Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3851856 A
Publication typeGrant
Publication dateDec 3, 1974
Filing dateMay 25, 1972
Priority dateMay 25, 1972
Publication numberUS 3851856 A, US 3851856A, US-A-3851856, US3851856 A, US3851856A
InventorsBerg H
Original AssigneeHb Contracting
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Shoring jacking
US 3851856 A
Abstract
A jack is disclosed consisting of a piston and cylinder unit which can be expanded by introduction of compressed gas into the cylinder so as to engage two opposed surfaces to be shored. A rotatable collar is mounted on the end of the cylinder receiving the piston and is provided with inclined cam profiles which when rotated engage a pin located in a diametric pair of holes provided in the piston. The collar can be locked against rotation when the cam profiles are in engagement with the pin so as to prevent retraction of the piston and cylinder unit from the shored surfaces if pressure is lost or released from the cylinder.
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

1451 Dec. 3, 1974 SHORING JACKING [75] Inventor: Harry Berg, Abbotsford, British Columbia, Canada [73] Assignee: H. B. Contracting Ltd., Surrey,

British Columbia, Canada 22 Filed: May 25,1972

21 Appl. No.2 256,731

[52] US. Cl. 254/93 R, 61/41 A [51] Int. Cl B66f 3/24 [58] Field of Search 254/93 R, 133 A; 248/354 H, 354 P; 6l/41 A [56] References Cited UNITED STATES PATENTS 1,590,830 6/1926 Jewkes 254/93 R 2,691,503 10/1954 Bigelow 254/93 R 3,321,182 5/1967 Elenburg 254/93 R 3,393,521 7/1968 Cammisa 61 41 A 3,470,699 10/1969 Cox 61/41 A FOREIGN PATENTS OR APPLICATIONS 6/1965 France 61/41 A 564,597 12/1957 Italy ..248/354P Primary Examiner-Al Lawrence Smith Assistant Examiner-Robert C. Watson Attorney, Agent, or FirmFeatherstonhaugh & Co.

[ 5 7 ABSTRACT A jack is disclosed consisting of a piston and cylinder unit which can be expanded by introduction of compressed gas into the cylinder so as to engage two opposed surfaces to be shored. A rotatable collar is mounted on the end of the cylinder receiving the piston and is provided with inclined cam profiles which when rotated engage a pin located in a diametric pair of holes provided in the piston. The collar can be locked against rotation when the cam profiles are in engagement with the pin so as to prevent retraction of the piston and cylinder unit from the shored surfaces if pressure is lost or released from the cylinder.

6 Claims, 3 Drawing Figures PATENTELUEB 1851 56 SHORING J ACKING The invention relates to shoring jacks of the kind comprising a piston and cylinder, particularly for the use in shoring trench walls.

In the shoring of trenches, it is necessary to hold the shoring boards tightly against the wall of the trench so as to prevent sloughing of the material behind the boards. If the boards are allowed to shift even by the most minute amount, the soil'cohesion is lost and it is usually impossible to prevent sloughing and maintain a full safe trench width. The use of a simple piston and cylinder type jack for shoring purposes is not satisfactory since it tends to relax and allow the boards to move away from the trench wall. This in turn produces the undesirable sloughing referred to above.

It is among the objects of the present invention to provide an improved piston and cylinder type shoring jack in which this difficulty is overcome.

The invention therefore provides a shoring jack comprising a piston and cylinder unit for location between two surfaces to be shored, the cylinder of said unit having inlet means for connection to a pressure source for expanding the unit into engagement with said surfaces, a collar mounted for rotation on the end of said cylinder receiving said piston, said collar having an end extending axially from said cylinders to surround the piston and being formed with an inclined circumferentially extending cam profile, means for releasably securing the collar against rotation relative to the cylinder, a cam element, and means for selectively locating said cam element at one of a plurality of positions along said piston for cooperating engagement with the cam profile, whereby, subsequent to pressurization of the cylinder, the jack can be retained in the resulting expanded condition by securing the cam on the piston adjacent to the cam profile, rotating the collar to bring the cam profileinto abutment with the cam element, and securing the collar against rotation relative to the cylinder to prevent the cam profile from disengaging from the cam element.

One embodiment of the invention will now be described with reference to the accompanying drawings in which FIG. 1 is an exploded view of a jack according to the invention.

FIG. 2 is a perspective view of one element of the jack of FIG. 1 and,

FIG. 3 is a side elevation showing the jack of FIG. 1 assembled and in use in a trench.

