US3104125A - Gas actuated power device - Google Patents

Description

P 1963 L.-H. GARLINGHOUSE 3,104,125

GAS ACTUATED POWER DEVICE Filed March 28, 1960 2 Sheets-Sheet 1 ESL/EH GQRL/NGHOUSE 84 L INVENTOR.

Q M 82 Zw /X AT TORN 5Y5 P 1963 L. H. GARLINGHOUSE 3,104,125

GAS ACTUATED POWER DEVICE Filed March 28, 1960 2 Sheets-Sheet 2 LESLJEE Gmzu/veyo USE [NIT/V701? ATTORN EYS United States Patent 3,104,125 GAS ACTUATED PUWER DEVKZE Leslie H. Garlinghouse, Pasadena, Calif, assignor to Garlinghouse Brothers, Los Angeles, Calif a copartnership Fiied Mar. 28, 1960, Ser. No. 17,880 Claims. ((1294-69) The invention relates to power actuated devices and has special reference to heavy duty devices such as power hooks, concrete placing buckets and the like which are lifted about construction jobs by cranes and other comparable transporting machinery from place to place where they need to be operated. Hooks, for example, need to be hooked and unhooked for placing heavy loads; concrete buckets need to be opened for dumping the heavy load of mixed concrete either in small quantities or the entire contents of the bucket all at one time and subsequently also need to be closed for reloading and also closed from a partly opened position if the contents are not entirely disposed of.

Heretofore compressed air has been depended upon for operations of this kind connected to the apparatus by means of a long high-pressure air line which can be readily hooked and unhooked to the air system on the bucket or similar device when ready for operation. The devices of the prior art, although effective where air is available, have limitations in that if the travel of the device exceeds the length of the air line either additional length of an air line must be interposed or the source of compressed air may have to be moved. Air lines of excessive length lose a considerable amount of pressure and have the further drawback of necessitating an unwieldy length of hose. On the other hand, compressing equipment, even though portable, cannot always be placed where needed close to the operation, and hence there are limitations where such equipment is used.

It is therefore among the objects of the invention to provide a new and improved portable power actuated device which is equipped with tanks capable of being filled with a compressed gas so that the power unit is self-contained and can be transported entirely free of any source of compressed air or other gas, necessitating only the manipulation of the suitable valve at the spot when the device is to be operated.

Another object of the invention is to provide a new and improved self-contained high-pressure gas operating mechanism which has a considerable capacity and consequently can be operated for long shifts without the necessity of renewal of the gas supply.

Still another object of the invention is to provide a new and improved portable self-contained gas actuated mechanism which is capable of using gases which can be liquefied at normal temperatures, but under considerable pressure, the device being so arranged that the pressure can be effectively reduced to a moderate operating pressure thereby to make use of relatively inexpensive piping and equipment which would not be possible if the full pressure of the liquefied gas were turned into the system.

Still further among the objects of the invention is to provide a new and improved portable gas pressure actuated device which is dependable under conditions of extremely great demand and where heavy loads are to be handled without a prospect of frosting or freezing as the high-pressure gas leaves the cylinders in which it is stored upon the device.

With these and other objects in view, the invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter set Patented Sept. .17, 1963 forth, pointed out in the appended claims and illustrated in the accompanying drawings.

In the drawings: a

FIG. 1 is a longitudinal sectional view of a concrete placing bucket chosen by way of example to which the gas pressure actuated system is attached in a portable fashion.

FIG. 2 is a fragmentary longitudinal view taken on the line 22 of FIG. 1.

FIG. 3 is a schematic view showing the various parts of the system interconnected in the same manner as shown in FIG. 1.

FIG. 4 is a side-e-levational view of a power hook with portions thereof broken away showing engagement of the hook with the bail of a bucket.

FIG. 5 is a fragmentary sectional view taken on the line 5-5 of FIG. 4.

FIG. 6 is a schematic view showing the hook in open position.

FIG. 7 is a schematic view similar to FIG. 6 showing the hook in closed position.

FIG. 8 is a schematic illustration of the gas circuit connected to the operating cylinder.

FIG. 9 is a fragmentary schematic representation of the gas circuit applied to the operating cylinder of the bucket of FIG. 1.

