Note: Descriptions are shown in the official language in which they were submitted.
CA 02536892 2006-02-17
1
TITLE OF THE INVENTION
Apparatus and method for rotating a cap relatively to a
container,
FIELD OF THE INVENTION
[0001] The present
invention relates generally to automated
manufacturing lines. More specifically, the present invention is concerned
with
an apparatus and a method for rotating a cap relatively to a container.
BACKGROUND OF THE INVENTION
[0002] There exist
many apparatuses for rotating caps relatively to
a container. For example, such apparatuses are used for screwing caps onto
containers or screwing off caps from containers.
[0003] Some of
these apparatuses include discs that rotate in
opposing directions. For example, US Patent 5918442 issued to Dewees on
July 6, 1999, describes such an apparatus. In these apparatuses, a container
is
moved toward the discs and the cap is positioned over the container. When
the cap reaches the discs, the discs engage the cap and rotate the discs
relatively to the container.
[0004] Since there
is typically a need to rotate the cap by a relatively
large angle, the discs must rotate relatively fast because the duration of the
engagement between the discs and the cap is relatively short. This causes the
discs to wear relatively fast. In addition, having discs that rotate at a
relatively
high speed tends to destabilize the container when the cap is engaged as an
impact produced onto the cap by the discs is then transmitted to the
container.
Furthermore, when a cap is screwed onto a container, the discs typically do
not
CA 02536892 2006-02-17
2
allow adjusting relatively precisely a torque applied to the cap.
[0005] In another type of device used for screwing caps onto
containers, two belts are used to apply forces onto opposite sides of a cap.
An
example of such a device is found in US Patent 3,280,534 issued to
Hildebrandt et al. on January 4, 1963. Once again, achieving a relatively
precise torque when screwing the cap is relatively hard to achieve using these
types of devices. Also, the speed of the belt is usually fixed. Therefore, it
is
relatively hard to select belt speeds that are suitable for both rotating the
cap
relatively fast when the cap is initially screwed onto the container and
producing a relatively slow rotation of the cap when the cap is almost
entirely
screwed onto the container.
[0006] Indeed, as the cap is screwed onto the container, a torque
applied by the rotating cap onto the container increases. At one point, the
cap
will slide relatively to the belts because typically, the force that is
applied onto
the cap is smaller than a force applied onto the container that resists
rotation. A
slipping belt wears off prematurely, may damage the cap and may destabilize
the container.
[0007] Against this background, there exists a need in the industry to
provide a novel apparatus and method for rotating a cap relatively to a
container.
OBJECTS OF THE INVENTION
[0008] An object of the present invention is therefore to provide an
improved method and apparatus for rotating a cap relatively to a container.
CA 02536892 2012-02-09
3
SUMMARY OF THE INVENTION
[0009] In a first broad aspect, the invention provides an apparatus
for rotating a cap relatively to a container. The container moves along a
5predetermined path at a container speed. The cap has a first and a second
cap engagement location. The first and second cap engagement locations are
circumferentially spaced apart relative to each other. The apparatus includes
a
first cap engaging component, the first cap engaging component including a
first component cap engaging surface for engaging the cap at the first cap
10engagement location and applying a first substantially tangential force
thereto.
The first cap engaging surface moves at a first speed when substantially in
register with the first cap engagement location. A second cap engaging
component includes a second component cap engaging surface for engaging
the cap at the second cap engagement location and applying a second
15substantially tangential force thereto. The second cap engaging surface
moves
at a second speed when substantially in register with the second cap
engagement location. The first and second cap engaging components are
operatively coupled to each other for maintaining substantially constant the
sum of the first and second speed.
20[0010] Advantageously, the claimed invention may use cap
engaging components having engaging surfaces that move at relatively low
speeds. Therefore, this reduces the wear of the belts as a difference between
the speed of a cap that is engaged and the belt is relatively small.
[0011] In some embodiments of the invention, the first and second
25cap engagement locations are substantially diametrically opposed relative to
each other. In these cases, in some embodiments, the sum of the first and
second speeds is about twice the container speed, which causes caps that
have a rotational symmetry to experience forces that move the center of these
CA 02536892 2006-02-17
4
caps at an average speed that is equal to the container speed.
Advantageously, the forces exerted onto the cap and the container when the
belts start engaging the cap are then minimized.