Referring first to FIG. 1, the jack 1 is shown comprises a cylinder 2 having a bearing plate 3 closing one end and a gas inlet connector 4 secured in the cylinder wall close to the bearing plate. Vent holes 5 are provided in the wall of the cylinder 2 approximately three quarters of the length of the cylinders from the bearing plate 3. A piston 6 is similarly closed at one end by a bearing plate 3. At its other end, the piston 6 is closed by an end wall 7 to which a rubber sealing cup 8 is secured by a bolt 9 extending through a retainer disc 10. The piston 6 is tubular and along its length is formed with pairs of diammetrically opposed holes 11 in which a pin 12 may be located. The bearing plates 3 are each 6 provided with adjustable set screws 3a for engagement with the shoring boards when the jack is in use, to prevent slippage.

A cylindrical collar 13 is provided through which the piston 6 may be introduced into the cylinder 2. One end of the collar 13 has a portion 14 of enlarged diameter extending to a step 15, the end 16 of the cylinder 2 being a slip fit into the portion 14 to abut the step 15. A threaded boss 17 is provided in the wall of the portion 14, with a threaded stud 18 being engaged in this boss. The boss 18 carries a handle 19 whereby. the stud can be tightened into engagement with the cylinder 2 to prevent relative rotation of the collar 13 relative to the cylinder. The handle 19 also carries a flange 20 which retains one end of a chain 21. The pin 12 is secured to the other end of the chain 21. The other end of the collar 13, as best seen in FIG. 2, is formed with a pair of symmetrical inclined circumferential camming surfaces 22 each extending through substantially and each terminating in stop faces 23 and 24 at their upper and lower ends respectively.

The jack is assembled by introducing the piston 6 through the collar 13 in the position shown in FIG. 1 and so that the cup 8 enters the cylinder 2. The jack is then collapsed until the end of the cylinder 2 bears on the step 15 and the piston is fully received in the cylinder.

FIG. 3 shows the jack in position in a trench supporting shoring boards 25. In order to locate the jack in the trench, the inlet connector 4 is first connected to the source of compressed gas 26 which may for example be CO through a pressure pipe 27 having a valve 28 therein. Valve 28 is opened to introduce gas under pressure into the cylinder 2 so that the piston extends until the bearing plates 3 bear against the shoring 25. The set screws 3a bite into the wood of the shoring boards to prevent any vertical movement of the jack. 1

The pin 12, which serves as a camming element, is then inserted through the pair of diametric holes 11 in the piston 6 which are nearest to the stop surfaces 24 at the lower ends of the inclined cams 22 on the collar 13. The collar 13 is then rotated until the inclined cams 22 are in firm abutting engagement with the pin and the collar is then locked by rotating the handle 19 to engage the stud 18 with the cylinder 2. The stop faces 23 prevent the pin 12 from overriding the ends of the camming surfaces 22 during rotation of the collar 13. Pres- V sure can then be released from the cylinder 2 by closing the valve 28 and removing the connector 27. The jack is held in the extended position by the abutment of the pin 12 with the cam surfaces.

In order to prevent over extension of the jack, the vent holes 5 provided in the wall of the cylinder 2 vent the gas from the cylinder 2 as soon as the piston 6 is ejected from the cylinder sufficiently far for the cup 8 to pass beyond the holes 5. As a result, no further extension of the jack takes place.

I claim:

1. A pneumatic jack for use in the shoring of trenches, comprising a piston and cylinder unit having a port for separately operable mechanical means engageable between the piston and cylinder for the secural and retention thereof against retraction from a random expanded condition, wherein said mechanical means comprises a collar formed with an internal annular step and rotatably engaging the end of said cylinder receiving said piston, said collar having an end extending axially from said cylinder to surround the piston, said end being formed with a pair of inclined circumferential surface profiles, each extending through substantially 180,

an abutting element, and

means for selectively locating said abutting element at one of a plurality of positions along said piston for abutting engagement with said surface profiles,

means for preventing rotation of said collar relative to said cylinder,

whereby, subsequent to the pressurization of said cylinder for an extension of the unit to a final extended condition which applies a shoring force to opposed shoring boards lining the walls of a trench, the abutting element can be located on the piston adjacent to the surface profiles and the collar rotated to bring the surface profiles into abutting engagement with the abutting element without further extension of the unit, and then secured.

2. A pneumatic jack as claimed in claim 1, wherein said collar is formed with stop faces at each end of each of said surface profiles.

3. A pneumatic jack as claimed in claim 1, wherein said means for selectively locating said cam element comprise a plurality of axially spaced diametric holes formed in said piston, said abutting element comprising a pin engageable selectively in any of said holes.

4. A pneumatic jack as claimed in claim 1, wherein said cylinder is formed with a plurality of circumferentially spaced vent holes to prevent extension of the jack beyond a predetermined amount 5. A pneumatic jack as claimed in claim 1 wherein the piston and cylinder unit is provided with a bearing plate at each end, each of said bearing plates including means for penetrative engagement with said shoring boards.

