US3056516A

US3056516A - Loading, hauling and dumping apparatus

Info

Publication number: US3056516A
Application number: US777934A
Authority: US
Inventors: Clayton K Cole
Original assignee: Heil Co
Current assignee: Heil Co
Priority date: 1958-12-03
Filing date: 1958-12-03
Publication date: 1962-10-02
Anticipated expiration: 1979-10-02

Description

Oct. 2, 1962 C. K. COLE LOADING, HAULING AND DUMPING APPARATUS Filed Deo. 5, 1958 5 Sheets-Sheet l DFGREES FROM HOR/ZNTAL.

Oct. 2, C. K COLE LOADING, HAULING AND DUMPING APPARATUS 5 Sheets-Shea?l 2 Filed Dec. 5, 1958 @egim f C026 Oct. 2, 1962 c. K. COLE LOADING, HAULING AND DUMPING APPARATUS 5 Sheets-Sheet 31 Filed Dec. 5, 1958 fnl/enfer.' C'Zcyfofz, ff Cole United States Patent Office 3,056,5l6 Patented Oct. 2, 1962 3,056,516 LUADENG, HAULING AND DUMPHNG APPARATUS Clayton K. Cole, Kalamazoo, Mich., assigner, by mesne assignments, to The Heil Co., Milwaukee, Wis. Filed Dec. 3, 19513, Ser. No. 777,934 8 Claims. (Q1. 214-77) This invention relates to a hoisting apparatus and particularly to an improved hydraulically operated hoist mechanism for use in loading, hauling and dumping apparatus. Certain types of hoisting apparatus employ a pivoted boom arrangement in lifting a load from a supporting surface such as the ground, for example7 to a carrying position on a truck chassis. The boom arms of the hoist mechanism are swung through a large arc in a substantially vertical plane in order to lift the load from the ground to the truck or vice versa. As the boom mechanism is swung upwardly from a substantially horizontal position the effective moment or lever arm of the load decreases and the torque required to swing the boom decreases correspondingly. In the past a hydraulically operated cylinder and piston arrangement have been connected directly to the boom to effect swinging of the boom from a substantially horizontal position to a position past the vertical or vice versa, that is generally through an arc of greater than 90. Such a mechanism is illustrated in the patent to Brooks No. 2,313,514. When the lifting of a load is commenced with the boom arms at a substantially horizontal position the force required to lift the load which is attached to the free end of the boom arms is quite large because of the torque exerted by the load through a long lever arm. Thus a substantially large effective lever arm is desirable for the lifting force to act through. If a boom mechanism is to be swung through a substantially large arc, for example greater than 90, such as is illustrated in the patent to Brooks No. 2,313,514, then the line of application of the lifting force provided by the cylinder and piston arrangement tends to approach a substantially dead center position, that is7 a position in which the effective lever arm becomes very small.

Accordingly, an object of this invention is to provide a hoist mechanism so constructed that a substantially large effective lever arm is available during the initial lifting of a load from its resting position outside of the truck chassis to a supported position on the truck and yet at the same time have a substantially large effective lever arm available to control the load during the remainder of its swing.

Another object of the present invention is to improve the overall mechanical efficiency of this type of hoist mechanism by providing means which will allow a smaller size piston and cylinder arrangement and a smaller volume pump to be used during high peak load conditions encountered during the early stage of a lifting operation.

Another object is to provide a link arm or motion transmitting means in conjunction with the boom arm which will be effective to maintain a substantially large effective lever arm during the latter portion of the swing of the lift arm during a loading movement, and a cam means for guiding the motion of the link arm during a portion of the swing of the lift arm.

