U.S. patent application number 09/818478 was filed with the patent office on 2002-11-21 for combined vertical and rotational motion indexing mechanism.
This patent application is currently assigned to Florida State University Research Foundation. Invention is credited to Dubas, Stephan T., Schlenoff, Joseph B..
Application Number | 20020170385 09/818478 |
Document ID | / |
Family ID | 25225634 |
Filed Date | 2002-11-21 |
United States Patent
Application |
20020170385 |
Kind Code |
A1 |
Dubas, Stephan T. ; et
al. |
November 21, 2002 |
COMBINED VERTICAL AND ROTATIONAL MOTION INDEXING MECHANISM
Abstract
A mechanical indexing device. The device comprises a mechanism
for converting linear motion into many different combinations of
linear and rotary motion, whereby an object can be moved along a
desired linear path and indexed through a desired arc of
rotation.
Inventors: |
Dubas, Stephan T.;
(Tallahassee, FL) ; Schlenoff, Joseph B.;
(Tallahassee, FL) |
Correspondence
Address: |
John Wiley Horton
Booth & Horton, P.A.
P.O. Drawer 840
Tallahassee
FL
32302
US
|
Assignee: |
Florida State University Research
Foundation
|
Family ID: |
25225634 |
Appl. No.: |
09/818478 |
Filed: |
March 27, 2001 |
Current U.S.
Class: |
74/816 ;
74/88 |
Current CPC
Class: |
Y10T 74/18024 20150115;
Y10T 74/1418 20150115; F16H 27/02 20130101; Y10T 74/14 20150115;
Y10T 74/1856 20150115; F16H 37/16 20130101 |
Class at
Publication: |
74/816 ;
74/88 |
International
Class: |
B23Q 016/02 |
Claims
Having described our invention, we claim:
1. A device for converting linear motion into a desired combination
of linear and rotational motion, comprising a. a linear motion
producing element, having a fixed lower portion, and a moveable
upper portion capable of moving between a lower position and an
upper position; b. a table, having a circular perimeter, affixed to
said moveable upper portion of said linear motion producing
element; c. a plurality of pegs, spaced evenly around said circular
perimeter of said table, and radiating outward therefrom; and d. an
indexer, having a near side and a far side, wherein said near side
is positioned proximate said circular perimeter of said table, and
wherein said near side opens into a slot, being sized to receive
one of said pegs and being shaped to guide said one of said pegs to
create said desired combination of linear and rotational motion of
said table as said movable upper portion of said linear motion
producing element moves from said lower position to said upper
position and back to said lower position.
2. The device as recited in claim 1, wherein said linear motion
producing element is an air cylinder, and wherein said moveable
upper portion comprises a cylinder rod.
3. The device as recited in claim 1, wherein said linear motion
producing element is a hydraulic cylinder, and wherein said
moveable upper portion comprises a cylinder rod.
4. The device as recited in claim 1, wherein said slot in said
indexer comprises: a. a first vertical portion, oriented to produce
a purely linear and substantially vertical motion of said table; b.
a first angled portion, immediately following and connected to said
first vertical portion, oriented to produce a combination of linear
and rotary motion of said table; c. a second vertical portion,
immediately following and connected to said first angled portion,
oriented to produce a purely linear and substantially vertical
motion of said table; and d. a second angled portion, immediately
following and connected to said second vertical portion, oriented
to produce a combination of linear and rotary motion of said
table.
5. The device as recited in claim 4, wherein: a. said first angled
portion has a lower extreme and an upper extreme; b. said second
vertical portion has a lower extreme and an upper extreme; and c.
said upper extreme of said first angled portion is higher than said
lower extreme of said second vertical portion.
6. The device as recited in claim 2, further comprising an
additional angled portion immediately preceding and directly
connected to said first vertical portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the field of mechanisms. More
specifically, the invention comprises a mechanism for converting
linear motion into a combination of linear and rotary motion,
whereby an object can be moved along a desired linear path and
indexed through a desired arc of rotation.
[0003] 2. Description of the Related Art
[0004] Numerous prior art devices are designed to convert rotary
motion into linear motion. U.S. Pat. No. 1,016,611 to Chilton
(1912) discloses a bottle filling and capping machine. This machine
is comprised of a rotating carousel. A mechanism (see FIG. 10)
converts the rotating motion into linear motion for the bottles.
Thus, as the carousel turns, the bottles are moved up and down to
the appropriate positions for the capping process.
[0005] A similar approach is taken in U.S. Pat. No. 2,517,592 to
Nordquist (1950). A camming surface (designated as "68" in FIG. 1)
is used to raise and lower jars as they move on a rotating
carousel. U.S. Pat. No. 2,638,259 to Garrett (1953) uses a similar
camming surface (see FIG. 1).
