US3487952A - Material lift and press - Google Patents

Description

1970 B. E. c5wENs ET AL 3,487,952

MATERIAL LIFT AND PRESS Filed Feb. 13, 1967 9 Sheets-Sheet 1 I80 INVENTORS. BERNARD E. OWENS PAT MAHER MALL/NCKRODT 8 MALL/NC/(RODT 23g? w Jan. 6, 1970 E; OWENS ET AL MATERIAL LIFT AND PRESS 9 Sheets-$heet 2 Filed Feb. 1 196';

Jan. 6, 1970 B. E. OWENS ET AL 3,487,952

MATERIAL LIFT AND PRESS Filed Feb. 13, 196'? 9 Sheets-Sheet a HIM I 1 [1 I82 [56c I IVIOM D1130 15Gb v I860 A f2 ho 13 I 172" F 62 I62 V I 22/ 59 0 3x I62 20 0 77 o use 1-H 75 5a 1 I69 $77 59 77 x 45 x 5 O 45 r 58 5s 53 J 53 47 46 23 23 3s '1 23w so 23 47 INVENTORSI BERNARD E. OWENS PAT MAHER MALLl/VC/(RODT 8 MALL/NC/(ROD7 Jan. 6, 1970 B. E. ()WENS ET AL MATER L LIFT AND PRESS 9 Sheets-Sheet 4 Filed Feb. 13, 19m

JNVENTORS BERNARD E. OWENS BY: PAT lMAHER MALL/NCKRODTG MALL INC/(R007 Jail 5, 1970 B. E. OWENS ET AL 3,487,952

MATERIAL LIFT AND PRESS Filed Feb. 13, 1967 9 Sheets-Sheet 5 FIG 5 "use INVENTORS BERNARD E. OWENS PAT MAHER MALL/NCKRODTB MALL/NCKRQDT EgZ-W Jan. Q 1970 Fil ed Feb. 13, 1967 a. E; OWENS ET AL 3,487,952

MATERIAL LIFT AND PRESS 9 Sheets5heet 6 INVENTORS BERNARD E. OWENS PAT MAHER MALL/NCKRODT' 8 MALL /NCK/?O0T Jan, 5,, E9 30 5 E OWENS ET AL l -437,952

MA'I'ERIAL LIFT AND PRESS Filed Feb 13, 1967 9 Shets-$heet 7 "I2 \wmwvy 1 M B. E. bwENs ET AL MATERIAL LIFT AND PRESS Jan. 6, 1970 9 Sheets-Shee t 8 Filed Feb. 13, 196'? 0 0 mm m 5 OF. N f TWR M WO 0, WE M/V I M D M PO m 5 B M.

Jan. 6, 19 70 Filed Feb. 13, 1967 B. a owzws ET AL 3,487,952

MATERIAL LIFT AND PRESS 9 Sheets-Sheet 3 FIG. I4

INVENTORS: BERNARID E. OWENS BY: PAT MAHER za m United States Patent ABSTRACT OF THE DISCLOSURE An easily assembled device for receiving large, flat, construction materials, for elevating them into position and for pressing them fiat against a ceiling surface. It includes a vertically adjustable scaffold, a pivoted, derricktype lift unit and a press assembly for holding the material tightly against a ceiling surface.

BRIEF SUMMARY OF THE INVENTION This invention relates to apparatus for elevating sheettype construction materials such as panels of plywood or sheet rock and for pressing these materials tightly against a ceiling surface while they are nailed or otherwise secured in place.

In the past a number of devices have been developed for elevating and positioning sheet materials but none have been entirely satisfactory.

We have found that for such a device to be practical it must enable fewer men to do at least the same amount of work, in an easier manner, as could heretofore be performed by a larger work crew. The work of lifting the sheet material must be eliminated, the press must securely hold the sheet material against the ceiling and the worker must be positioned to easily fasten the sheet material to the ceiling, regardless of its height.

On a typical construction project, in the past, a minimum of four men have been required for an efficient sheet-rock ceiling installation. Two men have been required to transport sheets of material to a conveyor that carries the material up to two other men on a scaffold, custom constructed to place the workers thereon at a convenient working height where they can readily reach the ceiling surface. The two men on the scaffold have then had to lift the sheet-rock into place on the ceiling, and while holding it tightly against the surface, nail or otherwise secure it in place. The men must stop operations frequently to reposition the scaffolding.