Although only two forms of the invention, namely, a power hook and a concrete placing bucket, have been shown by way of example, it is to be understood that this is exemplary only of typical devices which can be operated by the system and that the system contemplates installation on other comparable devices and sundry material handling mechanisms which can be operated by movement of a lever.

In an embodiment of the invention chosen for the purpose of illustration there is shown a frame 10 which in this instance is a concrete placing bucket provided with a sling or bad 11 to which a lifting device may be attached by means of a cable (not shown) to some stationary support for lifting the frame about from place to place as for example from one part of a stationary sup port to another. The frame is provided with a lower rim 13 upon which it can rest and an upper reinforcing ring 14 to which the brackets are secured. A hopper 15 is located within the frame and extends downwardly so that the outlet end 16 lies immediately above the rim 13. Gates 17 swung on arms 18 pivoted on shafts 19 swing in opposite directions to open and close the outlet end. A spring 20 normally holds the gates in closed position. Arcuate racks 21 mesh with each other so that when an actuator lever 22 secured to one only of the arms 18 is manipulated, both gates open and close at the same time.

Portions of the frame structure contribute appreciably in the operating relationship of the bucket and its mechanism. It will be noted that the frame 10 extends entirely around the hopper 15 at a distance spaced sufficiently from the inwardly tapering walls of the bucket to entirely encase the mechanism. The lower rim 13 extends a distance somewhat lower than all of the interior parts and protrudes outwardly therefrom to serve the purpose of not only a bumper when the bucket is hauled about but also as a stand when the 'bucket is lowered to some surface. Stiffening angles 23 may the used about the hopper. Intermediate channels 25 surrounding an intermediate area of the hopper serve as a means for anchoring plates 26 above which the arms 18 are pivoted. The structure on opposite sides is substantially identical and hence one side only is shown in the drawings.

The inwardly sloping character of the hopper leaves an ample space 27 which entirely surrounds the lower end of the hopper inwardly with respect to the frame 10.

For manipulating the gates, there is provided a pneumatic ram or cylinder 30. The cylinder is secured at its upper end to a plate 31 with the assistance of a bracket 32 which forms part of the head of the cylinder. The cylinder is provided with a piston 33 shown schematically in FIG. 3 to which is attached a piston rod 34 extending through a suitable packing 35 downwardly toward the lever 22 to which it is pivotally attached by means of a link 36. Clearly, therefore, as the piston is reciprocated the piston rod and lever 22 will pull the gates to open position when the piston moves upwardly as viewed in FIGS. 1 and 3 and will move the gates to closed position when the piston moves downwardly.

Power for actuating the pneumatic ram or cylinder is supplied from tanks 40, 41 and 42. The tanks are designed to contain gas under pressure and in quantity sufficient to operate the device for considerable periods of time. The pressure present in the tanks is many times greater than the operating pressures of the pneumatic cylinder, but by reason of employment of the circuit shown and described, the high-pressure present in the cylinder is reduced to an operating pressure before traveling to the ram, and because of this system exceedingly high tank pressures can be employed thereby to make possible the storage of operating gas in substantial quantities. It will further be understood that devices of the type herein described as, for example, the concrete placing bucket are relatively rugged pieces of equipment.

The lifts which make use of handling devices of this kind are capable of heavy loads. Also the structure of the device as previously noted is specially adapted to protection of the parts when banged about in the midst of concrete forms, scaffolding and structures already present in the vicinity. Hence, the equipment is capable of having installed therein tanks of considerable cubic capacity at the protected locations and aggregating in number sufiicient to have available large volumes of the chosen actuating fluid.

Various different types of fiuids which act as gases under ordinary operating pressures may be employed although some have been found more advantageous than others. A fluid found particularly advantageous is carbon dioxide which can be stored in the tanks either in liquid or solid form depending upon the pressures employed. The carbon dioxide gas is relatively inexpensive and has the further advantage of being harmless when exhausted into the atmosphere in the vicinity of the operation.

Other gases which in practice have been found utilizable include the liquid petroleum gases such as butane, propane and glotane. The physical properties of the gases mentioned permit them to he used advantageously in that substantial quantities can be stored in the spaces available in the tanks and the cost is not excessive. Such gases, however, are used preferably in open spaces where discharge periodically of small quantities from the apparatus will not create a hazardous condition because of their combustible nature.

