U.S. patent application number 09/855906 was filed with the patent office on 2001-11-22 for keyed hub and core for ribbon supply.
Invention is credited to Christensen, Christopher R., Clemans, Jimmy L., Colonel, Kenneth, Hitz, Mark A..
Application Number | 20010042810 09/855906 |
Document ID | / |
Family ID | 26899657 |
Filed Date | 2001-11-22 |
United States Patent
Application |
20010042810 |
Kind Code |
A1 |
Christensen, Christopher R. ;
et al. |
November 22, 2001 |
Keyed hub and core for ribbon supply
Abstract
A core/hub assembly for a printing device that provides for easy
alignment and insertion, and maintains a secure interface to
prevent slippage of the core during printer operation, is
disclosed. A hub includes keys mounted at a proximal end which
serve to transmit torque when engaged with a core. The hub further
includes splines configured to be received within a core and
provide longitudinal support thereto. A core includes a plurality
of longitudinally extending ribs that cooperate to form channels
configured to receive the splines of the hub. A portion of the ribs
include compliant radially oriented leaf springs which center the
core on the hub and provide a physical fit of the core on the hub
by engaging the keys at the proximal end of the core when properly
inserted therein.
Inventors: |
Christensen, Christopher R.;
(Orlando, FL) ; Clemans, Jimmy L.; (Leesburgh,
FL) ; Colonel, Kenneth; (Oviedo, FL) ; Hitz,
Mark A.; (Lake Mary, FL) |
Correspondence
Address: |
Pitney Bowes Inc.
Intellectual Property & Technology Law Department
35 Waterview Drive
P.O.Box 3000
Shelton
CT
06484
US
|
Family ID: |
26899657 |
Appl. No.: |
09/855906 |
Filed: |
May 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60204644 |
May 17, 2000 |
|
|
|
Current U.S.
Class: |
242/597.2 ;
242/597.6; 242/611.2 |
Current CPC
Class: |
B65H 75/10 20130101;
B65H 2402/61 20130101; B65H 75/30 20130101; B65H 75/08
20130101 |
Class at
Publication: |
242/597.2 ;
242/597.6; 242/611.2 |
International
Class: |
B65H 018/04; B65H
075/10; B65H 075/30 |
Claims
What is claimed is:
1. A ribbon core and hub assembly comprising: a hub comprising: a
plurality of longitudinal splines, a first portion of said
plurality of splines having a first key, a second portion of said
plurality of splines having a second key; and a core comprising: a
first plurality of longitudinal ribs, said first plurality of ribs
having a respective leaf spring at a first end of said core,
adjacent pairs of said leaf spring and respective ribs forming a
respective channel in said core, wherein when said core is mounted
on said hub, at least one respective leaf spring engages a
respective first key and applies pressure thereto, and at least one
said adjacent pair of said leaf springs receives said second key in
said formed channel, thereby securing said core to said hub.
2. The ribbon core and hub assembly according to claim 1, wherein
said first and second portions of said plurality of splines are
each provided in respective corresponding pairs of splines located
on opposite sides of said hub.
3. The ribbon core and hub assembly according to claim 2, wherein
said hub has a first diameter measured across one of said
corresponding pairs of said first portion of said plurality of
splines, and a second diameter measured across one of said
corresponding pairs of said second portion of said plurality of
splines, said second diameter being greater than said first
diameter.
4. The ribbon core and hub assembly according to claim 1, wherein
said first key is raised from said hub a first height, and said
second key is raised from said hub a second height, said second
height being greater than said first height.
5. The ribbon core and hub assembly according to claim 1, wherein
said plurality of splines includes four splines, said first portion
of said plurality of splines includes a first pair of splines
located on opposite sides of said hub, and said second portion of
said plurality of splines includes a second pair of splines located
on opposite sides of said hub and spaced equidistant from said
first pair of splines.
6. The ribbon and core assembly according to claim 1, wherein a
width of said plurality of splines tapers on an end opposite said
first and second keys.
7. The ribbon core and hub assembly according to claim 1, wherein
said core further comprises: a second plurality of longitudinal
ribs, each of said second plurality of ribs being located in a
respective channel.