Objects of the present invention are to provide a scaffold that is easily repositioned and adjusted to place workers thereon at a height where they can conveniently reach any normal ceiling surface and to provide a lift that will raise sheet material into an overhead position and then tightly hold it against the ceiling surface, and to perform these operations faster and with less manpower than has heretofore been required.

In accomplishing these objects we utilize a self-elevating scaffold that includes walkways on which one or more workers can stand and members that telescope over supporting legs of the scaffold to support the walkways, a derrick type lift unit and a press assembly.

The entire apparatus is constructed to be assembled or disassembled quickly, without special tools and without specially trained personnel.

Locking wheels are provided on the legs so that the entire assembly can be readily repositioned.

There is shown in the accompanying drawing a specific embodiment of the invention representing what is presently regarded as the best mode of carrying out the generic concepts in actual practice. From the detailed description of this presently preferred form of the invention, other more specific objects and features will become apparent.

3,487,952 Patented Jan. 6, 1970 ice THE DRAWINGS FIG. 1 is a side perspective view of the invention, partially broken away for clarity, and with the lift shown in its elevated position supporting a sheet of building material and with the press unit extended;

FIG. 2, a similar view, with the lift shown partially lowered by full lines and fully lowered in dotted lines;

FIG. 3, a front perspective view, partially broken away for clarity, and with the lift unit in its elevated position and the press assembly extended;

FIG. 4, a top plan view with the lift removed;

FIG. 5, a perspective view, partially broken away, with the lift unit removed for clarity, and with the cables arranged for self-elevating of the scaffold;

FIG. 6', an enlarged perspective view of the press assembly, with the lift unit being shown fragmentarily;

FIG. 7, a still further enlarged vertical section, taken on the line 77 of FIG. 8 and showing interior details of the press assembly;

FIG. 8, a fragmentary vertical section taken on the line 8-8 of FIG. 7, and showing the displacement of the pulleys inside the press assembly;

FIG. 9, a horizontal section taken on the line 9--9 of FIG. 8;

FIGS. 10 and 11, schematic representations, showing the telescoping action of the press assembly, and drawn to a reduced scale;

FIG. 12, an enlarged and exploded perspective view of the drive means for the lift unit and thepress assembly;

FIG. 13, a vertical section taken on the line 1313 of FIG. 12;

FIG. 14, an enlarged and exploded perspective view of a typical connector for the scaffold, taken within the line 14-14 of FIG. 1; and

FIG. 15, a vertical section taken on the line 1515 of FIG. 1, and showing the sheet material, sliding, table-type support structure.

DETAILED DESCRIPTION The scaffold The scaffold includes four legs 23, each of which has a locking wheel 24, of commercially available type on its bottom end.

A connector 25 (FIG. 14) is affixed to each leg adjacent to its lower end by sliding a tubular section 26 over the leg. A pin 27 is inserted through the tubular section 26 and through the leg 23 and is then rotated until a flange 2-8 on the pin is wedged beneath a finger 29 carried by the tubular section. The coaction between flange 28 and finger 29 prevents the pin inadvertently working out to release the connector.

A plate 30 is fixed to and extends outwardly from each tubular section 26 and a hole 31 in each plate 30 is arranged to receive pin 32 that is passed downwardly through a clevis 33 on the end of a diagonal brace 34.

A pair of the diagonal braces 34 extend diagonally between legs and are pivotally interconnected at 35 to facilitate assembly.

Side braces 36 extend between the legs 23 at each side of the scaffold and each brace has a clevis 37 on each end that is adapted to fit onto a plate 30 of a connector 25 so that a pin 38 can be inserted downwardly through the clevis and a hole 39 in the plate 30 to secure them 7 together.

A bracket 40, FIG. 14, on the side of each tubular section 26 supports a nut 41 into which a bolt 42 is threaded.