[0006] More camming surfaces capable of converting rotary motion to
linear motion are disclosed in U.S. Pat. No. 3,139,914 to Bingham
(1961) and U.S. Pat. No. 3,335,767 to Manas (1967). Like the
Chilton, Nordquist, and Garrett devices, the Bingham and Manas
devices convert the machine's primary rotary motion into a
reciprocating linear motion. All these devices--Chilton, Nordquist,
Garrett, Bingham, and Manas--convert continuous rotary motion into
rotary motion with an added reciprocating linear motion. It is
significant to note that the rotary motion is always present in
these devices; i.e., they are incapable of producing a purely
linear motion at any point.
[0007] A different approach is disclosed in U.S. Pat. No. 4,027,767
to Gluck (1977). The Gluck device uses a slotted cylinder with a
following peg riding in the slot in order to produce reciprocating
linear motion (See FIG. 1). The Gluck device also uses a 6 position
indexing gear (element "17" in FIG. 3) to index a turntable ("19")
through several set indexing points. Thus, the device (which is
actually a combination of several mechanisms) is capable of
indexing a turntable to a fixed position, moving it up and down,
then indexing it to another position. In other words, it can have
purely linear or rotary motion at a given point. Unfortunately, the
Gluck device is rather complex--employing several mechanisms to
achieve the desired linear and rotary motion.
[0008] Some devices are, of course, capable of converting a
primarily linear motion into rotary motion. One such device is
disclosed in U.S. Pat. No. 5,806,404 to Sher (1998). The Sher
device uses a reciprocating piston as the driving mechanism (such
as found in a pneumatic driving system). A pair of pegs riding in a
groove convert this reciprocating linear motion to a continuous
rotary motion (see FIGS. 2, 3, and 5). The actual object being
moved (a cutter head) simultaneously exhibits rotary and linear
motion; i.e., the device is incapable of producing purely linear or
rotary motion.
[0009] Accordingly, the prior art devices are limited in that they:
(1) Are incapable of producing purely linear motion; and/or (2)
Require a complex combination of several mechanisms to achieve
linear motion without rotary motion.
BRIEF SUMMARY OF THE INVENTION
[0010] It is desirable to index a table through a fixed arc, and to
then move the table up and down in a purely linear fashion. This
type of motion is useful in many processes, particularly where one
wishes to bring a polar array of objects into contact with another
stationary object so that some operation can be performed.
[0011] The present invention seeks to create this type of motion
using only the reciprocating linear motion of an air cylinder as
the driving force. Referring to FIG. 1, air cylinder 12 is affixed
to base 10. Air cylinder 12 has cylinder rod 14, which moves up and
down as air pressure is applied to port 16 (typically by an air
hose--not shown). Table 18 is attached to the upper end of cylinder
rod 14. FIG. 1 shows table 18 in its lowered position.
[0012] Turning now to FIG. 2, air pressure has been applied to air
cylinder 12, with the result that table 18 has been lifted to its
upper position. This movement--between FIG. 1 and FIG.
2--constitutes the linear input motion which drives the device. To
lower table 18, the air pressure is shut off to air cylinder 12.
Gravity then pulls table 18 back down to its lowered position.
[0013] Turning to FIG. 3, the reader will observe that table 18 has
several pegs 20 spaced evenly around its perimeter. Indexer 26 is
positioned close by the perimeter of table 18. Indexer 26 has slot
38 cut completely through its thickness. Pegs 20 are sized to fit
within slot 38. Slot 38 is designed to convert a portion of the
aforementioned linear motion into an indexing rotary motion--as
will be explained in more detail subsequently.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] FIG. 1 is an isometric view, showing the proposed
invention.
[0015] FIG. 2 is an isometric view, showing the table in its raised
position.
[0016] FIG. 3 is an isometric view, showing the indexer.
[0017] FIG. 4 is an isometric view, showing more details of the
indexer.
[0018] FIG. 5 is an isometric view, showing the table in its
lowered position.
[0019] FIG. 6 is an isometric view, showing the table as it begins
to rise, and its interaction with the indexer.
[0020] FIG. 7 is an isometric view, showing the table as it
continues to rise, and its interaction with the indexer.
[0021] FIG. 8 is an isometric view, showing the table as it reaches
its apex, and its interaction with the indexer.
[0022] FIG. 9 is an isometric view, showing the table as it falls,
and its interaction with the indexer.
[0023] FIG. 10 is an isometric view, showing the table as it falls,
and its interaction with the indexer.
[0024] FIG. 11 is an isometric view, showing the relief cuts needed
in the indexer bracket.
[0025] FIG. 12 is an isometric view, showing beakers in place on
the table and a sample holding stand, with the table in its lowered
position.
[0026] FIG. 13 is an isometric view, showing beakers in place on
the table and a sample holding stand, with the table in its raised
position.
