US3221837A

US3221837A - Scaffold with folding stairway

Info

Publication number: US3221837A
Application number: US314216A
Authority: US
Inventors: Robert E Fisher
Original assignee: Up Right Inc
Current assignee: Up Right Inc
Priority date: 1963-10-07
Filing date: 1963-10-07
Publication date: 1965-12-07
Anticipated expiration: 1982-12-07
Also published as: GB1032472A

Description

Dec. 7, 1965 Filed Oct. 7, 19

ii F is- 23 R. E. FISHER SCAFFOLD WITH FOLDING STAIRWAY FIG-/ 4 Sheets-Sheet 1 IN VEN TOR. Paaier 5 F/s/rie Dec. 7, 1965 R. FISHER SCAFFOLD WITH FOLDING STAIRWAY 4 Sheets-Sheet 2 Filed Oct. 7, 1963 IN VENTOR. 205597 .5 Phi/1'52 prrazvim' Dec. 7, 1965 R. E. FISHER 3,221,837

SGAFFOLD WITH FOLDING STAIRWAY Filed Oct. 7, 1963 4 Sheets-Sheet 5 INVENTOIR. Pau'ir E. Fun? BY MM Ww lrraelviKi Dec. 7, 1965 R. E. FISHER 7 3,221,837

SCAFFOLD WITH FOLDING STAIRWAY Filed Oct. '7, 1963 4 Sheets-Sheet 4 IN VENTOR Pdii7 5 1 -75115:

United States Patent Office Patented Dec. 7, 1965 3,221,837 SCAFFOLD WITH FOLDING STAIRWAY Robert E. Fisher, Berkeley, Calif., assignor to Up-Right, Inc., Alameda, Calif., a corporation of California Filed Oct. 7, 1963, Ser. No. 314,216 10 Claims. (Cl. 182-115) This invention relates to stairway scaffolds of the type having a platform, two end-supporting sections, and a diagonal stairway section, all interhinged so that the four sections can be erected from a fiat package into a working scaffold and then folded back into the flat package for storage and transportation.

In particular, this invention relates to stairway scaffolds of the type shown in United States Letters Patent No. 2,438,173 and constitutes an improvement thereon. In this former patent, the four sections of the scaffold fold into a flat bundle of three-tube thickness, with the stairway section projecting from the portion of the bundle formed by the superposed platform and end sections. The projecting stairway section is disadvantageous, because more space is required to store the folded scaffolds and the stairway section is prone to abuse when the scaffold is folded.

Additionally, the scaffold of this prior patent is relatively hard to erect by a single mechanic when a second or additional scaffold unit is erected on top of a lower scaffold unit in the construction of a tower, since in the erection of the upper scaffold the entire scaffold must be raised from a flat position on the lower scaffold to enable an end of the upper scaffold to be inserted into and connected to the vertical tubings of the lower scaffold unit. During the time that the upper scaffold is raised from a flat position, it is more difficult to handle by the mechanic, particularly if he is inexperienced or elderly.

The present scaffold is designed to overcome these disadvantages. First, the stairway section is hinged in such a manner that the scaffold when folded will still be of a three-tube thickness with the stairway section disposed completely within the periphery of the bundle formed by the platform and end sections. Secondly, the scaffold unit has a different manner of unfolding, as compared with the scaffold shown in the above-mentioned patent, to enable the mechanic to erect and connect the upper scaffold unit to the lower unit more readily.

Other objects and advantages will become apparent in the course of the following detailed description.

In the drawings, forming a part of this application, and in which like parts are referred to by like reference numerals throughout the same:

FIG. 1 illustrates, in perspective, two scaffold units, constructed in accordance with the invention, erected one on top of the other.

FIG. 2 is a sectional detail, taken on line 22 of FIG. 1, showing the manner whereby the upper and lower scaffold units are secured together.

FIG. 3 is an exploded view of the elements of the upper scaffold unit of FIG. 1 illustrating their relative positions when the scaffold unit is folded into a flat package.

