US2691963A

US2691963A - Double-acting, telescopic cylinder assembly

Info

Publication number: US2691963A
Application number: US254500A
Authority: US
Inventors: James H Seng
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-11-02
Filing date: 1951-11-02
Publication date: 1954-10-19
Anticipated expiration: 1971-10-19

Description

Oct. 19, 1954 J. H. SENG 2,691,963

DOUBLE-ACTING, TELESCOPIC CYLINDER ASSEMBLY Filed Nov. 2, 1951 2 Sheets-Sheet 1 INVENTOR James H-SENG ATTORNEKS J. H. SENG 2 Sheets-Sheet 2 r 1 1; v II DOUBLE-ACTING. TELESCOPIC CYLINDER ASSEMBLY INVENTOR JAMEs H. Sens ATTORNEYS mm 7 Wm Filed Nov. 2, 1951 Oct. 19, 1954 Patented Oct. 19, 1 954 UNITED STATES PATENT OFFICE DOUBLE-ACTING, TELESCOPIC CYLINDER ASSEMBLY James H. Seng, Salina, Kans.

Application November 2, 1951, Serial No. 254,500

2 Claims. .1

This invention relates to double-acting, telescopic cylinder assemblies, and more particularly to a double-acting, hydraulic cylinder assembly having telescopically associated parts for increasing the range of elongation of the cylinder assembly.

It is among the objects of the invention to provide an improved hydraulic cylinder assembly which includes telescopically associated parts, so that a large elongation can be obtained in comparison with the collapsed or retracted length of the assembly; which is hydraulically operated in both expanding or elongating and its collapsing or contracting movements; which applies fluid pressure to each of the telescopically associated parts in both directions of movement; which provides substantially equal pressure areas on all of the telescopically associated parts; which includes adjustable means for limiting its elongation; which may be installed on various machines such as power shovels, bulldozers, cranes and vehicles; and which is simple and durable in construction, economical to manufacture, easy to install, and positive and effective in operation.

Other objects and advantages will become apparent from a consideration of the following description and appended claims in conjunction with the accompanying drawings, wherein:

Figure 1 is a side elevational view of a bulldozer shovel showing a cylinder assembly illustrative of the invention operatively installed thereon;

Figure 2 is a side elevational view on an enlarged scale of the hydraulic cylinder assembly, a portion being broken away and shown in crosssection to better illustrate the construction thereof;

Figure 3 is a cross-sectional view on an enlarged scale on the line 33 of Figure 2;

Figure 4 is a transverse cross-sectional view on the line d l of Figure 3;

Figure 5 is a fragmentary cross-sectional view on the line 55 of Figure 3;

Figure 6 is a transverse cross-sectional view on the line 6-6 of Figure 3; and

Figure '7 is a side elevational view of a somewhat modified form of cylinder assembly, parts being broken away and shown in cross-section to better illustrate the construction thereof.

With continued reference to the drawings, the bulldozer scoop or shovel assembly, illustrated by way of example in Figure 1, includes a pair of spaced apart and substantially parallel booms, one of which is indicated at I0, disposed one at each side of a tractor, not illustrated. A bulldozer blade I I is secured near its bottom edge to the front ends of the booms and is braced in operative position by links, one of which is indicated at I 2, each secured at one end to the blade II at the corresponding end of the latter and above the front end of the corresponding boom 10 and secured at its rear end to the upper end of a lug I3 projecting upwardly from the corresponding boom at a location spaced rearwardly from the blade. The link [2 may be made adjustable to vary the inclination of the bulldozer blade as may be desired. Arms, as indicated at M, extend upwardly and forwardly from the upper edge of the blade ll, one at each end of the blade, and a clamshell bucket I5 is secured at its upper edge to the ends of the arms I l for upward and downward swinging movement relative to the blade II. An arm [6 projects upwardly from the link 12 at the end of the link remote from the blade I I, and this arm is provided with an aperture near its upper end. Arms, as indicated at ll, project upwardly from the bucket l5, one at each end and near the upper edge of the bucket and these arms are also provided with apertures near their upper ends. Hydraulic cylinder assemblies, as generally indicated at l8, are disposed one at each end of the bulldozer blade H and connected between the corresponding arms l6 and I! for tilting or swinging the bucket I5 relative to the blade ll, these assemblies being connected to the hydraulic system of the associated tractor and operated by manually actuated valves located convenient to the tractor operator.

As the hydraulic cylinder assemblies of the present invention may be operatively mounted on various machines for various purposes, as may be desired, the above brief description of one exemplary installation is considered sufiicient to fully disclose the utility of the device.