Inorganic gases of certain kinds are also usable as, for example, nitrogen where especially high pressures can be accommodated in the tanks, and where the cost consideration is less critical. Carbon dioxide gas will be referred to primarily in the description inasmuch as it offers an extremely desirable operating gas the action of which is readily explainable. Accordingly, it may be assumed that the tanks 40, 41 and 42 have been charged with liquefied or solidified carbon dioxide gas under pressures in the neighborhood of 1500 lbs. per square inch initially. It should be understood in suggesting an initial charging pressure that the pressure will depend to some degree on the particular tanks chosen, the size of the tanks and the charging equipment available. Practical operating pressures may range all the way from 700 lbs. per square inch to 1500 lbs. per square inch or slightly higher or lower depending upon local conditions. The tanks when l full of liquefied gas may weigh from 50-150 lbs. each and even though of appreciable weight can readily be accommodated by the equipment herein shown and described.

Where buckets of large capacity are equipped with the gas pressure system, three tanks may be needed as illustrated in the drawings, but it will be understood that for lighter equipment two or perhaps only one tank may sufiice. Since the tanks must be periodically removed when empty and replaced with charged tanks, a releasable mounting is desirable. In the chosen embodiment there is provided a cradle 43 at the base of each tank, the cradle being fastened to the rim 13 by suitable conventional fastening means.

A band 44 secured to appropriate channels 25 serves to clamp the tank in each instance properly, the band being supplied with a suitable conventional fastener 45 which can readily be released and secured whenever a tank needs replacement.

When a multiple number of tanks are employed, they are manifolded together by employment of a manifold 46 to which gas lines 47, 48 and 49 are connected, the gas lines feeding respectively from the tanks 40, 4-1 and 42. In order that any one or all of the tanks may be removed at one time, each tank is provided with a shut-off valve 50 at the tank which communicates through a short line 51 with a coupling element 52 in turn connected to a coupling element 53 in the respective gas line. A valve 54 in the gas line is provided in order that a communication between the manifold and the respective tank can be shut off at any time especially when the coupling elements 52, 53 are to be separated. The main gas high-pressure supply line 56 connected to a main gas low-pressure supply line 56 leads from the manifold 46 to the cylinder 30. In the main gas supply line 56 is a pressure reducing valve 57 of sufiicient capacity to reduce the aggregate of pressure from the tanks to the working pressure for the cylinder 30. The system performs efiectively when the working pressure on the downstream side of the pressure reducing valve is about 100 lbs. per square inch. It should further be noted that where a multiple number of tanks are manifolded together to supply a single main gas supply line at a pressure substantially less than the pressure present in the manifold, the manifold should be of substantial capacity materially greater than the capacity of the low-pressure gas supply line 56'.

In some instances a pressure relief valve 58 may be provided for the high pressure supply line 56 in order to prevent accumulation of pressure in the line 56 above a certain optimum amount. Since the tanks 40, 41, 42 are usually fused, a relief valve can be dispensed with in the manifold 46.

In the low-pressure main gas supply line 56' is an operating valve 59 which is adapted to be manipulated by pull ropes 60 and 61 in order to turn the operating valve either to open position, closed position or exhaust position. The pull ropes can extend outwardly or downwardly from the device in any desired manner so as to be within reach of an operator positioned in the vicinity of the device when operation is desired.

The low-pressure main gas supply line 56' connects through a fitting 62 to a feed line 63 and thence through a fitting 64 to a line 65 supplying the cylinder 39. It will be noted that the lower end of the cylinder receiving as it does gas under pressure directly from the source of supply may be considered as the high-pressure end of the cylinder.

Also extending from the fitting 64 is a reservoir supply line 67 which connects directly to a reservoir 68. A check valve 69 in the reservoir supply line is set in a direction such that once gas has been passed to the reservoir, it cannot back-flow through the reservoir supply line 67. Inasmuch as the pressure on the downstream side of the reducing valve 57 is set at some low point such as about 100 lbs. per sq. in, this will become the pressure in the reservoir as well as the pressure at the high-pressure end of the cylinder. For purposes of description the cylinder may be said to be divided by the piston into a high-pressure chamber 71 and a lowpressure chamber 72.. A filter 73 protects the cylinder and the reservoir and appropriate portions of the system from harmful foreign particles which might otherwise be carried into the operating portion of the system.