8. The ribbon and core assembly according to claim 7, wherein said
second plurality of ribs terminate before reaching said first end
of said core.
9. The ribbon and core assembly according to claim 7, wherein said
first plurality of ribs have a first height, and said second
plurality of ribs have a second height, said first height being
greater than said second height.
10. The ribbon and core assembly according to claim 1, wherein said
first plurality of ribs includes six ribs, each of said six ribs
having a respective leaf spring at said one end of said core.
11. A core adapted to be removably mounted on a hub, said hub
having a plurality of splines, a first key on at least one of said
plurality of splines and a second key on at least another of said
plurality of splines, said core comprising: a first plurality of
longitudinal ribs, said first plurality of ribs having a respective
leaf spring at a first end of said core, adjacent pairs of said
leaf spring and respective ribs forming a respective channel in
said core, wherein when said core is mounted on said hub, at least
one of said respective leaf springs engages said first key and
applies pressure thereto, and at least one adjacent pair of said
leaf springs receives said second key in said formed channel,
thereby securing said core to said hub.
12. The core according to claim 11, further comprising: a second
plurality of longitudinal ribs, each of said second plurality of
ribs being located in a respective channel.
13. The core according to claim 12, wherein said second plurality
of ribs terminate before reaching said first end of said core.
14. The core according to claim 12, wherein said first plurality of
ribs have a first height, and said second plurality of ribs have a
second height, said first height being greater than said second
height.
15. The core according to claim 11, wherein said first plurality of
ribs includes six ribs, each of said six ribs having a respective
leaf spring at said one end of said core.
16. The core according to claim 11, further comprising: an outer
surface adapted to have a ribbon secured thereto, said ribbon being
wound around said outer surface of said core.
17. A hub for mounting a ribbon/core combination, said hub
comprising: a plurality of longitudinal splines, a first portion of
said plurality of splines having a first key, a second portion of
said plurality of splines having a second key, wherein when said
ribbon/core assembly is mounted on said hub, said first key is
adapted to engage a respective leaf spring of said ribbon/core
assembly, said leaf spring applying pressure to said first key, and
said second key is adapted to be received in a channel formed by
adjacent leaf springs of said ribbon/core assembly, thereby
securing said ribbon/core assembly to said hub.
18. The hub according to claim 17, wherein said first and second
portions of said plurality of splines are each provided in
respective corresponding pairs of splines located on opposite sides
of said hub.
19. The hub according to claim 18, wherein said hub has a first
diameter measured across one of said corresponding pairs of said
first portion of said plurality of splines, and a second diameter
measured across one of said corresponding pairs of said second
portion of said plurality of splines, said second diameter being
greater than said first diameter.
20. The hub according to claim 17, wherein said first key is raised
from said hub a first height, and said second key is raised from
said hub a second height, said second height being greater than
said first height.
21. The hub according to claim 17, wherein said plurality of
splines includes four splines, said first portion of said plurality
of splines includes a first pair of splines located on opposite
sides of said hub, and said second portion of said plurality of
splines includes a second pair of splines located on opposite sides
of said hub and spaced equidistant from said first pair of
splines.
22. The hub according to claim 17, wherein a width of said
plurality of splines tapers on an end opposite said first and
second keys.
23. A core and hub assembly, said core adapted to be mounted on
said hub, said core comprising a plurality of ribs, each of said
plurality of ribs having an integral leaf spring at one end of said
core, adjacent leaf springs forming a channel, said hub comprising
a plurality of splines, each of said plurality of splines having a
first or second key, wherein when said core is mounted on said hub,
at least one respective leaf spring engages a respective first key
and applies pressure thereto, and at least one adjacent pair of
said leaf springs receives said second key in said formed channel,
thereby securing said core to said hub.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Application Ser. No. 60/204,644, entitled "Keyed Ribbon Supply,"
filed on May 17, 2000, the specification of which is hereby
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention disclosed herein relates generally to printer
ribbon supply spools, and more particularly to a core and hub
system for securing ribbon supply spools to printers.
