BOOM OPERATED DEMOLITION APPARATUS

Description

[0001] This invention relates to an apparatus for breaking composite material such as cement into a plurality of pieces.

[0002] Numerous types of apparatus have been devised for breaking surfaces such as concrete or asphalt pavement. Such apparatus may be referred to as demolition apparatus.

[0003] Known demolition apparatus are shown in US-A-3,319,724 and US-A-3,358,779. These known demolition apparatus are attached to a boom of an earthmoving machine for support of the apparatus. These known apparatus require a separate motor for operation thereof.

[0004] It is an object of this invention to provide demolition apparatus which is adapted to be attached to a boom of an earthmoving machine, but in which the demolition apparatus is operated by movement of the boom, without the use of a separate motor for operation of the demolition apparatus.

[0005] It is another object of this invention to provide such demolition apparatus which is capable of applying large forces in consideration of the physical size and weight of the apparatus. It is another object of this invention to provide such demolition apparatus which can be easily and readily attached to a boom of an earthmoving machine and detached therefrom.

[0006] It is another object of this invention to provide such demolition apparatus which can be operated at any desired angle, such as vertical operation for demolition of a pavement and such as horizontal operation for demolition of a wall or the like.

[0007] In US-A-3358779, a demolition apparatus is disclosed which is arranged to be carried by a movable boom-like member for moving the demolition apparatus towards and away from a surface to be demolished, the apparatus comprising a support structure which is arranged to be attached to the boom-like member; an axially movable power plunger supported by and extendable from the support structure for movement with respect to the support structure; a resilient member and means joining the resilient member to the support structure and to the power plunger whereby the resilient member urges the power plunger in a direction from the support structure; an actuator plunger positioned substantially parallel to the power plunger, the actuator plunger and the support structure being relatively movable, to load the power plunger by biasing of the resilient member; latch means to engage the power plunger as it is loaded; and release means to release the latch and permit the resilient member to force the rapid movement of the power plunger towards the surface to be demolished and, in accordance with the invention, such an apparatus is characterised in that the actuator plunger is supported by the support structure adjacent to the power plunger and has a portion extending from the support structure; and the latch means comprises a latch attached to the actuator plunger and engageable with a portion of the power plunger to maintain the position of the power plunger with respect to the actuator plunger; and the release means comprises an abutment member attached to the support structure and engageable with the latch upon relative movement of the plungers and the support structure; whereby when, in use, the support structure is moved on the boom-like member towards the surface to be demolished, the extending portion of the actuator plunger first engages the surface, and is then forced into the support structure, carrying the power plunger with it to stress the resilient member until the latch engages, and is released by, the abutment member.

[0008] In operation, the housing is moved toward a pavement or wall or the like 'which is to be demolished. As the housing is moved toward the pavement, the actuator plunger comes into engagement with the surface to be demolished. However, the power plunger is spaced from the surface. As continued movement of the housing toward the pavement surface occurs, the actuator plunger remains in engagement with the pavement, and the latch which is attached to the actuator plunger remains in engagement with the power plunger and maintains the position of the power plunger with respect to the surface. Therefore, continued movement of the housing toward the surface causes the actuator plunger and the power plunger to be positioned upwardly within the housing. Such relative movement between the power plunger and the housing is against the forces of the power spring.

[0009] This movement of the housing toward the surface continues until an abutment member comes into engagement with the latch which is attached to the actuator plunger. As the latch comes into engagement with the abutment member, the latch is operated and is released from engagement with the power plunger. When this occurs, the power spring instantaneously and rapidly forces the power plunger to travel into striking engagement with the pavement. The power plunger strikes the pavement with the energy of the power spring.

[0010] A demolition apparatus according to the invention will now be described with reference to the accompanying drawings, in which;

Fig. 1 is a side elevational view of a boom and boom arm of an earthmoving machine, showing a bucket attached to the boom arm for movement and operation with movement of the boom and the boom arm.

Fig. 2 is a side elevational view showing the demolition apparatus attached to the boom arm, replacing the bucket. The demolition apparatus is shown supported by the boom arm in a position spaced from a pavement to be demolished. In this figure the pavement is shown in section.

Fig. 3 is a side elevational view showing the boom and the boom arm of Figs. 1 and 2. This figure shows the actuator plunger of the demolition apparatus in engagement with a pavement surface.

