GB2069659A - Vibratory rammer - Google Patents

Abstract

In a vibratory rammer having rotary vibrators (5, 6) for driving in or withdrawing an object (11), a weight (13) is arranged to strike a holding anvil (21) attached to the housing (4) to amplify the movements of the object (11). The weight (13) is suspended by a spring (25) from a draw body (3) which is attached to the housing (4) and closes a space (12) containing the weight (13). This is useful particularly when driving in or withdrawing objects in clay- or loam- containing ground. The weight (13) can be locked to the housing (4) to disable the weight when operating in other types of ground. <IMAGE>

Description

SPECIFICATION Vibratory rammer The invention relates to a vibratory rammer for objects which are to be driven in or withdrawn or for other elements which can be driven in or withdrawn.

Vibratory rammers which are vibrated by vibrators are known for driving in and/or withdrawing planks, piles, pipes, sheet piling or other objects which are to be driven in or withdrawn. The object to be driven in or withdrawn is held on the vibratory rammer in a suitable manner and is withdrawn from the ground or driven into the ground by the vibrations of the vibratory rammer. In addition to being dependent upon the frequency and the amplitude of the vibrations produced, the efficacy of the working operation is also largely dependent upon the ground conditions prevailing at the place where the work is being performed. It has been found that the known vibratory rammers are not sufficiently economical in the case of, for example, clay-or loam-containing types of earth which are frequently encountered.The efficacy of the vibrations is frequently impaired by the static friction occurring between the earth and the object which is to be driven into, or withdrawn from, these types of earth. For structural and other reasons, it is inadmissible or impossible optionally to adapt the frequency and amplitude to the ground conditions, since it is possible that undesirable or even detrimental vibrations may occur in the ground or its environment, in buildings or other locations and may cause damage. A satisfactory gentler and more rapid movement of the object to be driven into or withdrawn from ground having an unfavourable nature of this kind cannot be obtained with conventional, known vibratory rammers.There is a need for a vibratory rammer which renders it possible reliably to perform the intended driving in and withdrawing operations in a simple and rapid manner even under the difficult conditions and ground conditions described.

An object of the invention is to provide a vibratory rammer having additional means for use under difficult ground conditions and other difficult conditions.

In a vibratory rammer according to the invention for objects which are to be driven in or withdrawn or for other elements which can be driven in or withdrawn, a weight is disposed between two vibrators and is displacea ble in the direction of vibration and, as a result of the vibrations of the vibrators, performs percussive movements which are transmissible to the object to be driven in or withdrawn and which serve to amplify the driving-in and withdrawing movements.

The movements of the object to be driven in or withdrawn are then effected by the resultant percussive movements of the weight in addition to the vibrations of the vibratory rammer. The continuous vibrations correspondingly maintain continuous movement of the object to the driven in or withdrawn, while the percussive movements from the weight additionally act upon the object to be driven in or withdrawn in the direction of its movement, so that the movement is amplified. Advantageously, the percussive movements assist the continuity of movement of the object to be driven in or withdrawn and prevent or reduce an increase in the troublesome static friction between the ground and the object to be driven in or withdrawn, so that the course of the working operation is effected more gently and efficientiy.

The construction and the arrangement may be such that each percussive movement of the weight in a given direction is effected by two vibrations of the vibrators. The number of percussive movements is dependent upon the number of vibrations. This has the advantage that the frequency of the vibrations determines and adapts the sequence of the impacts if the given conditions of the ground and/or the environment render this advantageous or necessary.

Furthermore, each vibrator may have an orbital or rotatable out-of balance mass, which out-of-balance masses rotate synchronously in opposite directions and impart common unidirectional vibrations of the two vibrators. Advantageously, two vibrators cooperate in pairs.

However, it is also possible to use several pairs of vibrators for one vibratory rammer.

Furthermore, the weight can be located In a space enclosed in a housing-like manner as to be displaceable towards a draw body against a spring element made from rubber, plastics material or other suitable material, and towards the object to be driven in or withdrawn against an extension, projection or other body which is releaseably or integrally connected to a holding member. Advantageously, each percussive movement of the weight is transmitted to the holding member, acting as an anvil, by an impact surface which is provided on the weight and which is adapted to an extension of the projection of the holding member. The housing can be rigidly connected to the holding member. Consequently, the percussive movements exerted by the weight are jointly absorbed by the housing and, together with the holding member, are transmitted to the object to be driven in or withdrawn.In this manner, the housing is provided, and suitable, for transmitting to the object to be driven in or withdrawn not only the vibrations produced by the vibrators but also the percussive movements of the weight stricking against the holding member.