From the reservoir 68 a supply line 74 extends into communication with a low-pressure supply line 75 which connects to the low-pressure chamber of the cylinder 30. Between the supply line 75 and the low-pressure supply line 74 is a series of valves comprising a pressure regulating valve 76, check valve 77 and a relief valve 78. A gauge 79 may also be employed on the downstream side of the pressure regulating valve to denote the pressure coming from the pressure regulating valve which ultimately :finds its way into the low-pressure chamber 72 of the cylinder.

Under circumstances where pressure in the reservoir is at about C) lbs. per square inch, effective operating performance can be enjoyed when the pressure regulating valve 76 reduces pressure to the low-pressure chamber of the cylinder to about lbs. per square inch. The effect of this relationship in operation is that when the gates are to be opened, a gas under pressure is introduced into the high-pressure chamber 7 1 of the cylinder. This is gas which has been once reduced in pressure from twk pressure to operating pressure. When operation is initiated, it may be assumed that there is a negligible pressure in the low-pressure chamber 72 and that air present in the cylinder at that time will be compressed as the piston 33 moves upwardly and will be forced outwardly into atmosphere through the relief valve 7 8 should the pressure exceed 20 lbs. per square inch in the particularly chosen example. At the same time gas under pressure is being supplied to the highpressure chamber 71, the gas is also being supplied to the reservoir 68 at the same pressure. When this has occurred for long enough to build up gas pressure in the reservoir 68 to about 100 lbs. per square inch, the second step in the cycle of operation is ready.

Where it is assumed that the first step opens the gates 17, the second step will be to close the gates 17. To accomplish this, the operating valve 59 is set to exhaust position in which pressure in the line 65 and in the lowpressure main gas supply line 56' is reduced to atmospheric pressure. This condition will also prevail in the reservoir supply line 67 as far as the check valve 69. At this stage of operation gas at 20- lbs. gage pressure passing from the reservoir 68 through the regulating valve 76 supplies the low-pressure chamber 72 with gas at 2.0 lbs. per square inch gage pressure sullicient to overcome the atmospheric pressure in the high-pressure supply chamber 71 and force the piston 33. and piston rod 34 downwardly which motion acting through the lever 22 closes the gates 17.

Thereafter, when opening operation is again desired, the operating valve 59 is turned to open position to permit gas to flow at 100 lbs/ sq. in. in the direction and through the system as previously described. When this gas pressure reaches the high-pressure chamber 71 and begins pressing against the piston 33, there will be 20 lbs. pressure in the low-pressure chamber 72 acting against the piston. There remains, however, a pressure diff r ntial f 80 ibs/ sq. in. which is sufficient to move the piston upwardly and which is the force which performs the Work of opening the gates 17 When it becomes necessary to stop the gates at any selected partially open position, the operating valve 59 is set to an adjustment Where exhaust is shut off and no gas flows. At this point pressures on opposite sides of the piston will temporarily equalize and the gates will remain in the selected position. position the gates can be moved in either direction either to further open position or to closed position.

Should an occasion arise where it might become desirable to use an outside gas supply as, for example, to conserve the pressure .in the tanks, or in the event that tanks might not be available, additional connections and fittings can be employed. Under such circumstances it may be assumed that there is available a compressor 3i) which supplies gas under pressure through a compressor line 81 to an operating valve 82. An outside pressure line 83 communicates between the operating valve 82 and a quick-connect coupling 84. The quick-connect coupling may be a conventional Westinghouse air brake connection or other appropriate conventional connection which can be quickly made and broken and which once made is capable of holding pressures at least as high as the selected opera-ting pressure of 100 lbs/sq. in. or something higher.