The hydraulic piston assembly includes a first cylinder 20 open at one .end and closed at the other, a second cylinder 2| telescopically received at one end in the open end of the first cylinder, a piston 22 surrounding the second cylinder at the end thereof disposed within said first cylinder and slidably engaging the inner surface of the first cylinder, a packing ring 23 secured in the first cylinder at the open end thereof and slidably engaging the outer surface of the second cylinder, a piston rod 24 received at one end in the end of the second cylinder disposed outwardly of the open end of the first cylinder, a piston 25 secured to the piston rod 24 of the cylinder 2|. cylinder 2| adjacent the packing ring 216 and 3 at the end of the latter disposed within the second cylinder, and a packing ring 26 secured in the end of the second cylinder which is disposed outwardly of the open end of the first cylinder and slidably engaging the piston rod.

The first cylinder 20 has an internal diameter greater than the external diameter of the second cylinder 2 and the piston 22 comprises an annular body or ring of elongated, rectangular cross-sectional shape threaded onto an externally screw-threaded portion 21 at the end of the second cylinder 2| disposed within the first cylinder 2|! and disposed in the circumferential space between the two cylinders. This piston has at least one annular groove 28 in its peripheral surface and a sealing ring 29 is seated in this groove and engages the inner surface of the cylinder 2|] to provide a fluid-tight seal between the piston and the cylinder 20. The packing ring 23 includes an annular or cylindrical portion 38 disposed in the circumferential space between the cylinders 2| and 20 at the open end of the cylinder 22 and an annular flange 3| extending outwardly from the cylindrical portion 3!! over the open end of the cylinder 20. The cylindrical portion-3B is provided withexternal and internal annular grooves, and

sealing rings

32 and 33 are seated in these grooves and respectively engage the inner surface of the cylinder 2c and the outer surface of the cylinder 2| to provide fluid-tight seals between the packing ring and these cylinders. An annular collar 34 surrounds the cylinder 20 near the open end thereof, and is held in place on the cylinder by a snap ring 35 seated in a groove provided in the exterior surface of the cylinder 2|! near the open end of the latter and received in an annular recess provided in the collar 34 around the inner edge of the collar. Flange bolts 36 extend through apertures in the flange 3| and are threaded into tapped holes in the collar 34 to maintain the packing ring 23 in place on the cylinder 2|].

The piston 25 has a central aperture therein which receives the reduced, externally screw threaded end portion 31 of the piston rod 24. A washer 38 is secured on the piston rod at the inner end of the screw-threaded portion 31 to provide an abutment for the piston 25, and a nut 39 is threaded onto the screw-threaded portion of the piston rod at the side of the piston opposite the abutment to maintain the piston on the piston rod. The piston 25 is provided with an annular groove in its peripheral surface, and a sealing ring 50 is seated in this groove and slidably engages the inner surface of the cylinder 2| to provide a fluid seal between the piston 25 and the cylinder 2|.

The cross-sectional area of the interior of the cylinder 2| is substantially equal to the difierence between the cross-sectional area of the interior of the cylinder 20 and the cross-sectional area of the interior of the cylinder 2|, so that the

pistons

22 and 25 have substantially the same effective pressure areas.

The packing ring 26 comprises a cylindrical portion 4| received in the end of the cylinder 2| remote from the piston 22 and having a bore slidably receiving the piston rod 24. This packing ring also includes a flange 42 extending outwardly from the cylindrical portion 4| at one end of the latter and overlying the adjacent end A collar 4'3 surrounds the is held in place on the cylinder 2| by a snap ring M seated in a groove provided in the outer surface of the cylinder 2| adjacent the end of the cylinder remote from the piston 22 and received in an annular recess in the collar 43 extending around the inner edge of the collar. Flange bolts 45 extend through apertures in the flange 42 of the packing ring 25 and are threaded into tapped holes in the collar 43 to secure the packing ring to the cylinder 2|.

The packing ring is provided with external and internal grooves receiving sealing rings 45 and 41, respectively, which slidably engage the inner surface of the cylinder 2| and the surface of the piston rod 2 8 to provide a fluid-tight seal between the cylinder 2| and the piston rod.

