U.S. patent number 3,623,538 [Application Number 04/827,619] was granted by the patent office on 1971-11-30 for power and free conveyor system.
This patent grant is currently assigned to Nakanishi Metal Works Co., Ltd.. Invention is credited to Koji Ota, Yukio Soma, Takao Wakabayashi.
United States Patent |
3,623,538 |
Wakabayashi , et
al. |
November 30, 1971 |
POWER AND FREE CONVEYOR SYSTEM
Abstract
A power and free conveyor system that has a number of carriers
and consists of a leading main free trolley and a rear subtrolley
provided with a rear cam for forcing up a pusher. Pushers are
attached at regular intervals to the driving chain, which is guided
by the power rail. The pushers are provided with rollers and are
linked to the forward tilting dog of the main free trolley. Next to
the free rail, which guides the free trolley, is a subrail, upon
which are both side rollers of the pusher. At a fixed point on the
free rail the carrier stopper is arranged which forces up the
pusher to release the engagement of the pusher and the free
trolley. At carrier-diverting points are pusher-ascending rails,
while on the diverting side behind the pusher ascending rail, the
pusher-guiding apparatus is provided.
Inventors: |
Wakabayashi; Takao (Osaka,
JA), Ota; Koji (Kyoto, JA), Soma; Yukio
(Osaka, JA) |
Assignee: |
Nakanishi Metal Works Co., Ltd.
(Osaka, JA)
|
Family
ID: |
27521845 |
Appl.
No.: |
04/827,619 |
Filed: |
May 26, 1969 |
Foreign Application Priority Data
|
|
|
|
|
May 30, 1968 [JA] |
|
|
43/37272 |
May 31, 1968 [JA] |
|
|
43/37130 |
May 31, 1968 [JA] |
|
|
43/37131 |
Jun 3, 1968 [JA] |
|
|
43/38108 |
Aug 30, 1968 [JA] |
|
|
43/62532 |
|
Current U.S.
Class: |
104/172.4;
104/96 |
Current CPC
Class: |
B61B
10/025 (20130101); B65G 19/02 (20130101); B65G
19/282 (20130101) |
Current International
Class: |
B61B
10/02 (20060101); B61B 10/00 (20060101); B65G
19/02 (20060101); B65G 19/00 (20060101); B65G
19/28 (20060101); B65g 017/42 () |
Field of
Search: |
;104/89,91,94,95,96,105,106,107,172S,178 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: La Point; Arthur L.
Assistant Examiner: Saifer; Robert
Claims
We claim:
1. A conveyor traveling along a conveyor line comprising in
combination, a power rail, a free rail which is provided beneath
said power rail in parallel there-to and at a suitable interval
therefrom to allow added components to pass through between both of
said rails, a conveying means with rollers provided with a movable
cam in contact with said free rail and which can freely move along
said rail, when coupled, and which is arranged above said free
rail, a power trolley below said power rail comprising rollers
which movably contact with said power rail for the movement of said
trolley below said rail, a moving means connected with said trolley
in order to make said trolley move along said power rail, a lever
means on said trolley comprising a pusher which can freely move
vertically and is arranged below said power rail to be coupled to a
coupling means and which is provided with rollers, at least on one
side, which combine said power trolley and a conveying means in
order to move it together with said power trolley, and a subrail
which is arranged at least on one side of said free rail to project
slightly upward from said rail in order to steadily keep up the
coupling state between said pusher and said free trolley, and which
guides said rollers of said pusher, an upper guide rail arranged in
a falling gradient section of the conveyor line and above said
subrail at a suitable interval in order to prevent said rollers on
at least said one side of said conveyor line which move along said
free rail from escaping upward, a bracket, upon which are arranged
lever means for a predetermined number of power trolleys connected
with said moving means and which is firmly fixed to the lower end
of said trolley to extend backward and angularly downward, and a
pusher which is fixed to said bracket by a pivot to freely swing
and extends forward and descendingly downward.
