US 3269570 A
Description (OCR text may contain errors)
Aug. 30. 1966 K. E. WALLBERG DEVICE FOR FASTENING WORKING TOOLS ON LIFTING LEVERS 0F LOADING TRUCKS 2 Sheets-Sheet l Filed March 12, 1965 Kmeujq INVENTOR.
BY @f1/W7 MKZ/L @jaw/L;s
Aug. 3o. 1966 K. E. w
DEVICE FOR A-LLBER ING WORKING TOOLS 0N 0F LOADING TRUCKS LIFTING Filed March 12, 1965 2 Sheets-Sheet 2 FASTEN LEVERS FIG.3
INVENTOR. @mall-01% PMM all@ United states Patent o 4 claims. (l. 214-131) The present invention relates to a device for fastening working tools on lifting levers of loading trucks, etc.
It is previously known to fasten working tools in the form of lloading buckets etc. on the lifting levers of loading trucks by means of down hitches fastened to the upper part of the working tool and hooks at the lower part of the working tool, it being possible to enter a frame articu- Alatedly connected to the lifting leve-rs and fasten it between -the hitches and the hooks. The 'fastening of the working tool to the fram-e is effected by means of a number of latch pins, which under the action of springs controllable from the drivers seat are pressed towards latch surfaces on the hooks.
It has turned out that such a fastening of the working tool to the frame by means of springs does not provide the necessary fastening, Vwhen the device is used with relatively heavy loading trucks.
One of the objects of lthe invention is `therefore to provide a fastening device, which advantageously can be used on band or 4-Wheel driven loading trucks.
According to the invention this object is substan-tially reached as each latch pin is articulatedly connected to a piston rod of a Working piston, which is movable in a compression cylinder mounted in the frame and connected to a hydraulic or pneumatic control device preferably `located at the drivers seat of the loading truck.
In this way a relatively simple but reliable fastening device is obtained, which also can be used on heavy loading trucks. In comparison with previously known fastening devices of the type mentioned above another advan tage is obtained, i.e. even if the Working tool is deformed or worn down so that the distances between the hitches and the hooks are considerably Vincreased or reduced, this is compensated by means of the variable piston stroke of the working piston.
Each hook is preferably provided with a notch, in which the free end of the latch pin can be entered and pressed by means of the working piston. The latch pin can preferably be controlled by at least one guide rail etc. It is also suitable that the latch pin is articulatedly connected to a rod, one end of which is articulatedly connected to the frame and the other end of the piston rod. The latch pin may consist of a pin movable in a guide. It is further suitable that Ithe free end of the latch pin co-operating with the hook is wedge-shaped and adapted to engage a hook provided with corresponding notch and latch surface. The working piston is preferably double-acting, and the control device is made as a double piston, which by means of a handle can be pushed in a second compression cylinder, which by tube lines is connected to the firstmentioned compression cylinder.
The invention is further described in the following in connection with accompanying drawings, which schematically and as examples -illustrate embodiments of the invention.
FIGURE 1 is a side view showing in section a frame articulatedly fastened to two lifting levers and a Working tool fastened thereto in the form of a lifting for-k only shown in part, FIGURE 2 -is a section of a control device shown on a larger scale for the Working piston shown in FIGURE 1 for fastening of the working tool to the frame,
and FIGURE 3 is a side view of another embodiment of the device shown in FIGURE 1.
In FIGURE l1 there is shown -a 4frame 1 known per se, which is fastened to two lifting levers 2, 2 of a loading truck not shown, which frame includes a bracket 3 and a compression cylinder 4 attached thereto, in which a movable double-acting piston -5 with piston rod 6 is adapted. The free end of the piston rod 6 is articulatedly connected to one end of a Irod 7, the -other end of which is ilexibly attached to a bracket 8 fastened to the frame. To the articulated arm 7 a down latch pin 9 is articulated edly connected, which is guided in a guide rail '10 attached to the yframe. The compression cylinder 4 is provided with two tube lines.11 and 1-2, |which are connected to a con-trol device I14 Ilocated at the drivers seat 1'3 (FIG- URE 2) of lthe loading truck comprising a double piston articulatedly connected to a handle 15 and designated by 16, 16.
r[the working tool shown is a lifting fork 17 which at yits upper part is provided with a number of hitches 118 and at its lower part wit-h a number of hooks 19 each having a notch 20 and a latch surface 21, in which notch 20 the -free end of the latch pin 9 is intended to engage upon fastening of the fork 17 to the frame of the lifting levers `2, 2. The frame 1 is'moreover provided with a horizon-tal rod 22, which is intended to engage the hitches 1-8 upon fastening of the working tool to the frame.
