Note: Descriptions are shown in the official language in which they were submitted.
2199591
ORBITAL MOTION MECHANISM
This inYention relates to an orbital or vibratory motion, more par~icularly
to the rnotion of an element or structure which ensures that all portions of
the element or structure partake of the same orbital or vibratory motion.
5 BACKGROUND OF~ THE INVENTIOI~I .
In various industries. particularly in the analytical chemical industry it is
necessary for the chemist to obtain information of the chemical
¢ornpositron of a sample, whether this be of the quantitative or qualitative
analysis of the sample. In v~riou~ situations variolls samples are taken,
10 and il is essential that each sample is treated iden~ically ~o ensure that
the results obTained are as the r~sult of the same treatment wilether it be
chemical analysis or physical analysis . Heat treatrnent and a~itation to
ensure Ihat the necessary actions ~al~en to ensure that each sample is
subject to the same process before analysis is undertaken.
15 Thus in the mining industry, large numbers of ore samples are taken, and
it is ne~ess~ry to ensure that each of these is subiect to idenlically the
same agitE~tion and heating to ensure that each sample is correctly
prepared for analysis, preferably where a larg~ number such as 12 or
rnore samples are being analysed at the same time This analysls may
2 0 take various forms, such as phy~ical, chemical, optical, electrical, indirect
and as noted this may ~e either quantitative or qualitative analysis.
However, no matter what type of analysis is involved it is essential that
each samplc bc prepared in an identical fashion
As various techniques for preparing samples require Ihat each sample
5 be vibrated or agitated for a specific period of time in controlled
conditions, this invention is ~ncerned with providing a rnechanism
whereby an element or object partakes over this whole surface or area
~ith the same motion so that all samples on s~id element or ~bject are
~ubject to the same treatment.
3 0 ln the preparation of samples, it is essential that all air bubbles be
rernoved from the s~mple while being agitated. To ensure thal Ihe alr
bubbles are rer~oved it is essenlial that the sample be agita~ed in its cup.
It h;~s been foun~ thar lo e~fectively remove the air bubbles from a cup
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that the agita~ion or orbital motion must be such that the air bubble is
moved to ~he wall of Ihe cup or holder in which the sample is positioned.
Thus the orbital motion or agitation must be greater than the diameter of
the cup or hcll~er holding the sample. If the movement is less than the
diameter of the cup or holder, then the air bubble will remain to~ rds the
centre and bottom of the cup or holder However by incre~sing the
movernent of the orbit~l motion or vibration Ihe bubble vvill move to the
~all of the ~up and then progress upwardly lo the surface ~f the sample
and thus escape from the sarnple Thus in a preferred form of the
1 0 invention the orbital motion is greater than the diameter of the cup or
hold~r in ~hich the sarnple is positioned.
Thus it is essential that where a number of sarnples are ~ein~ treated at
the same time, that all samples partake of the same vibratory or orbital
rnotion. Orbital sanding machines are known, ~ut while these are
1~ effective in the san~ing of wooden objects, it is kno~vn that if one portion
of the sandiny surface is restrained, the opposite portion of the sanding
mem~er partakes of an orbital motion which is t~ice the previolJs rnotion.
Orbital sanding machines are known for t~e sandin~ of ~~vooden objects.
in which an eccentric member partakes an orbital motion to a sanding
2 0 member, examples of such orbi~al drives are shown in US54S8533 and
US4754575.
~hus it is an object o~ this invention to pro~/ide an element, object or
anicle which when vibrated or provided with a motion such as an orbital
motion \~vill ensure Ihat all portions of the object or article will partake of
2 5 the same motion.
It is a further ~bject of the invention to provide an orbital motion for
treating a sample, in v~hich the orbital motion is such that the motion is
greale~ than that of the size of the container containing the sample.
In the example des~ribed the inv~ntion is described with reference to an
3 0 orbital motion for the agitation of ~ plurality of samples to be chemically analyse~.
In order to more fully describ~ the invention reference ~ill now be made
to the accompanying drawings in which;-
-
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Figure I is a sectional view of the orbital meGhani~m,
Figure 2 is an exploded vie~v showing the driue and driven plates and the
carns,
Figure 3 is a view of the machine in which the orbital motion drive is
S installed, and
~igure 4 is a view c~f the sample halder.