From the coupling 84 is an intake line 85 which connects with the fitting 62. A shut-oil valve 86 is provided in the line 85 and another shut-off valve 87 is provided in the low-pressure main gas supply line 56. Hence, when operation as a result of gas pressure from the tanks is to be discontinued for any reason, the shut-off valve 87 is closed and the shut-off valve 86 may then be opened. Thereafter, whenever the device is to be op erated, a connection is made through the coupling 84 thereby to interconnect the compressor 80 with the system.

From the foregoing description it will be understood that the system is an extremely versatile one being capable of a change over from a supply of gas self-contained in the unit to an outside source of gas under pressure and vice versa merely by manipulating two shut-01f valves and a quick-disconnect coupling 84. Although some modifications in the tank equipment might become desirable for accommodating gases of different kinds, the principle of operation remains the same and is one capable of making use of gases and almost any practical working level above 100 pounds in the tank portion of the device which is effectively reduced to operating pressure for the ram or cylinder 30 whether that pressure be 100 lbs. per square inch or considerably lower or higher than 100 lbs. per square inch. The relationship capable of moving the gates to open position, closed position or intermediate position remains.

In a second form of the invention the self-contained gas power actuator system is shown mounted for actuating a power hook. The hook is indicated generally by the reference character 90 where it is shown as carried by means of a cable 91 attached to a bracket 92, the bracket being broken away to show the relative location of the mechanism but comprising also a frame 93. In this embodimentlthe hook is shown attached to a bail 94 which forms a means of carrying an article 95 which may be a bucket or any other load which needs to be transported from place to place. The apparatus more particularly is one capable of lifting relatively heavy loads which may exceed many tons.

The hook portion of the apparatus, in fact, consists of two hook members 96 and 97 which are pivotally mounted upon a shaft 93 carried by the frame 93 to which the shaft is secured by appropriate nuts 99. Bronze bushings 100, 100 may be employed to improve the ease of rotation of the hook members about the shaft. Spacers 101 and 1432 fill the remainder of the space between par-ts of the bracket 92. Stiifening bolts 103, 104 and 105 assist in spacing opposite sides of the frame 93 and holding the sides in proper position with the help of a bolt 106 at the top of the bracket 92. An operating arm or extension 107 on the hook member 97 cooperates From partially open I 7 with a similar operating arm or extension 108 on the hook member 96 for opening and closing the hook as shown in FIGS. 6 and 7.

To perform the work of opening and closing the hook, there are provided a series of gas containers 109, 110 and 111 in the chosen embodiment which is for heavyduty work. These containers may be filled with an appropriate gas under pressure such as liquefied CO or any of the gas% suggested in connection with the first described embodiment of the invention. The containers are connected to a manifold 112 by means of pipes 113, 114 and 115 in which are appropriate check valves 116. If the individual valves are not used for relief, a relief valve 117 set at an appropriate pressure may be employed connected to a gas line 119 as shown.

Inasmuch as the container or tank pressure may be many hundreds of pounds or perhaps more than a thousand pounds, it is necessary for practical operation to reduce the pressure to a working pressure of, for example, about 100 lbs. and this is accomplished by employment of a reducing valve 118 in the gas line 119 leading from the manifold 112. A shut-off valve 120 may be inserted in the line 119 so that the line may be effectively turned off when not in operation. In the gas line 119 downstream from the reducing valve is a filter 123 and a gas receiver tank 124. Fnom the gas receiver tank a short line 125 connects with an automatic operating valve here shown as a four-way valve 126 which operates a ram indicated generally by the reference character 127. The ram may be described as comprising a cylinder 128 within which a piston 129 separates the cylinder into a forward acting or opening chamber 139 and a rearward acting or closing chamber 131. One gas line 132 supplies the forward acting chamber and another gas line 133 supplies the reverse acting chamber. The four-way valve 126 may operate in any approved conventional fashion such as when the valve is turned so as to supply gas under pressure to the line 132, the gas returning through the line 133 will be vented through an exhaust Vent 134 and, conversely, when the valve is passing gas to the line 133 gas under pressure from the opposite chamber through the line 132 will vent through the same vent 134.

