US1490116A - Charging device for concrete mixers - Google Patents

Description

April 15 1924.

E. H. LICHTENBERG CHARGING DEVICE FOR CONCRETE MIXER Filed June 21, 1922 Inventor E. Ii Liclz ienbezg I v 5 3 I 1 Wizneam- 13 I I r I M Mun-113$ Patented l5, i924.

ca rn r ERICH H. LIGHTENBERG, 0F MILW'AUKEE, WISCONSIN, ASSIGNOR TO KOEHRING- COM- PANY, O'F MILWAUKEE, WISCONSIN, A CORPORATION. V

CHARGING DEVICE FOR CONCRETE MIXERS.

Original application filed June 17, 1920, Serial No. 389,632. Divided and this application filed June 21, 1922. Serial No. 569,855.

To all whom 2'25 may concern.-

Be it known that I, Enron H. LICHTEN BERG, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of VVisccnsin, have in vented certain new and useful Improvements in Charging Devices for Concrete Mixers, of which the following is a specification.

The present invention relates to certain new and useful improvements in charging devices for concrete mixers of that general type which is illustrated by Patent No. 1,107,171 which was granted on August 11, 1914 to P; A. Koehring.

Among the objects of the invention is to provide a power driven charging device embodying novel means whereby the loading skip or hopper is started into motion with a slow speed so that there is a minimum amount of strain on the mechanism and the power is utilized in the most advantageous manner to overcome the initial inertia of the load. After the loading skip or hopper has been started into: motion there is a gradual acceleration of the speed thereof and then an automatic retarding of the speed as the loading skip or hopper approaches the limit of its movement where it discharges into the mixerf In other words the loading skip or hopper acquires its maximum speed at an intermediate point in its path of movement and the speed is gradually accelerated until thi maximum speed is reached and then gradually retarded as the loading skip reaches either limit of its movement. Such a construction reduces to a minimum the strain and shocks on the mechanism and enables the power to be utilized in the most advantageous and economical manner.

The subject matter for this application has been divided out of a co-pending application for a loading device which was filed by me on June 17, 1920 and is identified by Serial No. 889,632 patented June 26, 1923, Patent No. 1, l59,779.

For illustrative purposes one particular embodiment of my invention has been illus trated and will be described in detail, al though it will be understood that many modifications and changes can be made in the details of construction without departing in any manner from the spirit of the invention.

For a full understanding of the invention reference is to be had to the following description and accompanying drawing on which the figure is arear elevation of a power driven concrete mixer, provided with a charging device constructed in accordance with the invention.

Throughout the following description corresponding and like parts are referred to by like reference characters, and the same reference characters are used on the draw- 111g.

Referring to the drawing, the reference character A designates the skeleton supporting frame of a portable concrete mixer, said frame being mounted upon a truck B so that it can be readily moved from place to place. A conventional concrete mixer C is mounted. upon the frame A, and an engine D is provided for driving the mixer and other mechanisms mounted upon the frame and associated therewith. A loading skip E of a well known type is provided for charging the material and aggregates'into the drum of the mixer. This loading skip is pivotally mounted at 1 upon the frame A, and is adapted to swing up and down. When the loading skip is in a lowered position it rests upon the ground or road and the materials to be mixed are dumped or de posited therein. When the loading skip is swung upwardly and reaches the limit of its upward movement, the materials which were previously deposited therein are discharged by gravity into the drum of the mixer. A somewhat similar mechanism is disclosed in the Koehring Patent No. 1,101171, which was issued on August 11, 1914, and in view of the disclosure of this patent a further description of the mixer and specific construction of the loading skip is not thought to be necessary.

Extending transversely across the bottom of the loading skip E is a cross bar 2, and an intermediate portion of a cable 3 extends longitudinally of the cross bar and slidably engages the same. From the opposite ends of the cross bar the cable is carried upwardly and passesaround guide pulleys l which are suitably journaled upon the frame A. Afterextending around these pulleys the ends of the cable are carried downwardly and suitably anchored or secured to winding drums 5 on a skip operating shaft 6. This shaft is operatively connected tothe engine D in any suitable and conventional manner, such as that dis closed by the above identified Koehring patent. The shaft is shown as provided with a large drum 7, and this drum may have a cable connection with mechanism operatively driven by the engine D. This is a form of connection which is well known in the art and no claim to novelty is based thereon in this application.