6. A pneumatic jack for use in the shoring of trenches, comprising a cylinder having a bearing plate at a closed first end for engagement with a shoring board lining a wall of a trench to be shored, and a port for the introduction and release of gas under pressure,

valve means connected to said port,

a piston having another bearing plate at a first end for engagement with another shoring board lining an opposite wall of the trench to be shored, and a sealing cup secured at a second end which is received in the open second end of the cylinder, said piston being further provided with a plurality of axially spaced pairs of diametric holes,

said bearing plates being formed with threaded apertures each receiving axially adjustable set screws for penetrative engagement with said shoring boards,

a collar formed with a threaded radial aperture, and having an internal step engaging the second end of said cylinder, said collar being rotatable with respect to said cylinder, and having an axially extending end surrounding said piston and formed with a pair of symmetrical surface profiles each extending through substantially a threaded stud provided with a handle and engaging in said threaded radial aperture in said collar for releasably securing the collar against rotation relative to said cylinder, and

a pin engageable selectively in one of said pairs of diametric holes in the piston,

whereby, subsequent to pressurization of the cylinder to cause the bearing plates and set screws to engage the shoring boards, the piston and cylinder can be secured in the resulting extended condition and the valve means operated to release the gas under pressure after locating the pin in a pair of said holes ad jacent to the surface profiles, rotating the collar to bring the surface profiles into abutment with the pin without further extending the piston and cylinder, and securing the collar against rotation by tightening the threaded stud against the cylinder so as to prevent the surface profiles from disengaging from the pin.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT'NO. 3,851,856

DATED 3 December 3, 1974 INVENTOR( 3 Harry Berg It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Figures 1 and 2, reference numeral 18 should be added to indicate the stud which carries handle 19, this stud being threaded into threaded boss 1?.

Column 1, line 28, "cylinders" should read "cylinder".

Column 1, line 57, "cylinders" should read "cylinder".

Column 2, line 8, "boss 18" should read "stud l8".

Claim 1, line 3 should read: --a piston and cylinder unit having a port for the introduction and release of gas under pressure,-.

Signed and Scaled this Twenty-fifth Day of September I 979 [SEAL] Arrest:

LUTRELLE F. PARKER Arresting Officer Acting Commissioner of Patents and Trademarks

