U.S. patent application number 11/726649 was filed with the patent office on 2007-09-27 for sheet-feed separation mechanism, sheet feeding device, image reading device, and image forming apparatus.
This patent application is currently assigned to Kyocera Mita Corporation. Invention is credited to Tomoya Hotani.
Application Number | 20070222139 11/726649 |
Document ID | / |
Family ID | 38532535 |
Filed Date | 2007-09-27 |
United States Patent
Application |
20070222139 |
Kind Code |
A1 |
Hotani; Tomoya |
September 27, 2007 |
Sheet-feed separation mechanism, sheet feeding device, image
reading device, and image forming apparatus
Abstract
A sheet feeding device that draws out a sheet from a pile of
sheets, including: a sheet tray on which the pile of sheets is
placed; a sheet feeding roller whose peripheral surface is pressed
to abut on a top surface of an uppermost sheet in the pile of the
sheets at a downstream end in a sheet feeding direction of the pile
of sheets; a friction pad disposed oppositely to the sheet feeding
roller to form a nip portion for the sheet with the sheet feeding
roller; and a pushing member that pushes the friction pad in a
direction opposite to the sheet feeding direction.
Inventors: |
Hotani; Tomoya; (Osaka-shi,
JP) |
Correspondence
Address: |
CASELLA & HESPOS
274 MADISON AVENUE
NEW YORK
NY
10016
US
|
Assignee: |
Kyocera Mita Corporation
Osaka-shi
JP
|
Family ID: |
38532535 |
Appl. No.: |
11/726649 |
Filed: |
March 22, 2007 |
Current U.S.
Class: |
271/121 ;
271/122 |
Current CPC
Class: |
B65H 3/5223
20130101 |
Class at
Publication: |
271/121 ;
271/122 |
International
Class: |
B65H 3/52 20060101
B65H003/52 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 2006 |
JP |
2006-080495 |
Claims
1. A sheet-feed separation mechanism, comprising: a sheet feeding
roller that draws out a sheet; a friction pad disposed oppositely
to the sheet feeding roller to form a nip portion for the sheet
with the sheet feeding roller; and a pushing member that pushes the
friction pad in a direction opposite to the sheet feeding
direction.
2. The sheet-feed separation mechanism according to claim 1,
further comprising: a pad holder that supports the friction pad
with a top portion being exposed; and a seat that holds the pad
holder in a manner so as to be able to move in forward and reverse
directions with respect to the sheet feeding direction.
3. The sheet-feed separation mechanism according to claim 2,
wherein: an accommodation concave portion to accommodate the pad
holder in a movable manner is provided by making a recess in a top
surface of the seat.
4. The sheet-feed separation mechanism according to claim 1,
wherein: the pushing member is one of a coil spring, a plate
spring, and an elastomer.
5. A sheet feeding device that draws out a sheet from a pile of
sheets, comprising: a sheet tray on which the pile of sheets is
placed; a sheet feeding roller whose peripheral surface is pressed
to abut on a top surface of an uppermost sheet in the pile of the
sheets at a downstream end in a sheet feeding direction of the pile
of sheets; a friction pad disposed oppositely to the sheet feeding
roller to form a nip portion for the sheet with the sheet feeding
roller; and a pushing member that pushes the friction pad in a
direction opposite to the sheet feeding direction.
6. The sheet feeding device according to claim 5, further
comprising; a pad holder that supports the friction pad with a top
portion being exposed; and a seat that holds the pad holder in a
manner so as to be able to move in forward and reverse directions
with respect to the sheet feeding direction.
7. The sheet feeding device according to claim 6, wherein: an
accommodation concave portion to accommodate the pad holder in a
movable manner is provided by making a recess in a top surface of
the seat.
8. The sheet feeding device according to claim 5, wherein: the
pushing member is one of a coil spring, a plate spring, and an
elastomer.
9. An image reading device, comprising: a device body including an
image reading portion; and a document feeding device that feeds a
document sheet from which image information is read to the image
reading portion, wherein the document feeding device includes: a
sheet tray on which a pile of the document sheet is placed; a sheet
feeding roller whose peripheral surface is pressed to abut on a top
surface of an uppermost sheet in the pile at a downstream end in a
sheet feeding direction of the pile; a friction pad disposed
oppositely to the sheet feeding roller to form a nip portion for
the sheet with the sheet feeding roller; and a pushing member that
pushes the friction pad in a direction opposite to the sheet
feeding direction.
10. The image reading device according to claim 9, further
comprising: a pad holder that supports the friction pad with a top
portion being exposed; and a seat that holds the pad holder in a
manner so as to be able to move in forward and reverse directions
with respect to the sheet feeding direction.
11. The image reading device according to claim 10, wherein an
accommodation concave portion to accommodate the pad holder in a
movable manner is provided by making a recess in a top surface of
the seat.
12. The image reading device according to claim 9, wherein the
pushing member is one of a coil spring, a plate spring, and an
elastomer.
13. An image forming apparatus forming an image according to image
information, comprising: a first sheet feeding device that feeds a
transfer sheet; and/or a second sheet feeding device that feeds a
document sheet from which the image information is read, wherein
one or both of the first sheet feeding device and the second sheet
feeding device include: a sheet tray on which a pile of the
transfer sheet or the document sheet is placed; a sheet feeding
roller whose peripheral surface is pressed to abut on a top surface
of an uppermost sheet in the pile at a downstream end in a sheet
feeding direction of the pile; a friction pad disposed oppositely
to the sheet feeding roller to form a nip portion for the sheet
with the sheet feeding roller; and a pushing member that pushes the
friction pad in a direction opposite to the sheet feeding
direction.
14. The image forming apparatus according to claim 13, further
comprising: a pad holder that supports the friction pad with a top
portion being exposed; and a seat that holds the pad holder in a
manner so as to be able to move in forward and reverse directions
with respect to the sheet feeding direction.
15. The image forming apparatus according to claim 14, wherein: an
accommodation concave portion to accommodate the pad holder in a
movable manner is provided by making a recess in a top surface of
the seat.
16. The image forming apparatus according to claim 13, wherein: the
pushing member is one of a coil spring, a plate spring, and an
elastomer.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sheet-feed separation
mechanism and a sheet feeding device that feed sheets one by one
separately from a pile of sheets, and an image forming apparatus to
which these are applied.