The threaded end of bolt 42 engages a clamping plate 43 to force it against the tubular section. As is best seen in FIG. 3, a strong wire 44 can be clamped between each plate 43 and its associated tubular section 23 and when the wire is diagonally stretched between connectors on adjacent legs at the front and rear of the scaffold and is also connected to similar connectors 45 on telescoping sections 46, it serves as bracing against undesired spreading of the scaffold legs.

Cross braces 47 also extend between the forward legs 23 and the rear legs 23 to provide additional strengthening of the scaffold. The cross braces each include collars 48 at their ends that slide downwardly over the legs 23 to rest on the connectors 25.

Telescoping sections 46 are positioned on legs 23, by pins 49 that are inserted through holes in the telescoping sections and through corresponding ones of the holes 50 spaced along legs 23.

[In the event the device is to be used in connection with very high ceiling surfaces one or more additional sets of reinforcement structure comprising connectors 25, diagonal braces 34, side braces 36, wings 44 and crossbraces 47 can be used as additional reinforcement between the lowermost ones previously described and the telescoping sections 46. The additional sets of reinforcement structure will be telescoped over the legs before the telescoping sections 46 are positioned, so that as the telescoping sections are moved up the legs the sets of reinforcement structure can be pinned in place. The sets of reinforcement structure will then be interconnected by strong wires clamped in the same manner as wire 44.

Two of the telescoping sections 46 are respectively connected to opposite ends of a side rail 51 and the other two are similarly connected to another side rail 52. Each telescoping section has braces 53 and 54, FIG. 5, that support a shelf 55, and after the telescoping sections are secured to the legs 23 by pins 49, front cross brace 56 and rear cross brace 57 are secured to the braces 53, as shown.

Pulleys 58 are suspended from collars 59 that are slidable on each of the front and rear cross braces, 56 and 57, respectively, for use in raising the lift unit and press assembly to desired height, as will be further explained.

As is best seen in FIG. 4, each shelf includes a turned back flange 60, beneath which a flat foot-plate 61 of a leg 62 of the press assembly 22 can slide. A pin 63 is inserted downwardly through each flange 60, its associated foot-plate 61 and its shelf 55, to securely, but removably, hold the lift unit and press assembly in place.

The press assembly In addition to legs 62, each having a foot-plate 61, the press assembly 22 includes an outer tube 64, FIG. 6, having a collar 65 fixed at its upper end, to which the legs 62 are connected by pivot pins 66.

Another collar 67 is slidable on outer tube 64, between a lower stop 68 and upper stop 69, formed by the ends of a strap 70 that extends over the top of an inner tube 71 to hold a bracket 72 which carried a pivot pin 73 on which the derrick arm 74 of the lift unit 21 is mounted.

Braces 75 are pivotally connected at one end to, and extend outward from cars 76 on collar 67. The other ends of braces 75 are each pivotally connected to an ear 77 at the lower end of a leg 62, FIGS. l-3.

When legs 62 are extended to position the foot-plates 51 on shelves 55 and beneath flanges 60, collar 67 is noved down into engagement with stop 68 and the braces 75 extend substantially horizontal to keep the legs from :ollapsing. When the collar 67 is moved up tube 64 and he pins 63 are removed the legs 62 can be collapsed and the press assembly 22 can be removed from the scaffold.

=Inner tube 71 telesc p Within outer tube 64, FIGS- 7-11, and a hangar 80 extends through an opening 81 provided therefor in the upper end of the outer tube and through opposing slots 82 and 83 in the wall of the inner tube. A guide block 84 at one end of hangar 80 abuts the outside of the wall of outer tube 64, and a pm 85 inserted through the other end of the hangar holds the hangar against its being withdrawn.

A block 86 is suspended from hangar 80, inside inner tube 71 and a similar block 87 straddles an end member 88 that reaches across the lower end of inner tube 71 and extends upwardly into the tube. Block 86 supports two pulleys 89 and 90 that are mounted for rotation on non-aligned axes 91 and 92 respectively and block 87 supports pulleys 93 and 94 on similar non-aligned axes 95 and 96, respectively. The axes 91 and 95 extend parallel to one another and axes 92 and 96 similarly extend parallel to one another so that the strands of a hoist cable 98 that is anchored to the lower end of block 86 and that passes down around pulley 94, up over pulley 90, down around pulley 93 and up over pulley 89, out through guide block 84 before being anchored at its other end to a reel 100. Because the axes of the pulleys of each block 86 and 87 are non-aligned the cable can move freely within tube 71 and the multiple strands of the cable result in an increased mechanical advantage during operation of the press unit.