The winding drums 5 have a peculiar formation which is essential to carry out the idea of the present invention. Each of these drums is provided with a helical groove 5 which causes the cable to be wound thereon in a predetermined manner, and the drum is tapered toward opposite ends thereof. With this construction it will be obvious that when the skip operating shaft 6 is driven at certain speed, the winding or unwinding action of the drums 5 with respect to the cable 3 will be much more rapid at the intermediate larger portion of the drums than at the tapered or reduced end portions thereof. The loading skip thus acquires its maximum speed at an intermediate point in its path of movement, the speed being gradually accelerated from the time the loading skip is started into movement until the maximum speed is acquired, and then being gradually retarded until the loading skip reaches the limit of its movement.

When the loading skip is in a lowered position the materials for the next batch of concrete to be mixed in the drum are placed therein, and when it is desired to charge these materials into the drum, power is applied to the skip operating shaft 6 from the engine. This causes the cable ends 3 to be wound upon the drums 5, and the initial winding is at tapered or reduced ends of the drums, with the result that a minimum of speed and a maximum of power is available for overcoming the initial inertia of the loaded skip and starting the same into motion. After the skip has started on its upward movement the speed thereof is gradually acceleated, until the maximum speed is acquired at an intermediate point in the path of movement of the skip. The speed of movement of the skip is then gradually retarded as the cable ends approach the other reduced ends of the winding drums, the skip being brought to a stop when it reaches its upper limit of movement, at which position the contents thereof are discharged by gravity into the drum of the mixer. The power is thus utilized in the most effective manner for moving the loading skip and at the same time the charging operation iscompleted as quickly as possible and without any unnecessary loss of time, it being understood that time is always an important element in the operation of machines of this character.

It may be mentioned that the lifting crane F which is shown at the right hand side of the figure in the drawing is adapted to be utilized for swinging batch boxes over the loading skip for the purpose of discharging the contents of the batch boxes into the skip when the latter is in its lowered position. This loading crane is also operated from the engine D, and the mast 8 thereof is slidably mounted so that the foot 9 at the bottom thereof is normally held above the surface of the ground by the action of a spring 10. This loading crane is fully described and claimed in my copending application, Serial No. 389,632, filed June 17, 1920, of which this is a divisional application, and reference is made to the parent case for complete disclosure of the construction and manner of operation of this crane attachment.

It will be obvious, of course, that the winding drums 5 may be tapered only in one direction if the invention is used under conditions where it is not desired to retard the speed of the loading skip as it reaches the upper limit of its movement. The single taper would cause the loading skip to be started at a slow speed and the movements thereof gradually accelerated until the maximum speed was reached. Also, the shaft 6 may or may not be driven at a substantially constant speed, depending upon the particular mechanism with which the invention is used. The cable connected to the large drum 7 on the shaft 6 might, of course, cooperate with a tapered drum on the lower shaft, so that the shaft 6 itself would have a variable and accelerated speed. In all of these constructions, however, the essential idea of the device would be retained, namely, that of starting the loaded skip at a slow speed and then accelerating the speed thereof until the maximum speed is reached.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is,

In a machine of the class described, in combination, a portable support for concrete mixers or the like, a loading skip pivoted at one end to said support to move from a position substantially horizontal and resting upon the ground to a position in which it is elevated so as to assume an almost vertical adjustment for discharging its contents, an operating means for raising said skip from its lower position to its hi her position, comprising cable drum mec anism including drums mounted on the upper portion of the support somewhat adjacent to the point of higher adjustment of the skip when discharging, each of said drums embodying a cable winding surface, the intermediate portion of which is enlarged and the opposite ends of which are of reduced diameter, cables adapted to Wind about said drums and connected with the skip and means to operate the cables to cause Winding of the same on the drums to move the skip from its lower position to its higher position, the formation of the Winding surfaces of the drums being such that the cables are Wound on the reduced ends of the drums at initial slow speed until the skip is raised to the plane above the pivotal axis thereof, whereupon the movement of the

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