These and other objects and features of this invention will become apparent from the following description when taken with the accompanying drawings in which;

FIG. l is a side view in elevation of the rear portion of a truck showing a hydraulically operated hoist mechanism With a load attached which is in a supported position on the truck;

FIG. 2 is an enlarged fragmentary sectional view in elevation of a lift arm of a hoist mechanism and a link arm and a cam mechanism for guiding the link arm during a portion of its travel;

FIG. 3 is an elevation view in section taken substantially along the line 3-3 of FIG. 2;

FIG. 4 is a plan View in section taken substantially along the line 4-4 of FIG. 2;

FIG. 5 is a diagrammatic illustration of a lift arm of a hoist mechanism with the lift arm in a nearly horizontal position, that is, in a position it would normally be for attaching a load from outside the vehicle, together with a piston and cylinder arrangement for operating the hoist mechanism;

FlG. 6 is a diagrammatic illustration of the lift arm of FIG. 5 swung approximately half way through its normal arc and showing the position of the lift arm at which a cam mechanism begins to guide the link arm;

FIG. 7 is a diagrammatic illustration of the lift arm of FIG. 5 in the approximate position it would be when the lift arm is at the end of its swing or arc when depositing a load onto the truck;

FIG. 8 is a rear View of the truck showing companion lift arms mounted in channelways on opposite sides of a truck;

FlG. 9 is a graphical comparison of horsepower required by diferent hoist mechanisms to lift an equivalent load.

Referring to the drawings in detail and wherein likereference characters designate corresponding parts throughout the several views the letter A designates a motor truck only the rear portion of which is shown in FIG. 1; B a load or bucket handling unit; C a bucket or other load; and D a hoist mechanism.

The truck A may be of `any preferred type and as shown includes a chassis 10, front wheels (not shown) and rear wheels 12. A normal construction is used to support the rear of the truck A on the rear wheels 12.

The load handling unit B is mounted on the chassis 10 at the rear of the truck and comprises a platform 16 for receiving a load or bucket C. The platform 16 is secured to the chassis by any suitable means such as by welding. The load handling unit also comprises longitudinally extending channelways 18 (see FIGS. 1 and 4) comprising inner and

outer side plates

20 and 22 respectively and a hoist mechanism D. The channelways 18 are mounted on and secured to each side of the rear of the chassis 10, the platform 16 extending between the channelways.

The hoist mechanism D comprises companion lift arms or boom arms 24. The lift arms 24 are pivotally mounted at pivots 26 in the channelways 18 for fore and aft swinging movement from a first position 28 overhanging the end of the truck to a position 30 above the platform 16 of the truck.

The lift arms 24 are connected together at their free ends by a crossbar 32 so that they swing as a unit. At tached to the crossbar are suitable flexible connections such as chains 33, for example, which may be detachably connected to the load or bucket C.

The hoist mechanism D also comprises a pair of hoist units of similar construction and each includes a double acting hydraulic cylinder 34 and piston 36. Each cylinder is pivoted at its forward end on a horizontal pivot pin 38 between the inner and

outer side plates

20 and 22 of the channelways 18. Attached to each piston is a piston rod 40.

The hoist mechanism D also comprises a pair of m0- tion transmitting means or link arms 42 each of which is pivotally connected to the piston rods by a pivot pin 44 and to the lift arms 24 by a pivot pin 46. The pivot pin 44 has extensions 45 the purpose of which is hereinafter described. Thus movement of the pistons `36' in the cylinders 34 is transmitted to the lift arms 24 through the link arms 42.

Since the lift arms, link arms and hoist units and associated parts are of identical construction on each side of the vehicle in the embodiment described it will be understood that when any of these are referred to in the singular or with respect to only one side, the same description is applicable to the identical part on the other side.

In a preferred embodiment the link arms 42 are of substantially a triangular construction with

edges

48, 50, and 52 forming two sides and a base thereof respectively. The pivot pin 44 for connection of the link arm `42 to the piston rod 40 is located at the apex of the triangular construction. An extension 54 on the link arm 42 constructed substantially parallel to the edge vS is pivotally connected to the lift arm 24 by pivot pin `46. The base 52 of the link arm y42 may be maintained in a flush relationship with a flat portion 58 of the lift arm 24 as shown in FIGS. and 6, for example, so that when the lift arm 24 is in the position shown in either of those figures the link arm 42 functions as an integral portion of the lift arm 24. IIn the positions shown in FIGS. 5 and -6 the link arm 42 is actually an offset portion of the lift arm 24 providing a lever arm through which the force exerted by the hydraulic system acts.