[0027] FIG. 14 is a detail view of the items shown in FIG. 12.
1 REFERENCE NUMERALS IN THE DRAWINGS 10 base 12 air cylinder 14
cylinder rod 16 port 18 table 20 peg 22 indexer stand 24 indexer
bracket 26 indexer 28 sample stand 30 motor 32 sample 34 beaker 36
optional angled portion 38 slot 40 mounting point 42 start point 44
end point 46 second vertical portion 48 anti-reversing junction 50
first vertical portion 52 first angled portion 54 second angled
portion 56 relief cut
DESCRIPTION OF THE INVENTION
[0028] FIG. 1 depicts the most basic elements of the invention.
Base 10 is a substantially rigid plate for mounting the other
elements. Air cylinder 12 is attached to base 10. Cylinder rod 14
extends and retracts from air cylinder 12 as air pressure is
applied through port 16. Air pressure is conventionally applied
through a flexible hose, which is not shown. Table 18 is affixed to
the top of cylinder rod 14. FIG. 1 shows cylinder rod 14 in its
retracted position, which corresponds to table 18 being in its
lowered position.
[0029] In FIG. 2, air pressure has been applied and cylinder rod 14
has extended upward--as indicated by the arrow. Table 18 is
correspondingly raised to its upper position. Thus, the reader will
appreciate that a conventional air cyslinder is used to produce
purely vertical motion of an attached table.
[0030] FIG. 3 shows several additional elements. Indexer 26 is
mounted near the circumfrence of table 18. Indexer 26 is attached
to indexer bracket 24, which is held in place by indexer stand 22.
Indexer stand 22 is attached to base 10.
[0031] The reader will observe that table 18 has a number of evenly
spaced pegs 20 radiating outward from its circular perimeter.
Indexer 26 has slot 38 cut into its side facing table 18. Slot 38
is sized to receive and guide a peg 20 as table 18 is moved between
its lower and upper positions.
[0032] FIG. 4 shows indexer 26 in more detail. The reader will
observe that it has a curved shape, designed to fit closely against
the circular perimeter of table 18. FIG. 4 is looking at the near
side of indexer 26, which is the side facing table 18.
[0033] Slot 38 is comprised of several distinct portions. Start
point 42 is the point where a particular peg 20 will first enter
slot 38 (more detailed views describing the interaction of the slot
and the pegs follow). Optional angled portion 36 is the first
segment encountered. This segment is referred to as "optional"
because it is not essential to the operation of the device. The
remaining segments are first vertical portion 50, first angled
portion 48, second vertical portion 46, and second angled portion
54. End point 44 is the point where a particular peg 20 will leave
slot 38.
[0034] Four mounting points 40 are provided to mount indexer 26 to
indexer mounting bracket 24. Relief cuts 56 are provided to allow a
particular peg 20 to engage and disengage from indexer 26.
[0035] FIGS. 5 through 10 depict the interaction of a particular
peg 20 with indexer 26, with continuous reference also being made
to the details disclosed in FIG. 4. FIG. 5 shows table 18 in its
lower position, which represents the start of an indexing cycle.
The far side of indexer 26 is shown (opposite side from the one
depicted in FIG. 4) The right-hand of the two labeled pegs 20 is
poised to enter slot 38. Likewise, the lefthand peg 20 is poised to
disengage from slot 38.
[0036] FIG. 6 shows table 18 as it has started to move upward. The
reader will observe that the right-hand peg 20 has encountered
optional angled portion 36 and has moved into first vertical
portion 50. The result is that table 18 has rotated slightly
clockwise (as viewed from above) as it rose, and then transitioned
to purely vertical motion--as indicated by the arrow. The reader
will observe that the lefthand peg 20 is completely disengaged.
[0037] FIG. 7 shows table 18 as it has moved further upward. The
right-hand peg 20 has moved through first angled portion 52. During
that portion, table 18 rotated clockwise as it rose. As shown, the
right-hand peg 20 has entered second vertical portion 46. Table 18
will only move vertically during this phase because the right-hand
peg 20 remains within second vertical portion 46.
[0038] FIG. 8 shows table 18 at the upper limit of its travel. Its
motion is purely vertical. After the point shown in FIG. 8, the air
pressure will be released from air cylinder 12 and gravity will
pull table 18 downward. It is important for the reader to
appreciate that the motion of table 18 is purely an up and down
stroke near the top of its cycle. This motion is desirable for many
operations--as will be explained subsequently.
[0039] As table 18 descends from the position shown in FIG. 8, the
right-hand peg 20 will encounter anti-reversing junction 48. The
design of this junction is obviously significant. First angled
portion 52 intersects second vertical portion 46 a significant
distance upward from the lower extreme of second vertical portion
46 (the upper extreme of first angled portion 52 is higher than the
lower extreme of second vertical portion 46). The junction is
designed to ensure that the right-hand peg 20 descends to the
bottom of second vertical portion 46, rather than going back into
first angled portion 52.