2. In a conveyor having:
a. a power rail (1) held in space and generally disposed parallel
to the surface beneath said rail;
b. a free rail (15) under said power rail and parallel thereto,
disposed at a suitable distance therefrom so that additional
components can pass therebetween;
c. at least one conveying means (20) with rollers (38) movably
connected to said free rail (15), for free movement therealong
beneath said rail;
d. coupling means (18, 19) arranged above and connected to said
conveying means which when engaged will then move said conveying
means along said rail;
e. a power trolley (5) mounted under said power rail (1) including
rollers movably connected to said power rail for movement of said
trolley under said rail;
f. moving means (7) connected with said power trolley (5) for
moving said trolley along said power rail (1);
g. lever means on said power trolley including a pusher (9) with
rollers (13, 14) disposed under said power rail (1) to engage said
coupling means (18, 19) for linking said power trolley and said
conveying means so as to move said conveying means with said power
trolley; a bracket (8) in which are disposed said lever means
firmly fixed to the lower end of said power trolley to extend
backward and angularly downward, said pusher being fixed to said
bracket by a pivot to freely swing and extends forward and
angularly downward;
h. subrails (37) which are arranged on both sides of said free rail
projecting slightly over said rail to maintain the coupling state
between said pusher and said free trolley by guiding said rollers
(13, 14), said rollers normally rolling on said subrails;
i. a stopper having a pusher force plate (39) with an upper end
(39a) coinciding with a moving locus of the lower end of one of
said rollers (13, 14) in a normal condition and which will project
upward from said locus when said lever means is released from said
coupling means so that at least one of said conveying means will be
stopped, the improvement therein wherein:
j. said coupling means includes a leading main free trolley which
has a pair of tilting dogs (18, 19) engaged by said pusher (9) and
a rear subfree trolley which is connected with said main free
trolley at the rear end section of which is a cam element (21)
having a U-shaped notch (32), said cam element being fixed to said
subfree trolley so as to swing horizontally at the curved section
of the conveyor line along the inner side of said subrail.
3. A conveyor as claimed in claim 2, wherein said pusher force
plate (39) has a polygon shape and can freely rotate, while in said
subrail with an upper side in the same horizontal plane as the
upper end of the subrail, a first gradient side and a second
gradient side, making a obtuse angle, and when said pusher force
plate is rotated for a fixed angle, the first gradient side rises
up to be horizontal to project above said sub-rail and is
positioned at a height over said tilting dogs (18, 19).
4. A conveyor as claimed in claim 3, including a pressure cylinder
means disposed over said power rail, a bell crank lever, a
connecting lever, and a rod connecting said pressure cylinder means
and said force plate so as to rotate said force plate.
5. A conveyor as claimed in claim 4, including a second power rail,
said first and second power rails having curved sections and a
converting point, a first pusher ascending rail with roller
leading-in gradient sections and roller-discharging gradient
sections respectively provided along and above said curved sections
of said rails, a pusher leading-in means behind said first
pusher-ascending rail, but above said first free rail and at an
interval slightly wider than the diameter of said rollers of said
pusher.
6. The conveyor as claimed in claim 5, including a fixed upper
plate of said roller leading-in means, a movable lower plate which
is arranged at a fixed interval from said fixed upper plate and
which said rollers of said pusher contact and a spring which
constantly presses down on said lower plate.
7. The conveyor according to claim 5, wherein said pusher has
inside and outside rollers, and the inside roller pushes the rear
end section of said cam, while the outside roller contacts said
roller leading-in means.
Description
The present invention relates to an improved power and free
conveyor system, especially a conveyor provided with a mechanism to
release the engagement between the front tilting dog of a free
trolley and the thrusting pusher.
It should be noted that, throughout the text of the specification
and claims, the words "forwards" and "rearwards" refer to the
advancing direction of the trolley conveyor, i.e., "forwards" is
the side of an advancing direction of the conveyor, while
"rearwards" is the side of its reverse direction.
The power and trolley conveyor connects the driving power of the
power trolley to the free trolley through the intermediary of the
pusher, and when goods are transported by said conveyor, it
sometimes becomes necessary to separate the carrier from the pusher
of the driving chain and to temporarily stop in order to carry out
loading and unloading of the goods as well as the process work,
inspection and testing in the intermediate stage of the
transporting process, and also to divert the carrier from one power
rail to the other power rail. Hitherto, the rail section, which can
be moved upward or downward by means of an oil pressure or an air
pressure instrument has been provided in a section of either the
power rail or the free rail, and through this arrangement, the
power trolley or the free trolley has been temporarily moved
vertically and, by freeing the pusher from either one of these
trolleys, the carrier has been stopped. However, when such a
conventional apparatus is used, the load, due to the force of the
tension of the chain as well as the load of the trolley, will have
influence on it. If the power rail is moved upward, while the free
rail is moved upward, the load of the transported goods will fall,
so it is necessary to have a stronger oil or air pressure
instrument, which naturally entails a higher cost of the
apparatus.
