[0001] The invention concerns apparatus for picking objects from one location and placing
them in another. More particularly, the invention concerns apparatus for picking cartridges
for photographic film from a lighted environment, placing them in a darkened environment,
and vice versa.
[0002] In the manufacture of photographic film cartridges, a wound spool or scroll of film
has been installed in a cartridge shell, after which the shell has been closed to
a light-tight configuration to prevent exposure of the film prior to installation
in a customer's camera. Commonly assigned US-A-2,940,232 and US-A-5,044,144 disclose
apparatus for assembling such cartridges, each of which operates virtually entirely
in a dark room. Other types of cartridges have been assembled by first making a preliminary
assembly of the parts of the cartridge shell in a lighted room and then passing the
preliminary assembly into a dark room for installation of the film and final closure
of the cartridge. US-A-3,364,552 discloses an apparatus for assembling such cartridges
in which the preliminary assembly is moved on a conveyor in the lighted room to a
first transfer wheel positioned in a light trap chamber. The first transfer wheel
passes the assembly along a serpentine path within the chamber to a second transfer
wheel which passes the assembly to a further conveyor in the dark room. Apparatus
for transfer of exposed film cartridges from a lighted room to a dark room is shown
in US-A-4,076,135 in which the cartridges are fed by gravity along an enclosed chute
from a lighted room to a dark room. Light is excluded from the dark room by a plurality
of apertured shutters which control movement of the cartridges along the chute.
[0003] While apparatus of the types just described has achieved a considerable level of
success, more recent cartridge designs, such as that shown in commonly assigned US-A-5,319,407
are to be completely assembled, without film, in a lighted room, after which the empty
cartridge must be transferred to a dark room where a strip of film can be wound into
the cartridge. Thus, a need has developed for an improved apparatus for rapidly and
reliably moving such cartridges between lighted and darkened environments.
[0004] A primary objective of the invention is to provide an apparatus for picking an empty
cartridge from a lighted room and placing it in a dark room for further processing,
such as installation of photographic film.
[0005] Another objective is to provide such an apparatus which includes an effective light
lock, is very reliable and can be synchronously timed to the operation of an apparatus
for installing film into the cartridge.
[0006] Still another objective is to provide such an apparatus which is capable of moving
the cartridges with well controlled velocities and accelerations and with a high degree
of accuracy and repeatability.
[0007] Yet another objective is to provide such an apparatus with features for inhibiting
its operation during some cycles of operation and for preventing overload of its components
in the event of a malfunction.
[0008] These objectives are given only by way of illustrative examples; thus other desirable
objectives and advantages inherently achieved by my invention may occur or become
apparent to those skilled in the art.
[0009] My invention is defined by the claims. One embodiment, of my apparatus is particularly
suited for moving photographic film cartridges between lighted and darkened environments.
The apparatus includes a frame and a cartridge transfer assembly moveably supported
by the frame for movement between a first position for access to the lighted environment
and a second position for access to the darkened environment. A first actuator moves
the transfer assembly between the first and second positions. An extendible transfer
arm is included in the transfer assembly; and a pickup head, supported by the extendible
transfer arm, is provided for grasping a cartridge or releasing a cartridge. A second
actuator moves the pickup head back and forth with the extendible transfer arm at
each of the first and second positions. A light-tight enclosure surrounds the transfer
assembly and pickup head, the enclosure including a first opening to the lighted environment
at the first position and a second opening to the darkened environment at the second
position. A shutter assembly is associated with the enclosure and actuated by the
first actuator, for sequentially blocking the second opening as the transfer assembly
approaches the first position and then unblocking the first opening; and for sequentially
blocking the first opening as the transfer assembly approaches the second position
and then unblocking the second opening.
[0010] The cartridge transfer assembly may be rotatably supported by the frame; the first
actuator may rotate the transfer assembly between the first and second positions;
the extendible transfer arm may be supported by a slide; and the second actuator may
move the transfer arm radially outward and inward at the first and second positions.
The transfer assembly may oscillate between the first and second positions. The cartridge
transfer arm may be mounted on a hollow shaft; and the second actuator may comprise
an actuator rod extended through the hollow shaft, the actuator rod having a driven
end and an output end. A cam may be supported by the frame and operatively connected
for synchronous rotation by the first actuator, the cam being engaged with the driven
end of the actuator rod; and a connector arm may be pivotably connected at one end
to the output end of the actuator rod and pivotably connected at another end to the
transfer arm, so that rotation of the cam causes translational movement of the actuator
rod which causes the connector arm to move the transfer arm radially relative to the
hollow shaft.