A rotating actuator 135 on the valve device may be connected to the conventional pneumatic valve interior operating means in such fashion that when the actuator is rotated it shifts the valve alternately from a position passing gas to the line 132 to a position passing gas to the line 133 and then again to line 132 as the actuator continues to be rotated. In the chosen embodiment, rotation is continuously in a clockwise direction as viewed in FIGS. 4, 6 and 7. To accomplish rotation, a ratchet wheel 136 is mounted upon the actuator and this wheel is moved by action of a dog 137 upon reciprocation of an operator rod 138, the rod being reciprocatably mounted in a platform 139 on the frame which supports the fourway valve 126 and the gas receiver 124. In the operator rod is a link 140 acting through a spring 141 to place a yielding connection in the operator rod to assure smoothness of operation. A pawl 142 prevents reverse rotation of the ratchet wheel 136.

To effect reciprocation of the actuator rod, there is provided a curved plate 143 pivotally secured to a bracket 144 on the frames. A trigger plate 145 is connected to the plate 143 and overlies another plate 146 which is jointed to the link 140 by means of a pin 147. The trigger lies at a location extending into a crotch 148 of the frame extending below the upper end of the crotch as shown particularly in FIGS. 4, 6 and 7. The trigger also lies substantially along the vertical center line of the hook midway between opposite hook members 96 and 97.

In operation when it is assumed that the hook members are closed and support the bail 94 as it then becomes desirable to release the bail by opening the hook members, the cable 91 is lowered until the article 95 rests on some supporting surface after which the cable is lowered still further a distance sutficient to have the hook members moved downwardly until the bail 94 moves to the dotted position 94 of FIG. 4. When this occurs, the bail will move against the trigger 145 which, acting through the operator rod 138 rotates the ratchet wheel 136 a distance sufiicient to shift the four-way valve to the new setting. It may be assumed that this is a setting passing gas under pressure to the line 133 and the forward acting or opening chamber 131. In this adjustment the piston 129 will move from left to right as viewed: in FIGS. 4, 6, 7 and 8, thereby moving a piston rod 149 from left to right as viewed in FIGS. 4, 6, 7 and 8. The piston rod is attached to the operator extension 107 and, inasmuch as the cylinder 128 is attached through a collar 150 to the operating extension 108, the hook members are moved from the closed position of FIGS. 4 and 7 to the open position of FIG. 6 which also is shown by dotted lines in FIG. 4. The cable 91 can then be elevated and the hook removed from the vicinity of the load.

When it again becomes desirable to close the book from the open position of FIG. 6, the cable 91 is again lowered with the open hook members spread on opposite sides of the bail 94. The cable is then lowered until the bail strikes the trigger 145 whereupon the operator rod 133 is again moved upwardly advancing the ratchet wheel 136 one more notch to a position wherein the adjustment of the four-way valve is changed. The new adjustment is one which passes gas under pressure to the line 132 and the closing or reverse-acting chamber 130 while, at the same time, venting gas from the chamber 131 through the line 133 and thence through the valve to the vent 134. Acting in this fashion, the piston rod 149 is moved from right to left as viewed in FIGS. 4, 6, 7 and 8. This has the effect of causing the operating extensions 107 and 108 to be spread apart and, at the same time, causing the hook members 96 and 97 to be moved together to the relationship shown in FIG. 7, closed under the bail '94. Now when the cable 91 is elevated, lifting the hook, the hook elements will engage the bail and the article can be lifted to a new location. Ends 151 and 152 may be used for resting the book as a whole upon some supporting surface when it is not in use in a fashion which prevents interference with the operating mechanism.

On those occasions where it may become desirable to use the operative mechanism of FIG. 8 in connection with a bucket of the type illustrated in FIGS. 1, 2 and 3, the cylinder 30 may be attached to the four-way valve 126 in the manner shown in FIG. 9 by connecting the line 132 to the chamber 72 and the line 133 to the chamber 71. The operator rod 138 and trigger 145 may be mounted to operate in a manner similar to that already described by having the trigger located where it can engage some portion of a stationary object 153. This is sufficient to manipulate the operator rod reciprocatably to shift the four-way valve 126 alternately from one position to the next. When gas is passed through the line 132 to the chamber 72, venting at the same time chamber 71, the piston rod 34 will move generally downwardly in a direction closing the gate 17. On the next alternate operation of the operator rod and four-way valve 126 the gas passed through the line 133 to the chamber 71 will operate to elevate the piston rod 34 as the chamber 72 is vented, thereby to open the gate 17.