The power rail is accompanied by the endless driving chain, and
therefore must also have an endless structure. The free rail can be
made to extend straight over a long distance in conformity with the
objects of transportation, however, the carrier must be diverted
from the first power rail to the second power rail. Hitherto the
first power rail has been bent upward in order to release the
pusher from its engagement with the tilting dog of the free
trolley. However, in order to send the carrier, which has lost the
advancing power received from the pusher, to the second power rail,
a special cylinder or feeder has been provided, and the speed of
the driving chains on both power rails had to be synchronized.
One of the objects of the present invention is to provide an
apparatus which can easily stop any required number of carriers
successively. Thus, there is no need for a section which can
temporarily move either the power rail or the free rail upward or
downward.
Another object of the invention is to provide an apparatus which
allows the carrier to be diverted from one endless power rail to
the other endless power rail, even when the speeds of the conveyors
of both rails are different from each other.
Still another object of the invention is to maintain a stable
condition of engagement between the free trolley and its thrusting
pusher at all times during the movement of the carrier, even at the
down grade section of the conveyor line.
Yet another object of the invention is to provide an apparatus
which can gather the carriers even at a curved section of the
conveyor line.
In short, the power and free conveyor system according to the
present invention comprises a power rail, a free rail which is
arranged beneath said power rail at a suitable interval, a driving
chain suspended from the power trolley, which rolls on the power
rail, a free trolley, which rolls on the free rail and which is
provided with front and back tilting dogs, a pusher with rollers on
both sides which can freely move vertically, and which is connected
to the driving chain that engages the front tilting dog of said
free trolley, and a subrail, upon which roll the rollers of the
pusher, arranged on the free rail.
The carrier comprises the leading main free trolley which has a
pair of tilting dogs, and the rear subfree trolley, which is
coupled to the main free trolley and which is provided with a cam
for forcing up the pusher, at the rear end of which is formed a
U-shaped notch which can freely rotate horizontally.
At a fixed point of the free rail a stopper is provided which
forces up the pusher to release its engagement with the free
trolley.
Other objects and advantages of the apparatus according to the
present invention with regard to its constitution and operation
will become clearer by reference to the accompanying drawings and
the detailed description in connection thereto, wherein:
FIG. 1 is the partly broken side view of the new power and free
conveyor of the invention equipped with the carrier pusher.
FIG. 2 is a sectional view taken along the line of 2--2 of FIG.
1.
FIG. 3 is also a sectional view taken along the line 3--3 of FIG.
1.
FIG. 4 is a partial side view showing the gathering state of the
carriers.
FIG. 5 is a horizontal sectional view showing the gathering state
of the carriers at the curved section of the conveyor line.
FIG. 6 is a horizontal sectional view of a reference example
showing a state wherein the carriers cannot be gathered at the
curved section of the conveyor line.
FIG. 7 is an enlarged sectional view taken along the line of 7--7
of FIG. 2.
FIG. 8 is an explanatory plan showing the necessity of gathering
the carriers at the curved section of the conveyor line.
FIG. 9 is a vertical sectional view of the movement of carriers at
the down grade section of the conveyor line.
FIG. 10 is a sectional view taken along the line 10--10 of FIG.
9.
FIG. 11 is a partial longitudinal section of a reference example of
the down grade section of the conveyor line same as FIG. 9, where
there is no upper subrail.
FIG. 12 is a side view of the pusher pressing down apparatus to be
used when switching the carrier from one endless power conveyor to
the other endless power conveyor.
FIG. 13 is the sectional view taken along the line of 13--13 of
FIG. 12.
FIG. 14 is a diagrammatical plan of the apparatus to switch the
carrier from one endless power rail to the other endless power
rail.
FIG. 15-17 are diagrammatical side view showing the switching
operations of the above-mentioned carrier.
Reference is now made to FIGS. 1-3, wherein the horizontal power
rail 1 is made of steel material, and is square in cross section
with a longitudinal slit 2 in the central part of the bottom wall.