To raise and lower the boom arms 24 oil is pumped to the rear and front ends of the cylinder 34 by a pump 60 through conduits 62 and `64 from an oil reservoir 66 having valves 68 for controlling the ingress and egress of the oil. On the inner and outer side plates and 22 on the inside of the channelways 18 upper and lower guideways or

rails

70 and 72 are attached such as `by welding, for example. An upper and lower rail is attached on the inside face of each outer side plate 22, and an upper and lower rail is attached on the inside face of each inner side plate 20 (see FIGS. 3 and 4). These rails act as a cam mechanism for the follower rollers 74 mounted Von extensions 45 of the pivot pin `44 which pivotally connects the link arm 42 to the'piston rod 40. The upper and lower rails are equidistantly spaced from each other along their full length and are respectively inclined upwardly in a rearward direction. The link arms 42 are so constructed that when the boom arms are lifted toward a position above the platform 16 of the truck the link arms will pass longitudinally between the rails positioned respectively on the inner and

outer side plates

20 and 22. At the same time the rollers 74 which project beyond the sides of the link arms are received between the upper and lower rails for guiding the fore and aft movement of the link arms.

IDescribing now the operation of the hoist mechanism it will be apparent from FIG. 1 and from FIG. 5 that when a -load or bucket C is attached to the end of lift arms 24 that the torque to be exerted for initial movement of the lift arms will be greatest when the lift arms are in a substantially horizontal position. As shown in FIG. 5 forces a and b `act through pivot point 26, the effective lever arms at that position being indicated by c and d for the forces a and b respectively. It will be noted that b and d are at approximately a 90 relationslu'p thus creating the maximum possible torsional -moment about the axis 26. As further lifting commences and the lift arms F move in a counter-clockwise direction the moment arm c shortens thus requiring less torsional force to lift the load C. However, the effective lever arm through which the force exerted by the hydraulic cylinder acts is also shortened. This concurrent action accounts for a-n approximately flat horsepower required curve during the iirst 45 of counter-clockwise travel from the position shown in FIG. 5. This is illustrated by the solid line curve 76 in yFIG. 9. When the lift arm 24 reaches approximately the position .shown in FIG. 6 which is approximately 60 from the initial substantially horizontal position, the rollers 74 attached to the link arm y42 strike the lower guide rails 72. The rollers 74 and the link arm 42 thus are guided out of their normal arcuate path, which arcuate path they would have followed if the guide rails were not present. Also at this stage the link arm 42 and the lift arm 24 cease to function as an integral unit, and the link arm begins to pivot on the boom arm 24 about pivot pin A46. If the link arm 42 and the lift arm 24 were actually an integral 4unit then when the lift arm 24 reaches a position as shown in FIG. 6 during a lifting motion, the apex of the triangular link arm would continue in its original arcuate path. Then the line of force exerted by the piston and cylinder arrangement would tend to assume almost a dead center position thus permitting very little control of the load. To overcome this difficulty what otherwise would be a solid boom arm has been made into two parts, that is, a lift arm 24 and a link arm 42, the latter being pivotable on the lift arm 24. The guide rails are so arranged that the roller end of the link arm 42 is guided in a path to compensate for the arcuate advance of the link arm 42 so as to permit the hoist mechanism to maintain control of the lift arm 24 and the load attached thereto.

