US3726349A - Hydraulically operable apparatus for making slit trenches - Google Patents

Abstract

A hydraulically operable implement for producing in the ground vertical deep slit trenches of narrow width which comprises a gripping device adapted to be actuated by an extra long boom and a dipper arm, in which said gripping device suspended on the lower end of beam means through the intervention of a rotatable head connected to the free end of a dipper arm and supporting said beam means is braced relative to said implement by a bridge pivotally connected to a carriage on said implement, the free end of said bridge being provided with a cradle frame extending around said beam means.

Description

United States Patent 1191 Heusler et al. 1 A r. W 1973 [54] HYDRAULICALLY OPERABLE [56] I References Cited APPARATUS FOR MAKING SLIT UNITED STATES PATENTS TRENCHES 2,639,048 5/1953 Glashaw ..2l4/l38 [75] Inventors: Helmut Heusler, Dortmund- 2,788,143 4/1957 LaTendresse .....2l4/147 G Kirchhorde; Dieter Maly, Lobe, 3,143,229 8/1964 Billings .214] 147 G both Germany 3,462,029 8/1969 Mork 114/133 [73] Assignee: ()renstein 8: Koppel Aktien- FOREIGN PATENTS OR APPLICATIONS gigg y 1,952,116 5/1970 Germany ..l7S/238 [22] Filed: Jan. 22, 1971 Primary Examiner-Gerald M. Forlenza Assistant Examiner-Lawrence J. Oresky 1 Appl' 108772 Attorney-Walter Becker Related US. Application Data 57 CT [63] Continuation-impart of Ser. No. 785,69l/Dec. 23,

1967, abandoned. A hydraulically operable implement for producing 1n the ground vertical deep slit trenches of narrow width [30] Foreign Application Priority Data which comprises a gripping device adapted to be actu- 3 .ated by an extra long boom and a dipper arm, in Dec.23, 1967 Germany ...P 16 4923.8 which Said g pp g device Suspended on the lower 1 end of beam means through the intervention of a [52] US. Cl. 175/45, 173/282, rotatable head connected to the free end of a dipper Int Cl E21b/47/0'2 arm and supporting said beam means is braced rela- [58] Field of Search ..214/138, 147, 147 G; r Sad Implement by a bndge pvmany nnected to a carriage on said implement, the free end of said bridge being provided with a cradle frame extending around said beam means.

4 Claims, 9 Drawing Figures PATEHTEB APR 1 01975 SHEET 1 [IF 4 FIG-4 PATENTED APR 1 0 I975 sum 2 OF 4 HYDRAULICALLY OPERABLE APPARATUS FOR MAKING SLllT TRENCHES This is a continuation-in-part of copending application Ser. No. 785,69lI-Ieusler et al. filed Dec. 20, 1968 now abandoned and belonging to the assignee of the present invention.

The present invention relates to a hydraulically operable device for digging slit trenches and, more specifically, concerns a device of the above mentioned type which is hydraulically operated and produces deep vertical slit trenches of small width while a gripping device, for instance a grab bucket, is actuated by means of an extra long boom and clipper arm.

According to a heretofore known device for digging such trenches, the boom of a dredge has connected thereto a vertically extending pipe which can be adjusted as to height. At the lower end of the pipe there are pivotally connected gripper bucket sections which are actuated hydraulically. Furthermore, parallel to said pipe there are arranged guiding means along which a rammer slides. Such a device is suitable for deeper excavations but requires relatively large space for the freedom of movement of the gripper device. For digging small slit trenches, as they are necessary when building tunnels for supporting the adjacent buildings or houses, such device is not suitable.

According to another heretofore known device for digging deep excavations, the boom of a dredge has connected thereto between said boom and the dipper arm an additional intermediate part in order to master the necessary kinematics during the deeper lowering of the gripping device. This last mentioned device makes it possible to realize deeper excavations than is customary with ordinary equipment. The additional actuation of said intermediate member by a hydraulic piston cylinder system results in an expensive construction which can effect only such excavations which do not have the relatively small dimensions as they are necessary for supporting walls during the building of tunnels.

It is, therefore, an object of the present invention to provide a hydraulically operable device for digging slit trenches while using only customary dredge equipment and'changing the kinematics thereto to a minimum extend and while the slit trench will have a minimum width.