[0003] 2. Description of the Related Art
[0004] Conventionally, a sheet-feed separation mechanism, such as
those disclosed in JP-A-4-354740 (Reference 1) and JP-A-2005-67784
(Reference 2), has been known.
[0005] The sheet-feed separation mechanism of Reference 1 is
provided correspondingly to a sheet feeding container (sheet tray)
in an image forming apparatus, such as a copying machine and a
facsimile machine, and it draws out sheets one by one from a pile
of sheets stored in the sheet tray and feeds them toward the image
forming apparatus. This sheet-feed separation mechanism is formed
of a sheet feeding roller that is provided at the downstream end in
a sheet carrying direction in the sheet tray and driven to rotate
about the central axis thereof, and a friction pad that abuts on
the peripheral surface of the sheet feeding roller at the lower
portion of the sheet feeding roller. The sheet feeding roller and
the friction pad are made of materials having large coefficients of
friction, such as rubber. The friction pad presses the peripheral
surface of the sheet feeding roller with a pushing force of the
spring.
[0006] In a pile of sheets stored in the sheet tray, the uppermost
sheet is pushed upward by specific pushing means while the top
surface thereof abuts on the lower peripheral surface of the sheet
feeding roller and the edge of the top surface at a downstream side
of the sheet is stopped by abutting on the friction pad. By
rotationally driving the sheet feeding roller in this state, the
uppermost sheet is pulled out from the sheet tray as it is guided
by the peripheral surface of the sheet feeding roller having a
large coefficient of friction, and fed to the inside of the image
forming apparatus.
[0007] With the sheet-feed separation mechanism configured as
above, in a case where, for example, two sheets are pulled out from
the sheet tray in association with the driven rotations of the
sheet feeding roller, these two sheets are brought in a state where
they are nipped between the peripheral surface of the sheet feeding
roller that is driven-rotating and the top surface of the friction
pad. In this state, the frictional force between the uppermost
sheet and the second sheet is not only smaller than the frictional
force between the uppermost sheet and the peripheral surface of the
sheet feeding roller, but is also smaller than the frictional force
between the second sheet and the top surface of the friction pad.
Hence, the uppermost sheet is pulled out by the sheet feeding
roller whereas the second sheet will not be pulled out as it is
interfered with by the friction pad. It is thus possible to prevent
an event that two sheets are fed at a time, that is, so-called
two-sheet feeding.
[0008] The sheet-feed separation mechanism of Reference 2 is
provided to the document tray of a copying machine, a facsimile
machine, or the like, and it draws out documents one by one from a
pile of documents that is formed of plural stacked documents and
placed on the document tray, and feeds them to the document reading
portion.
[0009] Basically, as with the one disclosed in Reference 1, this
separation mechanism is formed of a sheet feeding roller provided
at the end of the document tray on the document reading portion
side and driven to rotate about the central axis thereof, and a
friction pad that abuts on the peripheral surface of the sheet
feeding roller at the lower portion of the sheet feeding roller.
The two-sheet feeding of the documents is prevented by the same
function as that of Reference 1. However, in contrast to Reference
1 where the friction pad is not allowed to oscillate, the friction
pad is attached to the pad holder configured to be able to
oscillate in the top-bottom direction.
[0010] Reference 2 describes that it is possible to suppress
vibrations of a document by allowing the friction pad to oscillate
while the document is fed, which can in turn eliminate so-called
fluttering sounds produced when the document vibrates finely while
being fed.
[0011] Both the sheet-feed separation mechanisms of Reference 1 and
Reference 2, however, have a problem that the two-sheet feeding
occurs in some cases under a circumstance that the uppermost sheet
and the second sheet are not separated easily because each sheet is
not readily peeled at the edge in the pile of sheets depending on
the kinds of sheet or the cut finishing.
SUMMARY OF THE INVENTION
[0012] An advantage of the invention is to provide a sheet-feed
separation mechanism and a sheet feeding device capable of
preventing two-sheet feeding in a reliable manner, and an image
reading device or an image forming apparatus to which these are
applied.
[0013] A sheet-feed separation mechanism according to one aspect of
the invention that achieves the above advantage includes: a sheet
feeding roller that draws out a sheet; a friction pad disposed
oppositely to the sheet feeding roller to form a nip portion for
the sheet with the sheet feeding roller; and a pushing member that
pushes the friction pad in a direction opposite to the sheet
feeding direction.
[0014] A sheet feeding device according to another aspect of the
invention is a sheet feeding device that draws out a sheet from a
pile of sheets, including: a sheet tray on which the pile of sheets
is placed; a sheet feeding roller whose peripheral surface is
pressed to abut on a top surface of an uppermost sheet in the pile
of the sheets at a downstream end in a sheet feeding direction of
the pile of sheets; a friction pad disposed oppositely to the sheet
feeding roller to form a nip portion for the sheet with the sheet
feeding roller; and a pushing member that pushes the friction pad
in a direction opposite to the sheet feeding direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIGS. 1A and 1B are sectional side views of a printer to
which a sheet-feed separation mechanism according to one embodiment
of the invention is applied, FIG. 1A showing a state where a sheet
cassette is accommodated at an accommodation position and FIG. 1B
showing a state where the sheet cassette is pulled out to a
pull-out position.
[0016] FIG. 2 is a perspective view showing one embodiment of a
sheet feeding device.
[0017] FIG. 3 is an exploded perspective view showing one
embodiment of the sheet-feed separation mechanism.
[0018] FIG. 4 is an assembly perspective view of the sheet-feed
separation mechanism shown in FIG. 3.
[0019] FIGS. 5A and 5B are cross sections taken on line V-V of FIG.
4, FIG. 5A showing a state where a friction pad is located at a
home position and FIG. 5B showing a state where the friction pad is
located at a pushing force conferring position.
[0020] FIGS. 6A through 6E are explanatory views to describe the
function of the sheet-feed separation mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIGS. 1A and 1B are explanatory views when viewed in a
cross-sectional transverse plane schematically showing the inner
structure of one example of a printer 10 to which one embodiment of
a sheet-feed separation mechanism of the invention is applied. FIG.
1A shows a state where a sheet cassette 31 is accommodated at an
accommodation position T1, and FIG. 1B shows a state where the
sheet cassette 31 is pulled out to a pull-out position T2. In FIGS.
1A and 1B, the Y-Y direction is defined as the front-back
direction, and in particular, the -Y direction is defined as the
front and the +Y direction as the rear.