FIG. 4 is an elevational view of one of the hinge connections intermediate the ends of the stairway section.

FIGS. 5 and 6 are sectional views of the hinge connection of FIG. 4, taken on lines 5--5 and 66 thereof.

FIGS. 7A-7F are diagrammatic illustrations indicating the manner in which the upper scaffold unit of FIG. 1 is unfolded from a flat package to an erected position.

FIG. 8 is an exploded view of the elements of the lower scaffold unit of FIG. 1 illustrating their relative positions when the scaffold unit is folded into a fiat package.

FIG. 9 is a sectional view, taken on line 99 of FIG. 8, illustrating the details of the swinging latch.

Referring now to the drawings, FIG. 1 illustrates two

scaffold units

10 and 11, of the same type as shown in the above-referred-t-o United States Letters Patent No. 2,438,173, stacked on top of one another, and each having a platform section 12, two

end sections

13 and 14 and a diagonal stairway section 15.

The end section 13 of scaffold unit 10 comprises a rectangular frame formed of side, or vertical,

tubes

16 and 17,

horizontal end tubes

18 and 19 and an intermediate horizontal cross tube 20. Cross tube 20 may be omitted, as illustrated, from end section 13a of the lower scaffold unit 11.

The end section 14 similarly comprises a rectangular frame formed of side, or vertical,

tubes

21 and 22,

horizontal end tubes

23 and 24, and an intermediate horizontal cross tube 25. Cross tube 25 may be omitted, as illustrated, from end section 14 of the lower scaffold unit 11.

The platform 12 comprises four

parallel tubes

26, 27, 28 and 29 which are connected at one end to tube 18 of end section 13 by downwardly offset trunnion hinges 31, and are connected at their other ends to tubes 23 of end section 14 by upwardly offset trunnion hinges 32.

The stairway section 15 comprises upper and lower members 15a and 15b connected together by hinge connections 33. The upper stairway section 15a is comprised of

parallel tubes

34a and 35a, connected at their upper ends to tube 18 by downwardly offset trunnion hinges 36, and having step treads 37 connected therebetween. The lower stairway section 15b is comprised of

parallel tubes

34b and 35b, having step treads 37 connected therebetween, and having axially disposed detachable locking hooks 38 at the lower ends thereof for engagement with tube 24 of end section 14. The specific details of these hook connections are not important here, but may be of the type shown in full detail in United States Letters Patent No. 2,665,950.

The lower scaffold unit 11 is provided with locking casters on the ends of the

vertical tubes

16 and 17 of end section 13a and

tubes

21 and 22 of end section 14. A plywood sheet 39 i mounted on top of

platform tubes

26 and 27 to provide a walkway between the flights of stairs. The lower scaffold unit is also provided with foldable diagonal brace members 40, one on either side of the stairway 15 and extending from member 23 of end section 14 to member 19 of end section 13a. The specific details of these folding brace members are not important here, but may be of the type shown in full detail in application Serial No. 182,436, filed March 26, 1962, and assigned to the assignee of the present invention.

The upper and lower scaffold units are connected together as follows: Each of the

vertical tubing members

18, 19, 21 and 22 of the

end sections

13 and 14 of the upper scaffold unit 10 has a reduced-diameter pintle 41 secured in the lower end thereof, which pintle fits telescopically into the open upper ends of the corresponding tubular member of the lower scaffold unit 11, as best shown in FIG. 2. The pintles 41 and the

tubular members

18, 19, 21 and 22 have registering holes for the reception of pin 42, secured to spring clip 43, to lock the scaffolds against vertical separation.

Turning now to FIGS. 4-6, hinge connection 33 is formed by a clevis casting 44 and a tongue casting 45, pivotally connected together by roll pin 46 that is tight in the tongue and free to rotate and slide in the clevis. The pivotal connection provided by roll pin 46 is downwardly offset from the axis of the stairway member tubes when the scaffold is erected. The clevis casting 44 has a stem 47 telescoped into the upper stairway tube 35a and held in place by a suitable bonding agent, as epoxy glue. The tongue casting 45 is similarly mounted and secured in the end of the lower stairway tube 3512.