[0012] In addition, while the sum of the first and second speeds is
constant, each of these speeds may individually vary for the duration over
which the cap is engaged. This allows rotation of the cap to be relatively
fast at
the beginning of the engagement and to have the first and second speeds
substantially equal at the end of the engagement. Therefore, when a cap is
completely screwed onto a bottle, there is no rotation of the cap relatively
to the
container and the cap and the container therefore only have a translational
motion.
[0013] In some embodiments of the invention, the sum of the first
and second speeds is maintained by having a differential interconnecting the
first and second cap engaging components. In other embodiments of the
invention, this relationship is maintained with the use of speed measuring
devices and motors that are interconnected with the controller that maintain
the
above mentioned relationship.
[0014] In another broad aspect, the invention provides a method for
rotating a cap relatively to a container, the container moving along a
predetermined path at a container speed. The cap has a first and a second cap
engagement location, the first and second cap engagement locations being
circumferentially spaced apart relatively to each other. The method includes:
[0015] - engaging the cap at the first cap engagement location and
applying a first substantially tangential force thereto to move the first cap
engagement location at a first speed;
CA 02536892 2006-02-17
[0016] - engaging the cap at the second cap engagement location
and applying a second substantially tangential force thereto to move the
second cap engagement location at a second speed; and
[0017] - maintaining substantially constant the sum of the first and
second speeds while the cap is engaged at the first and second cap
engagement locations.
[0018] Other objects, advantages and features of the present
invention will become more apparent upon reading of the following non-
restrictive description of preferred embodiments thereof, given by way of
example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the appended drawings:
[0020] Figure 1A, in a perspective view, illustrates an apparatus for
rotating a cap relatively to a container in accordance with an embodiment of
the
present invention;
[0021] Figure 1B, in a front elevation view, illustrates the apparatus
of Figure 1;
[0022] Figure 1C, in a side elevation view, illustrates the apparatus
of Figure 1;
[0023] Figure 2, in a perspective view, illustrates a cap screwing
assembly of the apparatus of Figure 1, the cap screwing assembly including a
driven stage and a driving stage;
CA 02536892 2006-02-17
6
[0024] Figure 3A, in a partial perspective view, illustrates the driven
stage of the cap screwing assembly of Figure 1;
[0025] Figure 3B, in a partial top plan view, illustrates the driven
stage of the cap screwing assembly of Figure 1, the driven stage engaging a
container and a cap;
[0026] Figure 3C, in a partial side elevation view, illustrates the
driven stage of the apparatus of Figure 1;
[0027] Figure 4, in a top plan view, illustrates the driving stage of
the
apparatus of Figure 1;
[0028] Figure 5A, in a schematic view, illustrates a first step in the
operation of the apparatus of Figure 1 in accordance with an embodiment of
the present invention;
[0029] Figure 5B, in a schematic view, illustrates a second step in
the operation of the apparatus of Figure 1;
[0030] Figure 5C, in a schematic view, illustrates a third step in the
operation of the apparatus of Figure 1;
[0031] Figure 6A, in a schematic view, illustrates a first step in the
operation of the apparatus of Figure 1 in accordance with another embodiment
of the present invention;
[0032] Figure 6B, in a schematic view, illustrates a second step in
the operation of the apparatus of Figure 1;
CA 02536892 2006-02-17
7
[0033] Figure 6C, in a schematic view, illustrates a third step in the
operation of the apparatus of Figure 1;and
[0034] Figure 7, in a top plan view, illustrates a driven stage of an
apparatus for rotating a cap relatively to a container in accordance with
another
embodiment of the present invention.
DETAILED DESCRIPTION
[0035] Figures 1A, 1B and 1C illustrates an apparatus 10 for rotating
a cap 12 (not shown in Figures 1A, 1B and 1C) relatively to a container 14
(not
shown in Figures 1A, 1B and 1C). The apparatus 10 includes a cap screwing
assembly 11 mounted to a frame 13. In some embodiments of the invention,
the frame 13 allows for the adjustment of a height above a ground surface at
which the cap screwing assembly 11 is located.
[0036] Referring to Figure 2, the container 14 moves along a
predetermined path at a container speed generally indicated by the reference
numeral 20. For example, as seen in the drawings, the container 14 moves
onto a sliding rail 15 that defines the predetermined path and supports the
container 14. However, it is within the scope of the invention to support the
container in any other suitable manner.
[0037] The cap screwing assembly includes a driving stage 16 and a
driven stage 18. The driving stage 16 is coupled to the driven stage 18 so
that
power is provided to components of the driven stage 18 that engage the cap 12
and the container 14 to move the cap 12 and the container 14 through the
apparatus 10 and to rotate the cap 12 relatively to the container 14.