[0011] Means may be included for selectively disengaging the cam from the driven end of
the actuator rod, to inhibit radial movement of the transfer arm. This means may include
a cam follower supported by the driven end; a cam follower bracket attached to the
driven end; and a pneumatic actuator connected between the frame and the follower
bracket for selectively disengaging the cam follower from the cam. The connector arm
may be collapsible in case of overload applied to the pickup head. The cam preferably
causes the transfer arm to dwell at the first and second positions.
[0012] The shutter assembly may comprise a drum mounted for rotation with the transfer assembly;
a belt wrapped partially onto and attached to the drum, the belt being made from a
light impervious material but having a first aperture to be positioned opposite the
first opening in the first position and a second aperture to be positioned opposite
the second opening in the second position; and a plurality of rollers supported by
the enclosure for guiding the belt during rotation of the transfer arm and drum between
the first and second positions.
[0013] Numerous advantages are provided by the apparatus of my invention. The apparatus
is fully mechanically integrated to provide highly reliable means for moving film
cartridges from a lighted room into and out of a darkened enclosure. This enables
operation of associated apparatus and activities of human operators to be performed
in the lighted room. The cartridges can be picked and placed with great accuracy.
High operating speeds with controlled accelerations can be achieved. Operation of
the apparatus readily can be inhibited in case of a malfunction. Overload protection
is provided. A single shaft can be used to drive synchronously all the components
of the apparatus.
[0014] The foregoing and other objectives, features and advantages of the invention will
be apparent from the following more particular description of the invention, as illustrated
in the accompanying drawings.
[0015] Figure 1 shows an front elevation view, partially broken away and taken along line
1-1 of Figure 2, of the apparatus of the invention, with the collapsible connector
arm shown only fragmentarily.
[0016] Figure 2 shows a sectional view, partially broken away, taken along line 2-2 of Figure
1.
[0017] Figure 3 shows a side elevation view taken along line 3-3 of Figure 1.
[0018] Figure 4 shows a projected view, partially broken away, taken along line 4-4 of Figure
1, with the collapsible connector arm shown in detail.
[0019] Figure 5 shows a side elevation view of the actuators for the apparatus of Figures
1 to 4.
[0020] Figure 6 shows a plan view of the actuators of Figure 5, taken along line 6-6 of
Figure 5.
[0021] Figure 7 shows a side view of the collapsible connector link, taken along line 7-7
of Figure 4.
[0022] Figure 8 shows a section view taken along lines 8-8 of Figures 4 and 7.
[0023] Figure 9 shows a section view taken along line 9-9 of Figure 4.
[0024] Figure 10 shows a perspective view of certain components of the light lock enclosure,
with the front and back frame plates and the domed cover removed.
[0025] Figure 11 shows an exploded view of the components of Figure 10.
[0026] Figure 12 shows a typical timing diagram for operation of the apparatus.
[0027] Figure 13 shows a section view along line 13-13 of Figure 1.
[0028] Figure 14 shows a section view along line 14-14 of Figure 1.
[0029] Figure 15 shows a section view along line 15-15 of Figure 1.
[0030] Figure 16 shows a plan view of the front frame plate of the light-lock enclosure.
[0031] Figure 17 shows a plan view of the cover frame of the light-lock enclosure.
[0032] Figure 18 shows a plan view of the domed cover of the light-lock enclosure.
[0033] The following is a detailed description of my invention, reference being made to
the drawings in which the same reference numerals identify the same elements of structure
in each of the several Figures.