Reel 100 is carried by a frame 101 that is fixed to outer tube 64, and that has a shaft 102, FIG. 6 adapted to be gripped and rotated by the chuck 103, FIGS. 1, 2 and 4, of a reversible-type press motor of a drill 104. A dog and ratchet, not shown, can be used in conventional fashion to prevent inadvertent reversing of reel 100, should this be found desirable.

Operation of the motor of drill 104 to rotate shaft 102 counterclockwise (as viewed in FIG. 7) will wind hoist cable 98 onto reel 100 to thereby raise block 89 and lift the inner tube 71. Reverse operation of the motor allows the cable to unwind from reel 100 as the block 89 and inner tube 71 move down under their own weight and the weight of any additional load carried thereby. The gearing in press motor 104 will normally prevent too rapid lowering of the inner tube but, if desired, a separate brake, not shown, acting on the cable 89, the reel 100, or directly on the inner tube 71 can be used to positively prevent slippage of the inner tube.

The lift unit The lift unit 21, in addition to derrick arm 74 also includes another arm and a table assembly, shown generally at 111. A transverse pivot bar 112 is fixed by webs 112a, FIG. 3, to one end of derrick arm 74 and is arranged to be a pivot axis for a main frame 113 of the table assembly. Main frame 113 includes a pair of spaced side angles 114 that are rigidly interconnected by braces 115. A flange 116 depends from each side angle and each flange 116 releasably surrounds pivot bar 112 to provide pivot connections between the main frame and derrick arm 74.

Intermediate its length a bracket 117, FIG. 6, is fixed to derrick arm 74, with ears 118 that have holes therethrough adapted to be aligned with holes in bracket 72 and to have pivot pin 73 inserted therethrough. Thus the derrick is pivotable on the upper end of inner tube 71. A pulley 119 is carried by the other end of derrick arm 74 and is adapted to have a cable 120 passed therearound to pivot the derrick arm in a manner to be more fully explained.

An A-frame 121 is releasably connected to the underside of main frame 113. The A-frame includes a tubular center post 122, one end of which intersects a base member 123, and a pair of diagonal members 124 and 125 that connect the ends of base member 123 and the center post adjacent to its other end.

Upstanding flanges 126 on the base member, straddle members 127 that interconnect braces 115 of the mainframe and pins 128, inserted through matching holes in the flanges 126 and in the members 127, releasably hold the A-frame to the underside of the main frame. The A-frame is positioned such that when the derrick arm 74 is in its upright position (FIG. 1) the center post of the A-frame is moved against the derrick arm and a spring biased latch 129 snaps into the open end of the tubular center post to prevent inadvertent pivoting of the table assembly 111 and to hold the upper surface of the main frame 113 normal to the derrick arm and parallel to a ceiling surface, not shown. A handle 130 can be grasped to pull latch 129 from the center post, so that when the derrick arm is lowered the angular relationship between the derrick arm and the table assembly can change.

Arm 110, FIG. 6, is made up of telescoping sections 110a and 11011 and has one of its ends pivotally connected to diagonal member 124 of the A-frame and its other end releasably and pivotally connected to a collar 132 that is fixed to and carried by the lower ends of strap 70, by a pin 133. Thus collar 132 and arms 110 move up and down with strap 70 whenever the press unit is operated. A bolt 134, threaded into section 110a and abutting section 110b securely fixes the length of arm 110.

Arm 110 is substantially parallel with derrick arm 74 and the two arms form a parallel linkage that holds the upper surface of the table assembly substantially parallel with the ceiling until the arms have moved down past their horizontal positions.

The derrick arm 74 is pivoted between its upright position, FIG. 1, and its dotted line lowered position, FIG. 2, by action of cable 120. Cable 120 has one end releasably clamped between a member 135 fitted within a slotted bolt 136 and the head of the bolt 136a. Member 135 abuts the outer wall of tube 64 and as nut 137 is tightened on the bolt to pull it through the tube the head 136a is pulled against member 135 to securely clamp the end of cable 120 therebetween.