A power trolley 3 is provided with rollers 4 on the left and right
sides, and another pair of rollers 6 are also arranged on the left
and right sides. There is a pair of rollers for every fixed number
of trolleys 3 on the power rail 1. Because of the slit 2 in the
power rail 1, the trolley 3, by means of the rollers, can freely
roll on power rail 1. The endless driving chain 7 arranged beneath
the power rail 1 is made to move constantly in the direction of the
arrow shown in FIG. 1 by the motor and the conductive means which
are not illustrated, while the trolleys 3 and 5 are coupled thereto
at a fixed interval. On the lower end of the trolley 5 is a bracket
8 of a reverse U-shape in cross section, which projects backward
and angularly downward, against which the pusher 9 is fixed to
project forward and angularly downward, by means of a pivot 10 to
allow free swing, and is constantly pressed downward by the push
spring 11. On the rear section of the upper side of the pusher 9 is
a projection 12 which extends beneath the lower side of the upper
wall of the bracket 8, and when the pusher 9 tends to hang down
further from a certain point, said projection 12 will strike
against said bracket lower side to interrupt the pusher 9 limiting
the action of the pusher. On both sides of the lower end of the
pusher 9 are two rollers 13, 14 inside and outside.
A free rail 15 is provided at a suitable interval below the power
rail 1 and is constructed by using pairs of steel elements in a
lateral U-shape. It is connected to the power rail 1 by a coupling
frame 16 which is arranged at a fixed interval.
The carrier C includes a leading main free trolley 20, which has a
pair of tilting dogs 18, 19, and two intermediate free trolleys,
which are respectively provided with a hanger 24 and are fixed to
the lower end of said main free trolley by the pivot 23 so as to
freely swing. The respective free trolleys 20, 22 and 25 have a
pair of vertical rollers 38 in the front and the rear of the point
of the rail housing 15a on the free rail 15, where the rollers 38
are received and a horizontal roller 17 which rolls along the side
of the rail housing 15a. Free trolleys 20, 22 are connected by a
connecting rod 30 and are provided with a downward projecting piece
26 by means of the pivot 27. The downward projecting piece 26 and
the hanger 24 are provided with short and horizontal projections
26a and 24a to which are respectively arranged a forked joint 28 by
means of a pivot 29 so as to freely swing vertically. A U-shaped
section 30a, is provided at both ends of the connecting rod 30.
Said U-shaped section 30a is fastened by means of pivot 31 so as to
swing freely left and right. It is not necessary to provide an
intermediate free trolley. The hanger 24 may be arranged to the
main and subfree trolleys without an intermediate free trolley. The
tilting dogs 18, 19 are fixed to the trolley 20 in such a way that
they can both come down inwardly by means of pivot 27 and they can
stand upright by their dead load. Cam 21 is U-shaped with a bottom
plate 21a and a sideplate 21b which forms a cam surface, while its
latter half projects out behind the subfree trolley 22. At the
center of the rear section of the bottom plate 21a is a U-shaped
notch 32, the entrance of which is slightly opened. On the upper
surface of the subfree trolley 22 is a mount 33 for the cam 21,
which is fixed to said mount by means of bolt 34 and freely rotates
horizontally. On the bottom plate 21a of the cam 21 is a long hole
35 through which another bolt 36 is fixed to mount 33. On both
sides of the free rail 15, which is the main rail, is welded a
subrail 37 which projects slightly higher than free rail 15, and
receives outside roller 14 of pusher 9. Subrail 37 is a flat band
vertically erected. It can be of any shape as long as it will
receive the roller 14. The carrier stopper S is arranged on the
same level as carrier stopper S consists of a force plate 39 which
is of polygon shape, an upper side 39a which is horizontal and
located on the same horizontal plane as the upper end of the
subrail 37, a first inclined side 39b and a second inclined side
39c making an obtuse angle, and is fixed to the back side of the
lower end of the connecting rod 16. It is fixed to bracket 40 by
means of pivot 41 to freely rotate. On the lower section of force
plate 39 is a stop pin 42 projecting inward. It is made to come out
on the moving line of the pin 43 which is arranged to the free
trolley 20 to project outward, when ascending, as will be hereafter
explained. On the power rail 1, the base 44 is fixed to the
corresponding position of the force plate 39, and to this base 44
is fixed an air cylinder 45 by a fixture 46. In front of the air
cylinder 45 is fixed the bearing 48 of the crank shaft 47. To the
crank shaft 47 are fixed a front link 49 and a back link 50, which
constitute a bell crank with both ends and center respectively. The
end of the back link 50 is fixed to the end of rod 51 of the air
cylinder 45 by means of pivot 52 to freely swing, while the end of
the front link 49 is connected by means of pivot 54 to the
connecting rod 53 vertically erected on the outside of the force
plate 39. The subrail has a cut section 76 in order not to impede
the operation of the force plate 39.