Fig. 4 is a side elevational view showing a portion of the boom arm of the machine, with the demolition apparatus attached thereto and showing the positions of the power plunger and actuator plunger at the instant of release of the power plunger for striking action.

Fig. 5 is a side elevational view, similar to Fig. 4, but illustrating downward striking action of the power plunger.

Fig. 6 is a fragmentary sectional view illustrating demolition action created by successive operations of the power plunger of the demolition apparatus.

Fig. 7 is an enlarged side sectional view illustrating the position of the plungers of the demolition apparatus as shown in Figs. 2 and 3, as the demolition apparatus is being moved downwardly toward a surface for demolition thereof.

Fig. 8 is an enlarged sectional view similar to Fig. 7 but showing the position of the plungers during further downward movement of the housing and as the actuator plunger engages a surface to be demolished.

Fig. 9 is a fragmentary sectional view drawn on substantially the same scale as Figs. 7 and 8, and illustrating the positions of the elements and members of the demolition apparatus at the instant the power plunger is released for downward striking travel toward a surface for demolition thereof.

Fig. 10 is a sectional view similar to Figs. 7 and 8 and illustrating striking action of the power plunger after release thereof.

Figs. 1, 2, and 3 show a portion of a machine operation unit 20 which may be a tractor or carrier vehicle or the like, herein shown as an earthmoving machine.

[0011] Pivotally attached to the operation unit 20 is a boom 22. Pivotally attached to the boom 22 by means of a connection unit 24 is a boom or force arm 26.

[0012] Rigidly attached to the boom 22 intermediate the ends thereof is a connection unit 30. A linearly operable fluid motor 34 is pivotally attached to the operation unit 20 and to the connection unit 30. A linearly operable fluid motor 36 is pivotally attached to the connection unit 30 and has a piston rod 38 extending therefrom. The piston rod 38 is pivotally attached to the connection unit 24.

[0013] A linearly operable fluid motor 40 is pivotally attached to the connection unit 24 and has a piston rod 44 extending therefrom. A lever 46 is pivotally attached to the end of the piston rod 44. The lever 46 is also pivotally attached to the arm 26 adjacent the end thereof.

[0014] As shown in Fig. 1, the boom arm 26 has a bucket 50 pivotally attached thereto adjacent the end thereof for movement and operation by the operation unit 20. The bucket 50 is also pivotally attached to a link 52. The link 52 is also pivotally attached to the lever 46. The fluid motors 34, 36, and 40 are operated by control means, not shown, carried by the operation unit 20. Thus, the boom 22, the boom arm 26, and the bucket 50 are moved by operation of the operation unit 20.

[0015] When it is desired to attach demolition apparatus 60 of this invention to the boom arm 26, the bucket 50 is removed from the arm 26 and from the link 52. The demolition apparatus 60 of this invention includes a housing 64 which is provided with a bracket 62 which is pivotally attached to the end portion of the force arm 26 and to the link 52.

[0016] Within the housing 64 is a power plunger 68 which has an end 69. The power plunger 68 is mounted at the opposite ends of the housing 64 and extends from both of the opposite ends of the housing 64. The power plunger 68 is axially movable with respect to the housing 64.

[0017] As shown in Figs. 7, 8, and 10, within the housing 64 at the lower end thereof is a cushion 70. The power plunger 68 extends through the cushion 70. Encompassing the power plunger 68 and firmly secured thereto is a collar 72. Compressed between the collar 72 and the upper end of the housing 64 and encompassing, the power plunger 68 is a resilient or biasing member preferably in the form of a coil spring 76, for longitudinally biasing the power plunger 68 relative to the housing 64 and in a direction toward said end 69 of the power plunger 68.

[0018] Also, mounted within the housing 64 is an actuator plunger 80 which has an end 81. The actuator plunger 80 extends from both ends of the housing 64 and extends through the cushion 70. The actuator plunger 80 is axially movable with respect to the housing 64 between a first position (Fig. 7) and a second position (Figs. 8 & 9). Firmly secured to the actuator plunger 80 intermediate the ends thereof is a base 82. A lug 84 is secured to the base 82. Pivotally attached to the lug 84 and to the actuator plunger 80 is a latch 86. The latch 86 has an engagement portion 86e which is positioned adjacent the power plunger 68. A control spring 89 is compressed between the base 82 and the latch 86 and urges pivotal movement of the latch 86 in a counterclockwise direction as viewed in Figs. 7-10. The lug 84 is provided with a stop portion 84e which limits counterclockwise pivotal movement of the latch 86 to the position thereof shown in Figs. 7 and 8. Fixed within the housing 64, adjacent the actuator plunger 80, is an abutment member 90 which is engageable by the latch 86.

