US3430734A - Portable elevating apparatus - Google Patents

Description

March 4, 1969 E. P. EMBREE 3,430,734

PORTABLE ELEVATING APPARATUS Filed Aug. 16, 1967 Sheet of 2 INVENTOR. EARL P. EMBREE 2% M- e P ATTORN Y March 4, 1969 E. P. EMBREE 3,430,734

PORTABLE ELEVATING APPARATUS Filed Aug. 16, 1967 sheet 3 or 2 I NVEN TOR.

EARL P. EMBREE BY g Y ATTORNEY United States Patent ()fiiice Patented Mar. 4, 1969 2 Claims ABSTRACT OF THE DISCLOSURE A portable elevating apparatus includes a carriage that slides on a ladder and is controlled in its movement by the operator in the carriage. A hydraulic cylinder is mounted in the carriage and its piston rod has a cable or rope gearing so connected between the carriage and the top of the ladder as to move the carriage about four or five times as fast as the moving piston rod. The ladder carries a propping pole so that the operator can place the ladder near a fruit tree and use the carriage for lifting him to diiferent heights for picking fruit from the tree.

BACKGROUND OF THE INVENTION Field of the invention In the picking of fruit, portable ladders are used by the fruit pickers and they climb up and down them while picking fruit at different levels of the tree. This is tiring and time consuming. Adding a slidable carriage to the ladder with a hydraulic operating mechanism will not unduly increase the weight of the portable ladder if a smaller length cylinder is mounted directly on the carriage and a cable or rope gearing operatively connects the piston rod to the carriage and ladder so that a movement of the piston rod will move the carriage about four or five times as fast as the piston rod. The total weight of the ladder, carriage and operating mechanism can be less than sixty-five pounds which is not too difiicult or heavy for the fruit picker to carry.

Description of prior art Several patents disclose a ladder with a carriage that can move therealong but the source of power is placed at the base of the ladder rather than in the carriage. The mounting of the hydraulic power source on the carriage makes the entire mechanism more compact and lessens the weight of the entire device.

SUMMARY OF THE INVENTION An object of my invention is to provide a portable elevating apparatus in which a carriage is movable along a ladder which functions as an elongated carriage guide and supporting member. The power mechanism for moving the carriage is mounted in it rather than at the base of the ladder. A relatively short hydraulic cylinder is placed on the carriage and a cable or rope and pulley arrangement operatively connects the piston rod of the cylinder with the carriage and ladder so that the carriage will move along the ladder about four or five times the speed of the piston rod.

A further object of my invention is to provide a device of the type described that has a foot and hand control for operation by the operator while he stands on the carriage platform. The device is relatively simple in construction and is durable and eificient for the purpose intended.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevation of the device and shows the carriage slidably mounted on the ladder.

FIGURE 2 is a front elevation of the device when looking in the direction of the arrows 22 in FIGURE 1. FIGURE 3 is an enlarged horizontal section taken through the device substantially along the line 33 of FIGURE 1.

FIGURE 4 is a diagrammatic showing of the various parts of the carriage operating mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT In carrying out my invention I provide a portable ladder indicated generally at A, see FIGURES 1 and 2, that can be propped into an inclined operative position by a leg or prop B. The ladder has a top rung 1 and the upper end of the ladder prop B is pivotally connected at 2 to the top rung at the center thereof for supporting the ladder in an inclined position as shown in FIGURE 1. The ladder has two channel-shaped sides or runners 3 and 4 which are preferably made of aluminum in order to be light in weight and yet strong enough to slidably support a carriage, hereinafter described. Additional spaced apart rungs 5 are arcuate in shape, see FIGURE 3, and have their ends 5a secured to the outer sides of the runners 3 and 4 in any manner desired such as by welding or rivets. When the ladder A is to be carried, the prop B is swung down upon the ladder rungs 5 and in order that the main portion of the prop parallel the runners 3 and 4, the upper portion 6 of the prop is inclined slightly, see FIGURE 1, so as to extend from the uppermost arcuate rung 5 to the straight top rung 1 to which the prop is pivoted.

The lower end of the ladder A is supported above the ground C by spaced apart feet '7 and 8, see FIGURES 1 and 2. The foot 7 is curved outwardly and has its upper end welded or otherwise secured to the runner 3 of the ladder while the other foot 8 is also curved outwardly and has its upper end likewise secured to the other runner 4 of the ladder. A bracing bar 9 extends between the legs 7 and 8 and is secured to the lower end of the ladder A for supporting it above the ground. The lower ends of the outwardly curved legs 7 and 8, are spaced farther apart from each other than are the two elongated runners 3 and 4 of the ladder in order to give a wider support for the ladder.

I slidably mount an operator-supporting carriage on the two elongated channel-shaped runners or guide rails 3 and 4- of the ladder A, and the carriage is indicated generally at D, in FIGURES l, 2 and 3. In the enlarged top view of the carriage in FIGURE 3, it will be seen that it has a platform 10 for supporting the operator, and it also has an inclined front wall 11 that slidably contacts the front surfaces of the ladder runners 3 and 4. The front wall 11 is inclined at an obtuse angle to the platform 10 so that when the ladder is in operative or inclined position, as in FIGURE 1, the platform 10 will lie in a horizontal plane. Bracing rods 12 for the platform have their upper ends secured to the side edges of the front wall 11 and have their lower ends secured to the side edges of the outer corners 13 of the platform.