As shown by FIG. 1, the carrier C.sub.1, C.sub.2 moves in the
direction of the arrow together with the driving chain 7 by linking
the pusher 9 to the front tilting dog 18 of the leading main free
trolley 20. Although not illustrated, many carriers follow the
preceding carrier in the same way at a predetermined interval,
which is determined by the interval of the pusher 9 hanging down
from the driving chain 7. In order to stop the carriers 17 which
are moving in succession, the air cylinder 45 is activated to push
out the rod 51, so that the force plate 39 will rotate
counterclockwise for an angle .theta.1 with the pivot 41 as a
center, as shown by the chain line of FIG. 1. Consequently, the
first inclined side 39b will stand up horizontally and extend
higher than the subrail 37 to reach a height at least over the
tilting dogs 18, 19. In the front and back of the first inclined
side 39b, which has become horizontal, the upper side 39a and the
second inclined side 39c appear above the subrail 37 in an inclined
connection, and the main free trolley 20 of the carrier C.sub.1,
which is advancing first, will move along the interior side of the
force plate 39. Rollers 14, which are on both sides of the pusher 9
linked to the front tilting dog 18, will roll along the force plate
39, so that the pusher 9 will ascend against the force of push
spring 11 and separate itself from the front tilting dog 18, and
the pin 43 of the main free trolley 20 will strike against the stop
pin 42 of the force plate 39 and the first advancing carrier
C.sub.1 will stop. The first advancing carrier mentioned above is
used in this instance to mean the carrier which is the first one to
be stopped among many moving carriers. When the first carrier is
stopped, the second and succeeding carriers are still moving
together with the driving chain 7, and the front tilting dog 18 of
the main free trolley 20 of the second carrier C2 will enter into
the notched section 32 of the cam 21 of the subfree trolley 22 of
the first carrier C1 and pusher 9 which is linked to the front
tilting dog 18 will come off said tilting dog 18 and pass along the
front of subfree trolley 22, as the push spring 11 ascends, since
the rollers 14 on both sides of the pusher 9 roll up along the
sideplate 21b of the cam 21, and as a result, the second carrier
C.sub.2 will stop next to the first carrier C.sub.1 (See FIG. 4).
Said pusher 9 still continues to advance and ascends again at the
point of the force plate 39 to go over the main free trolley 20 of
the first carrier C.sub.1. In this way, the driving chain 7 with
the pusher 9 will continue to move, while the third and the
succeeding carriers for transporting the goods will successively
stop and accumulate.
In order to again move the group of accumulating carriers, the
stopper must be restored to its original condition. Pusher 9 which
came from behind, will push down forward, and back tilting dog 19
of the main free trolley 20 will be linked to the front tilting dog
18, so that the first carrier C.sub.1 will start to advance
together with the driving chain 7, and the back tilting dog 19 will
be restored to its original condition by its dead load, after
pusher 9 has passed. When the first carrier C.sub.1 moves, its
subfree trolley 22 will come off the main free trolley 20 of the
second carrier C.sub.2 which is stopping them, together with the
cam 21. Consequently, the second positioned pusher will be linked
to the front tilting dog 18 of the main free trolley 20 and the
second carrier C.sub.2 will be forced to advance. In this way, all
the carriers which have been stopped will successively start at
intervals between the respective pushers. The force plate 39 in the
above-mentioned example of the invention assumes a form to rotate
to push up the roller 9, and it will be noted that it can be made
to bring up and down the force plate which has a horizontal section
and the inclined section before and behind the former section, and
since the carrier C will stop, if the pusher 9 is removed from the
tilting dog 18, when the conveyor moves at a low speed, it is not
necessary to arrange the stop-pin 42 as well as the pin 43.
