US3685797A

US3685797A - Jack

Info

Publication number: US3685797A
Application number: US124189A
Authority: US
Inventors: Bengt Erik Orr
Original assignee: Electrolux AB
Current assignee: Electrolux AB
Priority date: 1970-03-13
Filing date: 1971-03-15
Publication date: 1972-08-22
Anticipated expiration: 1989-08-22
Also published as: SE338410B; DE2111375A1; GB1344134A; FR2081934A1; NL7103256A

Abstract

This invention relates to a jack having a compressed-air motor for operating a pump to supply liquid, such as oil, to a lifting cylinder. The compressed-air motor and pump form a unitary structure which is detachably connected to a frame upon which the lifting cylinder also is mounted. The frame has a base and is provided with passageways for conducting the liquid between the pump and lifting cylinder. The base is detachably mounted in an operative position by attaching means associated with a lifting device. A number of such attaching means each associated with a different type of lifting device can be employed to mount the base in an operative position, so that the aforementioned unitary structure or one like it can be detachably mounted in an operative position by any one of the attaching means for use in a particular kind of lifting operation.

Description

United States Patent Orr [541 JACK [72] Inventor: Bengt Erik Orr, Nas, Sweden [73] Assignee: Aktiebolaget Electrolux, Stockholm,

Sweden 22 Filed: March 15, 1971 [21] Appl.No.: 124,189

[30] Foreign Application Priority Data Marchl3, 1970 Sweden ..3338/70 521' U.S.Cl ..,....2s4/sB,2s4/93R 51 Int.Cl. ..B60pl/48 [58] Field of Search ..254/93 R, 93 H, 93 HD, 2 R, 254/2 B, 8 R, 8 B

[56] References Cited UNITED STATES PATENTS 3,433,458 3/ 1969 Sano ..254/93 R 3,595,525 7/1971 Yaste ..254/93 H 3,632,085 12/1969 Traywick ..254/93 R [151 3,685,797 Aug. 22, 1972 Primary ExaminerRobert C. Riordon Assistant Examiner-David R. Melton Attorney-Edmund A. Fenander 57 ABSTRACT This invention relates to a jack having 'a compressedair motor for operating a pump to supply liquid, such as oil, to a lifting cylinder. The compressed-air motor and pump form a unitary structure which is detachably connected to a frame upon which the lifting cylinder also is mounted. The frame has a base and is provided with passageways for conducting the liquid between the pump and lifting cylinder. The base is detachably mounted in an operative position by attaching means associated with a lifting device. A number of such attaching means each associated with a different type of lifting device can be employed to I mount the base in an operative position, so that the aforementioned unitary structure or one like it can be detachably mounted in an operative position by any one of the attaching means for use in a particular kind of lifting operation.

12 Claims, 5 Drawing Figures PATENTEU M1822 1912 'SHEEIJ.0F3,

IIIIIIIIII.

JACK

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to jacks having a lifting cylinder to which liquid, such as oil, for example, is conducted by a pump operated by a compressed-air motor.

2. Description of the Prior Art Jacks heretofore provided generally are of such construction that each jack can only be employed for a particular type of lifting operation. A particular jack usually has been required for each type of lifting operation which, for example, may involve special working conditions and lifting objects and material to-a certain height. Accordingly, it usually has been necessary to keep a variety of different jacks on hand tomeet all of the work problems that are encountered in practice. This is objectionable because this requires a substantial capital investment and high maintenance costs for stor-* ing and keeping a wide variety of jacks in repair.

SUMMARY OF THE INVENTION It is an object of my invention to provide an improved jack which can be used alone or with a variety of different types of lifting devices to meet practically all working conditions encountered in practice.

Another object of the invention is to provide a jack of this kind which can be readily maintained in proper working condition and is of such construction that it can be inspected andrepaired without difficulty.

The jack embodying my invention comprises a compressed-air motor for operating a pump to supply liquid, such as oil, for example, to a lifting cylinder. The compressed-air motor and pump form a unitary structure which is detachably connected to a frame upon which the lifting cylinder also is mounted. The frame has a base and is provided with passageways for conducting the liquid through and between the pump and lifting cylinder.

The base is detachably mounted in an operative position by attaching means associated with a lifting device. A number of such attaching means each associated with a different type of lifting device can be employed to mount the base in an operative position, so that the aforementioned unitary structure or one like it can be detachably mounted in an operative position by any one of the attaching means for use in a particular kind of lifting operation.

