US3421378A - Device for stepless variation of machine stroke length during operation - Google Patents

Description

Jan. 14, 1969 5 3,421,378

DEVICE FOR STEPLESS VARIATION OF MACHINE STROKE LENGTH DURING OPERATION Filed Sept. 12. 1 966 Sheet of 4 INVENTOR 6457/52 1 o'xwvc ATTORNEYS Jan. 14, 1969 DEVICE FOR STEPLESS VARIATION OF MACHINE STROKE LENGTH DURING OPERATION Filed Sept. 12. 1966 G. LCRINC Fig. 2

A T l a Fig. 3

Sheet 2 of 4 INVENTOR you-7,

ATTORNEYS Jan. 14, 1969 G. LORINC 3,421,373

DEVICE FOR STEPLESS VARIATION OF MACHINE STROKE LENGTH DURING OPERATION Filed Sept. 12, 1966 Sheet 2 of 4 INVENTOR GA'sP/e Ldie/A/c BY Z Z I ATTORNEYS G. LORINC 1 DEVICE FOR STEPLESS VARIATIONOF MACHINE STROKE Jan. 14, 1969 LENGTH DURING OPERATION Filed Sept. 12. 1966 Sheet INVENTOR GA'SPJR Adieu/c ATTORNEYS United States Patent 3,421,378 DEVICE FOR STEPLESS VARIATION OF MACHINE STROKE LENGTH DURING OPERATION Gaspar Ltirinc, Budapest, Hungary, assignor to Nikex Nehezipara Kulkereskedelmi Vallalat, Budapest, Hun- Filed Sept. 12, 1966, Ser. No. 578,867 Claims priority, applicaltgiim2 Hungary, Sept. 15, 1965,

U.S. Cl. 74-41 Claims Int. Cl. F1611 21/32 ABSTRACT OF THE DISCLOSURE Apparatus for adjusting during operation the stroke of a piston or other reciprocating member, from zero to a maximum, by means of a remote control, especially for mortar pumps. The apparatus includes a power-driven swinging slide, driven by an electromotor which is remotely controlled. The slide is suitably connected to the piston.

The conventional mortar pumps are used for conveying mortar or other similar material, such as concrete, from the spot of mixing to the place of use. The output required from such pumps varies in conformity with the conditions of work. Thus, for example, a much higher output is required for building a new wall than in the case of mechanical plastering or rendering.

It is, accordingly, essential to be able to vary the output of such pumps during their operation in a continuous manner, a requirement which could not be satisfied in a simple manner by conventional equipments. It is the objeet of the invention to alter the output of pumps and other machines or implements comprising pistons in such a manner that the stroke is adjusted, and to make such alteration continuous and effected by remote control. It is a further object of the invention to reduce the stroke to zero, so that feeding of mortar may be stopped with the machine still running.

It is a still further object of the invention to effect adjustment of the output by simple means, with full operational safety and without a shock effect, whereby the constituent parts of the machine are spared and their life may be considerably lengthened.

In order to realize these aims, the machine or implement according to the invention is built up so as to comprise on an alternating machine part, for instance on the piston rod, a swivelling slip block and a swinging slide displaceable in relation to said slip block, connected at one extremity to the drive gear, for instance to the crank rod, and at its other extremity to a movable carriage, however it does not communicate directly with the carriage but by means of two inserted members, one of which is a fork fastened to one of the extremities of the swinging slide, connected tilting to the other member, i.e. to the fixed fork which is secured on the carriage and is placed within the first mentioned fork. In this way an engagement constituted by an outer fixed and an inner tilting fork will come about. The inside fork is preferably fitted on cantilever pins, secured in the outside fork. The movable carriage can be actuated in both senses of rotation, it is preferably connected to a remote-controlled electromotor and limit switches are provided at the two end positions of the carriage.

The invention is illustrated more particularly by means of the attached drawings of two of its embodiments shown by way of example.

FIGURES 1 to 3 illustrate a device set to zero stroke coupled to a unilaterally working internal guide piston. FIG. 1 is a longitudinal section of the device in the plane F-G of the piston (FIG. 2). FIGURE 2 shows a cross section taken along C-D-E. FIGURE 3 is a section taken along the line A-B.

