U.S. patent number 3,589,242 [Application Number 04/850,995] was granted by the patent office on 1971-06-29 for single lever control for hoeing scraper components.
This patent grant is currently assigned to Caterpillar Tractor Co.. Invention is credited to Roy J. Barnes, Elmer R. Crabb, Robert A. Peterson, Donald H. Stroot.
United States Patent |
3,589,242 |
Peterson , et al. |
June 29, 1971 |
SINGLE LEVER CONTROL FOR HOEING SCRAPER COMPONENTS
Abstract
The earth handling components of a scraper of the kind having a
hoeing apron mounted on powered articulated linkage are actuated by
means of a single operator's control lever which may be pivoted
forwardly, backwardly or to either side and which may be lifted or
depressed or rotated in either of two directions, wherein each
motion operates a different one of a plurality of electrical
switches which control solenoid valves operating fluid jacks
coupled to the several scraper components. Ten different scraper
component movements may be initiated by appropriate positioning of
the single lever, either individually or in certain selected
combinations.
Inventors: |
Peterson; Robert A. (San
Leandro, CA), Barnes; Roy J. (Pleasanton, CA), Crabb;
Elmer R. (Morton, IL), Stroot; Donald H. (Castro Valley,
CA) |
Assignee: |
Caterpillar Tractor Co.
(Peoria, IL)
|
Family
ID: |
25309674 |
Appl.
No.: |
04/850,995 |
Filed: |
August 18, 1969 |
Current U.S.
Class: |
91/523; 60/911;
74/471R; 91/524; 91/527; 91/531; 137/636; 137/637; 37/425 |
Current CPC
Class: |
E02F
3/656 (20130101); E02F 3/651 (20130101); E02F
3/657 (20130101); E02F 3/6481 (20130101); E02F
3/652 (20130101); F15B 21/08 (20130101); Y10T
74/20012 (20150115); Y10S 60/911 (20130101); Y10T
137/87096 (20150401); Y10T 137/87056 (20150401) |
Current International
Class: |
E02F
3/65 (20060101); F15B 21/08 (20060101); F15B
21/00 (20060101); E02F 3/64 (20060101); F15b
013/06 (); F15b 021/08 () |
Field of
Search: |
;91/413 ;137/636,636.4
;74/4.71 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Geoghegan; Edward W.
Claims
What we claim is:
1. In apparatus having earth manipulating components operated by a
plurality of fluid jacks and having a source of fluid under
pressure and a plurality of control valves each connected between
said source of fluid and a separate one of said jacks, a control
system for actuating selected individual ones of said jacks
comprising:
a plurality of pilot means for operating a valve in response to
electrical signals, each of said control valves having at least one
of said pilot means coupled thereto,
an electrical power source,
an operator's control lever, wherein said control lever has a hand
grip portion which may be moved axially relative to a second
portion of said lever,
support means for said control lever providing for motion thereof
in any of a plurality of distinct directions wherein said lever
support means provides for tilting of said control lever in four
different directions relative to a normal position thereof,
a plurality of electrical switches each having an actuator
positioned for operation by a different one of said distinct
motions of said lever, wherein a different one of said plurality of
electrical switches is positioned for actuation by tilting of said
control lever in each of said four different directions and wherein
one of said plurality of electrical switches is positioned for
actuation by axial movement of said hand grip in a first direction,
and another one of said electrical switches is positioned for
actuation by movement of said hand grip in the opposite direction,
each of said switches being connected between said electrical power
source and separate ones of said pilot means whereby each of said
jacks may be controlled by a separate one of said motions of said
control lever.