[0004] 2. Background of the Invention
[0005] In the field of printer technology, a number of different
methods have been developed for applying ink to paper, cards, or
other print media in a controlled environment. In addition to
standard ink ribbons and hammers as are known in the art, various
other printer technologies have also been developed, such as, for
example, direct thermal and thermal transfer printing. Although the
different printer technologies may differ from each other in
significant ways, the different technologies typically have at
least two things in common: (i) they typically involve a controlled
transfer of the print substance from a substrate onto the print
media, and (ii) the act of printing depletes the print substance so
that the substrate must periodically be replaced. Accordingly,
replaceable ribbons, supply spools, and take-up spools are commonly
used in many different types of printers. The term ribbon, as used
herein, refers to any type of printer technology that employs a
flat, linear material wound around a spool.
[0006] Ribbon/spool combinations are usually sold as a single item.
Spools are also known as cores. Typically, each core is mounted on
a spindle, or hub, for operation, the hub being generally
cylindrical in shape and attached to a motor-operated assembly that
accurately controls the rotation of the core and ribbon. Since the
printer ribbons are required to be replaced, most printers that use
ribbons mounted on cores are designed such that the core containing
the ribbon can be replaced. It is preferable that such replacement
can be completed by a non-technical operator, without the use of
tools and with minimal instruction. Accordingly, the design of the
core/hub assembly must be such that aligning and inserting the core
on the hub and securing the core to the hub are easily performed.
Additionally, the interface between the hub and a mounted core
should be firm enough to keep the core (and associated ribbon
supply) accurately controlled during operation of the printer.
[0007] Thus, there exists a need for a core/hub assembly that
provides for easy alignment and insertion, and provides for a
secure interface to prevent slippage of the core during printer
operation.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to a core/hub assembly
that provides for easy alignment and insertion, and provides for a
secure interface to prevent slippage of the core during printer
operation.
[0009] In accordance with the present invention, a hub includes
keys mounted at a proximal end which serve to transmit torque when
engaged with a core. The hub further includes splines configured to
be received within a core and provide longitudinal support thereto.
A core includes a plurality of longitudinally extending ribs that
cooperate to form channels configured to receive the splines of the
hub. A portion of the ribs include compliant radially oriented leaf
springs at one end which center the core on the hub and provide a
physical fit of the core on the hub by engaging the keys at the
proximal end of the core when properly inserted therein. The
core/hub assembly configuration provides for simple loading of the
core on the hub and maintains a secure interface between the core
and hub to prevent slippage during use.
DESCRIPTION OF THE DRAWINGS
[0010] The above and other objects and advantages of the present
invention will be apparent upon consideration of the following
detailed description, taken in conjunction with accompanying
drawings, in which like reference characters refer to like parts
throughout, and in which:
[0011] FIG. 1 illustrates an overall view of a hub according to the
present invention;
[0012] FIG. 2 illustrates a side view of a hub according to the
present invention;
[0013] FIG. 3A illustrates an overall view of a core according to
the present invention viewed from one end;
[0014] FIG. 3B illustrates an overall view of a core according to
the present invention viewed from the other end;
[0015] FIG. 4 illustrates a cross-section of the core according to
the present invention; and
[0016] FIG. 5 illustrates a cross-sectional view of the core
mounted on the hub according to the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0017] In describing the present invention, reference is made to
the drawings, wherein there is seen in FIG. 1 a hub 10 according to
the present invention and in FIG. 2 a side view of hub 10. Hub 10
includes a plurality of longitudinal splines 12, 14, 16, 18
peripherally spaced on shaft 30. Shaft 30 is cylindrical in shape,
and tapers at the distal end 40 of hub 10. Splines 12, 14, 16, 18
can incorporate a radially inward taper 32 as they approach the
distal end 40, also referred to as the insertion end 40, of hub 10.
Additionally, the thickness of the outer edges 22, 24, 26, 28 of
splines 12, 14, 16, 18 tapers as the splines 12, 14, 16, 18
approach the distal end 40 of shaft 30. Preferably, corresponding
pairs of splines 12, 14, 16, 18 are provided on opposites sides of
shaft 30 spaced at 90 degree intervals. The height of splines 12
and 16, designated as h in FIG. 2, from the shaft 30 is greater
than the height of splines 14 and 18 from the shaft 30. It should
be noted that while four splines 12, 14, 16, 18 are illustrated,
the invention is not so limited and any number of splines may be
provided.