FIG. 9 shows a comparative set of curves comparing the horsepower required for raising the load by means of the hoist mechanism of the present invention (shown by the solid line 76) and the power required with the mechanism described in the patent to Brooks 2,313,514 (shown by the dash line 78). The horsepower required is plotted on the vertical axis and the boom travel in degrees from a substantially horizontal position (see FIG. 5) is plotted along the horizontal axis. The load, time cycle, and boom arm length were constant in both cases. It is at once apparent that the horsepower required during the initial movement is much higher with the device of the prior art. 'The new device permits approximately a flat horsepower required curve during approximately the first 45 of boom travel.

In summary, therefore, it will 4be seen that this invention advantageously provides a device whereby a smaller hydraulic piston and cylinder arrangement and smaller pump may be used to manipulate loads than could be used in hoisting apparatus of the prior art. Thus a better utilization of space is also made possible.

v.It is to be understood that the foregoing description is merely illustrative of the preferred embodiment of the invention and that the scope of this invention, therefore, is not to be limited thereto but is to be determined by the appended claims.

I claim:

1. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to and from said support means, a fluid pressure operated ram having one end pivotally connected to said support means and having its other end movable, rigid motion transmitting means pivotally connected at one end to said movable end of the ram at a location offset laterally from the pivotal mounting of the boom and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting means including arm means engageable with the boom during part of the movement of the boom to prevent movement `of the motion transmitting means relative to the boom `during said part of the movement of said boom away from a first position with the ram acting on said arm means as a lever, and means for causing relative movement between said boom and motion transmitting means during a latter part of the movement of said boom whereby the force of the ram is transferred to said pivotal connection between the motion transmitting mea-ns and the boom to maintain an effective lever arm for controlling a load carried by the boom.

2. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to and from said support means, a iluid pressure operated ram having one end pivotally connected to said support means and having its other end movable, rigid motion transmitting means pivotally connected at one end to said movable end of the ram and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting means including arm means rigid therewith which is so disposed as to brace against said boom when the latter is in a rst position to prevent movement of the motion transmitting means relative to the boom during a part of the movement of said boom away from said yrst position with the ram acting on said arm means as a lever, and means positioned to thereafter engage with said motion transmitting means to move said arm means out of bracing engagement with said boom during a latter part of the movement of said boom to permit relative movement between the boom and motion transmitting means whereby the force of the ram is transferred to said pivotal connection between the motion transmitting means and the boom to maintain an effective lever arm for controlling a load carried by said boom.

3. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to and from said support means, a iluid pressure operated ram having one end pivotally connected to said support means and having its other end movable, rigid motion transmitting means pivotally connected at one end to said movable end of the ram and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting means including arm means rigid therewith which is so disposed as to brace against said boom when the latter is in a first position to prevent movement of the motion transmitting means relative to the boom during a part of the movement of said boom away from said rst position with the ram acting on said arm means as a lever, cooperating cam elements on said support means and motion transmitting means positioned to move said arm means out of bracing engagement with said boom during a latter part of the movement of said boom to provide for relative movement between the motion transmitting means and the boom whereby the force of the ram is transferred to said pivotal connection between the motion transmitting means and the boom to maintain an effective lever arm for controlling a load carried by said boom.

4. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to `and from said support means, a fluid pressure operated ram having one end pivotally connected to said support means and having its other end movable, rigid motion transmitting means pivotally connected at one end to said movable end of the ram and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting means including arm means rigid therewith which is so disposed as to brace against said boom when the latter is in a rst position to prevent movement of the motion transmitting means relative to the boom during a part of the movement of said boom away from said first position with the ram acting on said arm means as a lever, and means positioned to thereafter engage with said motion transmitting means for causing relative movement between said boom and motion transmitting means to move said arm means out of bracing engagement with said boom during a latter part of the movement of said boom whereby the force of the ram is transferred to said pivotal connection between the motion transmitting means and the boom to maintain an effective lever arm for controlling a load carried by said boom.