[0022] The printer 10 includes a sheet feeding device 30 configured
to store sheets P1 used for print processing and to draw out sheets
P1 one by one from a stored pile of sheets P1 (a pile of sheets, P)
or to feed a sheet P1 manually. The printer 10 further includes an
image forming portion 20 that applies transfer processing of an
image to a sheet P1 fed from the sheet feeding device 30, a fixing
portion 27 that applies fixing processing to a sheet P1 done with
the transfer processing in the image forming portion 20, both of
which are installed inside an apparatus main body 11 at a position
above a partition wall 115. A sheet P1 done with the fixing
processing in the fixing portion 27 is discharged onto a sheet
discharge tray 117 formed on top of the apparatus main body 11.
[0023] The sheet feeding device 30 (sheet feeding device or first
sheet feeding device as claimed) is formed of a sheet cassette 31
attached to the apparatus main body 11 in a reattachable manner for
storing the pile of sheets, P, and a manual sheet feeding portion
38 provided at a front end portion of the sheet cassette 31. The
apparatus main body 11 is provided with a sheet feeding roller 311
having a large diameter for drawing out the sheets P1 one by one
from the top in the pile of sheets, P, at a position corresponding
to the upstream end (front side) of the sheet cassette 31, and a
carrying roller 312 having a small diameter at a position directly
above the sheet feeding roller 311.
[0024] A sheet P1 drawn out from the sheet cassette 31 by the
driving of the sheet feeding roller 311 is fed to the image forming
portion 20 via the carrying roller 312 by passing through a
sheet-feed carrying path 313 and a pair of register rollers 314
provided at the downstream end thereof. The sheet cassette 31 will
be described again below in reference to FIG. 2.
[0025] The image forming portion 20 is to apply the transfer
processing to a sheet P1 according to image information transmitted
from a computer or the like. The image forming portion 20 is formed
of a photoconductive drum 21 provided in a rotatable manner about
the central axis thereof extending in the right-left direction (a
direction perpendicular to the sheet surface of FIG. 1), plus a
charger 22, an exposing device 23, a developing device 24, a
transfer roller 25, and a cleaning device 26, which are disposed
sequentially in a clockwise direction from the position directly
above the photoconductive drum 21 to go along the peripheral
surface thereof.
[0026] The photoconductive drum 21 is to form an electrostatic
latent image and a toner image corresponding to the electrostatic
latent image on the peripheral surface thereof. An amorphous
silicon layer suitable to form an electrostatic latent image and a
toner image is layered on the peripheral surface of the
photoconductive drum 21.
[0027] The charger 22 is to form charges uniformly on the
peripheral surface of the photoconductive drum 21 that is rotating
about the central axis thereof in a clockwise direction. In this
embodiment, it adopts the corona discharge method, by which charges
are conferred to the peripheral surface of the photoconductive drum
21 by means of corona discharge from the wire. Instead of this
method, the charging roller method may be adopted, by which charges
are conferred to the peripheral surface of the photoconductive drum
21 while being driven rotated with its peripheral surface abutting
on the peripheral surface of the photoconductive drum 21.
[0028] The exposing device 23 irradiates a laser beam having
differences in intensity according to the image data sent from an
outside device, such as a computer, to the peripheral surface of
the photoconductive drum 21 that is rotating. Charges are erased
from a portion where a laser beam was irradiated, and an
electrostatic latent image is consequently formed on the peripheral
surface of the photoconductive drum 21.
[0029] The developing device 24 is to form a toner image on the
peripheral surface of the photoconductive drum 21 by supplying
toner particles contained in the developing agent to the peripheral
surface of the photoconductive drum 21 for the toner particles to
adhere onto the peripheral surface in a portion where the
electrostatic latent image has been formed. As the developing
agent, for example, those based on a two-component made of toner
and a carrier can be adopted. As the toner particles, fine powder
having a particle size of 6 to 12 .mu.m and formed by dispersing a
coloring agent, a charge control agent, and additive agents, such
as wax, into binder resin can be adopted. As the carrier, magnetic
particles having a particle size of 60 to 200 .mu.m, such as
magnetite (Fe.sub.3O.sub.4), can be adopted.
[0030] The transfer roller 25 transfers a toner image formed on the
peripheral surface of the photoconductive drum 21 and charged
positively onto a sheet P1 sent to a position directly below the
photoconductive drum 21. The transfer roller 25 confers negative
charges of the polarity opposite to that of the charges of the
toner image to the sheet P1.
[0031] A sheet P1 having reached the position directly below the
photoconductive drum 21 undergoes the transfer processing while
being pressed and nipped by the transfer roller 25 and the
photoconductive drum 21. The transfer processing is the processing
to strip the toner image on the peripheral surface of the
photoconductive drum 21 toward the surface of the negatively
charged sheet P1.
[0032] The cleaning device 26 is to clean the photoconductive drum
21 after the transfer processing to the sheet P1 by removing toner
remaining on the peripheral surface thereof. The peripheral surface
of the photoconductive drum 21 cleaned by the cleaning device 26
heads for the charger 22 again for the following image forming
processing.
[0033] The fixing portion 27 applies fixing processing by heating
to a toner image on the sheet P1 done with the transfer processing
in the image forming portion 20. The fixing portion 27 includes a
heat roller 271 to which a current-carrying heat generator, such as
a halogen lamp, is attached in the inside, and a pressure roller
272 disposed below the heat roller 271 in such a manner that their
peripheral surfaces oppose each other. A sheet P1 done with the
transfer processing undergoes fixing processing by receiving heat
from the heat roller 271 as it passes by the nip portion between
the heat roller 271 that is driven to rotate about the central axis
thereof in a clockwise direction and the pressure roller 272 that
is driven rotated about the central axis thereof in a
counter-clockwise direction. The sheet P1 done with the fixing
processing is discharged onto the sheet discharge tray 117 by
passing through a sheet discharging and carrying path 273.
[0034] The manual feeding portion 38 includes a front wall 381 and
a manual tray 382 supported on the front wall 381. The front wall
381 is used as a guide plane that guides a sheet P1 from the sheet
feeding roller 311 to the image forming portion 20.