[0034] Referring simultaneously to Figures 1 to 9, various features of an apparatus 10 according
to my invention may be understood. As seen in Figures 2, 5 and 6, a rigid machine
frame or face plate 12 has a back side 14 to which is mounted a conventional oscillating
drive 16 which produces an oscillating, approximately 90° rotary output in response
to a continuous rotary input. A continuous, rather than oscillating, rotary output
also could be used. A bore 18 through face plate 12 permits access to an output flange
20 of drive 16. Behind face plate 12 is mounted a line or drive shaft 22 which is
operatively connected to drive 16 by a chain or toothed belt 24. Shaft 22 also synchronously
drives an associated apparatus, not illustrated, for processing an empty film cartridge
in a dark room, such as for installing a strip of photographic film. As will be explained
with regard to Figure 12, the speed of rotation of shaft 22 is twice that of input
shaft 23 of drive 16. A support tube or shaft 26 is fixedly mounted for rotation with
flange 20. A ball spline 28 extends through a bore in drive 16 concentric with shaft
26. As seen in Figure 5, a bearing housing or ball spline nut 30 is mounted to the
back side of the casing of drive 16. The front end of the shaft of ball spline 28
is pinned to a shaft coupling 32 which extends beyond the front end of shaft 26. A
rotary bearing 34 is mounted to shaft 26 to support shaft coupling 32 and to permit
the coupling to rotate and move axially within shaft 26. A spherical bearing member
36 is mounted to the front end of coupling 32.
[0035] On the opposite side of face plate 12, as seen in Figures 5 and 6, the back end of
the shaft of ball spline 28 rotatably supports a cam follower 38. A plate cam 40,
mounted for rotation with shaft 22, engages cam follower 38; so that, rotation of
the cam will cause shaft coupling 32 to move axially within shaft 26. Means are provided
to ensure firm engagement between cam follower 38 and cam 40 and also to permit disengagement
of the two to inhibit movement of coupling 32. An L-shaped bracket 42 is fixedly attached
on one leg to the back end of the shaft of ball spline 28. On the other leg of the
bracket, a rod end 44 of a pneumatic actuator 46 is pivotably mounted. A cylinder
end 48 of actuator 46 is pivotably supported on a spline nut support bracket 50 mounted
on the back side of the casing of drive 16. Thus, when actuator 46 is extended by
application of high pressure air from a conventional source, not illustrated, cam
follower 38 is forced into engagement with cam 40. On the other hand, should it be
desired to inhibit movement of coupling 32, actuator 46 may be retracted to prevent
engagement between the cam follower and the cam.
[0036] Turning again to Figure 2, a cylindrical bearing housing 52 is fixedly mounted to
a front surface 54 of face plate 12, concentric with shaft 26. Within housing 52,
a pair of axially spaced bearings 56 are mounted with a bearing spacer 58 between
the bearings in the familiar fashion. A shutter belt drum 60 includes a hollow shaft
62 which is supported on the inner races of bearings 56. Drum 60 further includes
a cylindrical circumferential wall 64 for engaging and guiding a shutter belt 168,
to be described subsequently; and an annular back wall 66 extending between shaft
62 and wall 64. A split collar 68 is mounted on shaft 26 to prevent entry of light
between shaft 26 and shaft 62 from the back side of face plate 12.
[0037] As best seen in Figures 1 and 4, a cartridge transfer assembly is supported by shaft
26. A pinch boss 70 is mounted on shaft 26 within drum 60 and secured by a pair of
bolts 72. Mounted on one side of the pinch block is a drive bracket 74 which carries
a rearwardly extended drive pin 76 which engages a bushing 78 supported on back wall
66. Thus, drum 60 will rotate with shaft 26. Mounted on another side of the pinch
block are a pair of slide mount brackets 80, 82 which extend radially away from the
axis of shaft 26. Between the mount brackets are positioned a pair of radially moveable
slides 84. Mounted between slides 84 is a radially extended transfer arm 86. An opening
88 in circumferential wall 64 permits transfer arm 86 to move radially inward and
outward on the slides, the radially outermost position being shown in Figures 1 and
4. At its outer end, transfer arm 86 supports a vacuum pickup head 90 having a rather
semi-cylindrical cradle 92 for engaging and gripping an essentially cylindrical shell
of a cartridge for photographic film, such as the cartridge disclosed in commonly
assigned U.S. Patents 5,319,407; 5,347,334; and 5,357,303. Of course, other essentially
cylindrical cartridges or objects could be gripped using such a vacuum head. A vacuum
connector 94 extends from one side of transfer arm 86 to connect a source of vacuum,
not illustrated, to vacuum head 90 by means of internal passages, not illustrated,
which extend through the transfer arm. A further pneumatic connector 96 may be provided
to connect a passage from the vacuum head to a pressure sensor, not illustrated, for
detecting the presence of a cartridge properly engaged with the vacuum head. Connecting
conduit or tubing 98 from connector 94 extends rearward through an arcuate opening
100 in back wall 66 of drum 60 and exits the back of a light-lock enclosure 136, to
be described subsequently, as shown in Figure 3.