CII

5. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to and from said support means, -a fluid pressure operated ram having one end pivotally connected to said support means and having its other end movable, rigid motion transmitting means pivotally connected at one end to said movable end of the ram and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting means including arm means rigid therewith which is so disposed as to brace against said boom when the latter is in a rst position to prevent movement of the motion transmitting means relative to the boom during a part of the movement of said boom away from said rst position with the ram acting on said arm means as a lever, a cam track element on said support means and a cam follower element on said motion transmitting means, said cam elements being so located as to move said arm means out of bracing engagement with the boom during a latter part of the movement of said boom to permit relative movement between the motion transmitting means and boom whereby the force of the ram is transferred to said pivotal connection between the motion transmitting means and the boom to maintain an eiective lever arm for controlling a load carried by said boom.

6. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to and from said support means, a fluid pressure operated ram having one end pivotally connected to said support means and having its other end movable, rigid motion transmitting means pivotally connected at one end to said movable end of the ram and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting -means including arm means rigid therewith which is so disposed as to brace against said boom when the latter is in a rst position to prevent movement of the motion transmitting means relative to the boom during a part of the movement of said boom away from said first position with the ram `acting on said arm means as a lever, a cam track element on said support means and a cam follower element at the pivotal connection between said motion transmitting means and ram, said cam elements being so located as to move said arm means out of bracing engagement with the boom during a latter part of the movement of said boom to permit relative movement between the motion transmitting means and boom whereby the force of the ram is transferred to said pivotal connection between the motion transmitting means and the boom to maintain an effective lever arm for controlling a load carried by said boom.

7. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to and from said support means, a fluid pressure operated ram having one end pivotally connected to said support means and having its other end movable, rigid motion transmitting means pivotally connected at one end to said movable end of the ram and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting means including arm means rigid therewith which is so disposed as to brace against said boom when the latter is in a first position to prevent movement of the motion transmitting means relative to the boom during a part of the movement of said boom from said first position with the ram acting on said arm means as a lever, the pivotal connection between said ram means and motion transmitting means being movable from one side of dead center toward dead center during said part of the movement of said boom from said first position, cooperating means on the support means and motion transmitting means for thereafter engaging said motion transmitting means to move said pivotal connection past dead center to move said arm means out of bracing engagement with said boom during a latter part of the movement of said boom and provide for relative movement between the motion transmitting means and boom whereby the force of the ram is transferred to said pivotal connection between the motion transmitting means and the boom to maintain an effective lever arm for controlling a load carried by said boom.

8. In a loading apparatus the combination comprising support means, a boom pivotally mounted on said support means for lifting a load to and from said support means, a fluid pressure operated ram having one end pivotally connected to said support means and having a piston rod atits other end, rigid motion transmitting means pivotally connected at one end to said piston rod and at its other end to said boom at a location spaced outwardly of the boom from the pivotal connection between the latter and the support means, said motion transmitting means including arm means rigid therewith which is so disposed as to brace against said boom when the latter is in a rst position to prevent movement of the motion transmitting means relative to the boom during a part of the movement of said boom from said first position with the ram acting on said arm means as a lever, the pivotal connection between said piston rod and motion transmitting mechanism being movable from one side-of dead center toward dead center during said part of the movement of said boom from said first position, cooperating cam means on the support means and at the pivot between motion transmitting means and piston rod for thereafter moving said pivotal connection past dead center to move said arm means out of bracing engagement with said boom during a latter part of the movement of said boom and provide for relative movement between the motion transmitting means and boom whereby the force of the ram is transferred to said pivotal connection between the motion transmitting means and the boom to maintain an efective lever arm for controlling a load carried by said boom.

References Cited in the iile of this patent UNITED STATES PATENTS 859,970 Nilson July 16, 1907 2,190,869l Frentzel et al Feb. 20, 1940 2,353,655 Day July 18, 1944 2,386,216 Hay Oct. 9, 1945 2,689,053 Olson Sept. 14, 1954 2,727,639 Ball et al Dec. 20, 1955 2,979,214 Selzer Apr, 1l, 1961