Patent Publication Number: US-6655143-B2

Title: Autonomous gas powered ram

Description:
FIELD OF THE INVENTION 
     The present invention relates to an autonomous gas powered ram comprising an actuator that is movable from a first operative mode to a second operative mode, movement of the actuator towards the second operative mode is caused by the detonation of an explosive charge located within the ram. 
     BACKGROUND OF THE INVENTION 
     In many mechanical systems, it is often necessary to provide an actuator that can be used to activate a certain component or functions when an emergency arises. One specific example is to bring an elevator car to a stop. Current available technologies accomplish this task by using electrically, hydraulically or pneumatically powered sources. This approach is unsatisfactory because of the inherent complexity of the systems using these types of powered sources which reduces their reliability. Accordingly, there is a need in the industry to provide a novel device that can be used to provide or perform an emergency function and which is simple and more reliable than prior art systems. 
     SUMMARY OF THE INVENTION 
     As embodied and broadly described herein, the invention seeks to provide an autonomous gas powered ram, comprising: a main body having an internal cavity; an actuator mounted in said internal cavity, said actuator being movable in said cavity from a first operative mode to a second operative mode, in said first operative mode said actuator being in a first position relative to said main body, in said second operative mode said actuator being in a second position relative to said main body, said first position being different from said second position; an explosive charge located within said internal cavity, a detonation of said charge causing movement of said actuator towards said second operative mode; and a lock in said main body for preventing said actuator from moving to said first operative mode when said explosive charge has detonated. 
     As embodied and broadly described herein, the invention further seeks to provide a ram, comprising: a main body having an internal cavity; a piston slidingly mounted in said internal cavity and capable of movement therein; an actuator mounted in said main body, said piston being coupled to said actuator in a driving relationship, whereby movement of said piston in said internal cavity causes displacement of said actuator with relation to said main body; a fluid-pathway opening in said internal cavity for admitting pressurized working fluid to act on said piston to move said piston and displace said actuator; and an explosive charge located within said internal cavity, a detonation of said charge causing displacement of said actuator relative to said main body. 
     Preferably, the ram further comprises a piston capable of movement in the internal cavity, the actuator being connected to this piston whereby movement of the piston causes displacement of the actuator between the operative modes. The piston comprises a detonation chamber wherein the explosive charge is located. The ram also comprises an electric impulse pathway leading from the explosive charge to a sensor that is capable of detecting an operation failure. Upon detection of the operation failure, the explosive charge is triggered and the actuator is thus pushed in response to generation of the gas and move towards the second operative mode. 
     Most preferably, the piston is a first piston and the ram comprises a second piston mounted in the detonation chamber, the lock being mounted to this second piston. In fact, the second piston comprises latch members that prevent the actuator from moving to the first operative mode when the explosive charge has detonated. The lock mounted on the second piston is moveable along a first path of travel and the actuator connected to the first piston is moveable along a second path of travel, the first and the second paths of travel being parallel. The ram may include fluid-path openings for admitting pressurized working fluid to act on the piston. 
