GB2245521A - Portable pressure exerting device - Google Patents

Abstract

A portable pressure applying device, particularly, but not exclusively, for opening outwardly-hinged doors, comprises closable gripping jaws 15, 16 for gripping a hinge, first power operated means 23 for closing the jaws 15, 16 around the hinge and second power operated means 30 for applying pressure against a rigid structure, via plate 34, so as to exert a pulling force on the hinge gripped by the jaws. Power means 23 may pull a linkage to close scissors-type jaws (Fig. 2). Means 23, 30 are hydraulically operated. <IMAGE>

Description

PORTABLE PRESSURE EXERTING DEVICE This invention relates to a portable device for exerting pressure and particularly, but not exclusively, to a device for opening an outwardly-opening door.

In many fields nowadays, there are circumstances in which rapid and quiet entry to closed and locked premises is required. Some of the authorities who need or might need to make such entry are police, customs and excise personnel, bailiffs, firemen and (in non-civilian circumstances) personnel in the armed forces.

In the field of drug-taking and drug-dealing, it has been common (at least in the United Kingdom) for personnel from the respective agency to approach the premises as quietly as possible and then to smash the door down if it proved to be securely locked in order to prevent entry. By the time the door was down, the drugs (which the personnel had hoped to seize and to use as evidence of illegal use and/or dealing) could well have been washed away down a water closet or down a sink whose taps were left running.

Thus, a combination of the noise created in smashing down the door and the time taken to do it gives criminals valuable time within which to get rid of some or all of incriminating evidence.

In our British Patent No. 2,189,544 there is disclosed a device specifically adapted to open an inwardly-opening door comprising a first fluid-operated means and a second fluid-operated means, the first fluid-operated means being adapted to mount said second fluid-operated means securely on the jambs of a door frame in such a manner as to permit the door, which is connected to said door frame by hinge means and by locking means, to be moved relatively to said door frame by force (pressure) applied to the door by said mounted second fluid-operated means.

However such a device cannot be readily used to open an outwardly-opening door. An object of the present invention is to provide a fluid-operated pressure exerting device which can operate so as to be able to open outwardly-opening doors amongst other possible applications.

The invention provides a portable pressure applying device comprising closable gripping jaws for gripping a hinge or other grippable member, first power operated means for closing said jaws around the hinge or other member, and second power operated means for applying a pressure against a rigid structure so as to exert a pulling force on the hinge or other member gripped, in use, by said jaws.

Preferably said power operated means are fluid-operated. In such embodiments, diverter valve means may be provided, either on the device itself or on a separate pressurized fluid supplying unit, to apply fluid pressure to said first power operated means to close said jaws before applying fluid pressure to said second power operated means. Moreoever, said first and second power operated means may comprise first and second fluid pressure operated rams, respectively, located side by side with said first ram acting in a first direction to effect closure of said jaws and said second ram acting in a generally opposite direction to exert said pulling force. Preferably a pressure applying plate is provided at the free end of the piston rod of said second ram.

Preferably one of said gripping jaws is provided with a generally flat surface area at its free end to provide an abutment which tends to prevent rotation of the device when said second power operated means is actuated.

Said gripping jaws preferably comprise cooperating pincher-like gripping portions having internal, arcuate gripping surfaces for engaging around said hinge or other member. In practice, the radius of the profile of said gripping surfaces is selected to be as large as possible to accommodate hinges as well as larger objects, e.g. pipes but without severely weakening the jaws.

Said jaws may comprise a pair of jaw members having external cam surfaces engaged in a tapered seat, with said first power operated means adapted to act to pull the jaw members into the seat so as to effect closure of the jaws.

In other constructions, said jaws may comprise jaw members pivotally connected intermediate their length to form a scissor-type jaw mechanism with said first power operated means being connected to such mechanism so as to be operable to close the jaws. Said jaws may be provided with resilient means to bias the jaws to an open position thereof.

An elongate lateral projection may be provided on one of said jaws for abutting against one or more adjacent bars of a grille or similar hinged open work structure to be opened by the device.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a cross-section through a door opening device in accordance with the invention; Figure 2 is a cross-section through a second embodiment of the invention; Figures 3A and 3B are respectively a front view and a sectional view (along line A-A in Figure 3A) of a hinged grille; and, Figure 4 is an enlarged sectional detail of a modified version of the embodiment of Figure 1.