FIG. 4 is a longitudinal section of another embodiment and FIG. 5 is a cross section taken along lines A-B. FIG. 6 is a section along the plane C-D.

.In the outer fork-shaped extremity of the piston 2 or another machine part alternating in the body 1 there is arranged a slip block 3, the bilaterally extending pins of which are pivoting and supported on bearing covers 4. Longitudinally displaceable in a bore of the slip block 3 there is arranged a swinging slide 5 on one end (on the upper end in the figure) of which an inner tilting for 6 is secured by a nut. The outer smooth extremities of cantilever pins 7, on which an inner fork 6 may pivot, penetrate in the lower bores of fork 6. The pins 7 are fastened by means of a fine thread in an outer fixed fork 8, their outside extremities being for-med as screw heads. The swinging slide 5 is brought in swinging motion by a crank rod 11 actuated by a trunnion 10, through pin 12 seated in a fork-shaped extremity of the crank rod and in the extremity of the slide 5.

On a guide built of the machine body a movable carriage 13 is located, on which the outer fixed fork 8 is secured by means of a stud 14. In case of larger loads the fixed fork may be worked out of the same piece as the movable carriage 13, instead of being secured by studs. The swinging slide 5 in its swinging state can be displaced in respect to the slip block 3 by turning a screw spindle 15. The screw spindle 15 is turned by a wedged worm wheel 16 and an associated pulley 17, the latter being driven in both senses of rotation by a servo motor 18 in compliance with impulses coming from remote control push buttons.

The trunnion 10, caused to rotate by a driving means drives the swinging slide 5 by means of the crank rod 11. The slide 5 is tilted about the cantilever pins 7 to and fro, with the insertion of a titlting fork 6 which is connected, as represented in FIG. 1, to the upper part of the slide 5. The inner fork 6 is rotatably mounted of the outer fixed fork 8 which is connected by means of a nut 14 to the support carrier 13. It said carriage 13 is moved up and down, the slide 5 is displaced by means of the fork 8, the pin 7 and the fork 6, in relation to the block 3, so that the actual position of the carriage 13 determines the length of the stroke. The stroke is longest when the carriage is at the largest distance from the piston, and the piston stands still, i.e. the stroke is reduced to zero, if the centre point of the pin 7 is in the virtual extension of the centre line of the piston.

The carriage can be adjusted to any desired position during operation, so that the stroke may be easily adju-sted from zero to maximum without the need for cutting out the machine.

In FIGURES 4 to 6 the device is represented as conneoted to an inside and outside guided piston set to the maximum stroke length. The swinging slide consists of two parallel rods.

The piston or other alternating machine part moving in the body 1 has an inner passage and the slip block 3, turnable on a toggle 19 pressed into the piston body 2, is installed in this passage. The toggle is secured at both extremities by inner spring retainer rings 20. In the slip block 3 two slides 5 made of parallel compact or full rods interconnected at one end (the upper end in the figure) by means of the fork 6, at the other end (the lower one in the figure) by a pinned clamp 21, may freely be displaced in the slide block 3. In the inner, tilting fork 6 the outer fixed fork 8 is arranged. The fiat ends of the cantilever pins 7 are connected, preferably through self-aligning roller bearings 24, to the fork 6.

Hence, in addition to frictionless rotation and easily realizable lubrication, also inaccuracies arising of a possible processing or mounting error can be compensated.

The outer stationary fork 8 is fastened by means of a stud 14 to the carriage 13 moving on a guide 23. The swinging slide formed of parallel rods is set in motion by the crank rod 11 by means of the pin 12 seated in the fork-shaped extremity of the crank rod and in the bore of the pinned clamping member 21. Displacement is effected by turning the screw spindle 15, which is turned by the wedged worm wheel 16 and the associated pulley 17, the latter being driven in both senses of rotation by a servo motor 18 in compliance with impulses coming from the remote control push buttons.