2. In apparatus having earth manipulating components operated by a
plurality of fluid jacks and having a source of fluid under
pressure and a plurality of control valves each connected between
said source of fluid and a separate one of said jacks, a control
system for actuating selected individual ones of said jacks
comprising:
a plurality of pilot means for operating a valve in response to
electrical signals, each of said control valves having at least one
of said pilot means coupled thereto,
an electrical power source,
an operators control lever, wherein said control lever has a hand
grip portion which is rotatable and a base portion which is fixed
against rotation,
support means for said control lever providing for motion thereof
in any of a plurality of distinct directions wherein said lever
support means provides for tilting of said control lever in four
different directions relative to a normal position thereof, and
a plurality of electrical switches each having an actuator
positioned for operation by a different one of said distinct
motions of said lever, each of said switches being connected
between said electrical power source and separate ones of said
pilot means whereby each of said jacks may be controlled by a
separate one of said motions of said control lever, wherein a
different one of said plurality of electrical switches is
positioned for actuation by tilting of said control lever in each
of said four different directions and wherein at least one of said
electrical switches is secured to one of said portions of said
lever, and a tab for actuating said switch is secured to the other
of said portions of said lever whereby said switch is operated by
said tab upon rotation of said hand grip portion.
3. In apparatus having earth manipulating components operated by a
plurality of fluid jacks and having a source of fluid under
pressure and a plurality of control valves each connected between
said source of fluid and a separate one of said jacks, a control
system for actuating selected individual ones of said jacks
comprising:
a plurality of pilot means for operating a valve in response to
electrical signals, each of said control valves having at least one
of said pilot means coupled thereto,
an electrical power source,
an operators control lever, wherein said control lever has a plate
secured thereto and extending laterally therefrom whereby said
plate is tilted by pivoting motion of said lever,
support means for said control lever providing for motion thereof
in any of a plurality of distinct directions, said lever support
means being a universal joint providing for tilting of said control
lever in four different directions relative to a normal position
thereof,
a plurality of electrical switches each having an actuator
positioned for operation by a different one of said distinct
motions of said lever, each of said switches being connected
between said electrical power source and separate ones of said
pilot means whereby each of said jacks may be controlled by a
separate one of said motions of said control lever, wherein a
different one of said plurality of electrical switches is
positioned for actuation by tilting of said control lever in each
of said four different directions and whereby said control lever
may be pivoted for operation of at least two of said switches
simultaneously and wherein a plurality of said switches are mounted
on said plate at angularly spaced locations thereon relative to the
axis of said lever, and
stationary means disposed adjacent said plate and positioned to
depress the actuators of said switches when tilting movement of
said plate carries said actuators toward said stationary means.
4. In a scraper having earth manipulating components powered by
fluid operated jacks and having a source of fluid under pressure,
means for manually controlling said components comprising:
a plurality of valves connected between said source of fluid and
separate ones of said jacks and having at least three positions
including a first position at which opposite ends of the associated
jack are closed and a second position at which said fluid is
supplied to one end of the associated jack and a third position at
which fluid is supplied to the opposite end of the associated
jack,
a plurality of fluid pressure operated pilot means each coupled to
an associated one of said valves for shifting said valves between
said positions thereof and having biasing means normally urging
said associated one of said valves toward said first position
thereof, said pilot means being responsive to fluid pressure pilot
signals to shift said associated valve to said second and third
positions thereof,
a plurality of means for producing said fluid pressure pilot
signals in response to electrical signals, each being coupled to an
associated one of said pilot means,
a control lever having a hand grip section and a base section with
said hand grip section being movable in an axial direction and in
angular direction relative to said base section,
spring means connected between said hand grip section and said base
section of said control lever to urge said hand grip section toward
a predetermined normal axial and angular position relative to said
base section,
support means for said control lever having a universal joint
coupling said base section of said lever to stationary means
whereby said lever including said base section of said hand grip
section may be pivoted about said joint in any of a plurality of
directions,
an electrical power source, and
a plurality of electrical switches having movable actuators, each
switch being connected between said electrical power source and an
associated one of said pilot signal producing means and each having
said actuator thereof positioned for operation by said lever by
movement of said lever in a separate one of said axial and angular
and pivoting motions thereof.