     Alternatively, the ram comprises a lock being movable in the internal cavity along a first path of travel, the actuator being movable along a second path of travel, these paths of travel being perpendicular. In this variant, the actuator comprises a portion having a pointed piercing end. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A detailed description of the preferred embodiment of the invention is provided herein with reference to the following drawings, wherein: 
     FIG. 1 is a cross sectional view of an autonomous gas powered ram constructed in accordance with a first embodiment of the invention comprising an actuator connected to a piston; 
     FIG. 2 is a cross sectional view of the autonomous gas powered ram of FIG. 2 wherein the actuator is illustrated during its movement towards a second operative mode; 
     FIG. 3 is a cross sectional view of the autonomous gas powered ram of FIG. 1 wherein the actuator is illustrated in the second operative mode; 
     FIG. 4 is a cross sectional view of an autonomous gas powered ram constructed in accordance with a second embodiment; 
     FIG. 5 is a cross sectional view of the autonomous gas powered ram of FIG. 4 wherein the actuator is illustrated in the second operative mode; 
     FIG. 6 is a cross sectional view of an autonomous gas powered ram constructed in accordance with a third embodiment; 
     FIG. 7 is a cross sectional view of the autonomous gas powered ram of FIG. 6 wherein the actuator is illustrated in the second operative mode; 
     FIG. 8 is a cross sectional view of an autonomous gas powered ram constructed in accordance with a fourth embodiment comprising an actuator having a portion comprising a pointed piercing end; 
     FIG. 9 is a cross sectional view of the autonomous gas powered ram of FIG. 8 wherein the actuator is illustrated in the second operative mode; 
     FIG. 10 is a cross sectional view of an autonomous gas powered ram constructed in accordance with a firth embodiment comprising actuators having a portion comprising a pointed piercing end; and 
     FIG. 11 is a cross sectional view of the autonomous gas powered ram of FIG. 10 wherein actuators are illustrated in the second operative mode; 
    
    
     In the drawings, preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood that the description and drawings are only for the purpose of illustration and are an aid for understanding. They are not intended to be a definition of the limits of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1 to  3 , an autonomous gas powered ram constructed in accordance with the first embodiment of the invention is identified by the reference numeral  10 . 
     Autonomous gas powered ram  10  can be incorporated to any component such as an elevator, a crane, a lift, a door, a gate, wheels, gears or breaking devices for stopping the movement of a component upon detection of an operation failure, a fire or a hazardous operation condition. 
     For example, autonomous gas powered ram  10  can stop movement of an elevator, a gate or a lift upon detection of a rupture of a cable, it can block a doors of a building in its open position upon detection of a fire in order to permit evacuation of the persons situated in the building through this door, it can stop movement of a seat upon detection of a vehicle collision, it can stop movement of a vehicle upon detection of a failure of its breaking system or it can block a door of a building or an armored truck in its close position upon detection of the presence of a thief therein. 
     Autonomous gas powered ram  10  comprises a main body  12  having an internal cavity  14 . Main body  12  can be made of a variety of different materials and can be of a variety of different shapes. Autonomous gas powered ram  10  also comprises first and second end portions  16  and  18  closing said main body  12  at its ends. First end portion  16  comprises a chamber  20  having peripheral wall  22  and an abutting wall  24 . Second end portion  18  comprises a passageway  26  communicating with the exterior of main body  12 . Ram  10  may also comprise fluid-pathway openings  28  and  30  for admitting pressurized working fluid within main body  12 . 
     Ram  10  further comprises an actuator  38  connected to a piston  40 . Actuator  38  is connected to piston  40  with a ring  42  that electrically isolated actuator  38  from piston  40 . Piston  40  is therefore incapable of conducting any electricity that may be present in actuator  38 . 
     Piston  40  comprises an internal wall surrounding a detonation chamber  44  having an orifice  46  at an end portion  48 . Piston  40  also comprises an electrically conducting member  50  and sealing rings  52  mounted around piston  40 . Member  50  is made of an electrically conductive material capable of conducting a weak current (+/−25 mV for example). Sealing rings  52  are made of a synthetic material for maintaining a sealing engagement with the peripheral wall of internal cavity  14 . 
     Autonomous gas powered ram  10  also comprises a detonator  54  and an explosive charge  56  connected to detonator  54 . The explosive charge  56  is located within detonation chamber  44 . Detonator  54  is chemically sensitive and/or electro-sensitive in order to trigger explosive charge  56  upon detection of a chemical reaction or an electric current. Ram  10  also comprises an electric impulse pathway leading from explosive charge to the exterior of main body  12 . It is also understood that detonator  54  may trigger explosive charge  56  upon detection of a physical changes such as a pressure variation. Different suitable detonators are well known for the person skilled in the art and no further description is required concerning the various possibilities for triggering explosive charge  56 . 