Referring to Figure 1 of the drawings, there is illustrated a portable device for opening outwardly-opening doors. The device (10) comprises a jaw mounting block (11) having a taper seat (12) at the upper end thereof. Each side of the block (11) is covered by a face plate (13) to define a tapered cavity (14) in which a pair of pincer jaws (15,16) are received. The plate-like jaws (15,16) have external camming surfaces (17,18) which engage the opposite surfaces of the taper seat (12) respectively. Arcuate grooves (19,20) are formed in the projecting portions of the jaws (15,16) in confronting surfaces thereof adjacent the free ends of the jaws. These grooves (19,20) are sized to accommodate a door hinge.Preferably the grooves are sized to be as large as possible to accommodate a range of rod-like elements which may be of a larger size than a door hinge, for example pipes or reinforcing rods, so that the device can be used for a wide range of applications. For example the device could be used to remove a steel grille rather than a door with a bar of the grille being engaged within the cooperating grooves (19,20) in the closed position of the jaws (15,16). The size of the grooves (19,20) must of course be limited in order not to severely reduce the strength of the jaws themselves. The jaw (16) is provided with a flat end surface (21) for bearing against a door to be opened by the device in order to counteract any tendency of the device to rotate in operation.

The jaws are resiliently biassed by a U-shaped spring (22), or in other embodiments a coil spring, to their open positions.

A first hydraulic ram (23) is located on the underside of the jaw mounting block (11). The piston rod (24) of the ram (23) extends through aligned apertures in an end cap (25) of the ram cylinder (26) and in the jaw mounting block (11) so that it projects into the jaw receiving cavity (14).

The upper end of the piston rod (24) is formed with an outwardly projecting flange (27) which engages in cooperating recesses formed at the lower portion of the confronting surfaces of the jaws (15,16).

A second hydraulic ram (30) is located parallel to the first ram (23) on one side of the jaw mounting block (11).

The cylinder (31) of the ram (30) is located in a pair of spaced apart hoop plates (32,33) which project laterally from the jaw mounting block (11) and the hydraulic ram cylinder (26), respectively. A bearing plate (34) is provided at the free end of the piston rod (35) of the ram (30). A diverter valve (36) is located at the lower end of the cylinder (31) of the ram (30). A valve (36) has a first passageway (37) for connection at its lower end to either a hand-operated pump or a battery-driven pump which could be provided in a separate power pack for the unit. Each pump will be connected to an appropriate reservoir for hydraulic fluid. The upper end of the passage (37) is connected to a portion of the ram cylinder (26) above the piston therein.

The valve (36) has a second fluid passageway connection (38) controlled by a spring-loaded valve member (39). This fluid passage is connected to the lower end of the ram cylinder (31). The spring loading applied to the valve member (39) is adjustable so that the pressure at which the valve opens can be regulated as required. In other embodiments the diverter valve (36) may be provided in the separate power pack unit itself rather than on a tool. The arrangement shown in Figure 1 where the diverter valve is located on the tool itself would normally be for applications where a hand-operated pump is to be utilized with the device.

Operation of the above-described device to open an outwardly-opening door will now be described.

The tool is presented to the outside of the door so that the abutment surface (21) on the pincer jaw (16) is pressed flat against the door surface with the door hinge pin received in the groove (20) in that jaw. Pressurized hydraulic fluid is applied to the diverter valve (36) either from a hand pump or a separate power pack containing a battery-driven pump. The diverter valve operates so that initially the pressurized hydraulic fluid is only supplied to the ram (23) in order to move the piston therein downwardly against the action of a return spring (40) provided in the ram cylinder (26). The downward movement of the piston rod (24) draws the pincer jaws (15,16) into the taper seat (12) thereby causing closure of the pincer jaws around the hinge pin.When the pincer jaws can close no further around the hinge pin, the pressure within the ram (23) increases to a value sufficient to open the diverter valve (39) thereby allowing pressurized hydraulic fluid to pass into the second ram (30).

The ram (30) is thereby pressurized to extend so that the bearing plate (34) contacts and pushes against the door frame or surrounding wall structure. The reaction force causes the pincer jaws (15,16) with the hinge pin gripped therein to move in the opposite direction which results in the hinge with the door attached being pulled out of its frame. This sequence is repeated for each hinge until the door is removed from the frame.