5. The combination defined in claim 4 wherein a first switch plate
is secured to said base section of said control lever in spaced
relation from said universal joint and extends laterally from said
lever and wherein at least a portion of said switches are secured
to said first switch plate with said actuators of said switches
extending from said first switch plate and further comprising
stationary means situated adjacent said lever in spaced relation
from said first switch plate to contact said actuators of said
switches upon pivoting movement of said lever.
6. The combination defined in claim 5 wherein said hand grip
section of said lever has a shaft portion extending parallel to
said base section and being of greater length and whereas a second
switch plate is secured to said base section of said lever and
extends laterally therefrom and a third switch plate is secured to
said hand grip section of said lever in spaced relationship from
said first switch plate whereby axial movement of said hand grip
portion of said lever varies the spacing between said second and
third switch plates and wherein at least one of said switches is
secured to one of said second and third switch plates with the
actuator thereof extending therebetween whereby said one of said
switches is operated by axial movement of said hand grip portion of
said lever.
7. The combination defined in claim 6 wherein first and second ones
of said switches are carried on said second and third switch plates
respectively, each having an actuator extending toward the other of
said second and third switch plates, the actuator of said first
switch being spaced from said third switch plate when said hand
grip portion of said lever is in said normal position thereof
whereby axial movement of the control lever which reduces the space
between said second and third switch plates causes said actuator to
contact the opposite switch plate and be operated thereby, and
wherein said second switch has an actuator which extends from said
third switch plate to contact said second switch plate when said
hand grip portion of said lever is in said normal position thereof
whereby said actuator of said second switch is operated when the
said control lever is at said normal position thereof and is
released when said hand grip section is manipulated to increase the
spacing between said second and third switch plates whereby one of
said first switch is operated by axial movement of said control
lever in a first direction and said second switch is operated by
axial movement of the control lever in the opposite direction.
8. The combination defined in claim 6 wherein a pair of said
switches are mounted on one of said second and third switch plates
and further comprising at least one tab extending from the other of
said second and third switch plates whereby one of said pair of
switches is actuated upon rotation of said hand grip portion of
said lever in a first angular direction and the other of said pair
of switches is actuated upon rotation of said hand grip portion of
said lever in the opposite angular direction.
9. The combination defined in claim 4 wherein at least one of said
switches is mounted on said hand grip portion of said lever and has
a trip lever extending therefrom for manipulation by an operator's
hand.
Description
BACKGROUND OF THE INVENTION
This invention relates to earthmoving apparatus and more
particularly to control systems for actuating the load manipulating
components of scrapers and the like.
Scrapers and related earthmoving equipment generally have several
load manipulating elements which the operator must control while
simultaneously driving the vehicle. These include, for example, the
bowl, the apron and the ejector. Conventionally, these components
are each actuated by separate control levers. As a consequence,
there are times in the operating cycle when the operator must very
rapidly shift his hand back and forth between several control
levers while continuing to drive the vehicle. This can be very
taxing and is a situation in which errors can easily be made.
Moreover, the training period required to learn to operate the
scraper efficiently is undesirably long.
As more advanced earthmoving equipment is developed, the complexity
and difficulty of the operator's control manipulations increases.
Copending application Ser. No. 589,978 filed Oct. 27, 1966 and
entitled "Earthmoving Scraper with Multiply Articulated Apron
Structure," (now U.S. Pat. No. 3,471,952) for example, describes a
recently developed scraper with an apron which is coupled to the
bowl through linkage having three distinct pivot joints and
independent powered control of flexing about each joint whereby the
apron is made to perform a kind of hoeing motion to load material
into the bowl. While this provides an extremely efficient and
versatile self-loading action, it may be seen that the task of
individual controls are used to provide for the additional apron
motions.