     Upon detonation of explosive charge  56 , movement of piston  40  causes displacement of actuator  38  from a first operative mode to a second operative mode. In the first operative mode, actuator  38  is in a first position relative to main body  12  while, in the second operative mode, actuator  38  is in a second position relative to main body  12 . The first position of actuator  38  is different from its second position. 
     Autonomous gas powered ram  10  further comprises a second piston  58  having a stem  60  with an abutting member  62  at one end and a disc  64  at the other end. Second piston  58  is slidingly mounted within detonation chamber  44 . In fact, the diameter of disc  64  is slightly smaller than the one of detonation chamber  44  in order to allow displacement of second piston  58  relative to detonation chamber  44 . Second piston  58  also comprises latch members in the form of fins  66  attached at one of their ends to abutting member  62 . Second piston  58  with latch members constitutes a lock that prevents actuator  38  from moving to the first operative mode when explosive charge  56  has detonated, second piston  58  and actuator  38  being moveable along parallel axes. In fact, piston  40  is moveable in internal cavity  14  along a first path of travel while second piston  58  and detonation chamber  44  are moveable along a second path of travel, the first and second paths of travel being parallel and coaxial. 
     In FIG. 1, autonomous gas powered ram  10  is illustrated with actuator  38  being in the first operative mode wherein it is entirely confined within main body  12 . In operation, when an operation failure, a fire or a hazardous operation condition is detected wherein it is required that actuator  38  being actuated by an autonomous source, explosive charge  56  detonates and generates a quantity of gas injected into detonation chamber  44 . To this effect, detonator  54  may be connected to a sensor, and when an operation failure is detected, an electric current is supplied to detonator  54 . A chemical or physical reaction producing the same effect is also within the scope of the invention. The gas then expands within detonation chamber  44  and pistons  40  and  58  move relative to each other in response to generation of the gas. Movement of piston  40  causes displacement of actuator  38  towards the second operative mode (see FIG.  2 ). 
     It is understood that as soon as explosive charge  56  is triggered and the gas is generated into detonation chamber  44 , abutting member  62  abuts against abutting wall  24  and the gas pressure is applied afterwards on disc  64  thereby moving piston  40  relative to second piston  58 . 
     Detonation chamber  44  has a diameter that slightly increases towards orifice  46  to define a gap between disc  64  and the peripheral wall of detonation chamber  44  that progressively widens as second piston  58  projects from detonation chamber  44 , this gap allowing gas generated by the detonation of explosive charge to escape from detonation chamber  44 . In that sense, once explosive charge has detonated, detonation chamber  44  communicates with an expansion chamber  68  in order to allow gradual dissipation of pressure and heat. This leakage of gas is thus intended for avoiding an increase of temperature and/or pressure within detonation chamber  44  that can damage the various components of the autonomous gas powered ram of the invention. The volume of expansion chamber  68  may be five to fifteen times larger to the one of detonation chamber  44  in order to dissipate the heat and pressure generated in this detonation chamber. 
     As actuator  38  moves towards the second operative mode, fins  66  are withdrawn from detonation chamber  44 , and once they are entirely located outside this chamber, fins  66  then deploy and project transversally due to their resiliency. Once fins  66  have been entirely deployed, they no longer fit within detonation chamber  44  and instead engage end portion  48  of piston  40  thereby preventing actuator  38  from moving to the first operative mode. 
     Fins  66  mounted on second piston  58  thus constitute a lock that prevents actuator  38  from moving to first operative mode once it has moved into the second operative mode. This lock is moveable along a first path of travel and actuator  38  connected to first piston  40  is moveable along a second path of travel, the first and the second paths of travel being parallel. 
     Should the gas injected into detonation chamber  44  is eventually completely escape, then fins  66  still prevent actuator  38  from moving back towards the first operative mode. As seen in FIG. 4, actuator  38  projects from main body  12  in the second operative mode. 