Both the power rail 1 and the free rail 15 are fixed to the upper
and lower positions respectively by means of the connecting frame
16 as and, because there will be manufacturing errors in the
interval H (See FIG. 3) between these two rails, said interval
cannot remain the same at all points. Consequently, if there is no
subrail 37 and only the pusher 9 hangs down, the interval h between
the pusher 9 and the free rail will become irregularly larger or
smaller. When it becomes larger, there is no trouble. But, if it
becomes smaller, the pusher will not ascend, since the roller 14 of
pusher 9 will cut into the rear end of the sideplate 21b of the cam
21, because there is a gap between the lower side of the cam 21 and
the upper side of the free rail 15, when a group of carriers are
stopped. The rear end of the side plate 21b of the cam 21 is
pointed, and when there is resistance to the pusher 9, it tends to
descend, as shown in the drawing. As a result, the coupling between
the pusher 9 and the tilting dog 18 cannot be released. However, in
the power and free conveyor system according to the present
invention, the pusher 9 is arranged to the driving chain 7 and
freely moves vertically, while both sides are provided with rollers
14, and on both sides of the free rail 15 are fixed the subrail 37
projecting out slightly above said free rail 15, so that the
rollers 14 of the pusher 9 can roll along said subrail. As a
result, as can be seen from FIG. 3, the gap h between the rollers
14 and the free rail 15 will always be constant and the coupling
state of the pusher 9 and the tilting dog will also be kept
constant at all times. Consequently, when the carriers C are
stopped, the coupling between the pusher 9 and the tilting dog 18
will be smoothly released.
Reference will now be made to FIGS. 5-8, wherein the group of
carriers C is stopped at the curved section of the conveyor line,
i.e., the curved section 55 of the free rail 15, the cam 21 of the
carrier C.sub.y swings to the extent of an angle .theta.2 from the
center line 55 of the subtrolley 22 and its notch 32 cannot come
off the opposite gap of a pair of the free rails 15, as shown by
FIG. 5, because the cam 21 of the preceding carrier C.sub.y can
freely swing horizontally with pivot 34 as its supporting point,
and there is the subrail 37 in the free rail 15. Consequently, the
tilting dog 18 of the main free trolley 20 of the second positioned
carrier C.sub.z will enter into said notch 32 and it can stop in
the condition of above-mentioned FIG. 4. If cam 21 is fixed firmly
and there is no subrail 37, carrier C.sub.z will be in the
condition as shown by FIG. 6. In other words, since the cam 21
always coincides with the centerline of the subfree trolley 22, the
notch 32 will come off the opposite gap 57 of the free rail 15, and
the rear section of the cam 21 which is projecting out will come
into gap 57. As a result, the front tilting dog 18 of the main free
trolley 20 of the second positioned carrier C.sub.y will collide
with the rear section of said cam 21 and the rollers 14 of the
pusher 9 cannot roll up along the sideplate 21b of the cam 21.
Therefore, the coupling between the tilting dog 18 and the pusher 9
cannot be released, and in the curved section 55 of rail 15, there
will be no accumulation of carriers. This has several
disadvantages.
When goods are to be transported by the power and free conveyor,
the carrier must be separated from the pusher of the driving work,
inspection and testing of the goods in the intermediate works in
the transportation from loading to unloading, so that carriers will
accumulate. In order to utilize space advantageously, it is
desirable that, as shown by FIG. 8, the rails 1 and 15 are
meandering. But if the carriers cannot be accumulated at the curved
section 55, they will be accumulated only in the straight section
as illustrated. Consequently, when converting the leading carrier
C.sub.z for transportation in the second row from the bottom of
FIG. 8 to the first row, it can be carried out only after
detecting, by the use of such detectors 58 as the photoelectric
tube apparatus or the limit switch, that the leading carrier
C.sub.x in the first row has been already sent out and the carrier
C.sub.y at the rear of the same row has been shifted one step
forward. However, the interval between the carriers C.sub.x and
C.sub.y depends upon the accumulating conditions of the carriers;
it may be long on one occasion and short on the others. In other
words, since there will be a delicate difference in the stopping
gap of the mutually adjacent carriers because of the difference in
the operating speed of the driving chain 7 and the load of the
carriers, the stopping place of the last carrier C.sub.y of the
straight row cannot always be uniform. Consequently, it sometimes
happens that, though the carrier C.sub.y is still remaining in said
row, a signal telling its departure will be flashed. The leading
carrier C.sub.z of the second row from the bottom of FIG. 8 will
move to contact the preceding carrier C.sub.y, then both carriers
C.sub.y and C.sub.z will be in the condition as shown in FIG. 6
and, as the coupling of the tilting dog 18 and the pusher 9 is not
released, the driving chain 7 will be broken, and thus the stoppers
of the carriers will be arranged at their advancing ends of the
respective straight lines for accumulating sections. There are no
such disadvantages in the power and free conveyor system of the
present invention.