BRIEF DESCRIPTION OF THE DRAWING In the drawing,

FIG. 1 is an elevational view, partly broken away and in section, of a jack and a detachable support therefor embodying my invention;

FIG. 1a is a fragmentary perspective view of parts in FIG. 1 to illustrate details more clearly;

FIG. 2 is a vertical sectional view of the jack shown in FIG. 1;

FIG. 3 is a view more or less diagrammatically illustrating one application of the jack of FIGS. 1 and 2 with a particular lifting device constructed to lift objects and material to a relatively great height; and

FIG. 4 is a view illustrating another application of the jack of FIGS. 1 and 2 with a different kind of lifting device constructed to lift objects and material to even a greater height than in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, a compressed-air motor and pump comprise a unitary structure 10. The unitary structure 10 is detachably connected to a frame 12, as will be explained presently. A lifting cylinder 11 also is mounted on the frame 12. The unitary structure 10, which includes the compressed-air motor and pump, is

described and claimed in my co-pending application,

Ser. No. 124,188, filed Mar. 1971.

Briefly, the combined compressed-air motor and pump unit 10 includes a motor block 13,-a cylinder 14 having a piston 15 movable therein and a pump block 16. The motor block 13 has a bore 18 closed by a cover 17 in which a movable valve body 19 is disposed. The valve body 19 comprises a solid slide 20, an intermediate portion 21 and an end portion 22 to which a resilient sealing member 23 is fixed. The slide 20 has a flat surface 24 which, in the position shown in FIG. 2, engages a valve seat 25.

The motor block is provided with an inlet connection 26 for compressed air,

passageways

27 and 28 and a valve 29 for controlling the supply of compressed air to the cylinder 14. The block '13 also is formed with a cavity 30 anda passageway 31 for discharging compressed air to the atmosphere. The cylinder 14 is in communication with the bore 18 by a conduit 32.

The piston 15 is operatively associated with a return spring 33, a pump rod 34 and a pump housing 35. The pump housing 35 is threadedly connected to the pump block 16 in which are provided

valves

36 and 37,

passageways

38 and 39 and an outlet connection 40.

The combined motor and pump unit operates in the following manner.

When compressed air is supplied to the inlet 26, flow of compressed-air in the

passageways

27 and 28 is shut off because the ball of valve 29 shown in FIG. 2 is moved to a closed position at its seat. When the operating knob of the valve 29 is now pushed in, the ball will be moved downward and compressed air will be supplied to the cylinder 14. The piston 15 and the pump rod 34 will now be moved by the compressed air toward the pump block 16. When this occurs the conneclion of the duct 32 to the cylinder 14 will be uncovered and compressed air will flow to the bore 18 and effect movement of the valve body 19 to the left in. FIG. -2. Initially this will close the passageway 28 so that compressed air no longer will be supplied to the cylinder, and subsequently a connection will be opened from the cylinder space to the passageway 31 through the cavity 30 and the space around the intermediate portion 21 of the valve body 19 for discharging air to the atmosphere. The spring 33 returns the piston 15 and the pump rod 34 to the initial position illustrated in FIG. 2, the valve body 19 in turn being returned by the piston 15 to its position shown in FIG. 2. The operation just described will be repeated as long as the operating knob of the valve 29 is held in its in or operating position.

3 During movement of the pump rod 34 to the left in FIG. 2 liquid, such as oil, forexample, in the space'4l will be forced out from the pump through check valve 36' and connection 40. When the pump rod 34 moves to the-right in FIG. 2, liquid will be drawn into the space 41 through passageway 39 and check valve 37. When the operating knob of the valve 29 is released,

I the valve closes and the'compressed-air motor will part 42 formed with a groove 44 of annular form in the housing or casing 63. A shaft 64, which has

eccentric sections

65 and 66 and an operating handle 67-, .is supported in the connecting part 42 and end wall of the housing 63. The

sections

65 and 66 cooperate with the bottom of a recess 43.- The pump is sealed at 45 and is retained in the recess 43 by a hollow threaded screwi46 sealed at 46' defining a passageway.

passageways

38 and 39 of the pump communicate with the groove 44 which, through a passageway 47, communicates an annular'liquid space 48 defined by an outer casing 49 and an inner cylinder 11. The space 48communicates with the interior of the cylinder 11 an opening 50 and a leakage groove 51. Theinterior of the cylinder llalso is in communication with the connection 40 through a passageway 52 and hollow screw 46.