One means of simplifying the operator's task is to combine the
control of several components into one control lever whereby
movement of the lever in different ways actuates different ones of
the jacks which move scraper components. Such systems have
heretofore been devised for diverse kinds of apparatus including
earthmoving equipment. Prior single lever controls have required
very bulky, costly and cumbersome support linkages for connecting
the lever and associated control valves in a way which provides for
actuation of one valve without necessarily actuating any of the
others. The number of separate functions which can be controlled
with these complex prior single lever systems is still undesirably
small.
SUMMARY OF THE INVENTION
The present invention is a single lever system providing for
independent control of a large number of components of a scraper or
the like, without requiring bulky and complex mechanism associated
with the lever. In a preferred form, the lever may be tilted
forwardly, backwardly, and to either side, and may be raised,
depressed, or rotated in two directions, with each movement acting
to operate one of a plurality of electrical switches, each of which
is connected with a solenoid valve that controls a specific
operation of one of the powered components of the associated
apparatus. In one form of the invention, one or more additional
switches may be carried on the lever to control still other
functions without requiring removal of the operator's hands from
the lever.
Accordingly, it is an object of this invention to facilitate the
control of complex earthmoving apparatus.
It is another object of the invention to provide single lever
control of a plurality of powered earth manipulating components of
a scraper of the like with a minimum of mechanical complication and
bulk in the control lever structure.
It is still another object of the invention to provide a single
lever control for initiating a large number of different component
movements in a scraper wherein movement of the control lever to
initiate one operation may be selectively combined with movement of
the control lever to initiate certain other operations
simultaneously.
The invention together with further objects and advantages thereof
will best be understood by reference to the following specification
in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevation view of a hoeing scraper with the
control system for earth manipulating components being shown in
schematic form;
FIG. 2 is a section view of a single lever control and associated
mechanism for actuating all of the components of the scraper of
FIG. 1, which directly manipulate earth;
FIG. 3 is a section view of a portion of the mechanism of FIG. 2
taken along line III-III thereof;
FIG. 4 is a plan view of the single lever mechanism of FIG. 2;
FIG. 5 is a section view of the single lever control mechanism
taken along line V-V of FIG. 3;
FIG. 6 is a section view of the control lever mechanism taken along
line VI-VI of FIG. 3; and
FIG. 7 is a perspective view of the operator's station area of the
scraper of FIG. 1 showing certain of the controls thereat.
DESCRIPTION OF A PREFERRED EMBODIMENT
The control system of the present invention is applicable to a
variety of earthmoving vehicles wherein earth or other material is
manipulated by components powered by fluid motors such as hydraulic
jacks. Referring now to FIG. 1 of the drawing, there is shown a
scraper 11 of the general type described in the above identified
copending application Ser. No. 589,978 wherein a manipulatable
apron 12 is provided for the purpose of loading material into the
bowl 13 by a kind of hoeing action. Salient elements of such a
scraper 11 are a tractor 14 supporting the forward end of the bowl
13 through a gooseneck 16 and draft arms 17 and a rear frame 18
supporting the back end of the bowl and riding on rear wheels 19.
This particular scraper 11 is of the type having a supplementary
engine 21 carried on the rear frame 18 to drive the rear wheels 19
and to operate the several hydraulic jacks to be hereinafter
described.
Components of the scraper 11 directly concerned with manipulating
earth include a cutting edge 22 carried along the underside of the
open forward end of bowl 13. To raise and lower the bowl and
cutting edge, one or more bowl jacks 23 are connected between the
upper forward end of the bowl and an arm 24 which extends from
gooseneck 16. To discharge earth from bowl 13, the rear wall
thereof is defined by a movable ejector 26 and one or more ejector
jacks 27 are coupled thereto and to rear frame 18 to move the
ejector forwardly and rearwardly.
To support the manipulatable apron 12, a bail arm 28 is pivoted at
the lower end to each side of the bowl 13 and a jack 29 is
connected between each such arm and the bowl to selectively pivot
the arm about the coupling to the bowl.