[0035] Hereinafter, the sheet feeding device 30 will be described
in detail in reference to FIG. 2. FIG. 2 is a perspective view
showing one embodiment of the sheet feeding device 30. In FIG. 2,
the X-X direction is defined as the right-left direction and the
Y-Y direction is defined as the front-back direction. In
particular, the -X direction is defined as the left, the +X
direction as the right, the -Y direction as the front, and the +Y
direction as the rear.
[0036] The sheet feeding device 30 includes the sheet cassette 31
and the manual sheet feeding portion 38 formed at the front end
position of the sheet cassette 31. The sheet cassette 31 is formed
of an arc-shaped front plate 32 whose front surface is provided to
swell outwards (frontward) in an arc shape when viewed in a plane,
a bottom plate 33 provided to extend backward from the lower edge
of the arc-shaped front plate 32 on the back surface (rear surface)
side, and a pair of side plates 34 provided to stand upward from
the both sides on the right and the left of the bottom plate 33 and
extending in the front-back direction, and it exhibits a
rectangular box shape with an open top surface when viewed in a
plane.
[0037] A pair of guided protruding pieces 341 protruding in
directions opposite to each other is provided to each side plate 34
at an appropriate portion. Meanwhile, a pair of side plates 111
(FIG. 1B) of the apparatus main body 11 is provided with recesses
that define guide grooves 111a extending in the front-back
direction and corresponding to the guided protruding pieces 341.
The sheet cassette 31 is allowed to change the positions between an
accommodation position T1 (FIG. 1A) at which it is accommodated in
the apparatus main body 11 and a pull-out position T2 (FIG. 1B) at
which it protrudes to the outside from the apparatus main body 11,
as the respective guided protruding pieces 341 move in forward and
reverse directions by being guided by these guide grooves 111a.
[0038] The bottom plate 33 is provided with a front-back movement
guiding concave portion 331 that extends in the front-back
direction on the top surface side at the center position in the
right-left direction, and a front-back position limiting member 35
that is allowed to move in the front-back direction by being guided
by the front-back movement guiding concave portion 331. The
limiting member 35 is to limit the position of the rear end of the
pile of sheets, P (FIGS. 1A and 1B), placed on the bottom plate 33,
and has a horizontal plate 351 that slides inside the front-back
movement guiding concave portion 331 and a vertical plate 352
provided to stand up from the rear end portion of the horizontal
plate 351. The vertical plate 352 is moved to match the sheet size
and stopped by abutting on the rear end of the pile of sheets,
P.
[0039] In addition, the bottom plate 33 is provided with a
crosswise pair of right-left movement guiding concave portions 332
at the front position of the top surface, and a pair of right/left
position limiting members 36 that are allowed to move in the
right-left direction by being guided these right-left movement
guiding concave portions 332. These limiting members 36 are to
limit the right and left positions of the pile of sheets, P, placed
on the bottom plate 33, and have horizontal plates 361 that slide
inside the corresponding guiding concave portions 332 and vertical
plates 362 provided to stand up from the edge portions of the
corresponding horizontal plates 361 on the opposite sides in the
right-left direction. By moving these limiting members 36 by the
same quantity in the opposite directions to match the sheet size,
it is possible to pinch the pile of sheets, P, between the pair of
vertical plates 362.
[0040] The pile of sheets, P, placed on the bottom plate 33 of the
sheet cassette 31 is thus positioned inside the sheet cassette 31
with the front end being stopped by abutting on the front wall 381
by being pinched by the front-back position limiting member 35 and
the pair of right/left position limiting members 36.
[0041] At the front half position of the bottom plate 33, a pushing
plate 37 is provided, which pushes upward the front half of the
pile of sheets, P, placed in a state not to interfere with the
right/left position limiting members 36. The pushing plate 37 is
axially supported on a supporting shaft 371 (FIGS. 1A and 1B)
extending in the right-left direction at the rear end so as to be
able to rotate about the supporting shaft 371, and it is pushed
upward by a coil spring 372.
[0042] This configuration allows the uppermost sheet P1 in the pile
of sheets, P, loaded in the sheet cassette 31 to abut on the sheet
feeding roller 311 in a state where the sheet cassette 31 is
accommodated inside the apparatus main body 11 (FIG. 1A).
Accordingly, the sheets P1 in the pile of sheets, P, are
successively sent out toward the image forming portion 20 from the
top in association with the driven rotations of the sheet feeding
roller 311 via the sheet feeding roller 311, the carrying roller
312, the sheet-feed carrying path 313, and the pair of register
rollers 314.
[0043] In the sheet feeding device 30 configured as described
above, a sheet-feed separation mechanism 40 of the invention is
provided to the front wall 381. Hereinafter, the sheet-feed
separation mechanism 40 will be described in reference to FIG. 3
through FIG. 5B. FIG. 3 is an exploded perspective view showing one
embodiment of the sheet-feed separation mechanism 40, and FIG. 4 is
an assembly perspective view. FIGS. 5A and 5B are cross sections of
the sheet-feed separation mechanism 40 taken on line V-V of FIG. 4.
FIG. 5A shows a state where a friction pad 70 is located at a home
position S1, and FIG. 5B shows a state where the friction pad 70 is
located at a pushing force conferring position S2. The directions
indicated using X and Y in FIG. 3 through FIG. 5B are defined in
the same manner as FIG. 2, and X is defined as the right-left
direction (-X: left, +X: right) and Y is defined as the front-back
direction (-Y: front, +Y: rear).
[0044] As is shown in FIG. 3, the sheet-feed separation mechanism
40 is formed of a pedestal member (seat) 50 fit in the front wall
381 of the manual feeding portion 38 (FIG. 2) at the center
position in the right-left direction, a pad supporting movable
member (pad holder) 60 attached to the pedestal member 50 so as to
be movable in forward and reverse directions with respect to the
sheet carrying direction, a friction pad 70 attached to the pad
supporting movable member 60, and a coil spring 80 that pushes the
pad supporting movable member 60 so as to be pressed toward the
downstream end in the sheet carrying direction.
[0045] When viewed in a side plane corresponding to the rear
surface of the front wall 381, the pedestal member 50 is set in a
shape that the top half is bent forward. The pedestal member 50 is
formed of a crosswise pair of legs 51, and a pad holding member 52
bridged between the upper edge portions of the pair of legs 51 and
inclined forward by about 30.degree. with respect to a direction
along which the legs 51 extend.