Referring to the drawings the drive shaft 20 passes thro~gh a base plate
21, a counte~veight 22 being attached to and driven by the drive shaft
ZO. The countervveight Z2 is selecte~ to counte~ ~alance a driven pl~te
1 0 23 an~ any further member or holder attached to or aS an extension of
the driven plate to drive or hold or have Ihe samples positioned thereon
to be agitated. The drive ~haft 20 passes through the base plate Z1 and
drives an eccentric or cam ~4. The cam 24 has a firs~ circular portion 25
co-axial ~tvith the drive shaft ~0, the circular portion 25 being mounte~ in a
bearing 26 in a drive plate 27, the drive plate being connected to and
s~pported from the base plate 21 by a plurality of circumferentlally
spaced support pillars 28.
The carn Z4 has a circular recess ~9 offsel from the drive shaft 20 and
circular portion 25 into which circular reCess a spigot 3~ is mounted, the
2 0 spigot be:ing mounted by a bearing 31 in driven plate 23, 2he bearing
being retained by a bearing cap 33.
Thus the driven plate 23 will be caused to have an orbital motion on
rolation of the drive sha~ Z0. However to restrain or lock the driven plate
so that all portions of the plate will parlake of the same orbital motion, a
2 5 plurality of additional carns or eccentrics 32 are provided betvveen the
drive plate 27 and the driven plate 23. In ~he example four ad~itional
cams or ec~entrics 3Z are provided equally spaced a~ou~ lhe central
drive eccentric. Each of these additional eccentrics 32 are identical to
the drive eccentric 24, the eccentriGs 32 beiny idler eccentrics and are
3 0 not driven, However they control the movement of the driven plate to
ensure that all portions of the driven pl~te partake of the same identical
movernent. The plurality of cams or ~ccentrics other than the driven cam
or eccentric, thus ensure that the driven plate is in a sense locked to the
movement of the movement of the driven cam to thus ensure that all
2 1 9959 1
portions of the driven plate partake of the same orbital movement. E~ch
of the cams or e~centrics are retained in position by bearing retainer
caps 33.
In ~ preferred embodiment of the invention the cams or eccentrics 32 are
S constructed in two por~ions 34 and ~5, each being of identical shape and
diameter, the two portions 3~ and 3~i of each cam or eccentric being
joined to a disc 36. Thus portion 3~ is affached to the disc 36 by screws
37 Ihrough washer 38. Simila~ly the portion 3S is attached to the di~c by
screws 39 Ihrough washer 40. Eccentric portion 34 is mounted in
~earin~ ~1 which is positioned in hole 42 in the driven plate 23~ while
portion 35 is mo~lnted in bearing 43 positioned in a hc~le 44 Bearing
retainer caps 3~ are affixed to driven plate 23 by screws 45, while the
bearings 43 in the drive plate 27 are retained by a ~earin9 retainer plate
46 secured by screws 47.
15 In a preferred form, the invention is associated with a furnace 50 whereby
the samples may be heate~ while being agitated. Thus the driven plate
has releasably attached thereto a holder plate 51 to hold a plurality of
conTainers or crucibles 5Z, these being preferably of platinum The
mechanism as above desc~i~ed is preferably mounted on a slide 53 so
2 0 that it can be moved horizontally from a loa~ing posit10n to the heating
and agitation position in the furnace. The slide S3 is pre~erably driven by
a screw ~4 povvered by a stepper molor 55 so Ihat it ¢an be correctly
positioned in the loading position and also in the furnace, When the
mechanism slides to remove the holder plate 51 from Ihe furnace, the
2 5 ho~der plate is positioned over a cooling unit 56.
While the invention has been descrlbed with reference to the treatment of
ore samples, il is to be realised that the invention can be applied to any
industry or circurnstances where 11 is desired Ihat a unlform orbital motion
be imparted to an o~ject or article While the preferred forrn of the
3 0 invention describes a single po~vered eccentric, and four idler eccentrics
to lock or control the motion, it i~ to be realised Ihal three idler e¢centrics
will suitably control the motion, the control wiil be achieved by more ~han
t~o idlEr eccentrics. Also it may be desired that more than one eccentric
can be driven.
