Material handling bucket dual cylinder system

A material handling bucket dual cylinder system having two fluid valves and two fluid cylinder assemblies comprising a fluid system which controls the loading and dumping of a bucket. The system is arranged so that all of the fluid power can be directed for forceful action, such as loading the bucket, and the fluid power can also be utilized for a fast bucket action, such as dumping the bucket.

This invention relates to a material handling bucket dual cylinder system, 
and it is particularly useful in a backhoe bucket arrangement and is 
useful in directing all of the fluid power to the bucket, such as is 
desired when loading the bucket, and the fluid power can also be directed 
for dumping the bucket in a very fast action. 
BACKGROUND OF THE INVENTION 
The prior art is already aware of arrangements of material handling buckets 
which are under the control of fluid actuated apparatus, such as hydraulic 
cylinders. One isolated example of the arrangement in a backhoe is found 
in U.S. Pat. No. 3,220,579. It is the common practice in the prior art to 
have only one cylinder assembly for actuating a material handling bucket. 
Thus it is inherent in that arrangement that the bucket is moved with a 
certain force and at a certain speed, both consequences being determined 
by the capabilities of the fluid system and of the one cylinder itself. 
The present invention utilizes two fluid cylinders for actuating the 
bucket, and the use of two cylinders is more efficient and less expensive 
than the use of a single cylinder assembly. Further, the arrangement of 
two cylinder assemblies in the present invention permits a forceful action 
on the bucket and it also permits a fast action on the bucket. That is, 
both cylinders can be pressurized when a forceful action is desired, such 
as when loading the bucket, and only one of the two cylinders can be 
pressurized, when a fast action is desired such as for emptying the 
bucket. Accordingly, the present invention provides a material handling 
bucket dual cylinder system which permits and utilizes the full fluid 
power available for maximum forceful actions when desired, and it also 
permits and utilizes a fast fluid power action when that is desired such 
as in the dumping or cleaning or like maneuvering of the bucket. Further, 
the present invention accomplishes the aforementioned objectives with a 
minimum of apparatus and without complex valves and complex apparatus, and 
the apparatus is therefore efficient and reliable and easy to operate so 
that the desired forceful or fast maneuverings can be accomplished. 
Other objects and advantages will become apparent upon reading the 
following description in light of the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 schematically shows the apparatus of this invention, and that 
includes a first fluid valve 10 and a second fluid valve 11 and two fluid 
cylinder assemblies 12 and 13 and it includes fluid connecting lines 
shown, such as the line 14 connected between a fluid pump 16 and the valve 
10, and the lines 17 and 18 connecting between the valves 10 and 11, and 
the lines 19, 21, 22, and 23 connecting between the valve 11 and the 
cylinder assemblies 12 and 13. The system also includes a return fluid 
line 24 which extends to a reservoir 26. As shown in FIG. 1, one skilled 
in the art will readily understand that the fluid system is arranged to 
have the pump 16 supply fluid underpressure to the valves 10 and 11 and 
then to the cylinders 12 and 13, all depending upon the positioning of the 
valves 10 and 11, as explained hereinafter. Also, one skilled in the art 
will readily appreciate and understand that the cylinders 12 and 13 are 
connectable to a material handling bucket for the purpose of actuating the 
bucket to load and to dump the bucket, and the general arrangement of a 
hydraulic or fluid cylinder connected to a bucket is shown in U.S. Pat. 
No. 3,220,579, for instance. 
The first valve 10 is shown to be of an open-center type having the 
passageway 27 which permits the flow of fluid from the pump 16 and to the 
line 28 and back to the tank or reservoir 26. Also, the valve 10 is shown 
to be of a spool type, as is the valve 11, and the valve 10 is thus 
shiftable to where its other passageways can align with the lines 17 and 
18 to thereby pass fluid underpressure to the valve 11. A manual type of 
control 29 is schematically indicated in operative association with the 
valve 10 for the shifting of the valve spool designated 31. Accordingly, 
shifting the spool 31 to the right, as viewed in FIG. 1, will permit the 
spool passageway 32 to fluid-flow connect between the fluid line 33 and 
the fluid line 17 to thereby direct the fluid underpressure from the pump 
16 and to the line 17 and up to the valve 11. Likewise, the spool 
passageway 34 will fluid-flow connect between the line 18 and the line 24 
to direct the return from the valve 11 and back to the tank 26, all as 
indicated by the conventional showing of the valve 10 and as will be 
understood by one skilled in the art. Similarly, shifting the valve spool 
31 to the left, as viewed in FIG. 1, will cause the valve fluid passageway 
36 to fluid-flow connect between the line 33 and the line 18, to pass 
fluid to the valve 11 in that direction of flow, and, similarly, the valve 
fluid passageway 37 would then be connected between the line 17 and the 
line 24 for the return flow from the valve 11 and to the tank 26. 
Accordingly, the valve 10 passes fluid to the lines 17 and 18 in both 
directions of flow in each of the lines, for the desired forward or 
reverse type of fluid pressurizing of the valve 11. Also, a conventional 
type of fluid-flow check valve 38 is shown in the line 33 such that when 
the line 33 is under backflow type of pressure from the line 18, the valve 
38 will hold the pressure in the line 18, as desired and as will be 
apparent and is effective on the cylinder assemblies 12 and 13. 