From the foregoing description it will be clear that the device is one which is completely self-contained inasmuch as the containers 109, and 111 can be suitably mounted upon the frame 93 where they can be transported with the frame and the rest of the mechanism. The same general mounting scheme has already been described in connection with FIGS. 1, 2 and 3 and is appropriate to both types of devices. Similarly, the automatic opening and closing operation is equally adapted to both types of devices on those occasions where it might, for some reason, be desirable to move elements such as the gate 17 or the hook members 96, '97, to partially open or partially closed positions, the actuating mechanism'shown and described in connection with FIG. 3 is operable instead of the mechanism of FIG. 8. The same FIG. 3 mechanism can be installed with equal case on a frame such as the frame 93 to move appropriate operating extensions which may be those attached to hook members or may be attached to any one of a variety of devices to which the mechanism can be advantageously applied.

While the invention has herein been shown and de scribed in what conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having described the invention, what is claimed as new in support of Letters Patent is:

1. In a portable device comprising a frame and a material handling mechanism thereon having an operating arm the combination of a cable attached to the frame and to a stationary support for elevating and lowering said frame relative to the stationary support, a self-contained gas power actuator system on said frame for said operating arm comprising an operating cylinder, a double acting piston therein forming at opposite ends of the cylinder respectively a forward acting chamber and a reverse acting chamber, a gas supply under pressure therein, a gas line from the container, an operating valve device in the gas line downstream from said receiver having a forward position connecting said gas line with said forward acting chamber and exhausting said reverse chamber to atmosphere and a reverse position connecting said gas line to said reverse chamber and exhausting said forward chamber to atmosphere, a valve actuator on said operating valve device movable respectively to forward and reverse positions, an operator in driving relationship with the actuator including a trigger on the material handling mechanism at a location engageable with said stationary support, said operator being responsive to pressure on the trigger when the frame is lowered toward the stationary support whereby to effect a shifting of said operating arm respectively to forward and reverse positions.

2. In a portable device comprising a frame a cable attached to the frame and to a stationary support, and a material handling mechanism on the frame having an operating arm, a self-contained gas power actuator system for said operating arm mounted on the frame and comprising an operating cylinder, a double acting piston therein forming at opposite ends of the cylinder respectively a forward acting chamber and a reverse acting chamber, a container on the frame having a gas supply under pressure therein above operating pressure, a gas line from the container, a pressure reducing valve in the gas line, an operating valve device in the gas line having a forward position connecting said gas line with said forward acting chamber and exhausting said reverse chamber to atmosphere and a reverse position connecting said gas line to said reverse chamber and exhausting said forward chamber to atmosphere, a valve actuator on said opera-ting valve device movable respectively to forward and reverse positions, an operator in driving relationship with the actuator including a trigger on the material handling mechanism, said trigger having a position of operating engagement with said stationary support when the cable acts to lower the mechanism to the stationary support, said operator being responsive to pressure of the stationary support thereon whereby to effect a shifting of said operating arm respectively to forward and reverse positions.

3. -In a portable device comprising a frame a cable attached to said frame and to a stationary support, and a material handling mechanism on the frame having an operating arm, the combination of a self-contained gas power actuator system for said operating arm mounted on the frame and comprising an operating cylinder, a double acting piston therein forming at opposite ends of the cylinder respectively a forward acting chamber and a reverse acting chamber, a high pressure supply of gaseous substance comprising a container on the frame having a gas supply in iiquid condition, a gas line from the container, a pressure reducing valve in the gas line, a gas receiver in said gas line downstream from said reducing valve, an operating valve device in the gas line downstream from said reducing valve having a forward position connecting said gas line with said forward acting chamber and exhausting said reverse chamber to atmosphere and a reverse position connecting said gas line to said reverse chamber and exhausting said forward chamber to atmosphere, a valve actuator on said operating valve device movable alternately to forward and reverse positions, an operator in driving relationship with the actuator including a trigger on the material handling mechanism and a spring return therefor, said trigger having a position of operating engagement with the stationary support when the cable acts to lower the mechanism in said support, said operator being responsive to pressure of the stationary support thereon against said spring return whereby to effect a shifting of said operating arm alternately to forward and reverse positions.