A grid rid arm 31 is pivotably coupled to the upper end of each arm
28 and a jack 32 is connected therebetween to control the
inclination of arm 31 relative to arm 28. Apron 12 is pivoted to
the opposite end of arms 31 and still another jack 33 is connected
therebetween to selectively pivot the apron relative to the
intermediate arms. As there are three articulations between the
apron 12 and bowl 13 with independent powered control of pivoting
about each joint, the apron 12 may be made to undergo any desired
kind of hoeing motion to assist in the loading of earth into the
bowl 13, to reach out and pull heavy boulders into the bowl or for
a variety of other purposes as described in the hereinbefore
identified copending application.
Accordingly, in addition to manipulating the controls required for
driving the scraper 11, the operator must selectively actuate five
sets of jacks 23, 27, 29, 32 and 33 in the course of a normal
operating cycle and three of the sets of jacks 29, 32 and 33 must
be operated repetitively and with careful coordination to
accomplish the desired hoeing action. It may be seen that the
required control manipulations are difficult and taxing if
conventional separate levers are provided for each set of jacks.
The operator's task is greatly facilitated by the present invention
in that control of all of the above-mentioned jacks is effected by
manipulations at a single control lever 34.
As hereinafter will be discussed in more detail, movement of the
control lever 34 in different directions operates selected ones of
a series of electrical switches 36 which in turn control a series
of 10 solenoid valves 37 successive pairs of which actuate one of
five pneumatic cylinders 38 each being operative to pilot a
separate one of five spool valves 39 that act to extend or retract
one of the above described sets of hydraulic jacks.
Considering now the electrical and fluid circuit in greater detail,
jacks 23 are extended to lower bowl 13 or are contracted to raise
the bowl by shifting a three position spool valve 39A. Valve 39A
has a normal center or Hold position at which the fluid ports at
opposite ends of the jacks 23 are closed, a second position at
which a source of hydraulic fluid such as pump 41 is communicated
with a rod end of jacks 23 while the head end thereof is
communicated with a drain 42 to extend the jack and raise the bowl
13 and has a third position at which pump 41 is communicated with
the head end of the jack and the rod end is connected to drain 42
to lower the bowl. A relief valve 40 is connected directly between
pump 41 and drain 42 to pass the output of the pump to the drain at
those times when all valves 39 are closed. The pivot cylinder 38A
associated with spool valve 39A has a piston which is spring biased
to normally position the spool valve in the center or Hold setting.
A piston in pilot cylinder 38A is extended, to shift spool valve
39A to the second position thereof, by energizing a two position
solenoid valve 37A-1 which then supplies air under pressure to the
rod end of cylinder 38A. The piston in cylinder 38A is contracted,
to shift spool valve 39A to the third position, by deenergizing a
normally open solenoid valve 37A-2 which then supplies air to the
rod end of the cylinder. As will hereinafter be discussed in more
detail, movement of control lever 34 in a first direction closes a
normally open electrical switch 36A-1 to apply power from a battery
43 to solenoid valve 37A-1 while movement of the lever in an
opposite direction closes a switch 36A-2 to energize solenoid valve
37A-2.
The circuitry for operating the other spool valves 39 by an
appropriate movement of control lever 34 is essentially similar.
Thus, spool valve 39B is normally in the center or Hold position
due to the action of spring biasing in the associated pneumatic
pilot cylinder 38B and a piston in cylinder 38B may be extended or
contracted by energizing normally closed solenoid valves 37B-1 or
37B-2 respectively. Each such solenoid valve 37B-1 and 37B-2 may be
energized by closing normally open switches 36B-1 or 36B-2
respectively by an appropriate movement of the control lever 34.