The second valve 11 has a valve body 39 and a shiftable spool 41, and it 
also has two fluid ports designated 42 and 43 fluid-flow connected with 
the valve 10 through the lines 17 and 18, and it has four fluid ports 44, 
46, 47, and 48, fluid-flow connected with the cylinder assemblies 12 and 
13 through the lines 19, 21, 22, and 23, respectively. FIG. 2 shows the 
location of the six ports mentioned, and it will be seen that the ports 42 
and 43 are shown on the far side of the valve body 39, as viewed in FIG. 
2, and the ports 44 through 48 are as shown also. 
The valve 11 also has a plurality of fluid passageways 49, and these are 
shown to be concentric passageways within the housing 39 and spaced 
therealong and are actually shown to be six in number, and each of the 
passageways 49 is directly fluid-flow connected with one of the six ports 
described. Further, the spool 41 has a recessed portion 51 on each end 
thereof, and the spool 41 thus has a fluid passageway defined by the 
portion 51 extending between the spool enlarged ends 52 and the enlarged 
fluid sealing central portion 53 of the spool 41, and the spool therefore 
presents fluid passageways designated 54 on each opposite end of the spool 
41. 
Thus, it will be seen that the housing 39 has a central bore 56 which 
slidably receives the spool 41, and the spool has its opposite ends 
projecting into enclosures 57 suitably affixed to the housing 39. A 
compression spring 58 is in each enclosure 57, and a plate 59 abuts the 
inner end of each spring 58 and bears against the spool portion 52 to thus 
urge the spool 41 to a centered position, as shown in FIG. 2. Also, fluid 
connectors or nipples 61 are attached to the enclosures 57 to permit the 
introduction of fluid into the enclosures 57 and thereby force upon the 
plates 59 and thus position the spool 41, either by pressure or by a 
reduction of pressure, and the spool can also be manually or solenoid 
controlled, in any conventional manner, and the spool end 62 is shown 
extending outwardly of the enclosure 57 in FIG. 2, for the manual or 
solenoid control, as desired. 
FIG. 2 shows the spool 41 in the neutral position in that the spool fluid 
sealing enlarged circular portion 53 is central between the passageways 
and ports heretofore described. Also, in the FIG. 2 position, it will be 
seen and understood that fluid under pressure could be entering the valve 
11 through either port 42 or 43, depending upon the setting of the spool 
31 of valve 10, and thus the fluid would be directed through the valve 11 
and to the ports 44 and 46, or the ports 47 and 48, and therefore the 
similar ends of the cylinder assemblies 12 and 13 would be pressurized. By 
similar ends is meant either the head end or the rod end of the assemblies 
12 and 13. Of course assemblies 12 and 13 include cylinders 63 and pistons 
64 and rods 66. Therefore, if pressure were in the line 17 and directed to 
the port 42 and thus to the ports 44 and 46 and to the lines 19 and 21, 
then the rod ends of the assemblies 12 and 13 would be pressurized and 
that would give a maximum force to the system since both assemblies 12 and 
13 would be under fluid pressure. Therefore, depending upon which of the 
two similar ends of the two assemblies 12 and 13 are pressurized, and of 
course depending upon the connection of the assemblies 12 and 13 with a 
material handling bucket, such as a backhoe bucket, the maximum force can 
be applied to the bucket for a loading of the bucket, for instance. 
Accordingly, where the assemblies 12 and 13 are connected with a backhoe 
bucket in an arrangement such that extension of the assemblies 12 and 13 
will effect the loading action, then of course the pressurizing of the 
head ends of the assemblies 12 and 13 would be desired, and that of course 
would mean that the valve 11 would be in the position of FIG. 2 but with 
the pressure of the fluid extending into the lines 22 and 23. 
FIG. 3 shows a shifted position of the spool 41, and here it will be seen 
that the valve spool 31 could be set so that there would be fluid pressure 
at the port 43 and thus the port 48 would be under pressure and therefore 
the fluid pressure would be in the line 23 and thus only the head end of 
the cylinder assembly 13 would be pressurized. That condition could be 
utilized for a fast curl action of the backhoe bucket, since only one of 
the assemblies 12 and 13 is then subjected to fluid pressure, and that 
would create the lesser force but faster action, both of which would be 
desired. 
Finally, FIG. 4 shows a shifted position of the spool 41, and that position 
could be utilized for introducing pressure into the port 42 and to the 
port 44 and to the line 19 and thus to only the rod end of the assembly 
13. That condition could be achieved for the function of a fast dumping 
action of the backhoe bucket where the dumping action is achieved by a 
contraction of the cylinder assembly 13. Of course in both of the settings 
of the spool 41 in FIGS. 3 and 4, the opposite one of the ports 42 and 43 
is serving as the return port for the return flow through its respective 
line 17 or 18. 
With this arrangement, the valve 10 serves as a reversing type valve 
relative to the speed control valve 11 which in turn has fluid passageways 
fluid-flow connected with similar ends of the cylinder assemblies 12 and 
13. Further, the valve 11 has the plurality of passageways described, and 
it has the six ports described, and the spool 41 and the entire valve 11 
is arranged so that various combinations of the lines 44, 46, 47, and 48 
can be interconnected, such that the three lines 44, 46, and 47 are 
interconnected in the FIG. 3 position, for achieving the fast curl mode 
described, for instance. As such, there are three combinations of four 
fluid passageways in the valve 11.