CA 02536892 2006-02-17
8
[0038] The cap 12 is shown in Figure 2 in a partially screwed state.
The apparatus 10 is used to completely screw the cap 12 onto the container 14
by rotating the cap 12 relatively to the container 14. However, it is within
the
scope of the invention to have an apparatus similar to the apparatus 10 that
removes caps from containers. Also, the cap 12 and the container 14 are
shown as being substantially respectively disc-shaped and cylindrical.
However, apparatuses that may handle caps and containers having any other
suitable shape are also within the scope of the invention.
[0039] Referring to 3B, the cap 12 has a first and a second cap
engagement location 22 and 24. The first and second cap engagement
locations 22 and 24 are circumferentially spaced apart relatively to each
other.
For example, as shown in Figure 3B, the first and second cap engagement
locations 22 and 24 are substantially diametrically opposed relatively to each
other. However, in alternative embodiments of the invention, the first and
second cap engagement locations 22 and 24 are positioned at any other
suitable circumferential location.
[0040] Referring to Figures 3A, 3B, 3C, a pair of container moving
belt 26 and 28, move the container 14 in a substantially rectilinear path at
the
container speed 20 (not shown in Figure 3A). The container moving belts 26
and 28 are mounted to pulleys 27 (seen in Figure 3B) and move at substantially
equal speeds.
[0041] The driven stage 18 includes a first cap rotating station 19
and a second cap rotating station 19'. The first cap rotating station 19 and
the
second cap rotating station 19' sequentially engage the cap 12 and apply
forces onto the cap 12 to rotate the cap 12 relatively to the container 14.
[0042] Referring to Figure 3B, the first cap rotating station 19
CA 02536892 2006-02-17
9
includes a first cap engaging component 32. The first cap engaging component
32 includes a first component cap engaging surface 34 for engaging the cap 12
at the first cap engagement location 22 and applying a first substantially
tangential force thereto. The first cap engaging surface 34 moves at the first
speed, indicated by the arrow denoted by the reference numeral 36. The first
speed 36 is a speed at which the first component cap engaging surface 34
moves when the first cap engaging surface 34 is substantially in register with
the first cap engagement location 22.
[0043] Similarly, a second cap engaging component 38 includes a
second component cap engaging surface 35, for engaging the cap 12 at the
second cap engagement location 24 and applying a second substantially
tangential force thereto. The second cap engaging surface 35 moves at a
second speed when substantially in register with the second cap engagement
location, as indicated by the arrow 37.
[0044] The first and second cap engaging components 32 and 38
are operatively coupled to each other for maintaining substantially constant
the
sum of the first and second speeds 36 and 37. In some embodiments of the
invention, the first and second cap engaging surfaces 34 and 35 are located on
opposite sides of the predetermined path. However, it is within the scope of
the
invention to locate the first and second cap engaging surfaces 34 and 35 at
any
other suitable location.
[0045] The first and second cap engaging surfaces 34 and 35 define
respectively a first and a second cap contacting location 40 and 41. The first
and second cap contacting locations 40 and 41 define a lateral plane 42, the
lateral plane being substantially perpendicular to the first and second
tangential
forces and to the predetermined path.
CA 02536892 2006-02-17
[0046] In some embodiments of the invention, the first cap engaging
component 32 includes a first belt 44 mounted to both a first belt first
pulley 46
and a first belt second pulley 48. The first belt 44 defines the first
component
engaging surface 34.
[0047] Similarly, the second engaging component 38 includes a
second belt 50 mounted to both a second belt first pulley 52 and a second belt
second pulley 54, the second belt 50 including the second component
engaging surface 35. In some embodiments of the invention, as shown in
Figure 3B, the first and second belts 44 and 50 are each, at least in part,
parallel to the predetermined path.
[0048] While the apparatus 10 includes a second cap rotating station
19', in alternative embodiments of the invention, only the first cap rotating
station 19 is present. In yet other embodiments of the invention, more than
two
cap rotating stations are present in an apparatus similar to the apparatus 10.
[0049] The second cap rotating station 19' is substantially similar to
the first cap rotating station and will therefore not be described in further
details. In the drawings, reference numerals related to the second cap
rotating
station 19' and designating similar components are the same as the reference
numerals designating the components of the first cap rotating station with a 1
appended.
[0050] In some embodiments of the invention, the first cap rotating
station 19 is used to rotate the cap 12 at a relatively large speed and the
second cap rotating station 19' is used to apply a predetermined torque to the
cap 12. However, in alternative embodiments of the invention, the cap rotating
stations 19 and 19' are used in any other suitable manner.