[0019] For purposes of clarity, it should be understood that the spring means 77 for longitudinally biasing the power plunger 68 relative to the housing 64 and in a direction toward said end 69 of said power plunger 68 includes the spring 76, collar 72. Further, the means 83 for compressing said spring means 77 in response to moving the actuator plunger 80 from the first toward the second position and releasing said spring means 77 in response to the power plunger 68 having been moved toward the housing 64 a distance greater than said preselected distance (D) includes base 82, lug 84, lug portion 84e, latch 86, latch engagement portion 86e, coil spring 89, lug stop portion 84e, and abutment member 90. It should also be understood that the "trigger" mechanism, which consists of the latch 86, collar 72, and abutment member 90, can be of other construction without departing from this invention.

[0020] As stated above and as shown, the demolition apparatus 60 of this invention easily and readily replaces the bucket 50 which is shown attached to the boom arm 26. The bracket 62 of the housing 64 is pivotally attached to the end portion of the boom arm 26 and to the link 52. Movement of the boom 22 and the boom arm 26 thus moves the demolition apparatus.

[0021] In a demolition process using the demolition apparatus 60, the boom 22 and the boom arm 26 are operated to move the demolition apparatus 60 toward the surface to be demolished, as illustrated in Fig. 2. The actuator plunger 80 and the power plunger 68 are normally in their maximum extension positions, as shown in Figs. 2, 3, and 7. In this position, the power plunger 68 is spaced upwardly with respect to the actuator plunger 80. As the boom 22 and the arm 26 move the demolition apparatus 60 downwardly toward a pavement 96, the actuator plunger 80 is brought into engagement with the pavement 96, as illustrated in Fig. 3. The engagement portion 86e of the latch 86 which is attached to the actuator plunger 86 is in engagement, with the collar 72, which is secured to the power plunger 68. Therefore, as the boom 22 and the arm 26 continue to move the demolition apparatus 60 downwardly, the housing 64 is moved downward but the actuator plunger 80 and the power plunger 68 do not move. Therefore, there is relative movement between the plungers 80 and 68 and the housing 64. This downward movement of the housing 64 is against the compression forces of the spring 76 which encircles the power plunger 68 and which engages the collar 72 and the housing 64. This downward movement of the housing 64 continues until the abutment member 90 within the housing 64 engages the latch 86 which is carried by the actuator plunger 80, as shown in Fig. 9. This is at a location at which the power plunger 68 has been moved toward and relative to the housing 64 a distance greater than preselected distance "D". When this engagement occurs, the latch 86 is pivotally moved against the force of the control spring 89 and becomes disengaged from the collar 72 which is secured to the power plunger 68, as illustrated in Fig. 9. When the latch 86 releases the collar 72, the power spring 76 immediately forces the power plunger 68 downwardly at a high rate and with a significant force, as illustrated in Figs. 9 and 10. The power plunger 68 strikes the pavement 96 and crushes and breaks the pavement 96, as illustrated in Figs. 5 and 6. When the power plunger 68 reaches its maximum downward position as illustrated in Fig. 10, the collar 72 engages the cushion 70.

[0022] The demolition apparatus 60 is then again raised by the arm 26 and the boom 22, and the demolition apparatus 60 is moved to an adjacent position above the pavement 96. The housing 64 is again moved downwardly for engagement of the actuator plunger 80 with the pavement 96, and the operation is repeated to cause the power plunger 68 to strike the pavement in several adjacent locations. The pavement is broken and demolished, as illustrated in Fig. 6.

[0023] Thus, the demolition apparatus of this invention is operated without the use of a special motor for operation thereof. Movement of the boom arm 26 and the boom 22 with respect to the surface to be demolished causes operation of the demolition apparatus 60.

[0024] If it is desired to demolish a wall, ceiling, or the like, the boom 22 and the boom arm 26 are operated to change the angle of the housing 64.

[0025] Thus, the demolition apparatus 60 can be employed to demolish a surface which is substantially horizontal or a surface which is substantially vertical or a surface having any other angle. However, at some angles it is necessary to employ a return spring on the actuator plunger 80 for ease of operation.