[0018] A spline hub 50 is provided on the proximate end 42 of shaft
30. Spline hub 50 abuts shaft hub 60, which abuts the shaft hub end
62. Shaft hub 60 and shaft hub 62 are configured to attach hub 10
to a drive mechanism (not shown), such as the shaft of a servo
motor of a printing device. Preferably, the mounting is
accomplished by slots and grooves (not shown) in the shaft hub 60
and shaft hub end 62 and the interior of shaft 30. One or more
strengthening ribs 64 may be provided between shaft hub 60 and
shaft hub end 62.
[0019] Each of the splines 12, 14, 16, 18 terminates in a key 52,
54. Preferably, key 52 is provided on the pair of splines on
opposite sides of shaft 30, i.e., splines 12 and 16, while key 54
is provided on the other pair of splines, i.e., splines 14, 18.
Keys 52 may be provided with a shoulder 56. Each of keys 54 is
generally rectangular shaped and raised slightly from the surface
of spline hub 50, abutting against the shaft hub 60 as illustrated.
Each of keys 52 is also generally rectangular shaped with a
tapering end to form shoulder 56 where key 52 meets spline 12, 16.
Each of keys 52 is also raised from the surface of spline hub 50,
with the height of keys 52, designated h1 in FIG. 2, from the
surface of spline hub 50 being greater than the height of keys 54
from the surface of spline hub 50. Preferably, the height of keys
54 is approximately twice that of keys 52. Additionally, the width
of keys 54, designated w in FIG. 1, is preferably greater than the
width of keys 52.
[0020] FIG. 3A illustrates the mounting end 110 one end of a core
100 according to the present invention, while FIG. 3B illustrates
the distal end 130 of core 100. Core 100 is generally cylindrical
in shape and adapted to be placed onto hub 10 via the insertion end
40 of hub 10. Core 100 serves as the spool for an ink ribbon (not
shown) which is typically wrapped around the outer surface 102 of
core 100. Once the end of the ribbon is attached to core 100
through any appropriate means, the ribbon can be wound or unwound
from outer surface 102. As illustrated in FIG. 3B, the interior
surface 104 of core 100 is provided with a plurality of ribs 106,
108 running longitudinally along the inner surface 104. In a
preferred embodiment, there are six ribs 106 and six ribs 108,
equally spaced and alternating around the inner surface 104 of core
100. The height of ribs 106 is greater than the height of ribs 108.
Ribs 106 run the entire length of core 100, while the ribs 108
slope towards inner surface 104 and ribs 108 terminate before the
mounting end 110 as illustrated in FIGS. 3A and 4. Additionally, as
illustrated in FIG. 4A, the width of ribs 106 preferably tapers as
the rib runs from the mounting end 110 to the distal end 130.
[0021] Ribs 106 form a plurality of longitudinal extending channels
112 which are configured to receive a respective spline 12, 14, 16,
18 of hub 10. Each of ribs 106 terminates at mounting end 110 in an
integral radially oriented compliant leaf spring 116. Each leaf
spring 116 extends outwardly to each side of its respective rib
106, and has a slight curvature that parallels the curvature of
inner surface 104 of core 100. Leaf springs 116 further define
channels 112. The width of springs 116, designated as w1 in FIG.
3A, is preferably slightly greater than the width w of key 54.
[0022] The operation of hub 10 and core 100 is as follows. The
width of the hub 10 as measured across hub 10 from the top edge 22
of spline 12 to the top edge 26 of spline 16 is greater than the
diameter of core 100 as measured between the inner surface 126 of a
first spring 116 and the inner surface 126 of a second spring 116
located on the opposite side of inner surface 104, but less than
the full diameter of the inner surface 104 of core 100. The width
of the hub 10 as measured from the top edge 24 of spline 14 to the
top edge 28 of spline 18 is less than the diameter of core 100 as
measured between the inner surface 126 of a first spring 116 and
the inner surface 126 of a second spring 116 located on the
opposite side of inner surface 104. Accordingly, when the mounting
end 110 of core 100 is placed onto the insertion end 40 of hub 10,
the splines 12,16 will only fit in the channels 112 created by the
springs 116 and ribs 106. Thus, if an operator incorrectly aligns
the spines 12, 16 with the springs 116, the core 100 need only be
rotated at most 45 degrees to properly align the splines 12,16 with
a pair of corresponding channels 112. This allows for simple
loading of the core 100 onto hub 10, and avoids the problem
encountered with conventional core/hub combinations in which the
core must be rotated up to 180 degrees by the operator before the
core can be inserted onto the hub.