A piston 53 is movably disposed in the cylinder 11 and is provided with a seal 54 and a return spring 55. The spring 55 is secured to a loop 56 on the frame 12 and its tension is adjustable by an adjusting member 57 in threaded engagement with the piston53. To adjust the tension of the spring, the adjusting member 57 can beturned by an adjusting key which can be placed in a slot58 or threadedly connected in the threaded hole 59.

' In its top part the lifting cylinder 11 hasa seal 60 press fitted thereon. The lower part of the cylinder 11 is sealed at 61 and is press fitted in the frame 12.

When the pump is; operated by the compressed-air motor, liquid will be forced into the lower part of the cylinder 11 through the passageway 52 and the piston 53 will be moved upward. The-liquid in the upper part of I the cylinder 11 will be forced out of the cylinder v through the opening 50 to the annular space 48 and will leakage groove 51. Hence, the piston 53 will not con-.

tinue to move toward the seal 60. When it becomes necessary to dismantle the lifting cylinder, the opening 50 is closed. This can be done after first removing the cover plate 62. Thereafter, the seal 60 simply will be forced out by the pressure of the liquid acting on the seal When it is desired to return the piston 53 to its lower position, the knob of the valve36 is operated, that is,

pushed in. The liquid present under the piston 53 then will be forced back to the annular space 48 in a path of flow which includespassageway 52, hollow screw46, valve 36, passageway 38, groove and the passageway 47 As seen in FIG. 1, the unitary structure loformed by the'pump and compressed-air motor is provided with a

valves

36 and 29 in such manner that, when the operating handle 67 is moved to one side, one of the valves will be acted upongand, when the handle is moved to the other side, the other valve will be acted upon.

A tubular carrying handle 68 is connected to the frame 12 and to the cylinder 11 and has a connection 69 for supplying compressed air thereto from a source of supply. The compressed air flows into the handle from which it is conducted through a conduit 70 to inlet connection 26 in the motor block or head 13. The conduit70 is arranged within the carrying handle 68 so that the latter will serve as a water separator and a pressure equalizing chamber for the compressed air.

' As shown in FIG. l, the jack is mounted on a carriage 71 provided withwheels 72 and a bottomisupporting plate 73. .The' wheels and the bottom supporting plate 73 are connected in such manner that, whenthe jack is being used, the entire dead-weight load will be carried by the supporting plate 73 and the wheels72 will be relieved of carrying any part of, the load. When the carriage is being moved, its right-hand end in FIG. 1 will be raised which also lifts its bottom supporting plate 73 scopically fitting therein, whereby the length of theshaft can be adjusted; The operating shaft 75 at its 1 inner end has a fork 77 which cooperates with the operating handle 67 of the shaft 64. Hence, the extensible shaft 75 makes it possible to control the operation of the compressed-air'motor and pump when the carn'age lifted The jack is detachably mounted on the carriage 71 by a bracket 78 which is fixed at 78a to a fiat bottom part of the carriage and forms a groove or slot to receive and hold one end of the frame 12. A pivotable locking arm 79, which is pivotally mounted on the shaft 72a of the wheels 72, co-operates with the upper edge of the frame 12 at the opposite end thereof. The jack can be provided with jointing sleeves 80 which very in length. These are adapted to fit in the bore81 of the lifting cylinder, as seen in FIG. 2.

bodirnent and shown in FIGS. and la. In FIG. 3 the jack i is mounted in position so that the lifting cylinder 111, which is longer than the cylinder 11 in FIG. 1, will be horizontal and cooperates with a shaft 93, the outer end of which is provided with rollers 82 movable spaced guides-83. Further, the operating shaft 93 is pivotally connected to a lever 84 which cooperates with a slewing bracket 85, a linked arm 86 and a lifting platform 87 pivotally connected to the lever 84. Due to is pushed quite a distance under an object to be the articulated interconnection of these parts, a parallel motion-displacement of the lifting platform 87 is obtained during the lifting movement. With the device shown in FIG. 3 it is possible, if desired, to obtain an increased lifting force when an object is lifted to a great height.

With the lifting device shown in FIG. 4 an even greater lifting height can be obtained. The carriage 271, the wheels 272 and the supporting plate 273 cooperate in the manner shown in FIG. 3 and described above. In FIG. 4 the jack is pivotally mounted on the carriage 271 by a bridge 88 and acts on the lever 84a by a lifting rod 89. A slewing bracket 90 and linked arms 91 and 92 are articulatedly connected with the carriage 271, the lever 84a and the lifting platform 87a and effect a parallel displacement motion of the lifting platform 87a during the lifting movement.