For the purpose of disabiing or enabling the vibration-dependent. displacement movements of the weight, one side or each or two oppo sitely located sides of the weight preferably incorporates a locking slot, space or the like, such that an axially displaceable locking bolt.

pin or the like is insertable through the wall of the housing and is insertable into, and withdrawable from. its associated locking slot, space or the like. The possibility of disabling or enabling the percussive movements in this manner can be of particular advantage when, for a wide variety of reasons, specific working operations are to be performed intermittently, or entirely. without percussive movements.

The construction and arrangement of this device are simple and do not invoive any special expense. The device can be constructed for manual operation and can be actuated when the vibratory rammer is not operating.

The invention is further described, by way, of example, with reference to the drawings, in which: Figure 1 is a section through a vibratory rammer with its vibrators, Figure 2 is a section through the vibratory rammer with its movable weight, Figure 3 shows the vibratory rammer of Fig.

1 in its bottommost vibratory and working position upon impact of the weight on a holding anvil, and Figure 4 shows the vibratory rammer of Fig.

1 in its uppermost vibratory and working position with the space which exists between the weight and the holding anvil in the present instance.

A draw body 3 is suspended from a frame, support, hook or the like holding means 1 by means of a spring 2 or in some other manner and carries a one-part or multi-part housing 4.

The housing 4 accommodates two separate hollow cylindrical rotary vibrators 5 and 6 which are disposed axially parallel to one another. An out-of-balance mass 7 is provided in the vibrator 5 so as to be pivotable or rotatable about an axle 8, while an out-ofbalance mass 9 is rotatable or pivotable about an axle 10 in the vibrator 6. The out-ofbalance masses 7 and 9 rotate in synchronism in opposing directions, so that the two vibrators 5 and 6 together produce unidirectional vibrations which are transmitted to the housing 4 and then to the object 11 to be driven in or withdrawn. The out-of-balance masses 7 and 9 can be driven electrically, pneumatically, hydraulically, or in any other manner.

The out-of-balance masses 7 and 9 can be arranged and constructed optionally for either direction of rotation. it only has to be ensured that the two out-of-balance masses move in opposite directions simultaneously and in synchronism with one another.

A movable weight 1 3 is located between the vibrators 5 and 6 in a space 1 2 enclosed by the housing 4 and by other wall-like parts.

The weight 1 3 is displaceably held by a guide spindle 14 in a bore 1 5 in the housing 4. The guide spindle 1 4 is accommodated in a cavity-like recess 1 6 in the weight 1 3. The recess 1 6 can be sealed by a cover 1 7 which is secured by bolts, pins or in some other manner. Depressions, rings or the like 18 are provided in the cover 1 7 and in the bottom of the recess 1 6 for the purpose of holding and guiding the ends of the guide spindle 14. The weight 1 3 is constructed and arranged such that it is displaceable abruptly in the direction of vibration in dependence upon frequency by the vibrations of the vibrators 5 and 6.Advantageously, these percussive movements of the weight 1 3 are intended, for and suitable for, transmission to the object 11 to be rammed or withdrawn and for amplifying the ramming and withdrawal movements.

Advantageously, that side of the weight 1 3 which faces the object 11 to be driven in or withdrawn is provided with a depressed impact surface 19, or an impact surface of other construction, which strikes against a complementary extension, projection or some other construction 20 on a holding anvil 21. The extension or projection 20 can be releasably or integrally secured to the holding anvil 21.

A clamping device 22 serves to connect the object 11 to be rammed in or withdrawn to the holding anvil 21. The percussive movements of the weight 1 3 move the holding anvil 21 together with the object 11 which is to be driven in or withdrawn and which is secured to the holding anvil 21. These advantageous percussive movements which are produced and transmitted in addition to the vibrations for the movements of the object 11 to be rammed in or withdrawn, render it possible to perform the working operations in a simpler, gentler and economically favourable manner even under difficult ground conditions and difficult environmental conditions.The holding anvil 21 and the housing 4 are firmly interconnected, so that the percussive movements of the weight 13 are commoniy and simultaneously imparted to thse two parts and are transmitted in the intended manner.

Advantageously, the space 1 2 can be sealed at the bottom by a bottom wall 23 which is made entirely or partially from a sound-proofing material or some other material and which can be releaseably secured by bolts or some other means. The opposite side of the space 1 2 is sealed by an upper wall 24 which is made from metal or the like and which is releasably secured to the housing 4 by bolts or some other means. Advantageously, the upper wall 24 can be an individual element or it can be constituted by making the drawn body 3 of wall-like construction.

A spring element 25 made from rubber or other resilient material is disposed in the space 1 2 between the upper wall 24 and the cover 1 7 for the purpose of absorbing the axial movements of the guide spindle 1 4. The spring element 25 can be of hollow cylindrical configuration or other configuration and can be located on an intermediate plate or support 26. The upper region of the space 12 is defined by side walls 27 and 28 which are made entirelyor partially from a soundproofing material.