     If ram  10  includes fluid-pathway openings  28  and  30  for admitting pressurized working fluid acting on piston  40 , piston  40  is coupled to actuator  38  in a driving relationship whereby movement of piston  40  causes displacement of actuator  38  with relation to main body  12 . Moreover, the displacement of actuator  38  resulting from detonation of explosive charge  56  is independent from displacement of actuator  38  resulting from movement of piston  40  due to pressurized working fluid. 
     Second and third embodiments are illustrated in FIGS. 4 to  7 . Since these embodiments are similar to the first embodiment, the components used in common to the embodiments are identified by the same reference numerals, and a description of such components will be omitted herein. 
     In FIGS. 4 and 5, autonomous gas powered ram  100  comprises a spring  110  having a disc  112  at one end and an abutting portion  114  at the other end. In FIG. 4, autonomous gas powered ram  100  is illustrated with actuator  38  being in the first operative mode wherein it is entirely confined within main body  12 . 
     In operation, when an operation failure is detected, actuator  38  is displaced due to the gas pressure created within detonation chamber  44 . As actuator  38  moves towards the second operative mode, spring  110  is withdrawn from detonation chamber  44 , and once it is entirely located outside this chamber, spring  110  no longer fit within detonation chamber  44  since it is not compressed anymore. Spring  110  thus engages end portion  48  of piston  40  thereby preventing actuator  38  from moving to first operative mode (see FIG.  5 ). Spring  110  thus constitutes a lock moveable along a first path of travel while actuator  38  connected to first piston  40  is moveable along a second path of travel, the first and the second paths of travel being parallel. 
     In FIGS. 6 and 7, autonomous gas powered ram  200  comprises a second piston  210 . In FIG. 6, autonomous gas powered ram  200  is illustrated with actuator  38  being in first operative mode. 
     Second piston  210  comprises a stem  212  having an abutting portion  214  at one end and a disc  216  at the other end. Second piston  210  further comprises bendable fins  218  affixed at one end to abutting portion  214  and to disc  216  at the other end. 
     In operation, when an operation failure is detected, actuator  38  is displaced due to the gas pressure created within detonation chamber  44 . As actuator  38  moves towards the second operative mode, bendable fins  218  are withdrawn from detonation chamber  44 , and once they are entirely located outside this chamber, they do no longer fit within detonation chamber  44  since they are deformed upon movement of actuator  38  towards the first operative mode. Bendable fins  218  thus engage end portion  48  of piston  40  thereby preventing actuator  38  from further moving towards the first operative mode (see FIG.  7 ). It is understood that the size and material of bendable fins  218  is selected in order to allow the specific amount of deformation necessary to prevent actuator  38  from moving to the first operative mode. Bendable fins  218  mounted on second piston  210  thus constitute a lock that prevents actuator  38  from moving to first operative mode once it has moved into the second operative mode. This lock is moveable along a first path of travel and actuator  38  connected to first piston  40  is moveable along a second path of travel, the first and the second paths of travel being parallel. 
     With reference to FIGS. 8 and 9, an autonomous gas powered ram constructed in accordance with a fourth embodiment is identified by the reference numeral  300 . Autonomous gas powered ram  300  comprises a main body  302  having an internal cavity  304 . Autonomous gas powered ram  300  also comprises a lock  306  and an actuator  308  having first and second portions  310  and  312 . Second portion  312  comprises a pointed piercing end  314  capable of piercing a wall of a component during the movement of actuator  308 . Autonomous gas powered ram  300  also comprises an explosive charge  316  located within internal cavity  304 . 
     In operation, when an operation failure, a fire or a hazardous operation condition is detected wherein it is required that actuator  308  being actuated by an autonomous source, explosive charge  316  detonates and generates a quantity of gas injected into internal cavity  304 . To this effect, explosive charge  316  may be connected to a sensor, and when an operation failure is detected, an electric current is supplied to explosive charge  316 . A chemical or physical reaction producing the same effect is also within the scope of the invention. 