[0026] This apparatus may be used to break up into small pieces sheets of pavement or composite material 96 having (as shown in Figs. 4 and 5) opposed first and second surfaces 102, 103, a thickness, a first thickness portion 104 containing said first surface 102, and a second thickness portion 106 containing said second surface 103 and wherein said composite material 96 has greater strength in compression than in tension. An example of such composite material 96 is concrete containing Portland cement.

[0027] In the steps of this unique method, a holding pressure is exerted on the first surface of the composite material 96 in a direction generally toward the second surface 103. The holding pressure is then increased to a magnitude sufficient to generate tensile forces within said first thickness portion 104 and along said first surface 102. Thereafter, the increased magnitude holding pressure is maintained while impacting the first surface 102 in a direction generally toward said second surface and at a location spaced from the location of said holding pressure.

[0028] As described above, the holding or concrete bending pressure is exerted by actuator plunger 80 and the impacting force is exerted by power plunger 68.

[0029] One skilled in the art will quickly recognize that by exerting the increased holding pressure on the first surface of the concrete, the upper portion of the concrete will be subjected to tensile forces and the lower portion will be subjected to compression forces in response to generating bending forces on the concrete.

[0030] It has been discovered that when concrete has such forces imparted and then heavily impacted in the general vicinity of such bending forces, that the concrete will shatter and break into a significantly larger number of pieces to a significantly greater depth and the broken pieces will be smaller in size than where the composite material is impacted without exerting bending forces upon it. By the method of this invention, the inherent characteristics of concrete and other composite material, both man made and naturally occurring, are utilized to mechanically assist in the demolition process. It has also been observed that upon impact, major breaking lines radially downwardly and outwardly at approximately 45° angles, as shown in Fig. 5, as opposed to more conventional, substantially vertical, cracking that is produced by impacting the unstressed concrete.

[0031] The increased magnitude holding or bending pressures exerted on the concrete are naturally a function of the thickness of the concrete desired to be broken. The majority of concrete generally desired to be removed falls within a thickness of 12 inches (304.8 mm) or less. Preferred increased magnitude holding pressures are therefore in the range of about 600ps (41x105 Pa) to about 150 psi (10.3x105 Pa). This pressure is preferably exerted by a holding element or actuator plunger 80 having an end whose area is greater than about 7 square inches (4516mm²). At pressures below the preferred minimum, the upper surface of the concrete is not sufficiently stressed and breaking is undesirably inefficient and wastes manpower and expense. At pressures greater than the preferred maximum, the concrete is unnecessarily stressed which represents an undesirable waste of manpower and expense. Where the holding element has a surface area less than the preferred range, the concrete first surface is subjected to undesirable shear forces and where the surface is greater than that preferred area, the apparatus wastes material utilized for its construction and requires unnecessary power to move and handle the apparatus.

[0032] In breaking concrete, it has also been discovered that the distance between the holding force and the impact force should be greater than one inch and the concrete should be impacted at intervals not less than 5 inches (127 mm) from one another in order to break the concrete efficiently and effectively. At lesser distances apart an undesirable shearing action is produced and at less distances between impacts there is a waste of resources by over fracturing the concrete and/or failing to efficiently utilize the optimum lateral extent of concrete crack propagation.

Claims

1. Demolition apparatus (60) which is arranged to be carried by a movable boom-like member (20) for moving the demolition apparatus (60) towards and away from a surface to be demolished, the apparatus comprising a support structure (64) which is arranged to be attached to the boom-like member (20); an axially movable power plunger (68) supported by and extendable from the support structure (64) for movement with respect to the.support structure; a resilient member (76) and means joining the resilient member (76) to the support structure (64) and to the power plunger (68) whereby the resilient member urges the power plunger in a direction from the support structure; an actuator plunger (80) positioned substantially parallel to the power plunger, the actuator plunger (80) and the support structure being relatively movable to load the power plunger by biasing of the resilient member (76); latch means to engage the power plunger as it is loaded; and release means to release the latch and permit the resilient member (76) to force the rapid movement of the power plunger towards the surface to be demolished; characterised in that the actuator plunger (80) is supported by the support structure adjacent to the power plunger and has a portion extending from the support structure (64); and in that the latch means comprises a latch (86) attached to the actuator plunger (80) and engageable with a portion of the power plunger (68) to maintain the position of the power plunger with respect to the actuator plunger; and in that the release means comprises an abutment member (90) attached to the support structure (64) and engageable with the latch (86) upon relative movement of the plungers (68, 80) and the support structure; whereby when, in use, the support structure is moved on the boom-like member towards the surface to be demolished, the extending portion of the actuator plunger (80) first engages the surface, and is then forced into the support structure (64), carrying the power plunger (68) with it to stress the resilient member (76) until the latch (86) engages, and is released by, the abutment member (90).