[0046] The pad holding member 52 is set to a position at which the
surface thereof opposes the peripheral surface of the sheet feeding
roller 311 while the sheet cassette 31 is positioned at the
accommodation position T1 (FIG. 1A). The pad holding member 52
includes a surface plate 53 whose main surface side is inclined
upward toward the front, an almost vertical back surface plate 54
disposed oppositely to the surface plate 53 at the front, a
crosswise pair of side plates 55 each provided to bridge between
the back surface plate 54 and the front surface plate 53 on their
respective edges, a top plate 56 provided to bridge between the
back surface plate 54 and the front surface plate 53 on their
respective upper edge portions, and a bottom surface is an open
state. Each leg 51 is provided to extend downward from the lower
portion at the rear end of each side plate 55.
[0047] The surface plate 53 is provided with a rectangular
attachment concave portion 531 formed by providing a recess in
almost the entire surface for the pad supporting movable member 60
to be attached thereto. The recessed quantity of the attachment
concave portion 531 is set so that the depth across the surface is
slightly larger than the top-bottom dimension of the pad supporting
movable member 60. This configuration prevents the pad supporting
movable member 60 from protruding to the outside from the
attachment concave portion 531 when attached to the inside of the
attachment concave portion 531. A bottom surface plate 532 of the
attachment concave portion 531 formed in this manner is parallel to
the surface plate 53.
[0048] The bottom surface plate 532 is provided with a connecting
opening 533 that crosses the bottom surface plate 532 in the width
direction at the center position in the right-left direction. The
connecting opening 533 is provided to transmit a pushing force of
the coil spring 80 attached to the back surface of the bottom
surface plate 532 to the pad supporting movable member 60. Also,
the bottom surface plate 532 is provided with a crosswise pair of
guide rails 534 that swell toward the front surface and extend in
the width direction of the bottom surface plate 532. These guide
rails 534 are to guide movements of the pad supporting movable
member 60 inside the attachment concave portion 531.
[0049] The attachment concave portion 531 is set in such a manner
that the top-bottom width dimension is almost twice as large as the
width dimension of the pad supporting movable member 60, and the
right-left dimension is slightly larger than the right-left
dimension of the pad supporting movable member 60. This
configuration allows the pad supporting movable member 60 to move
in forward and reverse direction in the inclined direction by
sliding on the bottom surface plate 532 inside the attachment
concave portion 531 by a quantity almost comparable to its own
width dimension.
[0050] The pedestal member 50 configured in this manner has
supporting point shafts 57 provided to protrude in the opposite
directions at positions in close proximity to the legs 51 at the
lower portion of the side plates 55, and is supported on the front
wall 381 (FIG. 2) so as to be able to rotate about the supporting
point shafts 57. Also, the upper portion of the back surface plate
54 is pressed backward by a pushing force of a pressing spring 58.
Accordingly, the pedestal member 50 receives a pressing force
heading to a counter-clockwise direction about the supporting point
shafts 57 from the pressing spring 58, and the friction pad 70 is
pressed and stopped by abutting on the peripheral surface of the
sheet feeding roller 311.
[0051] The pad supporting movable member 60 is to support the
friction pad 70, and in this embodiment, it is formed by press
processing to bend a pair of side edge portions of a long metal
plate of a rectangular shape in the same direction. The pad
supporting movable member 60 formed in this manner includes a
bottom plate 61 whose dimension is set in such a manner that the
length dimension in the right-left direction is slightly smaller
than the inner dimension in the right-left direction of the
attachment concave portion 531, and a pair of side plates 62
provided to protrude upward from the both side edge portions of the
bottom plate 61 and extending in the right-left direction. The
height dimension of each side plate 62 is set to be slightly
smaller than the recessed quantity of the attachment concave
portion 531.
[0052] In the pad supporting movable member 60 configured in this
manner, the bottom plate 61 is provided with a pair of guided slits
611 made by means of punching whose position and dimension are set
in such manner that they externally fit to the pair of the guide
rails 534 provided to the bottom surface plate 532 of the pedestal
member 50 in a sliding contact state. As the pad supporting movable
member 60 is attached to the attachment concave portion 531, the
pair of guided grooves 611 fit to the corresponding guide rails
534. This allows the pad supporting movable member 60 to move in
forward and reverse directions in the width direction of the
attachment concave portion 531 in a stable state where each guided
groove 611 is guided by the corresponding guide rail 534.
[0053] Also, in the pad supporting movable member 60 configured in
this manner, the side plate 62 on the rear is provided with a
protruding piece 621 provided to protrude downward from the center
position in the right-left direction. In this embodiment, the
protruding piece 621 is formed by carving up the bottom plate 61
downward.
[0054] The protruding piece 621 is to support the base end (lower
portion) of the coil spring 80. In order to ensure this supporting,
a circular cylindrical piece 622 whose diameter dimension is
slightly smaller than the minor diameter dimension of the coil
spring 80 is provided to the protruding piece 621 on the front
surface side so as to protrude forward. By externally fitting the
base end side of the coil spring 80 to the circular column piece
622, the coil spring 80 is prevented from falling off from the
protruding piece 621.
[0055] The friction pad 70 is provided to prevent two-sheet feeding
of sheets P1 by forming a nip portion with the sheet feeding roller
311 and by nipping a sheet P1 therein. The friction pad 70 is set
in such a manner that the length dimension is almost equal to the
length dimension of the pad supporting movable member 60, the width
dimension is slightly larger than the inner dimension between the
pair of side plates 62 of the pad supporting movable members 60,
and the thickness dimension is slightly larger than the top-bottom
dimension of the side plate 62 of the pad supporting movable member
60.
[0056] The friction pad 70 is fit in a space between the pair of
side plates 62 while it undergoes compressive elastic deformation
in the width direction. When attached to the pad supporting movable
member 60, the friction pad 70 is inhibited from falling off from
the pad supporting movable member 60 by its own elasticity, and the
main surface side protrudes upward from the upper edge portion of
the respective side plates 62. As the pad supporting movable member
60 is attached to the attachment concave portion 531 in this state,
the top surface of the friction pad 70 slightly protrudes to the
outside from the attachment concave portion 531.
[0057] The friction pad 70 is made of an elastomer, such as rubber
and a soft synthetic resin material, and it confers an adequate
frictional force to a sheet P1 while the sheet P1 is nipped between
the sheet feeding roller 311 and the friction pad 70. The material
of the friction pad 70 is chosen so that the frictional force
developed between the friction pad 70 and the sheet P1 becomes
smaller than the frictional force developed between the sheet
feeding roller 311 and the sheet P1. This configuration allows the
sheet P1 nipped between the sheet feeding roller 311 and the
friction pad 70 to be drawn out from the pile of sheets, P, in
association with the rotations of the sheet feeding roller 311 as
the sheet feeding roller 311 rotates about the central axis
thereof.