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1590830 *Mar 14, 1925Jun 29, 1926Spencer JewkesPneumatic lifting jack
US2691503 *Mar 18, 1950Oct 12, 1954Goodman Mfg CoMine prop
US3321182 *Mar 26, 1965May 23, 1967Walker Neer Mfg CoCombination hydraulic jack and load holding mechanism
US3393521 *Nov 2, 1966Jul 23, 1968Francis S. CammisaExcavation shoring frame assemblies
US3470699 *May 16, 1968Oct 7, 1969Cox Andrew JSafety device for trenches and the like
FR1445633A * Title not available
IT564597A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4058983 *Feb 9, 1976Nov 22, 1977Griswold James LTrench shoring assembly with lifting attachment
US4591298 *Nov 2, 1984May 27, 1986Japan Speed Shore Co., Ltd.Expansion beam for shoring up sand guards
US4660806 *Sep 12, 1985Apr 28, 1987Masters Scott APush stick for plumb and line adjustment of stud walls
US4682914 *Dec 23, 1985Jul 28, 1987Isamu AiharaHydraulic trench support
US4787781 *May 14, 1987Nov 29, 1988Walter LipscombShoring device
US5232312 *Apr 24, 1992Aug 3, 1993Jennings Charles BShoring device
US5310290 *Mar 12, 1993May 10, 1994Spencer Dennis IProtective structure for excavations
US5499890 *Jul 8, 1994Mar 19, 1996Americ CorporationTrench shoring device with locking mechanism
US5513555 *Jan 21, 1994May 7, 1996Michael J. PlankQuick-release cam lock with locking pin
US5868060 *Jan 24, 1994Feb 9, 1999Speed Shore Corp.Quick-release cam lock
US6017170 *Jun 1, 1998Jan 25, 2000American Rescue Technologies, Inc.Adjustable self locking shoring strut
US6027102 *Apr 16, 1998Feb 22, 2000Krupa; Richard P.Hydraulic jack stand
US6039522 *Jan 19, 1999Mar 21, 2000Kinedyne CorporationAutomatic locking and unlocking shoring bar
US6158705 *Apr 9, 1999Dec 12, 2000Airshore International Direct Equipment West Ltd.Vehicle Stabilization and support tool
US6379084 *Dec 17, 1999Apr 30, 2002Jack Kennedy Metal Products And Buildings, Inc.Mine stopping
US6585231 *Jun 12, 2002Jul 1, 2003Anthony R. Fratoni, Jr.Pneumatic jack
US6616133 *Jul 18, 2001Sep 9, 2003Norgren Automotive, Inc.Linear actuator having an adjustable piston rod
US6682263Jan 29, 2003Jan 27, 2004Jack Kennedy Metal Products & Buildings, Inc.Multiple tier stopping and method of constructing stopping
US6715961Feb 1, 2002Apr 6, 2004Jack Kennedy Metal Products & Buildings, Inc.Method of supporting mine walls and installing a mine stopping
US6746183 *Sep 23, 2002Jun 8, 2004James G. SullivanShoring device with outer ratcheting collar
US6821057Apr 5, 2000Nov 23, 2004Maksim KadiuMagnetic shoring device
US6846132Jan 29, 2003Jan 25, 2005Jack Kennedy Metal Products & Buildings, Inc.Mine stopping and braces therefor
US6964542 *Apr 16, 2004Nov 15, 2005Sullivan James GPin and collar shoring device
US7048471Apr 15, 2003May 23, 2006Maksim KadiuShoring device
US7056067Oct 3, 2003Jun 6, 2006Max KadiuTrench shoring device
US7309190 *Nov 14, 2005Dec 18, 2007Sullivan James GShoring device with removable swivel side plates containing detente sphere attachments
US7309191Mar 2, 2004Dec 18, 2007Max KadiuShoring system
US7387470 *May 12, 2006Jun 17, 2008Mccracken RobertStackable concrete forming apparatus components
US7584932 *Oct 23, 2007Sep 8, 2009Lung Ching ShihConstruction prop
US7837413 *Jan 23, 2008Nov 23, 2010Kundel Sr RobertAdjustable trench box and spreader bar
US7967352 *Mar 26, 2008Jun 28, 2011Tandemloc, Inc.Load spreader bar end cap
US8382175Apr 29, 2011Feb 26, 2013Tandemloc, Inc.Load spreader bar pipe connection sleeve
US8616519Aug 23, 2011Dec 31, 2013Titan Formwork Systems, LlcShoring post with supplemental beam support
US8662476Jan 31, 2011Mar 4, 2014Weddle Tool CompanyPost ram
US9132993Jul 3, 2014Sep 15, 2015Tandemloc, Inc.Load spreader bar pipe connecting sleeve with offset end plate
US20070264089 *May 12, 2006Nov 15, 2007Mccracken RobertStackable concrete forming apparatus components
US20090058117 *Mar 26, 2008Mar 5, 2009Tandemloc, Inc.Load Spreader Bar System
US20090101774 *Oct 23, 2007Apr 23, 2009Lung Ching ShihProp
US20110206451 *Apr 29, 2011Aug 25, 2011Tandemloc, Inc.Load Spreader Bar Pipe Connection Sleeve
US20120080579 *Oct 3, 2011Apr 5, 2012Gray Manufacturing Company Inc.Air-assisted heavy equipment support stand
CN103003186A *Jun 1, 2011Mar 27, 2013荷马特罗有限公司Device comprising a cylinder, such as a spreader
CN103003186B *Jun 1, 2011Jun 24, 2015荷马特罗有限公司Device comprising a cylinder, such as a spreader
EP0477451A1 *Dec 24, 1990Apr 1, 1992Speed Shore CorporationNew and improved shoring shield
WO2009077793A1 *Dec 8, 2008Jun 25, 2009Petar KunicImproved structure of hydraulic sheeting support
WO2011152727A1 *Jun 1, 2011Dec 8, 2011B.V. Holmatro Industrial EquipmentDevice comprising a cylinder, such as a spreader
Classifications
U.S. Classification254/93.00R, 405/282
International ClassificationB66F3/36, B66F3/43, B66F3/26, B66F3/30, E02D17/08, B66F1/00, E02D17/06, B66F3/24
Cooperative ClassificationE02D17/083, B66F3/247
European ClassificationE02D17/08B, B66F3/24F
Legal Events
DateCodeEventDescription
Aug 29, 1983AS02Assignment of assignor's interest
Owner name: BERG,MARY 33320 BOURQUIN CRESCENT, ABBOTSFORD, BRI
Owner name: H.B. CONTRACTING LTD.
Effective date: 19830812
Aug 29, 1983ASAssignment
Owner name: BERG,MARY 33320 BOURQUIN CRESCENT, ABBOTSFORD, BRI
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:H.B. CONTRACTING LTD.;REEL/FRAME:004165/0166
Effective date: 19830812