4. In a power actuated portable hook comprising a frame, a cable support on said frame extending to a stationary support, a pair of pivotally mounted hook members on said frame cooperable with an external work element on said stationary support and an operating extension on the hook members the combination of a self-contained gas power actuator system for said operating extension comprising an operating cylinder, a double acting piston in said cylinder separating said cylinder into an opening chamber and a closing chamber, a container for a high pressure supply of gaseous substance, a gas line from the container, a four-way operating valve device in said gas line having an opening position connecting said gas line to the opening chamber and exhausting the closing chamber to atmosphere and a closing position connecting said gas line to the closing chamber and exhausting the opening chamber to atmosphere, a valve actuator on the valve device movable alternately to open and closed positions, an operator connected to the actuator and including a trigger movably mounted on the frame, said trigger having a location engageable with said work element when the frame is lowered by the cable to a position adjacent said support, said trigger being responsive to pressure exerted thereagainst by the external work element when the frame is lowered to alternately effect opening and closing of said hooks members.

5. In a power actuated portable hook comprising a frame, a cable support attached to said frame and to a stationary support, a pair of pivotally mounted hook members on said frame cooperable with an external work element on said support and an operating extension on the hook members the combination of a self-contained gas power actuator system for said operating extension comprising an operating cylinder, a double acting piston in said cylinder separating said cylinder into an opening chamber and a closing chamber, a container for a high pressure supply of gaseous substance, a gas line from the container, a pressure reducing valve in said gas line, an operating valve device in said gas line on the downstream side of said reducing valve and having an opening posi-- tion connecting said gas line to the opening chamber and exhausting the closing chamber to atmosphere and a closing position connecting said gas line to the closing chamber and exhausting the opening chamber to atmosphere, a valve actuator on the valve device movable alternately to open and closed positions, an operator connected to the actuator including an automatic return and including a trigger movably mounted on the frame at a location between said hook members, said trigger having a position engageable with said work element when the frame is lowered by the cable to a position adjacent said support, said trigger being responsive to pressure exerted thereagainst by the external work element when the frame is lowered to alternately effect opening and closing of said hook members.

References Cited in the file of this patent UNITED STATES PATENTS Eyster Apr. 19, 1898 l Gilli Sept. 23, 1941 ,1 Garlinghouse July 19, 1955 t Gossett et'al Oct. 14, 1958 Weaver Oct. 14, 1958 Landry Aug. 9, 1960 Schenk et a1. Dec. 6, 1960

Claims (1)

1. 3. IN A PORTABLE DEVICE COMPRISING A FRAME A CABLE ATTACHED TO SAID FRAME AND TO A STATIONARY SUPPORT, AND A MATERIAL HANDLING MECHANISM ON THE FRAME HAVING AN OPERATING ARM, THE COMBINATION OF A SELF-CONTAINED GAS POWER ACTUATOR SYSTEM FOR SAID OPERATING ARM MOUNTED ON THE FRAME AND COMPRISING AN OPERATING CYLINDER, A DOUBLE ACTING PISTON THEREIN FORMING AT OPPOSITE ENDS OF THE CYLINDER RESPECTIVELY A FORWARD ACTING CHAMBER AND A REVERSE ACTING CHAMBER, A HIGH PRESSURE SUPPLY OF GASEOUS SUBSTANCE COMPRISING A CONTAINER ON THE FRAME HAVING A GAS SUPPLY IN LIQUID CONDITION, A GAS LINE FROM THE CONTAINER, A PRESSURE REDUCING VALVE IN THE GAS LINE, A GAS RECEIVER IN SAID GAS LINE DOWNSTREAM FROM SAID REDUCING VALVE, AN OPERATING VALVE DEVICE IN THE GAS LINE DOWNSTREAM FROM SAID REDUCING VALVE HAVING A FORWARD POSITION CONNECTING SAID GAS LINE WITH SAID FORWARD ACTING CHAMBER AND EXHAUSTING SAID REVERSE CHAMBER TO ATMOSPHERE AND A REVERSE POSITION CONNECTING SAID GAS LINE TO SAID

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