[0058] As the material of the friction pad 70, for example,
urethane cork-rubber can be used. For the sheet feeding roller 311,
EPDM (Ethylene propylene dienmonomer) can be used. Besides the
foregoing, various kinds of elastomer can be adopted as long as it
satisfies the condition that a frictional force developed with the
sheet P1 is smaller with the friction pad 70 than with the sheet
feeding roller 311.
[0059] The coil spring 80 is to confer a pushing force to the pad
supporting movable member 60 to locate the friction pad 70 at the
home position S1 via the pad supporting movable member 60. As is
shown in FIGS. 5A and 5B, with this coil spring 80, one end portion
in a compressed state externally fits to the circular column piece
622 provided to the protruding piece 621 of the pad supporting
movable member 60, while the other end portion is stopped by
abutting on the corner defined by the back surface plate 54 and the
top plate 56 in the pad holding portion 52 of the pedestal member
50.
[0060] When the friction pad 70 is located at the home position S1
as is shown in FIG. 5A, the pushing force of the coil spring 80 is
smaller than the frictional force between the sheet P1 and the
friction pad 70. On the other hand, when the friction pad 70 is in
a state where it has moved to the pushing force conferring position
S2 as is shown in FIG. 5B, the pushing force of the coil spring 80
is larger than the frictional force between the sheet P1 and the
friction pad 70.
[0061] While the sheet feeding roller 311 is at rest, the friction
pad 70 is pressed backward by the pushing force of the coil spring
80 via the pad supporting movable member 60. The friction pad 70 is
thus located at the home position S1 as is shown in FIG. 5A.
[0062] On the contrary, when the sheet feeding roller 311 is driven
and starts to be driven to rotate about the central axis thereof in
a counter-clockwise direction while the uppermost sheet P1 in the
pile of sheets, P, abuts on the peripheral surface of the sheet
feeding roller 311, as is shown in FIG. 5B, the uppermost sheet P1
is guided by rotations of the sheet feeding roller 311 and pulled
out from the pile of sheets, P. Subsequently, the sheet P1 passes
by the nip portion N between the peripheral surface of the sheet
feeding roller 311 and the top surface of the friction pad 70.
[0063] In this instance, the friction pad 70 moves obliquely upward
toward the front while compressing the coil spring 80 against the
pushing force of the coil spring 80, which gives rise to a state
where the frictional force and the pushing force act against each
other. The friction pad 70 therefore ceases to move and is located
at the pushing force conferring position S2 (FIG. 5B) to confer the
pushing force of the coil spring 80 to the sheet P1.
[0064] The sheet P1 is drawn out from the pile of sheets, P1 in
this state. When the drawing out of the uppermost sheet P1 in the
pile of sheets, P, is completed, the friction pad 70 returns to the
home position S1 shown in FIG. 5A, and is used to draw out the
following sheet P1.
[0065] Hereinafter, the function of the sheet-feed separation
mechanism 40 will be described more in detail in reference to FIGS.
6A through 6E. FIG. 6A and FIG. 6B show a function of the
sheet-feed separation mechanism 40 with time when only a single
sheet P1 at the top is drawn out from the pile of sheets, P. FIG.
6C through FIG. 6E show a function of the sheet-feed separation
mechanism 40 with time in the case of so-called two-sheet drawing
by which two sheets P1, the uppermost sheet P1 and the second sheet
P1, are drawn out at a time from the pile of sheets, P. Indications
of the direction using Y in FIGS. 6A through 6E are the same as
those in FIG. 2 (-Y: front, +Y: rear).
[0066] Initially, the pedestal member 50 is pushed by the pushing
force of the pressing spring 58 about the supporting point shafts
57 in a counter-clockwise direction and the friction pad 70 is
pressed against the peripheral surface of the sheet feeding roller
311, which produces the nip portion N between the friction pad 70
and the sheet feeding roller 311 to nip a sheet P1.
[0067] As the sheet feeding roller 311 is driven to rotate about
the central axis thereof in a counter-clockwise direction in this
state (a state where the friction pad 70 is located at the home
position S1), the uppermost sheet P1 in the pile of the sheets, P,
pushed upward by the pushing plate 37 is drawn out forward as is
shown in FIG. 6A and the tip end of the sheets P1 reaches the nip
portion N. At a point in time at which the sheet P1 has reached the
nip portion N, the friction pad 70 stays at the home position
S1.
[0068] Because the driven rotations of the sheet feeding roller 311
are continued at this point in time, the sheet P1 is kept guided by
the rotations of the sheet feeding roller 311 and thereby moves
forward. In this instance, the friction pad 70 is guided by the
movement of the sheet P1 and moves obliquely upward toward the
front inside the attachment concave portion 531 against the pushing
force of the coil spring 80, and is thereby located at the pushing
force conferring position S2 as is shown in FIG. 6B.
[0069] In a state located at the pushing force conferring position
S2, the friction pad 70 tries to push the sheet P1 positioned in
the nip portion N backward using the pushing force of the coil
spring 80 having undergone compressive elastic deformation.
However, because the frictional force between the friction pad 70
and the sheet P1 is smaller than the frictional force between the
sheet feeding roller 311 and the sheet P1, the sheet P1 is pulled
forward in association with the rotations of the sheet feeding
roller 311 without being pushed back by the friction pad 70.
[0070] When the drawing out processing of the uppermost sheet P1
from the pile of sheets, P, is completed and the driven rotations
of the sheet feeding roller 311 are suspended to prepare for the
drawing out of the following sheet P1, the friction pad 70 is
returned to the home position S1 from the pushing force conferring
position S2 by the pushing force of the coil spring 80. By driving
and suspending the sheet feeding roller 311 repetitively, it is
possible to feed the sheets P1 one by one from the pile of sheets,
P, toward the image forming portion 20.