A pair of spaced apart, substantially parallel lugs 48 project outwardly from the end wall 49 of the cylinderzil substantially at the center of the end wall, and these lugs are provided with apertures 50 for receiving a pivot pin to pivotally secure the cylinder 20 to a cylinder-supporting portion of an associated mechanism, such as the link arm I6 in Figure 1. An apertured lug 5| is provided on the end of the piston rod 24 remote from the piston 25 for pivotally connecting this end of the piston rod to another portion of the supporting structure, such as the arm on the scoop l5, as shown .in Figure l.

The cylinder 20 is provided with externally screw-threaded,

hollow bosses

52 and 53 projecting laterally therefrom, one at each end of the cylinder, and communicating with the interior thereof. These bosses constitute fluid conduit fittings by means of which fluid pressure conduits, such .as the

conduits

54 and 55, are connected at their corresponding ends to the cylinder '20.

The packing ring .26 is provided with a drilled passage 56 extending from the side thereof to the end of the cylindrical portion 4| of this packing ring disposed inwardly of the cylinder 2|, and this passage is provided with a screw-threaded counterbore 51 in its end adjacent the side of the packing ring. A fitting 58 is threaded into the counterbore 51 and one end of a branch conduit 59 is secured to the fitting 58. The conduit 59 is secured at its other end to the adjacent end of the conduit 55 by means of a Y-fitting 60., on leg of which is connected to the fitting 53 by a conduit 6i which constitutes, in effect, a continuation of the conduit 55.

With this arrangement, when hydraulic fluid under pressure is supplied to the cylinder assembly through the conduit 5d and the conduit 55 is connected to a sump or vent, the piston 22 will be forced outwardly of the cylinder 20 away from the end wall 49 of this cylinder, forcing the cylinder 2| outwardly of the cylinder 22, and the piston 25 will be forced along the cylinder 2| in a direction away from the piston 22, forcing the piston rod 24 outwardly of the cylinder 2|. When the piston 22 contacts the packing ring 23 and the piston 25 contacts the packing ring 26, the maximum elongation of the assembly will have been obtained.

When the conduit 54 is connected to a sump or drain and fluid under pressure is supplied to the conduit 55, the fluid will act between the piston 22 and the packing ring 23 to force the cylinder 2| inwardly of the cylinder 20 until the collar 43 engages the outer end of the packing ring 23 and will act between the piston 25 and the, packing ring 26v to force the piston rod 24 inwardly of the cylinder 2| until the shoulder 62 at the inner end of the lug formation 5| on the piston rodcontacts the outer end of the packing ring 26, the cylinder assembly then being contracted to its shortest condition.

In the modified arrangement illustrated in Figure 7, instead of having the

collars

34 and 43, the flanges on the packing rings and the

flange bolts

36 and 45 connecting the packing ring flanges to the collars, the packing rings for the cylinders 20 and 2!, as indicated at 63 and 64, respectively, have externally screw-threaded, cylindrical portions received in the corresponding cylinders, and the cylinders are internally screw-threaded to receive the screw-threaded packing rings. The packing ring 63 is provided with an outwardly extending annular flange 65 of polygonal shape to receive a wrench for threading the packing ring 63 into and out of the cylinder 20 and the packing ring 64 is provided with an outwardly projecting annular flange 66 of polygonal shape for receiving a wrench to thread the packing ring 64 into and out of the cylinder 2|. The packing ring 63 is provided with two spaced apart, internal grooves receiving

sealing rings

61 and 68, respectively, which sealing rings slidably engage the outer surface of the cylinder 2| and the packing ring 64 is provided with two spaced apart, internal grooves receiving sealing rings 69 and which slidably engage the surface of the piston rod 24. In the arrangement illustrated in Figures 2 to 6, inclusive, the flange 42 of the packing ring 26 is provided with diametrically opposed extensions H and 72 each provided with an aperture spaced outwardly from the outer edge of the adjacent collar 13. The flange 3! of the packing ring 23 is provided with similar diametrically opposed

extensions

13 and 14, each of which is provided with an aperture spaced outwardly from the outer surface of the cylinder 20, and the collar 34 is provided with diametrically opposed extensions and 16, each of which is provided with an aperture in alignment with the aperture in the corresponding extension of the flange 3|. A rod E1 is received at one end in the aperture in the extension TI and secured therein by a nut [8 threaded onto the externally screw-threaded end portion of the red at the end of the packing ring 26 remote from the packing ring 3|. This rod H extends slidably through the registering apertures in the

extensions

13 and 15 of the packing ring 23 and collar 34, and is provided with a series of apertures 19 extending transversely therethrough at locations spaced apart longitudinally thereof. A similar rod 80 is received at one end in the aperture in the extension 12 of the packing ring flange 42, and a nut 81 is threaded onto the externally screw-threaded end portion of this red at the end of the packing ring 26 remote from the packing ring 23 to secure the rod in the corresponding aperture. This rod 80 extends slidably through the registering apertures in the

extensions

14 and 16 and is provided with a series of transversely extending apertures 82 spaced apart longitudinally of the rod.