A hand-operated actuator 22, represented by dashed lines in FIGURE 4, for example a crank, permits in emergency cases to shift and to control the slide 5 by hand-power. This hand-operated actuator may be employed on any embodiments of the device. Likewise, any of the embodiments can be fitted with limit switches for cutting out of the servo motor.

The advantages of the invention in relation to the known devices and its fields of application are numerous. So it is an important advantage that for concrete pumps after stopping the pump for short intervals the driving motor can be started unloaded and the motor, running at full speed, can be progressively loaded. The known devices do not afford this possibility.

Applied likewise in mortar pumps, the device according to the invention permits to efiect high pressure grout injection in damming works, storage dams, sluice chamber heads, subway tubbings and the like. The swinging slide, displaced from the zero stroke, forms an ever growing lever so that with the same motor, though with lessening mortar quantity transfer, a growing mortar pressure can be achieved. So until the cavity is not filled, a large quantity of mortar can be transferred essentially without pressure and when a counter pressure arises, the pressure can be increased up to the required value by displacing the swinging slide.

The device according to the invention can also be used in machines or implements other than mortar and conorete pumps, for instance in mining, in the chemical industry, in comminuting machines and sorters, in the building industry, in conveyors and wherever stroke actuation and stroke regulation is needed.

The device may be used also in presses, for instance for chip, fibre or plastic materials, where initial low pressure must be infinitely increased to a higher one.

I claim:

1. Apparatus for adjusting the stroke of a reciprocating member during operation, comprising a slip block tiltingly disposed on the reciprocating member, driving means for the, reciprocating member, a swinging slide fixed at one end on the driving means and displaceable along said slip block, a movable carriage, an inner fork connected to the swinging slide, and an outer fork mounted on the carriage, said swinging slide and movable carriage being tilta'bly interconnected by said forks.

2. Apparatus as claimed in claim 1, and a cantilever pin mounted in the outer fork, said inner .fork lbeing rotatable about said cantilever pin.

3. Apparatus as claimed in claim 1, said swinging slide being in the form of a rod displaceable in said slip block.

4. Apparatus as claimed in claim 1, said swinging slide consisting of two parallel rods clamped together at their ends, said inner fork clamping said rods together.

5. Apparatus as claimed in claim 1, and a remotely controlled electrically dn'ven servomotor for displacing said swinging slide.

6. Apparatus as claimed in claim 5, and limit switches for automatic cutout of said servomotor, and means mounting said limit switches :for adjusting to any of a plurality of desired positions.

7. Apparatus for adjusting the stroke of a reciprocating member during operation, comprising drive means for the reciprocating member, a slip block tiltingly disposed on said reciprocating member, a swinging slide fixed at one of its ends on said drive means and displaceable along said slip block, a movable carriage tiltingly connected to the other end of said swinging slide, an inner fork connected to the swinging slide, an outer fork mounted on the carriage and guided in a straight guide, the two forks connecting the said swinging slide to the movable carriage, a cantilever pin mounted in the inner fork, the inner fork being rotatable around said pin, said inner fork and pin and outer fork moving together with said carriage, and a remotely controlled electrically driven fixedly mounted servomotor for displacing said swinging slide.

8. Apparatus as claimed in claim 7, in Which the swinging slide has the form of a rod and is displaceable in the slip block.

9. Apparatus as claimed in claim 7, in which said swinging slide consists of two parallel rods clamped together at their ends, said inner fork clamping the said rods.

10. Apparatus as claimed in claim 7, and limit switches for automatic out-out of said servomotor, and means mounting the limit switches for adjusting to any of a plurality of desired positions.

References Cited UNITED STATES PATENTS 764,573 8/1904- Furru 7441 1,058,878 4/1913 Lowndes 64l8 1,369,164 2/1921 Christopher 74-46 2,391,418 12/1945 Hodgson et al 74625 2,548,807 4/1951 Morgan et al. 74-41 2,958,237 11/1960 Johnson 74-41 3,139,760 7/1964 Pfeifer 7444 FRED C. MATTERN, JR., Primary Examiner. W. S. RATLIFF, Assistant Examiner.

U.S. Cl. X.R. 64-18; 7446, 841

Images