2. Demolition apparatus according to claim 1 wherein the latch member (86) is pivotally supported by the actuator plunger (80).

3. Demolition apparatus according to claim 1 or claim 2 in which the power plunger (68) includes a collar (72) which is engaged by the latch member (86).

4. Demolition apparatus according to any one of the preceding claims, in which the support structure (64) is elongate and in which the actuator plunger (80) and the power plunger (68) are elongate substantially parallel cylindrical members.

5. Demolition apparatus according to claim 4, in which the support structure (64) comprises an elongate housing having a pair of opposed end walls (97, 98), and both the actuator plunger (80) and the power plunger (68) extend through both of the opposed end walls (97, 98).

6. Demolition apparatus according to any one of the preceding claims, in which the support structure (64) includes an attachment bracket (62) which is adapted to be pivotally attached to a movable boom-like member (20) for support thereby.

Ansprüche

1. Demoliervorrichtung (60) die zum Tragen durch ein bewegliches auslegeartiges Glied (20) geordnet ist, um die Demoliervorrichtung (60) zu einer zu demolierenden Oberfläche hin und von dieser wegzubewegen, wobei die Vorrichtung folgendes aufweist: eine Tragstruktur (64) angeordnet zur Befestigung an dem auslegeartigen Glied (20); ein axial beweglicher Leistungskolben (68) getragen durch und ausfahrbar gegenüber der Tragstruktur (64) zur Bewegung bezüglich der Tragstruktur; ein elastisches Glied (76) und Mittel zur Verbindung des elastischen Gliedes (76) mit der Tragstruktur (64) und mit dem Leistungskolben (68) wodurch das elastische Glied dem Leistungskolben in einer Richtung von der Tragstruktur wegrückt; ein Betätigungskolben (80) postitioniert im wesentlichen parallel zu dem Leistungskolben, wobei der Betätigungskolben (80) und die Tragstruktur relativ beweglich sind, um den Leistungskolben aufzuladen und zwar durch Vorspannen des elastischen Glieds (76); Verriegelungsmittel zum Eingriff mit dem Leistungskolben wenn dieser geladen ist; und Freigabemittel zum Freigeben der Verriegelung zum Gestatten, daß das elastische Glied (76) die schnelle Bewegung des Leistungskolbens zur zu demolierenden Oberfläche hin kraftvoll ausführt, dadurch gekennzeichnet, daß der Betätigungskolben (80) von der Tragstruktur benachbart zum Leistungskolben getragen wird und einen Teil aufweist, der sich von der Tragstruktur (64) aus erstreckt; und daß die Verriegelungsmittel eine Verriegelung (86) befestigt am Betätigungskolben (80) aufweist und zwar in Eingriff bringbar mit einem Teil des Leistungskolbens (68) um die Postition des Leistungskolbens bezüglich des Betätigungskolbens beizubehalten, und daß die Freigabemittel ein Anschlagglied (90) aufweisen, befestigt an der Tragstruktur (64) und in Eingriff bringbar mit der Verriegelung (86) bei relativer Bewegung der Kolben (68, 80) und der Tragstruktur, wodurch dann, wenn im Gebrauch die. Tragstruktur an dem auslegerartigen Glied zurzu demolierenden Oberfläche hinbewegt wird, der sich erstreckende Teil des Betätigungskolbens (80) zuerst mit der Oberfläche in Eingriff kommt und sodann in die Tragstruktur (64) gezwungen wird, wobei der Leistungskolben (68) mitgeführt wird um das elastische Glied (76) zu beanpruchen bis die Verriegelung (86) in Eingriff kommt, wobei die Freigabe durch das Anschlagglied (90) erfolgt.

2. Demoliervorrichtung nach Anspruch 1, wobei das Verriegelungsglied (86) schwenkbar durch den Betätigungskolben (80) gelagert ist.

3. Demoliervorrichtung nach Anspruch 1 oder 2, wobei der Leistungskolben (68) einen Kragen (72) aufweist der mit dem Verriegelungsglied (86) in Eingriff bringbar ist.