Stop pins, as indicated at 83 and 84, for the rod Ti, and 85 and 86 for the rod 80, are inserted through selected apertures in the rods and are engageable with the collar 15 and the flange 3! of the packing ring 23 to adjustably limit movements of the cylinder 2! relative to the cylinder 20.

With this arrangement, it is not necessary to have a specially designed cylinder assembly for each installation, but, by adjustably limiting the elongation of the assembly, assemblies of the same size can be used for various installations.

' or essential characteristics thereof.

The invention may be embodied in other specific forms without departing from the spirit The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed is:

1. An extensile hydraulic cylinder assembly comprising a first cylinder having an open end and a closed end, a secondcylinder having an external diameter less than the internal diameter of said first cylinder received at one end in the open end of the second cylinder and slidably engaging the inner surface of said first cylinder, a first packing ring secured to said first cylinder at the open end of the latter and slidably engaging the outer surface of said second cylinder, a piston rod extending at one end into the other end of said second cylinder, a second piston secured on said one end of said piston rod and slidably engaging the inner surface of said second cylinder, a second packing ring secured to said second cylinder at said other end of the latter and slidably engaging said piston rod, fluid conduit fittings disposed on and communicating with the interiors of said cylinders one at each end of said first cylinder and one at said other end of said second cylinder, each of said packing rings having an external flange provided with spaced apart extensions each having an aperture therethrough, adjusting rods extending slidably one through each extension on said first packing ring and one through each extension on said second packing ring, said adjusting rods being secured each at one end to said second packing ring and each adjusting rod having a series of apertures extending transversely therethrough at spaced apart locations therealong, and stop pins inserted through selected apertures in said adjusting rods and engageable with said first packing ring to provide limit stops for movements of said second cylinder relative to said first cylinder.

2. An extensile hydraulic cylinder assembly comprising a first cylinder having an open end and a closed end, a second cylinder having an external diameter less than the internal diameter of said first cylinder received at one end in the open end of the second cylinder and slidably engaging the inner surface of said first cylinder, a first packing ring secured to said first cylinder at the open end of the latter and slidably engaging the outer surface of said second cylinder, a piston rod extending at one end into the other end of said second cylinder, a second piston secured on said one end of said piston rod and slidably engaging the inner surface of said second cylinder, a second packing ring secured to said second cylinder at said other end of the latter and slidably engaging said piston rod, fluid conduit fittings disposed on and communicating with the interiors of said cylinders one at each end of said first cylinder and one at said other end of said second cylinder, each of said packing rings having an apertured external flange overlying the adjacent end of the associated cylinder, collars mounted one on each cylinder at the ends of said cylinders adjacent the corresponding packing rings, each of said collars having tapped holes therein, flange bolts extending through the anergtureszintsaidspacking ring fiangesandzthneaded' into the tapped hol'esimthecorresponding col.-

lars-to securesaidipackin'gringstmsaidacylindersa each of said; packing; rings; having an; external. flange-provided: with spaced: apart extensions and.

the: collar adj'acentezsaid. firstzpacking ring-having spaced apart; extensions, each; of: said extensions having" an aperturatherethrough, adjusting rods extending siidably; one through each. extension, 1

on said: first packing: ring and-1 through; the: ex,- tensions on the associated collar and each adiiiistiing rod having one end secured intheaperiture of a corresponding extensiononsaid' second packing ring and. each, having. a; series of. apertures extending transversely therethrough at spaced apart locations therealong and stop pins-inserted through selected apertures in: said adj usting" rods and engaging said first packing ringand said 8E collaradjacent, said: first packing ring to provide limit stop for movementsof said second cylinder relative to said first cylinder;

References Cited in. the: file of this patent UNITED STATES PATENTS Number Name Date 214,574; McGowan Apr. 22,1879 501,426 Kampff July 11, 1893 1,174,788 Winn Mar. 7, 1916 1,731,254 McNab Oct. 15, 1929 2,308;0'9.9 Obecny Jan. 12, 1943 2,390,702 Gailet a1 Dec. 11, 1945 2,442,306 McCormick May 25, 1948- FOREIGN PATENTS Number Country Date Great Britain 1882