As is seen in the drawings, the tongue 45 has a locking shoulder 48 engageable with a locking shoulder 49 formed in the clevis 44, which shoulders are held in normal locked position by the action of compression spring 51 that surrounds the roll pin 46 and acts upon the tongue and clevis castings.

To unlock the hinge connection 43, the stairway member tubes 35a and 3512 are forced out of axial alignment in the directions of the arrows shown in FIG. 5, against the bias of spring 51, to disengage the

locking shoulders

48 and 49. The lower stairway member 15b may now be swung around the roll pin connection to the clevis 44 to a position parallel to the, upper stairway member 15a, as indicated in the. dot-and-dash line of FIG. 4. To unfold the stairway member portions, member 15b is swung from the dot-and-dash line position to the position shown in FIGS. 4- and 5. When the stairway member tubes are fully aligned, the spring 46 will automatically move the tongue and clevis members relative to one another to engage the locking shoulders thereon.

The tongue and clevis castings cannot open any more than 180". because the surfaces thereof butt against each other at point 52. Thus, when the stairway members are opened up, as shown in FIG. 1, there will be no fear of downward collapse of the stairway if the hinge connections 43 were to he accidentally unlocked by a workman hitting sidewise against the stairway.

When the upper scaffold unit is folded into a fiat bundle, as illustrated in FIG. 3, the platform 12 and the two

end sections

13 and 14 will lie in three parallel planes, forming a three-tube bundle thickness. The stairway 15 is folded up upon itself, with the detachable connections 38 hooked to the horizontal cross tube of end section 13. The stairway member 15a will lie in the same plane as the platform 12 and the stairway member 15b will lie in the plane of end section 13.

When the lower scaffold unit 11 is folded into a flat bundle, as illustrated in FIG. 8, the stairway members 15a and 15b are secured in parallel relation by the swinging latch 55. This latch, best illustrated in FIG. 9, comprises resilient strap material having one end 56 wrapped around stairway member tube a and free to swing thereon. The other end 57 of the latch is curved to fit stairway member tube 35b and may be snapped off of that tube and moved to the dotted line position of FIG. 9 to disengage the latch.

To erect the upper scaffold unit 10 on top of an alreadyerected scaffold unit 11, the folded unit 10 is brought to scaffold unit 11 and leaned up against the unit 11 with the end section 14 of the upper unit closest to the lower unit 11, as shown in FIG. 7A. The workman then ascends the stairway 15 of the lower unit and pulls the upper unit 10 on top of the lower unit, as indicated in FIG. 7B.

The platform 12, end section 13 and folded stairway 14 are then pivoted, as a unit, around hinge connections 32, to the vertical position illustrated in FIG. 7C, and the pintles 41 of end section 13 are inserted into the upper ends of the

tubes

16 and 17 of the end section 13a of the lower scaffold unit. During this step the end section 14 of the upper, scaffold unit remains motionless on top of the lower scaffold. The locking clips 43 can now be connected to prevent separation of the end sections 13 and 13a of the scaffold units.

Or, if the workman desires to lift the upper unit 10 vet-- tically at the other end of lower scaffold unit 11, he may do so as indicated in FIG. 7C as shown in dotted lines. Lifting the upper scaffold unit 10in this manner permits direct insertion of the pintles 41 of end section 13 in the upper ends of

tubes

16 and 17 of the lower scaffold unit.

Next, the platform section-12 is swung up 90 to a horizontal position, and the other end section 14 is swung up to a vertical position, as indicated in FIG. 7D. The pintles 41 of end section 14 are inserted into the end section of the lower scaffold unit and are locked in place by the locking clips 43.