Figure 2 shows a second embodiment. This embodiment is generally similar in construction and operation to the device shown in Figure 1 with the exception of the construction of the pincer jaw mechanism. Like parts in both drawings have been given similar reference numerals and the following description will be restricted to the differences between the two constructions. The jaw mounting block (llA) in this embodiment has a cylindrical jaw receiving recess (12A) rather than the tapered seat (12) of the first embodiment. The pincer jaws (50,51) are arcuate members which are pivotally connected at (52) intermediate their lengths. The pincer jaw (51) is formed at its free end with a flat abutment surface (53) for the same purpose as the abutment (21) of the jaw (16) in the first embodiment.The upper end of the piston rod (24) of ram (23) is formed with a clevis (56) which pivotally mounts a pair of links (57,58), the upper ends of which are pivotally connected to the lower ends of the jaws (51,50), respectively, by pins (55,54). A jaw opening spring (59) is provided to act between the links (57,58). In this way the pincer jaw is provided in the form of a scissor-type mechanism. When the jaw (51) is engaged behind a door hinge pin with its abutment surface (53) against the door, the ram (23) is operated to draw its piston rod (40) downwardly thereby closing the scissor-mechanism such that the pincer jaws (50,51) firmly grip the door hinge pin. The remaining operation of the device is similar to that of the first embodiment described above.

The door breaking devices illustrated in Figure 1 and Figure 2 can be used interchangeably with the doorbreakers shown in our GB Patent 2,189,544 with a common power pack for supplying pressurized hydraulic fluid to provide a set enabling the forceable opening of both inward opening and outwardly opening doors.

In practice, the working pressure of hydraulic fluid applied to the device can be of the order of 3000 psi, or a potential operating pressure of 10,000 p.s.i. when a hand pump is used, with the diverter valve being set to operate in the range of 1200 to 1500 psi.

Figure 4 illustrates a modified version of the device of Figure 1 for use in opening a hinged grille (50) over a door or a window (51), as illustrated in Figures 3A and 3B.

The jaw (16) is fitted with a removable laterally projecting strong steel bar (4), e.g. a round bar, socketted into a hole (3) in a side face of the jaw. The bar (4) bears against the outer face of adjacent bars (53) of the grille (50) to prevent rotation of the device when the ram (30) is actuated to act against the door or window surrounding structure (52) with the grille hinge (2) gripped by the jaws (15,16).

Claims (12)

1. A portable pressure applying device comprising closable gripping jaws for gripping a hinge or other grippable member, first power operated means for closing said jaws around the hinge or other member, and second power operated means for applying a pressure against a rigid structure so as to exert a pulling force on the hinge or other member gripped, in use, by said jaws.

2. A device according to Claim 1 wherein said power operated means are fluid-operated.

3. A device according to Claim 2 wherein diverter valve means are provided, either on the device itself or on a separate pressurized fluid supplying unit, to apply fluid pressure to said first power operated means to close said jaws before applying fluid pressure to said second power operated means.

4. A device according to any one of Claims 1 - 3 wherein said first and second power operated means comprise first and second fluid pressure operated rams, respectively, located side by side with said first ram acting in a first direction to effect closure of said jaws and said second ram acting in a generally opposite direction to exert said pulling force.

5. A device according to Claim 4 wherein a pressure applying plate is provided at the free end of the piston rod of said second ram.

6. A device according to any one of Claims 1 - 5 wherein one of said gripping jaws is provided with a generally flat surface area at its free end to provide an abutment which tends to prevent rotation of the device when said second power operated means is actuated.

7. A device according to any one of Claims 1 - 6 wherein said gripping jaws comprise cooperating pincher-like gripping portions having internal, arcuate gripping surfaces for engaging around said hinge or other member.

8. A device according to any one of Claims 1 - 7 wherein said jaws comprise a pair of jaw members having external cam surfaces engaged in a tapered seat, with said first power operated means adapted to act to pull the jaw members into the seat so as to effect closure of the jaws.

9. A device according to any one of Claims 1 - 7 wherein said jaws comprise jaw members pivotally connected intermediate their length to form a scissor-type jaw mechanism with said first power operated means being connected to such mechanism so as to be operable to close the jaws.

10. A device according to any one of Claims 1 - 9 wherein said jaws are provided with resilient means to bias the jaws to an open position thereof.

11. A device according to any one of Claims 1 - 10 wherein an elongate lateral projection is provided on one of said jaws for abutting against a grille or other similar open work hinged member to counteract rotation of the device when the second power operated means are actuated.

12. A portable pressure applying device substantially as hereinbefore described with reference to and as illustrated in Figure 1 or Figure 2, or Figure 4 of the accompanying drawings.