[0038] As shown fragmentarily in Figures 1 and 2 and in detail in Figure 4, spherical bearing
36 and transfer arm 86 are pivotably connected to a collapsible connector arm 102.
A clevis end 104 is connected to opposite sides of arm 86 at pivot 106, while a socket
joint 108 is connected to bearing 36. As seen in Figures 2 and 4, a disk-shaped hose
guard 110 is mounted to the end of shaft 26 to prevent entanglement of tubing 98 and
connector arm 102 during oscillating rotation of shaft 26. The tubing is routed to
the right of guard 110, as viewed in Figure 2. Guard 110 includes a radial cut-out,
not illustrated, for passage of connector arm 102. Arm 102 comprises a radially outer
link 112 and a radially inner link 114 joined by a collapsible joint 116. As shown
in Figures 4 and 7 to 9, within joint 116, link 112 includes a planar base wall 118
from which extend a pair of parallel side walls 120. Positioned between walls 120,
link 114 includes a planar outer wall 122 from which depends a pair of elongated spring
retention ribs 124. A pair of elongated roller guides 126 is connected between walls
120 and ribs 124. A compression spring 128 is captured between ribs 124. As seen in
Figure 9, spring 128 is held in place at one end by a spring mount 130 supported by
base wall 118. The other end of the spring is held by a similar spring mount, not
illustrated, supported on the underside of outer wall 122. To prevent spring 128 from
forcing links 112, 114 apart, a spring stop 132 is mounted to the free end of outer
wall 122, as seen in Figure 9, in position to engage mount 130. At the free end of
base wall 118, not illustrated, a similar spring stop is mounted to engage the other,
similar spring mount. Thus, if excessive axial force is applied to collapsible arm
102, spring 128 will compress further to allow the arm to shorten and prevent damage.
When the excessive force is relieved, the spring expands to its previous length to
reestablish the desired length the arm.
[0039] As seen in Figure 2, bearing housing 52 includes at its front end a peripheral flange
134 on which is mounted a light-lock enclosure 136. A back frame plate 138 is bolted
directly to flange 134. A front frame plate 140, also shown in Figure 16, is mounted
in front of frame plate 138 by means of a pair of spacer blocks 142, 144 visible in
Figures 1 and 3 and a pair of spacer posts 146, 148 visible in Figures 1 and 13. A
thin gauge, peripheral, light-tight cover shell 150 is captured by a pair of peripheral
grooves 152, 154 provided in frame plates 138, 140, respectively. To enable transfer
arm 86 and vacuum head 90 to extend from within enclosure 136, shell 150 is provided
with an opening 156 from a lighted area and an opening 158 into a dark room area 160.
[0040] Flangeless rollers 162 are mounted between frame plates 138, 140 at essentially right
angle corners of enclosure 136, as seen in Figure 13. Flanged rollers 164 are mounted
between the frame plates at locations along the periphery of enclosure 136 between
rollers 162. Finally, flanged rollers 166 are mounted between the frame plates near
shutter belt drum 60 at about the circumferential limits of travel of transfer arm
86, to guide the shutter belt from the drum. Since rollers 162, 164 are difficult
to observe in the assembled apparatus, their shafts may be provided with end bosses
163 which extend through openings in front plate 140 and support end disks 165. Thus,
an operator can observe disks 165 to confirm that rollers 162, 164 are rotating properly.
A light impervious shutter belt 168 is threaded about drum 60, over the inner sides
of rollers 166 and over the outer sides of rollers 162, 164. The ends of belt 168
are led through an opening 63 in circumferential wall 64 and are held within drum
60 by a clamping block 170 mounted on a radially moveable slide 172 supported by back
wall 66. A set screw 174, threaded through an adjustment block 176 mounted on wall
66, bears on a take-up bracket 178 attached to slide 172. The ends of the belt are
clamped into block 170 and then the radial position of the block is adjusted by rotating
set screw 174 until an appropriate level of tension is achieved in the belt.