The carriage D has a housing indicated generally at E for enclosing most of the operating mechanism for moving the carriage along the ladder, see FIGURES 1 and 3. The housing has an outer wall 14 and two parallel side walls 15 and 16 that extend between the outer wall and the front carriage wall 11. Any means for slidably connecting the carriage D to the ladder A may be used and I have illustrated in FIGURE 3, the two side walls 15 and 16 slidably contacting the .inner edges of the channel shaped ladder runners 3 and 4, respectively. Carriage guide shoes 17 and 18 in the shape of angle brackets are secured to the outer surfaces of the housing side walls 15 and 16 respectively, and slidably contact with the inner surfaces of the channel- shaped runners 3 and 4, respectively. The housing side walls 15 and 16 slide against the ladder runners 3 and 4 and prevent any lateral movement of the carriage with respect to the ladder.

I will now describe the mechanism for operating the carriage D, on the ladder A. FIGURE 3 shows most of the mechanism contained in the housing E while FIGURE 4 illustrates the different parts of the mechanism diagrammatically. A small portable engine or motor F has a shaft 19 for operating a hydraulic pump G and the latter pumps fluid from a tank H to a valve by means of a conduit 20. A second conduit 21 leads from the valve J to the tank H and returns the fluid to the tank when the valve handle or lever 22 is in neutral position. The valve J is preferably mounted on the front wall 11 of the carriage D in a position where the operator can manipulate the handle 22 while standing on the carriage platform 10.

I provide a foot control for operating the valve lever or handle 22. In FIGURES 2, 3 and 4, I disclose a footactuated member K that can slide or pivot in a horizontal plane on the carriage platform 10. I do not illustrate any particular pivot or guide means for the member K. FIG- URE 4 shows the foot-actuated member K in neutral position. A flexible cable indicated generally at L operatively connects the member K with the valve lever 22. The member K receives the toe portion of the operators foot and when the member is shifted to the right from NEUTRAL to UP position, the flexible cable will swing the lever 22 from the full line position shown in FIGURE 4 into the dotted upwardly inclined position shown in the same figure. I will explain hereinafter how this movement of the foot actuated member K will cause the carriage D, to move upwardly on the ladder A. When the member K is moved to the left in FIGURE 4 from NEUTRAL to DOWN position, the valve lever 22 will be swung into the other dotted line position and the carriage will move downwardly on the ladder. FIGURES 2 and 3 show the flexible shaft L as being disposed on the front face of the carriage wall 11, but it could be disposed in the housing E.

The hydraulic mechanism for moving the carriage on the ladder comprises a cylinder M that is mounted in the housing B, see FIGURES 3 and 4. A piston 23 is slidably mounted in the cylinder and a piston rod 24 extends from the piston and out through the lower end of the cylinder. The free end of the piston rod 24 carries a cross head 25 that has a pulley or sheave rotatably mounted at each end thereof. A cable or rope 26 has one end secured to the cylinder M, at 27, and is then passed around one of the pulleys 28, carried by the cross head 25. An idler pulley 29 is rotatably carried by the cylinder M, and the cable 26 is passed over this pulley. From here the cable is passed around the other idler pulley 30, mounted on the cross head 25, and then the cable extends up to the top rung 1 of the ladder A, and is secured thereto at 31, see FIGURE 2. The pulleys 28, 29 and 30 and the man ner of passing the cable or rope 26 around them and securing the rope ends to the cylinder M, at 26 and to the top rung 1 of the ladder forms a rope gearing arrangement that will provide a ratio of about four-to-one in moving the carriage D, faster than the moving piston rod. A conduit 32, see FIGURE 4, extends from the valve J to the top of the cylinder M.

OPERATION the foot control member K for moving it to the right in FIGURE 4, for swinging the valve handle 22 into UP position or he can actuate the handle by hand.

The engine F operates the pump G and the latter will withdraw fluid from the tank or reservoir H and send it through the conduit 20 to the valve J. If the valve handle 22 is in NEUTRAL position, the fluid will return from the valve to the reservoir H by the conduit 21. As soon as the operator swings the valve handle 22 into UP position either by his hand or by manipulating the member K with his foot, the fluid will flow into the top of the cylinder M by means of the conduit 32 rather than flow back into the reservoir through the conduit 21. The fluid in the cylinder will force the piston 23 and the piston rod 24 downwardly with respect to the cylinder and the piston rod will force the pulleys 28 and 30 against the looped portions of the cable 26, see FIGURE 4. Since one end of the cable or rope 26 is anchored to the cylinder =M, at 27 and the other end is secured to the top ladder rung 1 at 31, the looped portions of the cable around the pulleys 28 and 30 and around the idler pulley 29 on the cylinder M, will cause both the piston rod 24 and the cylinder to move upwardly along the ladder A, the cylinder moving about four times as fast as the piston rod and carrying the carriage D upwardly therewith. The length of the stroke of the piston rod 24 in the cylinder is predetermined so that when the piston 23 reaches the bottom of the cylinder M, the cylinder will have moved the carriage to the top of the ladder A.