The above object and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. ll illustrates in side view an earth dredger with a gripping device shown outside the slit trench dug thereby.

' FIG. 2 is a side view of the device according to the invention with the gripping device partially lowered between the walls of the slit trench.

FIG. 3 is a side view similar to that of FIG. 2 but with the gripping device lowered to the bottom of the slit trench.

FIG. 4 shows on a larger scale thanFIG. 1 the lower portion thereof with the cradle frame.

FIG. 5 is a top view of FIG. 4. FIG. 6 shows an enlarged side view of the gripping device of FIG. 4 as seen in the direction ofthe arrow A FIG. 7 is a side view showing fastening of the connection rod to the gripper device stem.

FIG. 8'shows another embodiment of structure similar to that of FIG. 6 based on FIG. 1 modified with rigid fastening of the gripper device on a connection rod or beam.

The dredger according to the present invention is characterized primarily in that the gripping device is suspended on a beam which in its turn is carried by a rotatable head pivotally connected to the free end of the dipper arm of the dredger. Furthermore, the said gripping device is braced against the dredger by means of a bridge which is pivotally connected to the upper carriage of the dredger, the free end of said bridge being provided with a cradle frame which surrounds the free end of the connecting beam.

According to a further development of the present invention, the cradle frame is so mounted on the free end of the bridge that the cradle frame is journalled to carry out a pendulum movement with respect to the free end of the bridge.

In view of the pivotal support of the gripping device on the dredger by means of the bridge, it will be assured that the gripping device is prevented from carrying out a pendulum movement during a pivoting operation of the boom, even if it should be particularly long, and of the dipper arm so that the introduction of the gripping device during the excavation even of a narrow slit trench having a depth of up to 30 meters will be effected in a precise manner. In order to assure a fast operation of the gripping device, the actuation of the boom and 'of the dipper arm can be effected by the actuation thereof by means of a potentiometer system independently of the operator and in conformity with the respective position of the gripping device.

For purposes of facilitating the operation, means may be provided which enable the operator to ascertain the closing of the gripping device at the bottom of the slit trench so that he can initiate the upward stroke of said gripping device.

Referring now to the drawings in detail, the upper carriage l of an earth dredger movable by a caterpillar track mechanism 2 has pivotally connected thereto a boom 4 which is operable by a hydraulic cylinder piston system 3. Pivotally connected at 7 to the boom 4 is an extraordinarily long dipper arm 6 which at 7a is operatively connected to a hydraulic cylinder piston system 5 for actuation of said dipper arm 6. The free end 8 of said dipper arm 6 is pivotally connected to a rotatable head 9 which in its turn carries a connecting beam 10, in this particular instance a lattice beam. Mounted on the connecting beam are guiding members 11 by means of which the connecting beam 10 during the lowering thereof is guided into the slit trench 13 defined by the walls 12. In order to secure a certain distance of the dredger from the slit trench 13 to be dug, the upper carriage 1 has at the pivot 15 pivotally connected thereto a bridge 14. At a pivot 17 on the free end 18 of the connecting beam 10, the cradle frame 16 may be so arranged that it surrounds the gripping device 20 which is pivotally suspended at 19 on the free end of the connecting beam 10. I

The operation of the dredger according to the present invention is as follows. The operator drives the dredger toward the area where the slit trench is to be dug while spacing said dredger from said area in conformity with the length of the bridge 14. The boom 4 and the dipper arm 6 will occupy their highest also most vertical position, and the gripping device 20 will be directly above the slit trench to be dug. If now the operator starts to lower the gripping device, the connecting beam passes through the cradle frame (FIG. 2). When the gripping device reaches the bottom 21 of the slit trench 13, the gripping device closes and a switch (not shown) actuated during the closing movement conveys a corresponding indication to the operator by means of a lamp which lights up and is located in the operators cab.

FIG. 8 represents another embodiment of the attachment of the gripping device 20' at a lower end 18' of the connection rod 10; while the concern with FIG. 6 is with a movable fastening by way of Cardan or gimbal ring linkage, according to FIG. 8 a rigid fastening of the gripping device 20' on the connection 10 is provided. For both embodiments there exists that the holding means 20a respectively 20a and 20b movably passes through the cradle frame 16 respectively 16. By way of holding means or cams 18a, 18a secured at the lower end I8, 18 there is taking along of the cradle frame 16, 16' during lifting of the gripping device, which means by way of actuation of the connection rod 10. It becomes clear from FIG. representing a plan view how the connection rod respectively the lower end 18, cams 18a, cradle frame and bridge 14 are arranged with respect to each other. Views of FIG. 5, FIG. 6 and FIG. 8 include the foregoing reference numerals.