[0071] The function of the friction pad 70 when two sheets P1 are
drawn out at a time from the pile of sheets, P, in association with
the driven rotations of the sheet feeding roller 311 will now be
described in reference to FIG. 6C through FIG. 6E. In a case where
two sheets P1 are drawn out at a time from the pile of sheets, P,
in association with driven rotations of the sheet feeding roller
311, as is shown in FIG. 6C, two sheets P1 (hereinafter, the
uppermost sheet P1 is referred to as the uppermost sheet P11 and
the second sheet P1 as the following sheet P12) reach the nip
portion N at the same time.
[0072] In this state, as the driven rotations of the sheet feeding
roller 311 are continued, the friction pad 70 is guided by the two
sheets P1 that rotate in association with the sheet feeding roller
311, and, as is shown in FIG. 6D, is moved once to the pushing
force conferring position S2. In this instance, static friction is
acting between the uppermost sheet P11 and the following sheet
P12.
[0073] However, because the frictional force between the uppermost
sheet P11 and the sheet feeding roller 311 is larger than the
frictional force between the uppermost sheet P11 and the following
sheet P12 and the pushing force of the coil spring 80 heading
backward is conferred to the following sheet P12 via the friction
pad 70 owing to the frictional force between the friction pad 70
and the following sheet P12, sliding occurs between the uppermost
sheet P11 and the following sheet P12. This gives rise to dynamical
friction between the uppermost sheet P11 and the following sheet
P12.
[0074] Because the dynamical friction is smaller than the static
friction, the friction pad 70 is no longer able to stay at the
pushing force conferring position S2 against the pushing force of
the coil spring 80. Accordingly, under the circumstances that the
uppermost sheet P11 is guided by the sheet feeding roller 311 and
kept drawn out forward, as is shown in FIG. 6E, the friction pad 70
is moved toward the home position S1 together with the following
sheet P12 by the pushing force of the coil spring 80.
[0075] As has been described, even when two sheets P1 are drawn out
at a time from the pile of sheets, P, in association with driven
rotations of the sheet feeding roller 311, as is shown in FIG. 6E,
the friction pad 70, on which the following sheet P12 is abutting,
pushes the following sheet P12 backward by the pushing force of the
coil spring 80. It is thus possible to prevent reliably two sheets
P1 from being fed at a time toward the image forming portion 20 by
the sheet feeding roller 311.
[0076] Besides a case where two sheets P1 are drawn out at a time,
in a case where three or more sheets P1 are drawn out at a time, it
is also possible to prevent reliably more than one sheet P1 from
being fed to the image forming portion 20 by the function of the
friction pad 70 to which the pushing force is conferred from the
coil spring 80 in the same manner as above.
[0077] As has been described in detail, the sheet-feed separation
mechanism 40 of this embodiment includes the sheet feeding roller
311 whose peripheral surface is pressed to abut on the top surface
of the uppermost sheet P1 at the downstream end of the pile of
sheets, P, placed on the pushing plate 37 in the sheet cassette 31,
and the friction pad 70 disposed oppositely to the sheet feeding
roller 311 at the lower portion via the uppermost sheet P1. The
friction pad 70 is pushed in a direction opposite to the sheet
carrying direction by the pushing force of the coil spring 80.
[0078] Hence, even when more than one sheet is drawn out at a time
from the pile of sheets, P, the uppermost sheet P1 is fed by being
guided by the driven rotations of the sheet feeding roller 311
whereas the second sheet P1 is pushed backward in association with
the friction pad 70 that was shifted once to the pushing force
conferring position S2 from the home position S1 and is now
returned to the home position S1 by the pushing force of the coil
spring 80. It is thus possible to prevent reliably the occurrence
of an inconvenience that more than one sheet P1 is fed to the image
forming portion 20 at a time.
[0079] A frictional force or the like between the sheets varies
with the kind of the sheets P1, and so does a force needed to
appropriately draw out the sheet P1. In this embodiment, however,
the friction pad 70 moves to a position corresponding to the
frictional force between the sheets. Hence, the friction pad 70
moves to the appropriate position that can act against the
frictional force between the sheets whenever two sheets are drawn
out regardless of the kind of sheets. The friction pad 70 is then
pushed back by the coil sprig 80 together with the second sheet
alone. In short, the invention is applicable to a pile of sheets
having a different peeling force between the sheets. It is
therefore possible to prevent reliably the occurrence of an
inconvenience that a defect (that is, two-sheet feeding) occurs in
the drawing out of a sheet P1 depending on the kind of the sheet
P1.
[0080] In addition, when the sheet P1 fed from the pile of sheets,
P, moves during the driven rotations of the sheet feeding roller
311 while being nipped between the sheet feeding roller 311 and the
friction pad 70, vibrations resulting from frictional sliding of
the sheet P1 on the friction pad 70 are absorbed by expansion and
contraction of the coil spring 80. It is thus possible to prevent
reliably the occurrence of so-called fluttering sound produced as
the sheet P1 trembles due to the vibrations.
[0081] In the embodiment above, the pad supporting movable member
60 that supports the friction pad 70 with the top portion being
exposed is provided, and the pedestal member 50 that holds the pad
supporting movable member 60 to be able to move in the sheet
carrying direction is also provided. The friction pad 70 is
therefore attached to the pedestal member 50 in a movable manner
via the pad supporting movable member 60 in a stable state.
[0082] The accommodation concave portion that accommodates the pad
supporting movable member 60 in a movable manner is provided by
making a recess in the top surface of the pedestal member 50. This
configuration stabilizes the attachment state of the friction pad
70 to the pedestal member 50.
[0083] It should be appreciated that the invention is not limited
to the embodiment above and includes the contents as follows.
[0084] (1) In the foregoing embodiment, the printer 10 is described
as an example of the image forming apparatus to which the
sheet-feed separation mechanism 40 is applied. The invention,
however, is also applicable to a copying machine and a facsimile
machine, and further to a scanner or the like that reads a document
image and transmits the image information to another device, such
as a computer. In a case where the image forming apparatus is a
copying machine, a document feeding device (second sheet feeding
device) that feeds documents, from which image information is read,
is provided as the sheet feeding device of the invention in
addition to the sheet cassette 31 (first sheet feeding device).
When the image forming apparatus is the scanner i.e. an image
reading device, the sheet cassette 31 is omitted, and the document
feeding device that feeds a document to an image reading portion
provided in a body of the image reading device alone is provided.
Incidentally, when the image forming apparatus is the scanner,
tailoring the image information read from the document so as to be
transmitted to an outside device, such as a computer, is included
in the concept of the image formation of the invention.