As shown in FIGS. 9-11, in the down grade section 59 of the
conveyor line, the upper subrail 60 is arranged with a fixed gap
above the lower subrail 37, i.e., slightly above the moving locus
of the roller 14 of the pusher 9, both parallel, and it is welded
to the supporting element 61 to project out inside the connecting
frame 16.
While the accumulation of the carriers C will be effected as
above-mentioned, the pusher 9 and the main free trolley 20 should
not be separated during the movement of the carriers C.
In the power and free conveyor according to the present invention,
the pusher 9 is arranged to the power trolley 3, which drives along
the power rail 1, to freely swing and to project forward and
angularly downward. As a result, in the horizontal section and the
rising gradient of the conveyor line, the pusher 9 is firmly
coupled to the front tilting dog 18 of the main free trolley 20 as
shown by FIG. 1 and it will never come off, because when there is a
resistance in the advancing pusher 9, a downward moment will be
generated. Since the pusher 9 is arranged forward and angularly
downward to freely swing, so that its coupling with the front
tilting dog 18 will become steadier, especially in case of a rising
gradient. If the pusher 9 is reversely arranged to freely swing
vertically or backward and askant downward, an upward moment will
be generated, then there is a resistance in the advancing pusher 9,
and it tends to come off the front tilting dog 18. On the other
hand, if the pusher 9 is fixed vertically as in a conventional
system, the above-mentioned accumulating operation of the carriers
cannot be carried out.
However, when the pusher 9 is arranged to freely swing forward and
angularly downward, it will act excellently as above mentioned, in
the horizontal section and the rising gradient section of the
conveyor line. However, there will be a problem in case of a
falling gradient as follows:
As the speed of the carrier C becomes higher than the driving chain
7 by the gravity of the load suspended from the hanger 24, the
pusher 9 will be coupled to the rear tilting dog 19 of the main
free trolley 20. As a result, the pusher 9 will be pushed from
behind by the rear tilting dog 19 and the upward movement will be
generated. If there is no subrail 60, the pusher 9 will rotate
clockwise as shown in FIG. 11 and it will come off the tilting dog
19, so that there will be a danger that the pusher 9 alone will run
by itself. In this respect, however, the power and free conveyor
system of the present invention provides the upper subrail 60
slightly above the moving locus of the roller 14 arranged on the
side of the pusher 9 in parallel to the free rail 15 in the falling
gradient. Therefore, the roller 14 will be pressed down from above
to firmly prevent the pusher 9 from getting away and impedes the
carrier C to run by itself.
In FIGS. 12 and 13, is shown the pusher-guiding means P provided
above the moving line of the outside roller 14 of the pusher 9.
Said pusher guiding means P is constituted by the upper plates 63
which are bilateral and cross-sectionally reverse U-shaped and
which are welded to the supporting elements 62 which have a
cross-sectional L-shape, and which are fixed to the connecting
frame 16, the lower plates 64 which are provided beneath the
respective upper plates 63 at a fixed interval, the laterally
U-shaped connecting elements 67 which connect the lower plates 64
to the upper plates 63 by means of the pivots 65, 66 to freely move
up and down, and the coiled tension spring 71 spanned between the
adjusting bolt 69 fixed to the fitting 68 vertically attached to
the lower surface of the upper plate 63 and the shaft 70 provided
below the center of the connecting element 67. At the front and
rear ends of the lower plate 64 are formed the roller leading-in
gradient section 64a and the roller discharging gradient section
64b to extend upward from the horizontal section of the lower plate
64 respectively.
In FIG. 14, are shown the first and second pusher ascending rails
72 and 73, which are formed by oppositely facing the
cross-sectional L-shaped steel pieces. They are both made to
coincide respectively with the curves of the first power rail 74
and the second power rail 75, both of which are shown by the
centerlines, and they are positioned at the height where the pusher
9 can be separated upward from the tilting dog 18 of the main free
trolley 20. At the front and rear ends of the first
pusher-ascending rail 72 are respectively formed the roller
leading-in gradient 72a and the roller-discharging gradient section
72b. Likewise at the front and rear ends of the second pusher
ascending rail 73 are formed the roller leading-in gradient section
73a and the roller discharging gradient section 73b. All these
gradient sections 72a, 72b, 73a and 73b extend downward from the
horizontal sections of 72 and 73. The roller leading-in gradient
72a of the first ascending rail 72 is positioned behind the curve
initial point A, while the roller discharging gradient 73b of the
second ascending rail 73 is before the curve terminal point B. The
lower plate 64 of said pusher leading-in apparatus P has a length
greater than the interval between the curve initial point A and the
curve terminal point B.