When the frame 1 in a way known per se is entered between the hitches 18 and the hooks 19, it bears against the vertical part of the lifting fork 17, after which the handle 15 (FIG. 2) for the control device 14 is turned in the direction B of the arrow. The pressure medium in the tube line 11 then pushes the working piston 5 t-o the position shown in FIG. 1, where the piston rod puts a down pressure on the latch pin 9, which is brought into the notch 20 and fastens the frame to the Ilifting fork. When the handle 1'5 is turned in the direction A of the arrow, the pressure medium in the tube line -12 pushes the piston 5 upwards, the latch pin 9 being drawn out of the notch 20 in the hook 19 and the frame 1 being released from the fork 17.`
In FIG. 3 a modified embodiment of the latch pin is shown consisting of a pin 9' running in a guide 10', the free end of which is wedge-shaped and is adapted t-o engage a hook 19 provided with a corresponding notch 20 and latch surface 21.
By the invention the advantage is also obtained that no clearance or relative movement between the latch pins 9 and 9 respectively and the hooks 19 and 19 respec tively in the fastening position can occur, as the latch pins 9 and 9 respectively, during the work of the loading truck are pressed firmly into the notch 5, 20 and 20', respectively, looseness being avoided and no essential disturbing sound between the latch pins and the ho-oks and their latch surfaces occurring any longer. As the pushing of the latch hooks 9 and 9 respectively to the notches and the latch surfaces in the respective hooks 19, 19 is hydraulic or pneumatic, all the latch pins will receive the same contact pressure and fastening effect, even if one of the latch pins should be inconsiderably deformed or for other reasons should have another fastening position than the other latch pin or pins.
The embodiments described above and shown on the drawing are of course only to be regarded as non-limiting examples, and their details can be modified in several ways within the sc-ope of the following patent claims. Thus it is possible to use, in loading trucks with hydraulic control of the lifting levers, 2 the hydraulic system that the loading truck already is provided with, the tube lines 11, I12, connected to the cylinder 4 being connected to the hydraulic system of the truck. In this case the safety valve already existing may be used at possible overload of the device.
1. A device for fastening a working tool having at least one down hitch adjacent to the upper end thereof and at least one hook having a notch adjacent to the lower end thereof to the lifting levers of a loading machine comprising a frame articulated t-o said lifting levers, means on said frame adapted to engage the hitch on said working tool and secure said tool against movement downwardly or laterally relative to said frame, a rst cylinder connected at its upper end to said frame, a double acting piston in said first cylinder, a piston rod connected to said piston and extending downwardly beyond the lower end of said rst cylinder, means for -introducing pressure rfluid into the opposite ends of said rst cylinder to move said piston upwardly and downwardly, a latching pin con- -nected at its upper end to said piston rod and extending downwardly toward said hook, a guide for said latching pin rigidly secured to said frame, the downward and upward movement of said piston 'being suicient to engage and disengage said latching pin with and from said notch respectively.
2. A device as dei-ined in claim 1 comprising an arm articulatedly connected to said frame below said rst cylinder, said piston Irod and said latching pin being articulatedly connected to said arm.
3. A device as dened in claim 1 in which the lower end of said latching pin is Wedge shaped.
4. A device as dened in claim 1 comprising means secured to said loading machine .for controlling the supply of pressure fluid to said rst cylinder, said means cornprising a second cylinder, a double piston therein controlling outlets of pressure uid therefrom to said first cylinder and a handle for moving said double piston in said second cylinder.
References Cited by the Examiner UNITED STATES PATENTS 3,204,793 9/ 1965 Lane 214-145 FOREIGN PATENTS 91,351, 3/1958 Norway.
HUGO O. SCHULZ, Primary Examiner.