CA 02536892 2006-02-17
11
[0051] As shown in Figure 2, the driving and driven stages 16 and
18 are interconnected to allow the belts 44 and 50, the belts 44' and 50', and
the container moving belts 26 and 28 to be moved pair wise relatively to each
other so as to vary a spacing therebetween. This allows using the apparatus
with containers 14 and caps 12 having different dimensions. For example,
for the first cap rotating station 19, a distance between the first and second
cap
engaging surfaces 34 and 35 is selectively adjustable between a first inter-
engaging component distance and a second inter-engaging component
distance larger than the first inter-engaging component distance. The belts 44
and 50, the belts 44' and 50', and the container moving belts 26 and 28 are
interconnected to be able to be moved relative to each other in a conventional
manner. The reader skilled in the art will readily appreciate that in other
embodiments of the invention, the belts 44 and 50, the belts 44' and 50', the
container moving belts 26 and 28, or any combination thereof are not movable
relatively to each other so as to vary a spacing therebetween.
[0052] Referring to Figure 2, the driving stage 16 includes a support
plate 58 to which driving components are secured. The driving stage 16
includes a motor 60 that is connected to axles that drive the belts 44 and 50,
the belts 44' and 50', and the container moving belts 26 and 28 as described
hereinbelow.
[0053] The driving stage 16 includes first and second differentials 62
and 64. The differentials 62 and 64 are devices that each has an input and two
outputs. When the input is rotated at a predetermined rotational speed, the
two
outputs are driven such that the sum of the rotational speeds of the two
outputs
is equal to twice the predetermined speed. The exact rotational speed of the
two outputs depends on torques resisting the rotation of the two outputs.
Differentials are well known in the art and the differentials 62 and 64 are
therefore not described in further details herein.
CA 02536892 2006-02-17
12
[0054] Also, the
driving stage 16 includes first and second brakes 66
and 68. The brakes 66 and 68 may be applied to create a frictional force
between two rotating components of the apparatus 10. Typically, this
frictional
force is adjustable to allow the rotating components of the apparatus 10 to
rotate at the same angular speed if a torque exerted on these two components
is below a predetermined torque. If the torque is larger than the
predetermined
torque, these two components rotate with different angular speeds as two
surfaces in the brakes slip relatively to each other.
[0055] As more
clearly seen in Figure 4, the motor 60 drives a
pulley 86 that drives the input of the first differential 62 through a belt
72. In
turn, the input of the first differential 62 also drives the input of the
differential
64 through a belt 74. The outputs of the first differential 62 are connected
to a
first gear 78 and to the pulley 46' that drives the first belt 34' of the
second cap
rotating station 19' (not seen in Figure 4). Similarly, the outputs of the
second
differential 64 are connected to a second gear 82 and to the pulley 46 that
drives first belt 44 of the first cap rotating station 19 (not seen in Figure
4). The
first gear 78 engages a third gear 80 that drives the second belt 35' of the
second cap rotating station 19' (not seen in Figure 4).
[0056] The first
brake 66 is configured such that when the first brake
66 is engaged, a force is exerted against a movement of the second belt 35' of
the second cap rotating station 19'. To that effect, the first brake 66 is
coupled
to an arm 86 that is itself coupled to a load cell 88. The load cell 88 is not
necessarily present in all embodiments of the invention and may be replaced,
for example, by a member extending from the plate 58. When present, the load
cell 88 allows measuring a torque exerted onto the brake 66. When the first
brake 66 is not engaged, the second belt 35' of the second cap rotating
station
19' is driven directly by the output of the first differential 62 that is
coupled to
the first gear 78.
CA 02536892 2006-02-17
13
[0057] A fourth gear 84 engages the second gear 82. This second
gear 84 is connected to the second belt 50 of the first cap rotating station
19
(not seen in Figure 4). A belt 76 connects the input of the second
differential 64
to the second brake 68. When the second brake 68 is engaged, the input of the
second differential 64 and the output of the second differential 64 that
connects
to the second gear 82 are locked. This causes the second belt 50 of the first
cap rotating station 19 to be driven by the motor 60. When the second brake 68
is not engaged, the output of the second differential 64 that connects to the
second gear 82 drives the second belt 50 of the first cap rotating station 19
without interference from the input of the second differential 64.