[0041] As shown in Figure 11, belt 168 includes an aperture 180 for registration with opening
156 and an aperture 182 for registration with opening 158. Apertures 180, 182 are
spaced along belt 168 so that when one aperture is in registration with its respective
opening, the other aperture is positioned well to one side of its respective opening,
thus ensuring that openings 156, 158 will never be open simultaneously into enclosure
136. To provide further assurance against leakage of light into enclosure 136 through
openings 156, 158, a supplemental light-lock baffle 184 is provided between rollers
162; so that, belt 168 passes between peripheral shell 150 and baffle 184. As shown
in Figures 10 and 11, the baffle includes partially cylindrical portions 185 which
enclose rollers 162, 164. The baffle may be made from thin gauge metal and is captured
by a pair of peripheral grooves 186, 188 provided in frame plates 138, 140, respectively.
See Figures 13 and 14. Baffle 184 includes an aperture 190 for permanent registration
with opening 156 and an aperture 192 for permanent registration with opening 158.
[0042] Light-lock enclosure 136 is closed by means of a domed closure shown in Figures 1,
3 and 16 to 18. As seen in Figures 1 and 16, front frame plate 140 includes a central
opening 194 having an essentially semicircular peripheral portion 196 and an arcuate
or fan-shaped peripheral portion 198. A pair of radially inwardly projecting flanges
200 are provided for mounting of rollers 166. On the underside of plate 140, as viewed
in Figure 16, mounting pockets 202 are provided for rollers 162 and mounting pockets
204 are provided for rollers 164. These pockets appear also in the broken away corners
of Figure 1. On the upper side of plate 140, a peripheral groove 206 surrounds opening
194 to receive a lower land on a cover frame to be described subsequently. A hinge
block 208, shown in Figure 1, is provided for the closure. Mounted on plate 140 is
a cover frame 210, shown in Figure 17, which includes a central opening 212 having
an essentially semicircular peripheral portion 214 and an arcuate or fan-shaped peripheral
portion 216. On the underside of frame 210, a peripheral land 218, shown in phantom
lines in Figure 17, is provided for mating with groove 206 on plate 140 to ensure
light-tightness. On the upper side of frame 210, a peripheral groove 220 surrounds
opening 212 to receive a lower land on a domed cover to be described subsequently.
A pair of hinge bosses 222, 224 are provided for connection to hinge block 208 by
suitable hinge pins 225 shown in Figure 1. A radially extended lifting flange 226,
opposite the hinge bosses, provides a convenient attachment place for a handle 228,
as shown in Figures 1 and 3. Finally, a light-tight domed cover 230 is mounted to
cover frame 210. The domed cover includes an essentially conical half portion 232;
a faceted, fan-shaped half portion 234; and a top panel 236, all suitably joined to
provide a light-tight shell. On the under edge of cover 230, a peripheral land 238
is provided for mating with groove 220 in frame 210. Preferably, a suitable opaque
epoxy is used to seal land 238 within groove 220 to ensure light-tightness.
[0043] In operation of the apparatus of my invention, a cartridge 240 to be moved from a
lighted environment is presented on a suitable conveyor 242 opposite opening 156,
as shown fragmentarily in Figure 3. From the position illustrated in Figure 2, at
which point both oscillating drive 16 and cam 40 are dwelling until a previous cartridge
on vacuum head 90 has been removed by means not illustrated, the apparatus operates
following the cycle illustrated schematically in Figure 12. While oscillating drive
16 dwells and shaft 26 is stationary, cam 40 causes shaft coupling 32 to extend to
the position shown fragmentarily in Figure 2, thus causing connector arm 102 to pull
transfer arm 86 and vacuum head 90 radially inwardly through opening 158 into light-lock
enclosure 136. Oscillating drive 16 then rotates shaft 26 about 90° counter-clockwise,
as seen in Figure 1, until vacuum head 90 is opposite opening 156, at which point
the drive again dwells. Rotation of shaft 26 also rotates shutter drum 60 which pulls
along shutter belt 168 to first cover opening 158 and then expose opening 156, as
the positions of apertures 180, 182 change during rotation. Cam 40 then causes shaft
coupling 32 to retract to the position shown in full in Figure 3, thus causing connector
arm 102 to push transfer arm 86 and vacuum head radially outwardly through opening
156. Drive 16 and cam 40 then dwell until cartridge 240 has been gripped by vacuum
head 90 for removal from conveyor 242. The process then repeats, in reverse.