Similarly, spool valve 39C is spring biased to the center or Hold
position by the associated pneumatic pilot cylinder 38C a piston of
which may be extended or contracted, to shift spool valve 39C to
the second or third positions thereof, by energization of solenoid
valves 37C-1 or 37C-2 respectively. Closing of normally open
switches 36C-1 and 36C-2 respectively energize solenoid valves
37C-1 and 37C-2. Similarly, closing of electrical switches 36D-1 or
36D-2 by appropriate movements of the control lever 34 energize
solenoid valves 37D-1 and 37D-2 respectively to extend or contract
a piston in the pneumatic pilot cylinder 38D which operates spool
valve 39D and which is similarly spring biased by cylinder 38D to
the center or Hold setting.
The final spool valve 39E controlling the ejector jack 27 is
actuated by a single three position switch 36E. Switch 36E has a
center setting at which both of the associated solenoid valves
37E-1 and 37E-2 are deenergized and therefore the associated
pneumatic pilot cylinder 38E, through the spring bias action on a
piston therein, holds spool valve 39E at the center of Hold
setting. Actuation of switch 36E in one direction energizes
solenoid valve 37E-1 to apply air pressure to the head end of
cylinder 38E thereby shifting spool valve 39E in a first direction
while at the other setting of switch 36E, solenoid valve 37E-2 is
energized pressurizing the rod end of cylinder 38E to shift spool
valve 39E to the third position thereof.
Under certain conditions it may be desirable to obtain a float
condition in the jacks 29, which pivot arms 28, and in the jacks
33, which pivot the apron 12, the float condition being a direct
communication between the rod and head ends of the jacks whereby
the jacks may extend or contract under the influence of external
forces acting thereon. Rather than complicate the associated spool
valves 39D, 39E and related circuitry for this purpose, normally
closed foot pedal operated valves 44 and 46 are provided for
communicating opposite ends of jacks 29 and 33 respectively.
Thus, control of all of the jacks 23, 27, 29, 32, and 33 may be
effected by operating appropriate ones of the electrical switches
36. FIGS. 2 to 6 illustrate a construction for the control lever 34
and associated mechanism whereby all of the above described
switches 36 are operatable singly or in certain compatible
combinations by different manipulations thereat. Referring
initially to FIG. 2 in particular, the control lever 34 is
supported in a rectangular housing 47 having a removable cover
plate 48 with an opening 49 at the center through which the lower
portion of the lever extends into the housing. Control lever 34 has
an upper handgrip portion 51 bent into a U-shape whereby it may be
comfortably grasped by the operator's hand and which is secured to
the upper end of a center shaft portion 52 of the lever that
extends down through opening 49 into housing 47. The handgrip
portion 51 attached center shaft 52 of the control lever may be
tilted forwardly and backwardly as illustrated by arcs B1 and B2 in
FIG. 3 and may also be tilted to the left as illustrated by arc C1
in FIG. 2 or to the right as illustrated by arc C2 therein.
Handgrip portion 51 may also be raised as illustrated by arrow A1
and depressed as illustrated by arrow A2 in FIG. 2 and may be
rotated as illustrated by arc D1 in FIG. 4 or rotated in the
opposite sense as illustrated by arc D2 therein.
To provide for these motions, with reference again to FIG. 2,
center shaft portion 52 of the control lever extends axially
through a cylindrical outer shaft 54 which is journaled in the
opening 49 of housing cover plate 48 by a universal type of joint
53. In particular, universal joint 53 may be a body of rubber or
other flexible resilient material of generally annular
configuration which is secured to the rim of opening 49 by an
annular ring 57. Joint 53 has an axial passage 55 through which the
upper end of outer shaft 54 extends, the upper end of shaft 54
being of reduced diameter to form a shelf 58 thereon against which
a metal sleeve 56, secured to the material of joint 53 within the
axial passage therethrough, is abutted. Shaft 54 is threaded to
receive a nut 59 which secures the shaft to joint 53. Owing to the
resiliency of joint 53, outer shaft 54 may be tilted in any of the
above described directions but is held against any significant
axial movement. Center shaft 52 however is slidable in either
direction within the outer shaft 54 to provide for the desired
raising or depression of control lever 34.