FIGS. 7, 7a and 8 show structure similar to that in the foregoing description and accordingly similar reference numerals are applied thereto. FIG. 8 has primes'added to corresponding reference numerals.

FIG. 8 shows another embodiment of structure similar to that of FIG. 6 based on FIG. 1 modified with rigid fastening of the gripper device on a connection rod or beam.

It may be added that, when the operator starts to lower the gripping device, the sinking movement of the gripping device is preferably automatically controlled by an electrically programmed closing movement. Anybody skilled in the art of electrically programming control movements will be able to lay out a corresponding control circuit which is suitable for this purpose in view of the operations to be carried out.

The upper carriage l of an earth excavator movable by a caterpillar track mechanism 2 is pivotally connected by way of hydraulic cylinder piston means 3 to a boom 4 operable thereby. An extraordinarily long dipper arm 6 to be actuated is pivotally connected at the turning point or pivot 7 on the boom 4 by way of a hydraulic cylinder piston means 5.

At a free end 8 of the dipper arm 6 there is hung up a connection rod 10, in this case a lattice work, grill or trellis, subject to intermediate connection of the turning or rotatable head 9. Guiding members 11 are mounted on the connecting rod or beam 10 by means of which the connection rod or beam 10 can be guided during lowering into the slit trench 13 formed by way of the slit walls 12. In order to attain a particular spacing of the excavator from the slit trench 13 to be produced, there is a bridge 14 pivotally journalled in a turning point or pivot 15 on the upper carriage 1. Rather than at the free end 18 of the connection rod or beam 10,

the cradle frame 16 can also be so secured that the same surrounds the gripping device 20 pivotally hung up in the turning or rotatable point 19 on the free end 18 of the connection rod or beam 10.

The manner of operation is as follows: The excavator is driven by the operator into a location or spacing from the slit trench 13 to be produced by way of the length of the bridge determining such spacing. Thereby the boom 4 and the dipper arm 6 are found in the highest, approximately vertical positioning and the gripping device 20 is located directly above the slit trench to be produced. If the operator now begins the lowering of the gripping device, there is thus controlled the sinking or deepening movement of the gripping device by way of the closing movement with the aid of the length of the boom and dipper arm characterized with respect to each other. Hereby the connection rod or beam 10 glides or slides through the cradle frame 16 (FIG. 2). When the gripping device reaches the bottom 21 of the slit trench 13, the gripping device closes itself and a switch actuated during the closing movement indicates this by way of a lamp illuminated in the excavator guide stand or control platform 1a. The hydraulically actuated apparatus for production of vertical, deep slit trenches with a narrow or nominal width in the ground whereby a gripping device is actuated by means of an extraordinarily long beam and dipper arm on the excavator can be characterized thereby that a gripping device 20 is supported relative to the excavator or dredger subject to intermediate connection by way of a bridge 14 pivotally journalled on an upper carriage 1 of the dredger subject to intermediate connection by way of a rotating head 9 on a connection rod or beam 10 relative to a free end 8 of the dipper arm 6 to which the rotating head 9 is secured; the bridge at its free end is provided with a cradle frame 16 surrounding the free end of the connection rod or beam 10. The gripping device 20 is surrounded by the cradle frame 16 journalled in the manner of a pendulum at the free end of the bridge 14. The gripping device is provided with an indicating end switch actuating means to represent closure of the gripping device-being completed upon the bottom of the trench and this switch means results in energization of a lamp actuated in the excavator control stand or plateform-cab.