The operator can stop the upward movement of the carriage D, along the ladder A, at any place desired by merely swinging the valve handle 22, back into NEU- TRAL position. This will stop further flow of fluid into the cylinder M, and instead the pump G will force the fluid from the valve 1, back to the reservoir H, by means of the conduit 21. The trapped fluid in the cylinder top will hold the carriage D at the level to which it has been raised on the ladder.

When the operator wishes to descend to any level on the ladder, he swings the valve handle 22 into DOWN position or he moves his foot member K to the left in FIGURE 4. This will cause the valve J to permit the reverse flow of fluid from the cylinder M, through the conduit 32, valve J, and conduit 21, back to the reservoir or tank H. The weight of the carriage and operating mechanism is suflicient to force the piston 23 upwardly in the cylinder M to force the fluid back through the conduit 32 when the valve handle 22 is in DOWN" position. The speed of descent is controlled by the amount of fluid the valve I will permit to flow from the cylinder into the valve and on through the conduit 21 to the reservoir or tank 4. The conduit 21 is large enough in capacity to also receive the fluid from the valve I, that has entered it from the conduit 20, because the engine F, and pump G, are continuously operating during the downward movement of the carriage -D, and the reverse flow of fluid in the conduit 32.

When the ladder A is held in operative position by the prop or ladder tongue B, the top of the ladder will be about twelve feet above the ground. The ladder has a width of about sixteen inches although I do not wish to be confined to any exact measurements. Most of the parts will be made of aluminum so as to make the device light in weight. A two and one-half or a three horsepower engine F, is suflicient to operate the hydraulic mechanism. The four-to-one speed ratio produced by the idler pulleys and cable or rope 26 will move the carriage D, so that at no time will the piston rod 24 and pulleys 28 and 30 strike the ground C. The height of the carriage front wall 11 is about thirty-six to thirty-eight inches high and this will permit the operator to lean against the wall while standing on the platform 10 during the picking of fruit from a tree.

A smaller length cylinder M, may be used when it is mounted on the carriage D, than when the cylinder is mounted on the ladder A. Also there is less length for the controls when the carriage lifting mechanism is all mounted in the carriage rather than placed on the ground. The speed of moving the carriage D, on the ladder A, is increased by the use of the idler pulleys and the manner of passing the cable or rope 26 around them so as to provide a fouror five-to-one ratio. A fruit picker is handicapped in having to continually climb up and down a ladder while picking the fruit. It is both tiring to the picker and slows him down in his work. The hydraulically moved carriage will lift the picker more quickly than he can climb the ladder and with no physical effort on his part.

I claim:

1. A portable elevating apparatus comprising:

(a) an elongated carriage guide and supporting member including a pair of spaced apart and parallel guide rails;

(b) spaced apart rungs interconnecting said guide rails and being arcuate-shaped in parallel planes that extend at right angles to the lengths of said guide rails;

(c) an elongated prop having an end pivotally connected to an end of said supporting member for holding the latter at an upwardly inclined position with respect to the ground;

(d) a carriage slidably mounted on said guide and supporting member and having a platform and a front wall, the latter lying adjacent to a plane in which said guide rails lie;

(e) hydraulic means supported by said carriage and moving through the spaces afforded by the arcuateshaped rungs when the carriage moves along said guide rails, said means including a cylinder and piston rod whose common axis parallels the lengths of said guide rails, the piston rod moving downwardly with respect to the cylinder and carriage as the rod is moved out of the cylinder;

(f) rope-geared means interconnecting the carriage, piston rod and said guide and supporting member for lifting said carriage along said guide and supporting member faster than said piston rod moves downwardly with respect to said cylinder so that the piston rod will have a relative upward movement with re spect to the guide rails as the carriage moves upwardly from its initial starting position; and

(g) valve-controlled means for directing fluid into and out from said cylinder for moving said piston rod with respect to said cylinder, whereby said carriage is moved.

2. The combination as set forth in claim 1: and in which (a) a portion of said elongated prop, that lies adjacent to the end pivotally connected to said supporting member, is inclined at an angle to the remaining part of the prop so that this remaining part can contact with the arcuate portions of said rungs and lie parallel with said guide rails when said prop is swung into inoperative position preparatory to transporting the device.

References Cited UNITED STATES PATENTS 2,538,517 1/1951 Hayden 18726 2,931,461 4/ 1960 Lawson 187-26 3,127,952 4/1964 Baerg 187-14 FOREIGN PATENTS 1,157,310 5/1958 France.

1,015,255 12/ 1965 Great Britain.

RICHARD E. AEGERTER, Primary Examiner. HARVEY C. HORNSBY, Assistant Examiner.

US. Cl. X.R.

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