4. Demoliervorrichtung nach einem der vorherigen Ansprüche, wobei die Tragstruktur (64) langgestreckt ist und in der der Betätigungskolben (80) und der Leistungskolben (68) langgestreckte in wesentlichen parallele zylindrische Glieder sind.

5. Demoliervorrichtung nach Anspruch 4, wobei die Tragstruktur (64) ein langgestrecktes Gehäuse aufweist mit einem Paar von entgegengesetzt liegenden Endwänden (97,98) und daß sowohl der Betätigungskolben (80) als auch der Leistungskolben (68) sich durch beide entgegengesetzt liegende Endwände (97, 98) erstrecken.

6. Demoliervorrichtung nach einem der vorhergehenden Ansprüche, wobei die Tragvorrichtung (64) einen Befestigungsbügel (62) aufweist, der geeignet ist, um schwenkbar an dem beweglichen auslegerartigem Glied (20) befestigt zu seien, zwar um dadurch getragen zu werden.

Revendications

1. Appareil de démolition (60) qui est conçu pour être supporté par un élément déplaçable du type à flèche (20) prévu pour rapprocher et éloigner l'appareil de démolition (60) d'une surface devant être démolie, l'appareil comprenant une structure de support (64) qui est conçue pour être fixée à l'élément du type à flèche (20); un piston de puissance déplaçable axialement (68) supporté par la structure de support (64) et pouvant être déployé à partir de celle-ci en vue d'un déplacement par rapport à elle; un élément élastique (76) et un moyen reliant l'élément élastique (76) à la structure de support (64) et au piston de puissance (68), moyennant quoi l'élément élastique sollicite le piston de puissance dans une direction depuis la structure de support; un piston actionneur (80) positionné de manière sensiblement parallèle au piston de puissance, le piston actionneur (80) et la structure de support étant déplaçable l'un par rapport à l'autre pour charger le piston de puissance en sollicitant l'élément élastique (76); un moyen d'enclenchement pour venir en prise avec le piston de puissance pendant la mise en charge de celui-ci; et un moyen de dégagement pour libérer le dispositif d'enclenchement et permettre à l'élément élastique (76) de forcer le déplacement rapide du piston de puissance vers la surface devant être démolie, caractérisé en ce que le piston actionneur (80) est supporté par la structure de support à proximité du piston de puissance et comporte une partie s'étendant depuis la structure de support (64); et en ce que le moyen d'enclenchement comprend un dispositif d'enclenchement (86) fixé au piston actionneur (80) et pouvant être mis en prise avec une partie du piston de puissance (68) pour maintenir la position du piston de puissance par rapport au piston actionneur; et en ce que le moyen de désengagement comprend un élément de butée (90) fixé à la structure de support (64) et pouvant être mis en prise avec le dispositif d'enclenchement (86) lors d'un déplacement relatif des pistons (68, 80) et la structure de support; moyennant quoi, lorsque, en utilisation, la structure de support est déplacée sur l'élément du type à flèche vers la surface devant être démolie, la partie déployée du piston actionneur (80) vient d'abord en contact avec la surface et est ensuite forcée dans la structure de support (64) en portant le piston de puissance (68) avec elle pour contrain- dre l'élément élastique (76) jusqu'à ce que le dispositif d'enclenchement (86) vienne en prise avec l'élément de butée (90) et soit libéré par celui-ci.

2. Appareil de démolition selon la revendication 1, dans lequel l'élément d'enclenchement (90) est supporté de manière pivotante par le piston actionneur (80).

3. Appareil de démolition selon la revendication 1 ou la revendication 2, dans lequel le piston de puissance (68) comprend un anneau (72) avec lequel l'élément d'enclenchement (86) est en prise.

4. Appareil de démolition selon l'une quelconque des revendications précédentes, dans lequel la structure de support (64) est allongée et dans lequel le piston actionneur (80) et le piston de puissance (68) sont des éléments cylindriques allongés sensiblement parallèles.

5. Appareil de démolition selon la revendication 4, dans lequel la structure de support (64) comprend un bâti allongé comportant deux parois d'extrémités opposées (97 98) et dans lequel le piston actionneur (80) et le piston de puissance (68) s'étendent tous les deux à travers les deux parois d'extrémités opposées (97, 98).

6. Appareil de démolition selon l'une quelconque des revendications précédentes, dans lequel la structure de support (64) comprend une patte d'attache (62) qui est prévue pour être fixée de manière pivotante à l'élément mobile du type à flèche (20) pour être supporté par celui-ci.

Drawing