The rail or track guided special slit dredgers or excavators are used predominantly at large construction locations. The gripping basket is secured hereby on a positively guided beam or stem which exerts a high loading upon the gripping basket (around four tons). High excavating capability can be attained thereby also with tightly compacted ground. In addition, the closing and opening of the gripping device is achieved hydraulically. The removal of slit or trench walls previously occurred exclusively with rope or cable excavators which were equipped with special gripping means (slit wall grippers). The grippers, mostly constructed by building firms themselves have relatively long guide means. The journalling locations are well closed off or sealed. The side walls and the bottom of the gripper shells are provided with slits so .that liquid suspension can flow away. The width and depth of the slit walls depend upon the purpose of utilization. At present in Germany mainly 600 millimeter and 800 millimeter widths and as far as 30 meter depths are produced with respect to the slit walls. There is, however, a trend toward more narrow (400 millimeter) and wider (as far as over 1,000 millimeter) slit walls to be established.

The manner of slit production, whether a continuing slit or individual layers are excavated depends upon the local characteristics; for instance, the type of grour'id, the height of the ground water, eventual loading along the slit by way of traffic or buildings. Mostly the slit is produced by individual layers, the length of which is at least as large as the opening width of the gripping means utilized and amounting to a maximum as far as over 6 meters.

One utilizes hereby two methods as follows:

1. Continually advancing toward both sides (layers l, 2,3,4,5 and so forth).

2. lntermittently advancing toward both sides (layers 1, 3, 5, 7 and so forth and then the intermediate layers 2, 4, 6 and so forth).

Upon start of the excavating work there is introduced or filled-in a suitable suspension, for instance, Botonit as far as to the height of the leading wall of which the hydrostatic pressure is to hinder the collapse of the trench or slit. The suspension (thixotropic liquid) must be post-filled according to the particular excavation or removal corresponding thereto. Pure suspension does not attack metallic work materials. The suspension contaminated during the excavation or removal leads to strong wear of the journalling locations. For this'reason, the journalling locations on the gripping device must be well sealed and closed off.

I The slit or trench walls are strengthened corresponding to the static requirements. Prior to the introduction of the strengthening, the slit or trench bottom is worked over and cleaned. The strengthening is prefabricated according to the layer lengths corresponding to the individual baskets or containers and the same are installed with the aid of auto cranes or tower rotating crane means.

In order to attain the desired side profiles during the layering, one utilizes, for example, semi-circular profile tube means which remain in the slit or trench until after the concreting as a kind of lining. One or two pipes or tubes are needed according to the particular operating technique selected for each layer and the outer diameter of the pipes or tubes equals the slit wall width.

If one selects the continually advancing slit excavation toward both sides, then for the first layer one needs two tubes or pipes and for each further layer only one additional tube or pipe would be needed.

With the second method, there are two tubes or pipes at a time necessary in the layers 1, 3, and so forth while for the intermediate layers (2, 4, 6 andso forth) no tubes are any more necessary or needed. After the cementing or concreting, the tubes or pipes are either pulled with a crane or with a hydraulic pulling apparatus (pulling strength l00-l20 Mp).

The slit wall'manner of construction lately has been utilized more frequently, for instance, with street car underpass'es, department stores, underground garages, high rise buildings, underground railroad construction and many others. The latter mannerof construction more and more replaces the previously utilized methods (predominately large cities utilization thereof occurs). I r

The present invention concerns hydraulically operated apparatus for producing vertical, deep slit trenches of narrow width in the ground whereby a gripping device is actuated by an extra long boom and a dipper arm or stem.

In recent years, concrete walls have been produced more frequentlyin construction ground. This method generally has been known for several decades; production of narrow, elongated and unlined trench construction or excavations is new herewith for receiving the concrete. These slit-formed construction trenches can remain unlined when afluid or liquid introduced during the excavating operation can bring about standing capability of the walls. The slit manner of construction offers a series of advantages. Slits are utilized in those cases in which the traffic must be maintained also during the construction operation. The slits are produced with gripping devices in individual sections or segments of which the length is at least as large as the opening width of the gripping devices utilized which can amount to a maximum as far as over 6 years. With a known apparatus for excavating, there is a vertically standing pipe or tube fastened to the boom of an excavator and this pipe or tube can be adjusted according to the height. At the lower end of the tube, there are gripping shelves linked thereto which are actuated hydraulically. Additionally, a guide means is provided parallel to the tube along which a ram bar glides or slides. Such an arrangement is suitable for deeper excavations, requires, however, space for the freedom of movement of the gripping means. Such an apparatus is not suitable for producing narrower slit trenches as, for instance, during tunnel construction for support of adjoining property and buildings as would be necessary for adjoining property and buildings.