[0085] (2) In the foregoing embodiment, the sheet cassette 31 for
storing a transfer sheet with which the transferring processing of
an image is performed is described as an example of the sheet
feeding device to which the sheet-feed separation device 40 is
applied. However, in a case where the image forming apparatus is a
copying machine or a facsimile machine, a so-called document
feeding tray that feeds the documents toward the image reading
portion provided in the apparatus body may be used.
[0086] (3) In the foregoing embodiment, the coil spring 80 is
described as an example of the pushing member that confers a
pushing force to the friction pad 70 via the pad supporting movable
member 60. Instead of this member, a plate spring or an elastomer,
such as rubber, may be used depending on the situations. In a case
where the pushing member is made of rubber or the like, for
example, a rubber piece in the shape of a strip, a round rod, or a
tube is prepared, and one end of such a rubber piece is attached to
the protruding piece 621 while the other end is fixed to the back
surface plate 54 or the top plate 56. Even with the use of such a
pushing member, it is possible to confer an adequate pushing force
to the pad supporting movable member 60 owing to the elasticity of
the rubber piece.
[0087] (4) In the foregoing embodiment, the pushing force of the
coil spring 80 is made smaller than the frictional force between
the sheet P1 and the friction pad 70 in a state where the friction
pad 70 is at the home position S1. Instead of this configuration,
it may be configured in such a manner that the pushing force of the
coil spring 80 is made slightly larger than the frictional force
with the friction pad 70 in a state where it is located at the home
position S1, so that the friction pad 70 stays at the home position
S1 during normal sheet feeding, and moves to the pushing force
conferring position S2 only when a special sheet (sheet having a
large coefficient of friction) is fed.
[0088] (5) In the foregoing embodiment, the pad supporting movable
member 60 is formed by bending the metal plate. However, instead of
such a metal plate, a resin molded article may be used.
[0089] The specific embodiment described above includes inventions
having the following configurations.
[0090] A sheet-feed separation mechanism according to one aspect of
the invention includes: a sheet feeding roller that draws out a
sheet; a friction pad disposed oppositely to the sheet feeding
roller to form a nip portion for the sheet with the sheet feeding
roller; and a pushing member that pushes the friction pad in a
direction opposite to the sheet feeding direction.
[0091] A sheet feeding device according to another aspect of the
invention is a sheet feeding device that draws out a sheet from a
pile of sheets, including: a sheet tray on which the pile of sheets
is placed; a sheet feeding roller whose peripheral surface is
pressed to abut on a top surface of an uppermost sheet in the pile
of the sheets at a downstream end in a sheet feeding direction of
the pile of sheets; a friction pad disposed oppositely to the sheet
feeding roller to form a nip portion for the sheet with the sheet
feeding roller; and a pushing member that pushes the friction pad
in a direction opposite to the sheet feeding direction.
[0092] An image reading device according to yet another aspect of
the invention includes: a device body having an image reading
portion; and a document feeding device that feeds a document sheet
from which image information is read to the image reading portion,
wherein the document feeding device includes: a sheet tray on which
a pile of the document sheet is placed; a sheet feeding roller
whose peripheral surface is pressed to abut on a top surface of an
uppermost sheet in the pile at a downstream end in a sheet feeding
direction of the pile; a friction pad disposed oppositely to the
sheet feeding roller to form a nip portion for the sheet with the
sheet feeding roller; and a pushing member that pushes the friction
pad in a direction opposite to the sheet feeding direction.
[0093] An image forming apparatus according to still another aspect
of the invention is an image forming apparatus that forms an image
according to image information, including a first sheet feeding
device that feeds a transfer sheet, and/or a second sheet feeding
device that feeds a document sheet from which the image information
is read, wherein one or both of the first sheet feeding device and
the second sheet feeding device include: a sheet tray on which a
pile of the transfer sheet or the document sheet is placed; a sheet
feeding roller whose peripheral surface is pressed to abut on a top
surface of an uppermost sheet in the pile at a downstream end in a
sheet feeding direction of the pile; a friction pad disposed
oppositely to the sheet feeding roller to form a nip portion for
the sheet with the sheet feeding roller; and a pushing member that
pushes the friction pad in a direction opposite to the sheet
feeding direction.
[0094] According to these configurations, even when more than one
sheet is drawn out at a time from a pile of sheets, the second
sheet is pushed backward by the friction pad to which the pushing
force is conferred while the uppermost sheet in the pile of sheets
is being fed by the sheet feeding roller. Moreover, because the
friction pad moves in response to a frictional force between the
sheets, it can be applied to a pile of sheets of any kind having a
different peeling force between the sheets. It is thus possible to
prevent reliably an inconvenience that more than one sheet is fed
toward the sheet-feed destination at a time regardless of the kinds
of sheets.
[0095] In addition, when a sheet drawn out from the pile of sheets
moves in association with the driven rotations of the sheet feeding
roller while being nipped between the sheet feeding roller and the
friction pad, vibrations resulting from frictional sliding between
the sheet and the friction pad are absorbed by the pushing member.
It is thus possible to prevent reliably the occurrence of so-called
fluttering sounds produced when the sheet trembles due to
vibrations.
[0096] In the configuration described above, it is preferable to
further include a pad holder that supports the friction pad with a
top portion being exposed, and a seat that holds the pad holder in
a manner so as to be able to move in forward and reverse directions
with respect to the sheet feeding direction. According to this
configuration, it is possible to attach the friction pad to the
seat in a movable manner via the pad supporting movable member in a
stable state.
[0097] In this case, it is preferable that an accommodation concave
portion to accommodate the pad holder in a movable manner is
provided by making a recess in a top surface of the seat. According
to this configuration, the attachment state of the friction pad to
the seat can be stabilized.
[0098] In the configuration described above, the pushing member can
be one of a coil spring, a plate spring, and an elastomer.
According to this configuration, it is possible to choose the
pushing member that best suits the situation.
[0099] This application is based on patent application No.
2006-080495 filed in Japan, the contents of which are hereby
incorporated by references.
[0100] As this invention may be embodied in several forms without
departing from the spirit of essential characteristics thereof, the
present embodiment is therefore illustrative and not restrictive,
since the scope of the invention is defined by the appended claims
rather than by the description preceding them, and all changes that
fall within metes and bounds of the claims, or equivalence of such
metes and bounds are therefore intended to embraced by the
claims.
* * * * *