The lifting devices shown in FIGS. 3 and 4 can, of course, be provided with operating handles like the handles 64 and 75 in FIG. 1. Also the attachment of the jack to the carriages 171- and 271 can be accomplished in a manner like that shown in FIGS. 1 and 1a and described above.

I claim:

1. A jack having, in combination, a lifting cylinder, a pump for pumping liquid, such as oil, for example, to said lifting cylinder, a compressed-air motor for operating said pump, said compressed-air motor and said pump comprising a unitary structure, a frame, means for mounting said lifting cylinder on said frame, means for detachably connecting said unitary structure on said frame, said frame having passageway means for conducting liquid between said lifting cylinder and said pump, said frame having a base, and attaching means associated with a lifting device for detachably mounting said base in an operative position on the device.

2. The combination set forth in claim 1 including additional attaching means each associated with a different lifting device, each of said attaching means being capable of coacting with said base for detachably mounting said base on a particular lifting device.

3. The combination set forth in claim 1 in which said pump includes a part at the end of I said unitary structure which has several passageways and said frame has several passageways forming said passageway means and includes a first part formed with a recess in which said pump part is disposed, means including a hollow screw for securing said pump part to said first frame part, said screw having a passageway extending therethrough in communication with one of the passageways in said pump part and one of the passageways in said frame, respectively, when said pump part is secured to said first frame part, said recess having at least one groove when said pump part is disposed therein which is in communication with another of said passageways in said pump part and another of said passageways in said frame.

4. The combination set forth in claim 3 in which the frame has a second recess in which an end of said lifting cylinder is disposed, a passageway in said frame being in communication with said cylinder at the vicinity of said second recess.

5. The combination set forth in claim 4 comprising a circuit for circulating liquid, such as oil, for example, through and between said pump and said lifting cylinder, said circuit including said passageways and said groove, and said lifting cylinder including structure defining a reservoir for holding a body of the liquid, said reservoir being in communication with a passageway in said frame and with said lifting cylinder.

6. The combination set forth in claim 1 in which said compressed-air motor comprises control means including first valve structure for controlling the operation of said motor, said lifting cylinder including a lifting piston, a circuit including said passageway means for circulating liquid, such as oil, for example, through and between said pump and said lifting cylinder, control means including second valve structure for controlling the circulation of liquid in said circuit, said unitary structure being enclosed by a casing, a rotatable shaft, means including said casing and said frame for supporting said shaft, said shaft having an operating handle and eccentric sections for operating said first and second valve structures to render said compressed-air motor operable or inoperable and torender said circuit operable or inoperable to supply liquid to said lifting cylinder for lifting purposes, and said second valve structure functioning, when said circuit is inoperable to supply liquid to said lifting cylinder for lifting purposes, to provide a path of flow for liquid in said circuit from said lifting cylinder which permits said piston to move when said jack is being lowered.

7. The combination set forth in claim 1 which in- 8. The combination set forth in claim 1 which includes a carriage having wheels, means including said base and said attaching means for fixing the jack to said carriage, a supporting plate on said carriage, and said supporting plate and said wheels being so constructed and arranged that, when said jack is stationary, substantially all of the dead-weight load on the jack will be carried by said supporting plate.

9. The combination set forth in claim .8 in which said attaching means comprises a bracket, one end of said vase engaging said bracket, means on said carriage comprising a pivoted locking arm movable between locking and unlocking positions, and said locking arm in its locking position bearing against the opposite end of said base at the upper edge thereof.

10. The combination set forth in claim 6 which includes a carriage having wheels, means including said base and said attaching means for fixing the jack to said carriage, a supporting plate on said carriage, and said supporting plate and said wheels being so constructed and arranged that, when said jack is stationary, substantially all of the dead-weight load on the jack will be carried by said supporting plate, anoperating shaft having a plurality of sections, one of said sections being axially movable with respect to the other, said operating operating shaft, said lifting-cylinder being disposed horizontally on said carriage, said lifting cylinder and operating shaft and lifting arm being'so constructed and arranged that said operating shaft, responsive to said lifting cylinder, displaces the lower end of said lifting arm horizontally, a first linked arm pivotally connected to said carriage and lifting arm, respectively, and a second linked arm pivotally connected to said lifting platform and said first linked arm, respectively,

to impart-a parallel motion displacement of said lifting platform duringlifting movement thereof. v.