[0058] The motor 60 also drives another output gear (not shown in
the drawings) that is linked through a belt 92 to another pulley 94. The
pulley
94 drives the container moving belt 26 at a predetermined speed directly
through the pulley 94. Also, a fifth gear 96 rotates at the same rotational
speed
as the pulley 94. This fifth gear engages a sixth gear 98 that drives the
container moving belt 28.
[0059] The gears 78, 80, 82, 84, 96 and 98 are linked to their
respective pulleys 48', 54', 48, 54 and 27 that drive their respect belts 44',
50',
44, 50, 26 and 28 through universal joints 100 (better shown in Figure 3A).
The
universal joints 100 allow to vary pair wise a spacing between the belts 26
and
28, 44 and 50, and 44' and 50' while keeping constant the positions of the
driving components.
[0060] In some embodiments of the invention, the differentials 62
and 64, as well as the gears 78, 80, 82 and 84 are selected such that the sum
of the first and second speeds 36 and 37 is about twice the container speed
20.
However, in alternative embodiments of the invention, this sum is any other
suitable sum.
CA 02536892 2006-02-17
14
[0061] Also, while the first and second cap rotating stations 19 and
19' in the device 10 are such that they have the same sum of their respective
first and second speeds 36, 37 and 36', 37', it is within the scope of the
invention to have the sum of the first and second speeds 36, 37 and 36', 37'
of
the first and second cap rotating stations 19 and 19' differ from each other.
[0062] The load cell 88 is provided for measuring the torque applied
onto the first brake 66. This torque depends on the torque applied by the
belts
44' and 50' of the second cap rotating station 19' to the cap 12. The reader
skilled in the art will readily appreciate how to compute from a force
measurement at the load cell 88 the torque applied on the cap 12.
[0063] The brakes 66 and 68 are able to apply a variable load to the
cap engaging components. Adjustment of this load allows selecting of the
torque to which the cap 12 is to be screwed. More specifically, the maximal
torque exerted on the cap is about equal to the torque exerted by the brakes
66
and 68 multiplied by a factor that depends on the diameters of the components
that connect the brakes 66 and 68 to the belts 44', 50' and 44, 50. Such
factors
depend on the exact configuration of the apparatus 10 and are readily
computed by the reader skilled in the art.
[0064] Indeed, when for example the torque exerted on the cap 12
reaches a predetermined torque, the brake 66 starts to slip and the first
differential 62 causes the belts 44' and 50' to move at the same speed. In
turn,
this stops the rotation of the 12 relatively to the container 14.
[0065] In alternative embodiments of the invention, not shown in the
drawings, a cap torque controller is coupled to the load cell 88 for receiving
a
measurement of the torque exerted onto the cap 12. The cap torque controller
is operatively coupled to the brake 66 for substantially eliminating the load
CA 02536892 2006-02-17
applied by the brake 66 when the magnitude of the torque exerted onto the cap
12 reaches a predetermined magnitude.
[0066] In use, the container 14 is moved by being engaged by the
container moving belts 26 and 28. These belts move at the same speed in
opposite rotation directions, which makes them have the same container speed
at the locations wherein the container 14 is engaged. The gears 96 and 98
ensure that the first and second belts 26 and 28 rotate in opposite directions
with substantially equal rotations speeds.
[0067] Figures 5A, 5B and 5C illustrate schematically the operation
of the second cap rotating station 19'. In these Figures, the first brake 66
is
engaged to apply a predetermined load to the second belt 50'. Also, the cap 12
and the container 14 are illustrated as having different diameters for clarity
reasons.
[0068] As shown in Figure 5A, initially the cap 12 is only partially
screwed onto the container 14 and therefore applies no, or a relatively small,
torque to the second belt 50'. In this configuration, the first differential
62
ensures that the first speed 36' equal to about twice the container speed 20'
and that the second speed 37' is equal to about 0.
[0069] This produces a relatively fast rotation of the cap 12
relatively
to the container 14. Subsequently, as the cap 12 is further screwed onto the
container 14, the cap encounters a resistance to its rotation caused by its
engagement to the container 14. This causes the second speed 37' to increase
while the first speed 36' decreases, as shown in Figure 5B.
[0070] Finally, as seen in Figure 5C, the force exerted by the cap 12
CA 02536892 2006-02-17
16
onto the belts 44' and 50' reaches a value such that the first brake 66 slips.
The
first differential 62 then causes the first and second speeds 36' and 37' to
be
substantially equal to each other and substantially equal to the container
speed
20. Since the belts 44' and 50' rotate in opposing directions, but are facing
each other, the point of contact between the cap 12 and the belt 44' and 50'
move at the same speed, in the same direction.