[0023] When the splines 12, 16 are aligned with a pair of
corresponding channels 112 in core 100, the splines 14, 18 will be
aligned with a corresponding pair of springs 116. As noted above,
the width of the hub 10 as measured from the top edge 24 of spline
14 to the top edge 28 of spline 18 is less than the diameter of
core 100 as measured between the inner surface 126 of a first
spring 116 and the inner surface 126 of a second spring 116 located
on the opposite side of inner surface 104. Accordingly, as the core
100 is inserted onto the hub 10 in a longitudinal direction, the
splines 12, 16 will be guided by a corresponding pair of channels
112 and the splines 14, 18 will be adjacent to a corresponding pair
of springs 116. As the insertion end 110 of core 100 approaches the
shaft hub 60, the keys 52 on splines 12, 16 will be captured
between the outer edges of the adjacent springs 116 that form the
respective channel 112 into which the splines 12, 16 are inserted.
Additionally, the keys 54 of splines 14, 18 will engage the inner
surface 126 of the springs 116 to which splines 14,18 were
adjacent. When the keys 54 engage the inner surface 126 of springs
116, the outer edges of the springs 116 are urged towards the inner
surface 104 of core 100 as the curvature of springs 116 is reduced
due to the pressure of the engaging keys 54. The pressure between
the springs 116 and keys 54 provides a snug fit of core 100 onto
hub 10. The mounting end 110 of core 100 will be adjacent to, and
preferably abuts against, shaft hub 60 when fully inserted.
[0024] FIG. 5 illustrates a cross sectional diagram of a hub 10
taken across line 5a-5b of FIG. 2 when a core 100 is fully mounted.
As shown in FIG. 5, the keys 52 are caught in corresponding
channels 112 adjacent to the edges of the springs 116 defining the
channels 112. The catching of keys 52 between the edges of springs
116 serves to transmit torque from the hub 10 to the core 100 and
prevents rotational slippage of the core 100. Keys 54 are engaged
with a corresponding pair of springs 116, and the pressure from
springs 116 exerted on keys 54 effectively secures core 100,
preventing both longitudinal and rotational movement of core 100
with respect to hub 10 and additionally serves to transmit torque
from the hub 10 to core 100. The catching of keys 52 between
corresponding springs 116 and the engagement of keys 54 by
corresponding springs 116 provides a secure interface between the
core 100 and hub 10 to prevent slippage during use.
[0025] It should also be noted that the core 100 and hub 10 of the
present invention allow an operator to easily determine that the
core 100 is inserted onto the hub 10 in the wrong direction, i.e.,
the mounting end 110 of core 100 is not adjacent the shaft hub 60.
If an operator slides the distal end 130 of core 100 onto hub 10,
the keys 52 will not be caught between corresponding springs 116
and the keys 54 will not be engaged by corresponding springs 116.
Accordingly, the core 100 will exhibit both longitudinal and
rotational movement with respect to hub 10, thereby indicating to
the operator that the core 100 is not properly mounted on the hub
10.
[0026] Thus, according to the present invention, a core/hub
assembly that provides for easy alignment and insertion, and
provides for a secure interface to prevent slippage of the core
during printer operation, is provided.
[0027] While a preferred embodiment of the invention has been
described and illustrated above, it should be understood that this
is exemplary of the invention and is not to be considered as
limiting. Additions, deletions, substitutions, and other
modifications can be made without departing from the spirit or
scope of the present invention. Accordingly, the invention is not
to be considered as limited by the foregoing description but is
only limited by the scope of the appended claims.
* * * * *