, l2. Thecombination set forth in claim'8 in-which said means for fixing the jack to said carriageincludes structure for tumably mounting said base thereon, a-

lifting rod, a lifting arm,'the jack cooperating with said lifting rod which in turn acts on said lifting arm, means including two linked arms for pivotally connecting said lifting ann tosaid carriage to develop a lifting movement, means for articulatedly connecting one of said linked arms to the other of said linked arms, a lifting platform, means for coupling the other of said linked arms to said lifting platform, and meals for pivotally at,- taching said lifting platform to said lifting arm to impart a parallel motion displacement of said lifting platform during lifling movement thereof.

Claims

3. The combination set forth in claim 1 in which said pump includes a part at the end of said unitary structure which has several passageways and said frame has several passageways forming said passageway means and includes a first part formed with a recess in which said pump part is disposed, means including a hollow screw for securing said pump part to said first frame part, said screw having a passageway extending therethrough in communication with one of the passageways in said pump part and one of the passageways in said frame, respectively, when said pump part is secured to said first frame part, said recess having at least one groove when said pump part is disposed therein which is in communication with another of said passageways in said pump part and another of said passageways in said frame.

6. The combination set forth in claim 1 in which said compressed-air motor comprises control means including first valve structure for controlling the operation of said motor, said lifting cylinder including a lifting piston, a circuit including said passageway means for circulating liquid, such as oil, for example, through and between said pump and said lifting cylinder, control means including second valve structure for controlling the circulation of liquid in said circuit, said unitary structure being enclosed by a casing, a rotatable shaft, means including said casing and said frame for supporting said shaft, said shaft having an operating handle and eccentric sections for operating said first and second valve structures to render said compressed-air motor operable or inoperable and to render said circuit operable or inoperable to supply liquid to said lifting cylinder for lifting purposes, and said second valve structure functioning, when said circuit is inoperable to supply liquid to said lifting cylinder for lifting purposes, to provide a path of flow for liquid in said circuit from said lifting cylinder which permits said piston to move when said jack is being lowered.

7. The combination set forth in claim 1 which includes a handle for carrying said unitary structure, said handle comprising a hollow tubular member fixed to said frame, said tubular member having an inlet adapted to be connected to a source of supply of compressed air, said compressed-air motor having an inlet for compressed air, and conduit means for conduction compressed air from said tubular member to the compressed air inlet of said motor, said conduit means and said tubular member being so constructed and arranged that the latter functions as a water separator and a pressure equalizing chamber for the compressed air.

8. The combination set forth in claim 1 which includes a carriage having wheels, means including said base and said attaching means for fixing the jack to said carriage, a supporting plate on said carriage, and said supporting plate and said wheels being so constructed and arranged that, when said jack is stationary, substantially all of the dead-weight load on the jack will be carried by said supporting platE.

9. The combination set forth in claim 8 in which said attaching means comprises a bracket, one end of said base engaging said bracket, means on said carriage comprising a pivoted locking arm movable between locking and unlocking positions, and said locking arm in its locking position bearing against the opposite end of said base at the upper edge thereof.

10. The combination set forth in claim 6 which includes a carriage having wheels, means including said base and said attaching means for fixing the jack to said carriage, a supporting plate on said carriage, and said supporting plate and said wheels being so constructed and arranged that, when said jack is stationary, substantially all of the dead-weight load on the jack will be carried by said supporting plate, an operating shaft having a plurality of sections, one of said sections being axially movable with respect to the other, said operating shaft being turnable, means on said carriage for rotatably supporting said operating shaft, one end of said operating shaft coacting with the operating handle of said shaft having eccentric sections whereby turning movement of said operating shaft effects turning of said shaft having eccentric sections.

11. The combination set forth in claim 8 which includes a lifting arm provided with a lifting platform, an operating shaft, said lifting cylinder being disposed horizontally on said carriage, said lifting cylinder and operating shaft and lifting arm being so constructed and arranged that said operating shaft, responsive to said lifting cylinder, displaces the lower end of said lifting arm horizontally, a first linked arm pivotally connected to said carriage and lifting arm, respectively, and a second linked arm pivotally connected to said lifting platform and said first linked arm, respectively, to impart a parallel motion displacement of said lifting platform during lifting movement thereof.

12. The combination set forth in claim 8 in which said means for fixing the jack to said carriage includes structure for turnably mounting said base thereon, a lifting rod, a lifting arm, the jack cooperating with said lifting rod which in turn acts on said lifting arm, means including two linked arms for pivotally connecting said lifting arm to said carriage to develop a lifting movement, means for articulatedly connecting one of said linked arms to the other of said linked arms, a lifting platform, means for coupling the other of said linked arms to said lifting platform, and means for pivotally attaching said lifting platform to said lifting arm to impart a parallel motion displacement of said lifting platform during lifting movement thereof.