Having thus described my invention in sufficient detail to enable those skilled in
the art to make and use it, I claim as new and desire to secure Letters Patent for:
1. Apparatus for moving photographic film cartridges between lighted and darkened environments,
comprising:
a frame;
a cartridge transfer assembly moveably supported by the frame for movement between
a first position for access to the lighted environment and a second position for access
to the darkened environment;
a first actuator for moving the transfer assembly between the first and second positions;
an extendible transfer arm included in the transfer assembly;
a pickup head, supported by the extendible transfer arm, for grasping a cartridge
or releasing a cartridge;
a second actuator for moving the pickup head back and forth with the extendible transfer
arm at each of the first and second positions;
a light-tight enclosure surrounding the transfer assembly and pickup head, the enclosure
including a first opening to the lighted environment at the first position and a second
opening to the darkened environment at the second position; and
a shutter assembly associated with the enclosure and actuated by the first actuator,
for sequentially blocking the second opening as the transfer assembly approaches the
first position and then unblocking the first opening; and for sequentially blocking
the first opening as the transfer assembly approaches the second position and then
unblocking the second opening.
2. Apparatus as claimed in Claim 1, wherein the cartridge transfer assembly is rotatably
supported by the frame; the first actuator rotates the transfer assembly between the
first and second positions; the extendible transfer arm is supported by a slide; and
the second actuator moves the transfer arm radially outward and inward at the first
and second positions.
3. Apparatus as claimed in Claim 2, wherein the transfer assembly oscillates between
the first and second positions.
4. Apparatus as claimed in Claim 2, wherein the cartridge transfer arm is mounted on
a hollow shaft; and the second actuator comprises an actuator rod extended through
the hollow shaft, the actuator rod having a driven end and an output end; a cam supported
by the frame and operatively connected for synchronous rotation by the first actuator,
the cam being engaged with the driven end of the actuator rod; a connector arm pivotably
connected at one end to the output end of the actuator rod and pivotably connected
at another end to the transfer arm, so that rotation of the cam causes translational
movement of the actuator rod which causes the connector arm to move the transfer arm
radially relative to the hollow shaft.
5. Apparatus as claimed in Claim 4, further comprising means for selectively disengaging
the cam from the driven end of the actuator rod, to inhibit radial movement of the
transfer arm.
6. Apparatus as claimed in Claim 4, wherein the means for selectively disengaging comprises
a cam follower supported by the driven end; a cam follower bracket attached to the
driven end; and a pneumatic actuator connected between the frame and the follower
bracket for selectively disengaging the cam follower from the cam.
7. Apparatus as claimed in Claim 4, wherein the connector arm is collapsible in case
of overload applied to the pickup head.
8. Apparatus as claimed in Claim 4, wherein the cam causes the transfer arm to dwell
at the first and second positions.
9. Apparatus as claimed in Claim 2, wherein the shutter assembly comprises:
a drum mounted for rotation with the transfer assembly; a belt wrapped partially
onto and attached to the drum, the belt being made from a light impervious material
but having a first aperture to be positioned opposite the first opening in the first
position and a second aperture to be positioned opposite the second opening in the
second position; and a plurality of rollers supported by the enclosure for guiding
the belt during rotation of the transfer arm and drum between the first and second
positions.
10. Apparatus for moving objects from one location to another, comprising:
a frame;
a hollow shaft rotatably supported by the frame;
an object transfer assembly supported on the hollow shaft for movement between a first
position for access to one location and a second position for access to another location;
a first actuator for rotating the hollow shaft between the first and second positions;
an extendible transfer arm included in the transfer assembly;
a pickup head, supported by the extendible transfer arm, for grasping an object or
releasing an object; and
a second actuator for moving the pickup head back and forth with the extendible transfer
arm at each of the first and second positions, the second actuator comprising an actuator
rod extended through the hollow shaft, the actuator rod having a driven end and an
output end; a cam supported by the frame and operatively connected for synchronous
rotation by the first actuator, the cam being engaged with the driven end of the actuator
rod; a connector arm pivotably connected at one end to the output end of the actuator
rod and pivotably connected at another end to the transfer arm, whereby rotation of
the cam causes translational movement of the actuator rod which causes the connector
arm to move the transfer arm radially relative to the hollow shaft.