To provide spring biasing tending to hold the center shaft 52 at a
predetermined normal axial position relative to outer shaft 54, the
lower end thereof immediately below outer sleever 54 is reduced
diameter to form a shelf 61 against which an annular washer 62
abuts. A second such washer 63 is disposed on center shaft 52 in
downwardly spaced relationship to washer 62 and a compression
spring 64 is disposed between the two washers in coaxial
relationship to the center shaft. The lower washer 63 and thus
spring 64 and washer 62 are retained on center shaft 52 by a sleeve
66 disposed immediately below washer 63. A laterally extending
switchplate 67 is mounted on center shaft 52 below sleeve 66 and a
nut 68 is threadably engaged on the extreme lower end of inner
shaft 52 to lock sleeve 66 against a second shelf 70 thereon.
Thus if hand grip 51 is raised, center shaft 52 may slide upwardly
within outer shaft 54 causing washer 63 to compress spring 64
against washer 62. Similarly if hand grip 51 is depressed, center
shaft 52 may move downwardly within outer shaft 54 causing washer
62 to compress spring 64 against the lower washer 63. Thus, the
hand grip portion 51 of control lever 34 is always urged toward a
preferred axial position relative to outer sleeve 54.
To protect the joint 53 and associated mechanism without impeding
the several above described motions thereof, a flexible bellows
seal 69 is disposed coaxially around the upper end of center shaft
52 and is secured thereto. The lower outer end of seal 69 is
secured to housing top plate 48 by a clamping ring 71 secured by
bolts 72.
Outer shaft 54 has an intermediate switch plate 60 extending
laterally therefrom immediately above washer 62 and a top switch
plate 73 spaced upward from plate 60 and downwardly from the top
plate 48 of housing 47. Thus, there are three switch plates 67, 60
and 73 each of which is tilted when the hand grip 51 is pivoted in
any direction. In addition, axial movement between the lower switch
plate 67 and intermediate switch plate 60 is produced by raising or
lowering of the hand grip. The previously described electrical
switches 36, other than switch 36E, are each carried on one of the
switch plates 67, 60 or 73 in a position whereby each switch will
be operated by the appropriate motion of the hand grip 51.
Referring now to FIG. 5 in conjunction with FIG. 2, switch 36C-1
for example, is mounted on the underside of top switch plate 73 and
has an actuator 74 projecting upward therethrough in position to be
operated by contact with a ring 76 at the underside of housing top
plate 48 when hand grip 51 is tilted along arc C1. To avoid damage
to actuator 74 by overtravel of hand grip 51 along arc C1, a pin 77
projects upward from top switch plate 73, adjacent actuator 74,
whereby tilting of the top switch plate is stopped prior to the
point at which such damage would occur but after the actuator has
been depressed sufficiently to operate switch 36C-1.
Similarly, switch 36C-2 is mounted at the opposite side of plate 73
and has an actuator 74 extending upward therefrom to be operated by
contact with ring 76 when hand grip 51 is tilted along arc C2,
actuator 74 also being protected by an upwardly projecting pin
77.
Referring now to FIG. 5 in conjunction with FIG. 3, switches 36B-1
and 36B-2 are also mounted on plate 73 and are displaced 90.degree.
from switches 36C-1 and 36C-2 with respect to the axis of shaft 54.
Thus, the upwardly extending actuator 74 of switch 36B-1 will be
operated by contact with ring 76 when the hand grip 51 is tilted
along arc B1 while the actuator 74 of switch 36B-2 is operated when
the hand grip is tilted along arc B2. As in the previous instances,
each actuator 74 is protected by a pin 77 extending upward from
plate 73 in proximity to the associated actuator.