[0071] Suitably selecting the value of the force exerted by the cap 12
onto the belts 44' and 50' that causes the first brake 66 to slip allows to
screw
the cap 12 onto the container 14 at a predetermined torque.
[0072] In the first cap rotating station 19, the input of the second
differential 64 is coupled to the second brake 68. When the second brake 68 is
not engaged, the second brake 68 rotates relatively to the second belt first
pulley 52. In this case, the second differential 64 causes the first and
second
speeds 36 and 37 to be substantially identical.
[0073] When the brake 68 is engaged, the apparatus 10 operates as
seen in Figures 6A to 60. Initially, as illustrated in Figure 6A, the cap 12
is only
partially screwed onto the container 14 and therefore applies no, or a
relatively
small, torque to the second belt first pulley 52. The second belt first pulley
52 is
driven by the motor 60 and forces the second speed 37 to take a
predetermined value. For example, the second speed 37 is oriented in a
direction opposite to the orientation of the container speed 20. In turn, the
second differential 64 then causes the first speed 36 to be more than two
times
larger than the container speed 20. In this mode, a relatively fast rotation
of the
cap 12 occurs onto the bottle 14. This allows the use of belts 44' and 50'
that
are relatively short, which in turn helps in minimizing the size of the
apparatus
10.
CA 02536892 2006-02-17
17
[0074] As the cap 12 is screwed, the cap 12 begins to resist the
screwing motion. However, since the second belt 50 is driven by the motor 60,
the first and second speeds do not change, as seen in Figure 6B.
[0075] In some embodiments of the invention, as seen in Figure 6C,
the force exerted by the cap 12 onto the belts 44 and 50 reaches a value such
that the second brake 68 slips. The second differential 64 then causes the
first
and second speeds 36 and 37 to be substantially equal to each other and
substantially equal to the container speed 20. Since the belts 44 and 50
rotate
in opposing directions, but are facing each other, the points of contact
between
the cap 12 and the belt 44 and 50 move at the same speed, in the same
direction.
[0076] In other embodiments of the invention, the force exerted by
the cap 12 onto the belts 44 and 50 never reaches a value such that the
second brake 68 slips. In these embodiments, the situation illustrated in
Figure
6C does not occur.
[0077] In some embodiments of the invention, as seen in the
drawings, the sum of the first and second speeds is maintained by having the
differentials 62 and 64 interconnecting first and second cap engaging
components. In other embodiments of the invention, not shown in the drawings
this relationship is maintained with the use of speed measuring devices and
motors that are interconnected with the controller that maintain the above-
mentioned relationship.
[0078] Also, while the belts shown in the drawings are toothed belts,
it is also within the scope of the invention to use smooth belts when the
forces
exerted onto these belts allow doing so. Furthermore, in some embodiments of
the invention some belts and pulleys may be replaced by chains and sprocket
CA 02536892 2013-10-31
18
wheels or any other suitable devices having a similar function.
[0079] Figure 7 illustrates an alternative embodiment of the invention
wherein the belts and pulleys of the first and second cap rotating stations
are
absent. Instead, an alternative apparatus includes an alternative driven stage
518a. The driven stage 18a is similar to the driven stage 18 except that the
driven stage 18a includes a first cap rotating station 19a and a second cap
rotating station 19a'.
[0080] The first cap rotating station 19a includes first and second
cap engaging components 32a and 38a that are substantially disc-shaped and
10include respectively a first and a second peripheral surface 33a and 39a.
First
and second cap engaging surfaces are formed respectively by the first and
second peripheral surfaces 33a and 38a.
[0081] The second cap rotating station 19a' is similar to the first
cap
rotating station 19a and will therefore not be further described. The
15components of the second cap rotating station 19a' are denoted by the same
reference numerals as corresponding components of the first cap rotating
station 19a to which a' has been appended.
[0082] The driven stage 18a functions similarly to the driven stage
18. However, the duration of a contact between cap engaging surfaces and the
20cap 12 in the driven stage 18a are typically smaller than the duration of
the
contact between cap engaging surfaces and the cap 12 in the driven stage 18.
[0083] Although the present invention has been described
hereinabove by way of exemplary embodiments thereof, it will be readily
appreciated that many modifications are possible in the exemplary
CA 02536892 2013-10-31
19
embodiments without materially departing from the novel teachings and
advantages of this invention. Accordingly, the scope of the claims should not
be
limited by the exemplary embodiments, but should be given the broadest
interpretation consistent with the description as a whole.