The percussive movements of the weight 1 3 do not have to be used for all the working operations which are intended for the vibratory rammer. According to the prevailing conditions and circumstances, it may be advantageous or necessary to perform driving-in or with-drawing operations only intermittently or entireiy without percussive movements.

For this purpose, there is provided an optionally adjustable impar,t cut-out by which the movements of the weight 1 3 reiative to the housing 4 can be enabied or disabled.

Advantageously, one side or both sides of the weight 1 3 are provided with a respective locking slot 29 or the like. The adjacent wall of the housing 4 incorporates an opening 30 which is disposed at the same height as, and is the same size as, the locking slot 29 and in which is located a locking bolt, pin or element 31 which is displaceable into the locking slot 29. The percussive movements are disabled by inserting one or both of the locking bolts 31 into the respective locking slots 20 provided for this purpose in the weight 1 3. To enable the percussive movements, it is sufficient merely to withdraw the locking bolt 31 from its associated locking slot 29. The impact cut-out has the advantage that tasks in hand can be performed in an economically advantageous manner with or without percussive movements as required.

When in their positions shown in Fig. 3, the out-of-balance masses 7 and 9 have reached their bottom points and have brought the vibratory rammer into its lowest corresponding position. The weight 1 3 has then also been displaced in the direction of vibration, so that it has performed its percussive movement on the extension or projection 20. When in this position, the vibratory rammer has been subjected to the persussive movements of the weight 1 3 in addition to the vibrations originating from the vibrators 5 and 6 and their out-of-balance masses 7 and 9, and has transmitted them by way of the holding anvil 21 to the object 11 to be driven in or withdrawn.

The out-of-balance masses 7 and 9 can be selectively driven in either direction of rotation, care only having to be taken that they always rotate in synchronism in opposed directions.

The vibrations thus occurring cause movements of the weight 1 3 which are effected in the direction of vibration and which, advantageously are used as percussive movements. It has been found the spring weight system can be so turned that two vibrations of the vibrators 5 and 6 are required for each percussive movement in the same direction. Consequently, in the case of continuous vibrations.

the weight 1 3 moves alternately and successively in both directions of vibration.

When the vibratory rammer is in its position shown in Fig. 4, the out-of-balance masses 7 and 9 are located at their opposed top points.

Consequently, the vibratory rammer has also moved into its uppermost position, as will be ciearly seen from the diagrammatic distance data a and b relating to the plane of suspension. The vibrations effected during the change of position of the vibratory rammer have also caused upward displacement of the weight 13.The guide spindle 14 held in the recess 1 6 in the weight 1 3 has then been displaced axially in the bore 1 5. The spring element 25 advantageousiy held in the enclosed space 1 2 between the top wall 24 and the cover 1 7 resiliently absorbs the displacement of the weight 1 3. In this state, the impact surface 1 9 of the weight 1 3 has been raised from the projection or extension 20, so that no percussive movement takes place. If the out-of-balance masses 7 and 9 are maintained in continuous movement, the corresponding vibrations also take place and, in the manner described, percussive movements are additionally imparted successively and alternately to the object 11 to be driven in or withdrawn.

Claims (7)

1. A vibratory rammer for objects which are to be driven in or withdrawn on for other elements which can be driven in or withdrawn, in which a weight is disposed between at last two vibrators and is displaceable in the direction of vibration and, by means of the vibrations of the vibrators, performs percussive movements which are transmissible to the object to be driven in or withdrawn and which serve to intensify the driving-in or withdrawing movements.

2. A vibratory rammer as claimed in claim 1, in which each percussive movement of the weight in the same direction is effected by two vibrations of the vibrators.

3. A vibratory rammer as claimed in claim 1 or 2, in which each vibrator has a rotatable out-of-balance mass, which out-of-balance masses rotate in opposite directions in synchronism and impart common unidirectional vibrations of the two vibrators.

4. A vibratory rammer as claimed in any of claims 1 to 3, in which the percussive movements of the weight are transmissible to the object to be driven in or withdrawn by way of a holding member and a housing of the vibrators.

5. A vibratory rammer as claimed in claim 4, in which the weight is located in a space enclosed in the housing and is displaceable towards a draw body against a spring element and towards the object to be driven in or withdrawn against a projection or extension which is releasably or integrally connected to the holding member so that the latter acts as an anvil.

6. A vibratory rammer as claimed in claim 4 or 5, in which one side or each of the two oppositely located sides of the weight incorporates a locking slot or the like, such that an axially displaceably locking bolt, pin or the like is insertable through the wall of the housing and is insertable into, and withdrawable from. its associated locking slot for the purpose of disabling or enabling the vibrationdependent displacement movements of the weight.

7. A vibratory rammer constructed and adapted to operate substantially as herein described with reference to and as illustrated in the drawings.