Switches responsive to axial movement of center shaft 52 are
relative to outer shaft 54 include switch 36A-1 mounted on
intermediate switch plate 60 and having an actuator 74 extending
downwardly therefrom to a level slightly above that of the normal
position of lower switch plate 67 as shown in FIG. 3. Thus, switch
36A-1 is operated by contact of plate 67 with the actuator 74
thereof when hand grip 51 is raised as indicated by arrow A1 in
FIG. 2. Referring again to FIG. 3, normally closed switch 36A-2 is
mounted on lower switch plate 67 with an actuator 74 extending
upwardly therefrom to intermediate switch plate 60 which holds such
actuator in the operated position when hand grip 51 is in its
normal position. Thus, when hand grip 51 is depressed, lowering
plate 67 relative to plate 60, the actuator 74 of switch 36A-2 is
no longer contacted by plate 60 and the switch closes.
Referring now to FIG. 6 in conjunction with FIG. 2, switches
controlled by the rotational movement of the hand grip 51 are 36D-1
and 36D-2, both of which are mounted on the lowermost switch plate
67, both such switches have aligned facing actuators 74 which are
spaced apart a small distance. A tab 78 extends downwardly from
intermediate switch plate 60 between the two actuators and in
spaced relation from both thereof when the hand grip 51 is
unrotated from its normal position. To urge the hand grip 51 toward
the normal rotational position, a leaf spring 79 extends from a
post 81 on lower switch plate 67 to a spring housing 82 secured to
the intermediate switch plate 60. Spring 79 thus resists rotary
motion of the hand grip 51 and tends to maintain tab 78 midway
between the actuators 74 of switches 36D-1 and 36D-2. However,
rotation of hand grip 51 along arc D1 of FIG. 4 causes tab 78 to
operate switch 36D-1 while rotation in the opposite sense along arc
D2 moves the tab against the actuator of switch 36D-2.
Referring now again to FIG. 2 in particular, the final switch 36E
is mounted in the end of hand grip 51 and has a small actuator
lever 84 projecting therefrom for convenient operation by the
operator's thumb when his hand is clasping the hand grip. Pivoting
of trip lever 84 upward along arc E1 advances the ejector and
pivoting of lever 84 downward along arc E2 retracts the ejector as
hereinbefore described.
Accordingly, each of the switches 36 which control the jacks
associated with the elements of the scraper directly concerned with
manipulating earth may be operated by an appropriate movement at
the single lever 34 thereby greatly simplifying the operator's
task. Moreover, it should be noted that compatible combinations of
switches may be actuated at the same time by combining selected
ones of the above described control lever movements. For example,
hand grip 51 may be raised to actuate switch 36A-1 while it is
simultaneously rotated to actuate switch 36D-1 and tilted to
actuate switch 36B-1. It will be apparent that other combinations
of such movements may be made as desired. Further, to a
considerable extent the particular arrangement of switches
discussed above causes the m movements of the operator's hand to
resemble the resulting movement of the apron and associated
linkage. For example, the raising of the hand grip results in a
raising of the scraper apron 12 while a forward movement of the
hand grip tends to advance the apron, certain of the other
movements of the control lever being similarly correlated to a
limited extent with the resulting movements of the apron.
As shown in FIG. 7, the above described housing 47 is preferably
situated adjacent the operator's seat 86 with the hand grip 51
projecting therefrom in a position where it may readily be grasped
by the operator. This is most conveniently done if the housing 47
is positioned at one side of seat 86, slightly forward from the
seat and rearwardly from steering wheel 87 and is tilted slightly
by being mounted to the scraper by an acute angle bracket 88.
While the single lever control system as been herein described with
reference to a specific form of hoeing scraper, it will be apparent
that the invention is also applicable to related forms of scraper
which may not have the precise arrangement of earth manipulating
elements herein described. Where the arrangement of such elements
is less complex than that of the scraper herein described, certain
of the control functions herein described as associated with the
lever 34 may be eliminated.
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