly of claim 1 , wherein the hub further comprises a plurality of splines having curved ends extending toward the top portion.
3 . The assembly of claim 1 , wherein the crown has a narrow tip tapering laterally and radially outward, a guide portion having a width corresponding to a portion between the splines of the spool, and a center ridge extending from the narrow tip to the guide portion.
4 . The assembly of claim 1 , wherein at least one of the beams has a guide portion below the crown and extending outward, wherein the guide portion has a width corresponding to a portion between the splines of the spool.
5 . The assembly of claim 1 , wherein the hub further comprises a bottom portion have a ledge with a larger circumference than the cylindrical body.
6 . The assembly of claim 1 , wherein the spool further comprises an angled annular surface connecting the cylindrical ring with the flat disc.
7 . The assembly of claim 1 , wherein the flexible beams oppose each other.
8 . The assembly of claim 1 , wherein the top portion has a circumference smaller than the cylindrical body and an angled surface tapering toward the outer circumference of the cylindrical body.
9 . A hub and spool assembly for a ribbon printing system, comprising:
a hub having at least one spline with a curved end, at least two movable beams parallel to the spline, and a smoothly curved and tapered crown at the end of each beam; and
a spool having a plurality of curved and tapered splines along an interior portion of the spool, wherein the spline and crowns of the hub fit between the splines of the spool during an assembly of the hub and spool and when the hub and spool are fully assembled.
10 . The assembly of claim 9 , wherein the spool further comprises an angled annular surface between the curved and tapered portion of the splines and one of two planar surfaces of the spool.
11 . The assembly of claim 9 , wherein the hub further comprises an annular surface angled inward from the curved end of the spline to a top surface of the hub.
12 . The assembly of claim 9 , wherein at least one of the beams comprises a guide portion extending outward from the beam.
13 . The assembly of claim 9 , wherein at least one of the crowns comprises a guide portion extending from a bottom portion of the crown.
14 . The assembly of claim 9 , wherein the hub further comprises a bottom ledge extending beyond the at least one spline.
15 . The assembly of claim 9 , wherein the beams are connected to a bottom portion of the hub.
16 . The assembly of claim 9 , wherein the crowns extend above a top surface of the hub.