The stairway member 1517 is then detached from cross tube 20 of the end section 13 and the stairway is swung upwardly as in FIG. 7E, is fully extended and then brought back down to engage the locking hooks 38 with the tube 24 of the end section 14 to complete the erection. Since end section 13 is held at its bottom end against movement, no diagonal brace, such as brace 40 of the lower scaffold unit 11, is required.

To dismantle the scaffold after use, the above steps are simply reversed.

In determining the relative lengths of stairway members 15a and 15b of scaffold section 10, the combined length when aligned must, of course, be equal to the diagonal distance of the erected scaffold, and the member 15:: must be longer than the member 1512 so that the hook end portion of 15b will terminate short of end section member 18 when the scaffold is folded, as best seen in FIG. 3. The stairway member 15a can be of any length desired, as long as it is greater than member 15b and shorter than the distance between

members

18 and 19 of end section 13 to permit proper folding.

When the scaffold unit 10 is folded, the stairway member 15a is sandwiched between the end section cross tubes 20 and'25 so that no pivotal movement of these ladder parts about end tube 18 will occur, and the stairway member 15b is hooked to cross tube 20, so that the entire folded stairway is rigidly held completely within the folded package.

When the scaffold unit 11 is folded, as shown in FIG. 8, the stairway members 15a and 15b, secured together by latch 55, and the folding braces 40 lie completely within the folded package. The folded stairway is prevented from swinging through end section 13a because the ladder member 15a is sufficiently long enough so that the clevis casting 44 of the hinge connection 43 abuts, at 58, the horizontal tube 19 of end section 13a. Similarly, when the scaffold unit 11 is folded the clevis casting 44 abuts, adjacent surface 52 thereof, the horizontal tube 23 of end section 14, to prevent the folded ladder from swinging through end section 14. The corner braces 59 and 60 of end sections 13a and 14 also serve to maintain the folded ladder within the confines of the folded package.

It is to be understood that the form of the invention herein shown and described is to be taken as a preferred embodiment, and that various changes may be made in the shape, size and arrangement of parts without departing from the spirit of the invention or the scope of the attached claims;

Having thus described my invention, what I claim is 1. A folding scaffold comprising: first and second generally rectangular end sections; a platform pivotally connected at one end thereof to one end of said first end section and pivotally connected at its other end to one end of said second end section for enabling said scaffold to be folded into a package with the platform and end sections parallel to one another and to be erected with the end sections being vertical and the platform being horizontal; stairway comprising first and second members, the first member being longer than said second memhinge meansconnecting said first and second stairway members for enabling said members to be folded flat against each other and to be unfolded into linear relation;

' means pivotally connecting the end of said first stairway member opposite said hinge means to an end of said first end. section;

means on the end of said second stairway member opposite said hinge for detachably connecting said sec-- 0nd stairway member to a diagonally opposite end of said second end section when said end sections are erected and said stairway members are unfolded;

means for securing said stairway members when folded within said package formed by said platform and end sections when folded.

2. In a scaffold as set forth in claim 1 wherein said hinge means connecting said stairway members is comprised of two pivotally connected parts having abuttable means thereon to prevent more than 180 opening of said hinge means.

3. In a scaffold as set forth in claim 2 wherein the pivotal connection of said two hinge parts is downwardly offset from the stairway members when the scaffold is erected.

4. In a scaffold as set forth in claim 1 wherein said last-named means comprises an intermediate cross piece positioned on said first end section to be engaged by said means on the end of said second stairway member when said first and second stairway members are folded fiat against each other.

5. In a scaffold as set forth in claim 1 wherein said lastnamed means includes a latch means for securing said first and second stairway members together when folded, and further includes surfaces on each end section abuttable ith said first stairway member to prevent swinging movement of said stairway member through said end sections.