With a further known apparatus for producing termediate part on the boom of an earth excavating means and a dipper arm in order to control necessary movement or kinematics of the gripping means during deeper lowering or use thereof. Hereby deeper excavations can be attained than usual with normal equip- ,mcnt. The additional utilization of the intermediate piece by way of hydraulic cylinder means requires a complex device with which only excavations can be achieved which do not attain the nominal measure ments necessary for instance for support walls during tunnel construction.

The basis of the present invention lies in being able to produce very deep slit trenches with as small a width as possible with a usual excavating equipment subject to the least possible change in the movements or kinematics and the parts involved. The solution of this goal occurs inventively thereby that subject'to intermediate connection of a free end of the dipper arm a turning head is secured on a connection rod having a gripping means hanging or pendulously supported therefrom by way of a pivotally joumalled bridge on the super structure or upper vehicle portion of the excavating means, the bridge at its free end being provided with a cradled frame surrounding a free end of the connection rod and being backed or supported with respect to the excavator. The gripping device is joumalled surrounding the cradle frame in a swinging manner at the free end of the bridge. Due to the articulated support of the gripping device on the excavator by means of the bridge, there is achieved that the gripping device also does not swing or pendulate with extra long boom and dipper arm structure during a pivotal movement and the application thereof during excavation can also result in very narrow exact slits and as deep as from to meters. For facilitating operation, there can be provided an indicator by means of which the operator can determine the closing of the gripping device at the bottom of the slit and the operator can then initiate the upward stroke or movement of the device.

What we claim is:

1. A dredger for digging a slit trench of a narrow width, which includes: movable supporting means, an upper carriage rotatably supported by said supporting means, a boom having one end portion pivotally con nected to said carriage, first fluid operable cylinder piston means pivotally connected to said carriage and said boom for pivoting the latter, dipper arm means having one end portion thereof pivotally connected to the other end portion of said boom, second fluid operable cylinder piston means pivotally connected to said boom between the end portions thereof and also pivotally connected to one end portion of said dipper arm means for pivoting said dipper arm means about its pivotal connection with said boom, a head having the other end of said dipper arm means pivotally connected thereto, beam means having one end portion supported by said rotatable head, a gripping device pivotally supported by the other end portion of said beam means, bridge means having one end portion pivotally connected to said upper carriage, and a cradle frame supported by the other end portion of said bridge means and having said beam means shiftable reciprocably therein.

2. A dredger according to claim 1, in which said cradle frame is journalled at the other end portion of said bridge means pivotally suspending said gripping device in a manner similar to a swinging pendulum.

3. A dredger according to claim 2, in which said cradle frame surround said end portion of said bridge means pivotally suspending said gripping device.

4. A dredger according to claim 3, in which a switch means is provided on said gripping device and closure thereof occurs with trench bottoming, and an indicator lamp means energized by closure of said switch means as an operator control indicator.

Claims (4)

1. A dredger for digging a slit trench of a narrow width, which includes: movable supporting means, an upper carriage rotatably supported by said supporting means, a boom having one end portion pivotally connected to said carriage, first fluid operable cylinder piston means pivotally connected to said carriage and said boom for pivoting the latter, dipper arm means having one end portion thereof pivotally connected to the other end portion of said boom, second fluid operable cylinder piston means pivotally connected to said boom between the end portions thereof and also pivotally connected to one end portion of said dipper arm means for pivoting said dipper arm means about its pivotal connection with said boom, a head having the other end of said dipper arm means pivotally connected thereto, beam means having one end portion supported by said rotatable head, a gripping device pivotally supported by the other end portion of said beam means, bridge means having one end portion pivotally connected to said upper carriage, and a cradle frame supported by the other end portion of said bridge means and having said beam means shiftable reciprocably therein.

2. A dredger according to claim 1, in which said cradle frame is journalled at the other end portion of said bridge means pivotally suspending said gripping device in a manner similar to a swinging pendulum.

3. A dredger according to claim 2, in which said cradle frame surround said end portion of said bridge means pivotally suspending said gripping device.

4. A dredger according to claim 3, in which a switch means is provided on said gripping device and closure thereof occurs with trench bottoming, and an indicator laMp means energized by closure of said switch means as an operator control indicator.

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