The converting operation of the carrier C from the first ascending
rail 72 to the second ascending rail 73 will be described by making
reference to FIGS. 15-17, as follows:
The force plate 39 of the stopper S is returned from the ascending
position in FIG. 15 to the descending position in FIG. 16, then the
advancing pusher 9 will catch the front tilting dog 18 of the main
free trolley 20 of the carrier C and advance. As soon as the main
free trolley 20 passes the stopper S, the force plate 39 will be
immediately returned to the ascending position and the second
positioned carrier will be stopped. Meanwhile, said main free
trolley 20 will be moved by the pusher 9 to the first
pusher-ascending rail 72, as shown by FIG. 15. But, at this point,
the rollers 13, 14 of the pusher 9 will be led into the roller
leading-in gradient section 72a and move upward, so that the
coupling between the pusher 9 and the tilting dog 18 will be
released and the rollers 13, 14 of the pusher 9 will roll up the
first pusher ascending rail 72 and turn in accordance with the
curve of the first power rail 74. On the other hand, as the carrier
C will stop at the aforesaid position, the cam 21 of the subfree
trolley 22 will remain at the position where there is the pusher
leading-in apparatus P. When things are in this condition, the
second positioned pusher 9 advances and its inside roller 13
collides with the rear end of the cam 21 and slightly ascends along
its sideplate 21b. As the outside roller 14 will then collide with
the lower plate 64 of the pusher leading-in apparatus P, the pusher
9 will not ascend further, and since the outside roller 14 rolls
counterclockwise, while the inside roller 13 rolls clockwise and
pushes the cam from behind, the carrier C will advance, as shown by
FIG. 16, and its main free trolley 20 will come before the
roller-discharging gradient section 73b. When it is in this
condition, the pusher 9 of the second power rail 75, which has been
sent along the second pusher-ascending rail 73, will come down from
the roller-discharging gradient section 73b to be coupled to the
tilting dog 18 of said trolley 20 and I force the carrier C to come
within the scope of influence of the second power rail 75. In this
way, the converting operation of one carrier is completed, and any
number of carriers can be converted in like manner.
In the above-mentioned example of the invention, the stopper S is
arranged behind the pusher leading-in apparatus. But, when the
speed of the conveyor on the side of the second power rail is
greater than that of the conveyor on the side of the first power
rail 74, it is difficult for the respective pushers 9 on the side
of the second power rail 75 to catch the tilting dogs 18 of the
main free trolley 20 in succession, and there is no need to control
the leading-in operation of the carrier C. Consequently, there is
no need to provide the stopper in such a case. However, when the
speed of the conveyor on the side of the second power rail 75 is
lower than that of the conveyor on the side of the first power rail
74, because the length of the carrier C is not the same as the
pitch of the pusher 9, the pusher will not catch the tilting dog 18
of the carrier soon enough, in which case, it becomes necessary to
stop the carrier C once and control the leading-in operation to the
side of the second power rail 75.
Besides, in the above-mentioned example, the pusher leading-in
apparatus P is so constituted that, through the intermediary of the
connecting lever 67, which can freely swing, the lower plate 64 can
move upward. But, when a group of carriers C is stopped and
accumulated on the second power rail 75, trouble will occur, if the
cam 21, which is in the position of the pusher leading-in apparatus
P, is forcibly pushed from behind. Therefore, it has been arranged
so that pusher 9 can move upward, and if there is no accumulation
of carriers, lower plate 64 will be firmly fixed.
Further, in the above example, when one of the connecting elements
67 is extended upward to pass through the upper plate 63, the rod
of the air cylinder is arranged to come from the opposite side of
the tension spring, and projected out when the leading-in operation
is not carried out, and the connecting elements 67 will be inclined
further in resistance to the tension spring so that the lower plate
64 will ascend and the pusher 9 will move beyond the cam 21.
According to the power and free conveyor system of the invention,
the carrier can be smoothly converted, by a simple apparatus such
as above-mentioned, from one endless power rail to the other
endless power rail without difficulty.
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