6. A folding scaffold comprising:

first and second end sections each having opposed side tubes and opposed end tubes forming a rectangle;

a platform;

first and second offset hinges hingedly connecting said platform at one end thereof to one end tube of said first end section and at the other end thereof to one end tube of said second end section to enable said end sections and platform to be folded fiat into a package of three parallel planes with the platform being in the middle, and to enable the end sections and platform to be erected with the end sections being vertical and the platform horizontal;

a stairway comprising first and second members, the

first member being longer than the second member;

a third offset hinge connecting said first and second stairway members to enable said members to be folded fiat against each other and to be unfolded into aligned relationship;

a fourth offset hinge connecting said first stairway memher opposite said third hinge to an end tube of said first end section;

an axially disposed locking hook means on the end of said second stairway member for detachably engaging said second stairway member to a diagonally opposite end tube of said second end section when said scaffold is erected and said stairway members are unfolded;

said fourth offset hinge being offset to allow said first stairway member to be coplanar with said platform and said second stairway member to be coplanar with said first end section when said platform, end sections and ladder members are folded;

7. In a scaffold as set forth in claim 6 wherein said third offset hinge is comprised of two pivotally connected parts having abuttable means thereon to prevent more than opening of said hinge.

8. In a scaffold as set forth in claim 6 wherein the pivotal connection of said two parts of said third offset hinge is downwardly offset from the stairway members when the scaffold is erected.

9. In a scaffold as set forth in claim 6 wherein said last-named means comprises an intermediate cross piece positioned on said first end section to be engaged by said means on the end of said second stairway member when said first and second stairway members are folded flat against each other.

10. In a scaffold as set forth in claim 6 wherein said last-named means includes a latch means for securing said first and second stairway members together when folded, and further includes surfaces on each end section abuttable with said first stairway member to prevent swinging move ment of said stairway member through said end sections.

References Cited by the Examiner UNITED STATES PATENTS 938,016 10/1909 Niblack 182-152 1,085,629 2/1914 Perkins 182163 1,148,356 7/1915 Chickering l8288 2,438,173 3/1948 Johnson 182115 2,760,707 8/ 1956 Anderson 1 821 15 HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, Examiner.

Claims

1. A FOLDING SCAFFOLD COMPRISING: FIRST AND SECOND GENERALLY RECTANGULAR END SECTIONS; A PLATFORM PIVOTALLY CONNECTED AT ONE END THEREOF TO ONE END OF SAID FIRST END SECTION AND PIVOTALLY CONNECTED AT ITS OTHER END TO ONE END OF SAID SECOND END SECTION FOR ENABLING SAID SCAFFOLD TO BE FOLDED INTO A PACKAGE WITH THE PLATFORM AND END SECTIONS PARALLEL TO ONE ANOTHER AND TO BE ERECTED WITH THE END SECTIONS BEING VERTICAL AND THE PLATFORM BEING HORIZONTAL; A STAIRWAY COMPRISING FIRST AND SECOND MEMBERS, THE FIRST MEMBER BEING LONGER THAN SAID SECOND MEMBER; HINGE MEANS CONNECTING SAID FIRST AND SECOND STAIRWAY MEMBERS FOR ENABLING SAID MEMBERS TO BE FOLDED FLAT AGAINST EACH OTHER AND TO BE UNFOLDED INTO LINEAR RELATION; MEANS PIVOTALLY CONNECTING THE END OF SAID FIRST STAIRWAY MEMBER OPPOSITE SAID HINGE MEANS TO AN END OF SAID FIRST END SECTION; MEANS ON THE END OF SAID SECOND STAIRWAY MEMBER OPPOSITE SAID HINGE FOR DETACHABLY CONNECTING SAID SECOND STAIRWAY MEMBER TO A DIAGONALLY OPPOSITE END OF SAID SECOND END SECTION WHEN SAID END SECTIONS ARE ERECTED AND SAID STAIRWAY MEMBERS ARE UNFOLDED; MEANS FOR SECURING SAID STAIRWAY MEMBERS WHEN FOLDED WITHIN SAID PACKAGE FORMED BY SAID PLATFORM AND END SECTIONS WHEN FOLDED.