[0040] FIG. 9 shows the motion as table 18 descends. The right-hand
peg 20 has descended past anti-reversing joint 48 and entered
second angled portion 54. The motion of table 18 at this point is
downward translation accompanied by clockwise rotation. FIG. 10
shows further progress of this motion. The reader will observe that
the right-hand peg 20 is approaching the position that the lefthand
peg 20 occupied in FIG. 5. The reader will also observe that a new
peg 20 is about to enter start point 42. Thus, the cycle is
completed. Those skilled in the art will realize that by
configuring slot 38 to conform to the spacing between pegs 20, the
invention will continuously index via the simple raising and
lowering motion of air cylinder 12.
[0041] It is important to realize why optional angled portion 36 is
referred to as "optional." It is possible to design a functional
version of the device which omits this element. Those skilled in
the art will realize that as table 18 descends from FIG. 9 to FIG.
10, table 18 is rotating clockwise. If table 18 has any significant
mass, this rotation will produce angular momentum. Such angular
momentum will cause the peg 20 which is exiting slot 38 to rotate
clear and the next peg 20 to rotate into position until it come to
rest at the bottom of first vertical portion 50. Thus, the indexing
function of optional angled portion 36 is not needed.
[0042] However, those skilled in the art will also realize that
friction in the system may inhibit rotation as the device ages.
Without optional angled portion 36, one cannot guarantee that the
device will not reverse itself and become stuck in one indexing
cycle. Accordingly, the version using optional angled portion 36 is
the preferred embodiment.
[0043] FIG. 11 is a detailed view showing a relief cut 56 made in
indexer bracket 24. A similar cut is found in the far side of
indexer bracket 24. Such relief cuts are obviously necessary to
allow the free passage of pegs 20.
[0044] Having described the indexing and rotation mechanism in
great detail, one might naturally wish to know about some
applications for the mechanism. Accordingly, one particularly
suitable application will now be disclosed. However, it is
important for the reader to realize that the device has many
applications in many different fields. Its consideration should not
be limited to the following application.
[0045] FIG. 12 depicts table 18 holding eight beakers 34. Table 18
may optionally have a polar array of recesses sized to hold beakers
34, or any other desired object. Beakers 34 typically contain
liquids. Sample stand 28 is attached to base 10. It suspends sample
32 directly over one of the beakers 34. Motor 30 is provided to
spin sample 32, which is helpful in some situations. FIG. 12 shows
table 18 as a peg 20 has entered second vertical portion 46 of slot
38. As explained previously, the motion of table 38 at this point
is a purely up and down vertical stroke.
[0046] In FIG. 13, table 18 has moved to the upper limit of its
motion. As a result, sample 32 has been immersed within the
contents of the particular beaker 34. As the air pressure is
removed from air cylinder 12, the particular beaker 34 will drop
and sample 32 will pull free again. FIG. 14 shows a detail view of
sample 32 as it has pulled free of a particular beaker 34.
[0047] The indexing motion of the device means that each successive
beaker 34 will be brought directly beneath sample 32, then moved up
and down to immerse sample 32 within the contents of the
beaker.
[0048] As one particular example--sample 32 might be a silicon
wafer. The object would be to deposit very thin layers of
alternating polymers. Each successive beaker 34 would contain a
polymer solution having an opposite charge (being an ionic
solution) from its predecessor. As sample 32 is immersed in each
successive beaker 34, the alternating layers of polymers will
adhere to sample 32 and accumulate.
[0049] As another alternative, some of the beakers can contain
distilled water or other cleaning solutions to purify sample 32
between successive active solutions. Virtually any type of chemical
or process could be employed.
[0050] Control of the device is quite simple, as the only input
needed is the air pressure to air cylinder 12. This air pressure
can be controlled by a simple timer or a computer. Using a computer
allows the cycle times to be varied. Thus, sample 32 could be
immersed in some beakers for long periods and others for short
periods.
[0051] Accordingly, the reader will appreciate that the proposed
invention can readily create linear and rotary motion using only a
reciprocating linear input. The invention has further advantages in
that:
[0052] 1. Virtually any combination of linear and rotary motion can
be achieved by varying the design of slot 38;
[0053] 2. It allows purely linear motion over some parts of the
travel;
[0054] 3. It requires only a single control input; and
[0055] 4. It is quite simple.
[0056] Although the preceding description contains significant
detail, it should not be construed as limiting the scope of the
invention but rather as providing illustrations of the preferred
embodiment of the invention. The device could be applied to many
applications beyond chemical compositions, including spot welding,
galvanizing processes, adhesive application, etc. Thus, the scope
of the invention should be fixed by the following claims, rather
than by the examples given.
* * * * *