     The gas expands within internal cavity  304  and lock  306  is pushed in response to generation of the gas and actuator  308  is therefore displaced by engagement of lock  306  with first portion  310 . In fact, first portion  310  of actuator  308  and lock  306  comprise cooperating came surfaces such that displacement of lock  306  along a horizontal path of travel causes the displacement of actuator  308  along a perpendicular path of travel. Lock  306  is thus moveable along a first path of travel while actuator  308  is moveable along a second path of travel, these paths of travel being perpendicular. 
     Actuator  308  is therefore displaced towards a second operative mode wherein second portion  312  projects from main body  302  and pointed piercing end  314  may engage another component. In the second operative mode, lock  306  engages first portion  310  for preventing actuator  308  from moving to its initial position (see FIG.  9 ). 
     With reference to FIGS. 10 and 11, an autonomous gas powered ram constructed in accordance with a fifth embodiment is identified by the reference numeral  400 . Autonomous gas powered ram  400  comprises a main body  402  having an internal cavity  404 . Autonomous gas powered ram  400  also comprises a lock  406  and actuators  408 . Each actuator  408  comprises first and second portions  410  and  412 . Second portion  412  comprises a pointed piercing end  414  capable of piercing a wall of a component during the movement of actuator  408 . Furthermore, autonomous gas powered ram  400  comprises an explosive charge  416  located within internal cavity  404 . 
     In operation, when an operation failure, explosive charge  416  generates a quantity of gas injected into internal cavity  404 . The gas expands within internal cavity  404  and lock  406  is pushed in response to generation of the gas and actuators  408  are therefore displaced by engagement of lock  406  with first portions  410 . In fact, first portion  410  of actuator  408  and lock  306  comprise cooperating came surfaces such that displacement of lock  406  along a horizontal path of travel causes the displacement of actuators  308  along a perpendicular path of travel. Lock  406  is thus moveable along a first path of travel while actuators  408  is moveable along a second path of travel, these paths of travel being perpendicular. 
     Actuators  408  are therefore displaced towards a second operative mode wherein second portions  412  project from main body  402  and pointed piercing ends  414  may engage another component. In the second operative mode, lock  406  engages first portions  410  for preventing actuators  408  from moving to their initial position (see FIG.  11 ). 
     Autonomous gas powered ram  300  or  400  can be incorporated to any mechanical systems for stopping movement of the system. For example, autonomous gas powered ram  300  or  400  can be incorporated within the wheels of a vehicle for stopping the movement of the vehicle. 
     From the above, it is understood that the autonomous gas powered ram of the invention is actuated by an explosive charge that generates gas and its operation is therefore not dependent upon a source of power such as electrically, hydraulically or pneumatically powered sources. In that sense, even if the source of power is shut down due to a mechanical, electrical or other type of failure, autonomous gas powered ram will nevertheless operate in order to displace the actuator towards the second operative mode. 
     Similarly, for a ram comprising a fluid-pathway opening for admitting pressurized working fluid, if the source of power which provides pressurized working fluid to the ram is shut down due to a mechanical or electrical failure, or a leakage of the pressurized working fluid, the ram will nevertheless operate in order to displace the actuator towards the second operative mode. 
     It is understood that in the second operative mode, the actuator may project from the main body of the ram at its utmost distant position relative to the main body or it may retract within the main body at its utmost internal position relative to the main body. It is also understood that the movement imparted to the actuator due to the detonation of the explosive charge can be a movement of rotation, or translation, wherein the actuator is displaced between to different positions relative to the main body of the ram. 
     Furthermore, in order to stop the movement of components having different weights and speed, it is understood that more than one autonomous gas powered ram can be used and/or autonomous gas powered ram can be sized in function of the weight and maximum speed of a specific component. Hence, autonomous gas powered ram can comprise parts that are designed in order to withstand a maximum specific pressure and temperature. Furthermore, autonomous gas powered ram may be designed in order to comprise an explosive charge that will generate a pressure and move the actuator with a predetermined strength. 
     The above description of preferred embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the spirit and scope of the present invention. The scope of the invention is defined in the appended claims and their equivalents.