Cable 120, as has been noted before, passes around pulley 119, and then passes across pulleys 138 and 139 at the bottom of tube 64, around a pulley 140' on the end of a pivoted tension arm 141 and is anchored to a reel 142 rotatable with a shaft 143.

Tension arm 141 is pivotally mounted on the same shaft 144 as is the pulley 139, and springs 145 on the shaft each have one end anchored to a frame 146 fixed on the bottom of tube 64 and their other end anchored to a pin 147, projecting from the arm 141 such that the arm is biased counterclockwise, or down, as viewed in FIG. 6.

Rotation of reel 142 to take up cable 120, i.e. counterclockwise, pulls down on pulley 119 and the end of the derrick arm to which it is attached to thereby lift the table assembly 111. Rotation of reel 142 in the other direction allows the derrick arm to move toward its lowered position, under the weight of the table, any sheet material carried thereby, and the weight of the end of the derrick arm 74 and arm 110 to which the table assembly is attached. Spring biased arm 141 maintains tension on cable 120 whether the cable is being payed out or taken in.

The ends of shaft 143, FIG. 13, are each journaled for rotation in one leg of an angle plate 148, the other leg of which has a hole 149 therein adapted to receive a pin 149a that is inserted downwardly through a walkway plank 150 or 151 (FIG. 4). A large drive wheel 152 is fixed on the shaft 143 adjacent to the walkway plank 152 and a smaller wheel 153, driven by a mot-or 154, mounted on the walkway plank 151, engages the outer edge of wheel 152 to frictionally drive it. Both wheels 152 and 153 are preferably rubber coated to insure a positive drive. A stem 154a projects downwardly from 6 motor 154 and is adapted to fit into a socket 154b held on the underside of plank 151 by screws 154C.

Spaced holes 155 are provided around the periphery of wheel 153 and an angulated brake rod 156 has one leg 156a arranged such that its end can be moved into and out of the holes and another leg 156b on which a gripping handle 156e, FIGS. 1-4, is provided. lLeg 156a is slidable and rotatable through aligned tubes 157 that are secured to plank by bolts 158. A projection 159 (FIG. 4) from leg 15612 is arranged to contact a pin 160 protruding upwardly from the plank when the leg 156a is withdrawn from holes 155 and handle 1566 is rotated down, i.e. clockwise. The pin 160 then keeps the brake rod from inadvertently moving into a hole 155.

When the lift unit 21 has been operated to raise the table assembly 111 to desired height, handle 1561: is raised until projection 159' clears the top of pin 160 and the brake rod is then pushed through tubes 157 until the end of leg 156a is inserted into a hole 155. This immobilizes wheel 152, shaft 143 and reel 142.

Walkway planks 150 and 151 each have holes therethrough to enable them to be slipped over the legs 23 of the scaffold 20 and they each have notched members 161 on their undersurfaces that will straddle and rest on the legs 62 of the press unit. Legs 162, FIG. 3, also depend from the bottoms of these planks and extend into upright hollow posts 163 that are carried by each footplate 61 of the press unit. If desired, for additional strength, a pair of vertical braces 164, FIGS. 14, interconnected by cross braces 165 can be positioned between each plank 150 or 151 and the angle side rails 51 or 52 therebeneath that interconnect legs 23. As illustrated, the vertical braces 164 each are notched at the tops to engage a depending member 166 of the planks 150 and 151 and at their bottoms to engage a side rail '51 or 52.

If additional working area is desired one or more additional planks 167 can be used. These are carried by brackets 168 that are cantilevered out from a sleeve member 169 that fits over the legs 23 above the shelves 55.

Upright posts 170 can be threaded into or otherwise afiixed to the planks as desired, and safety rails made from rigid members 171 or flexible rope or cable, not shown, can be attached thereto for the safety of workers on the platform, with clamps, by tieing, or in any other suitable fashion.

THE OPERATION In use, the device is taken to a job site in a completely disassembled condition and two men can easily and quickly assemble it.

The lower section of the scaffold is assembled in the manner previously described, the walkways are positioned, the press assembly is put in place with its legs spread and the feet 61 fastened to shelves 55, the shaft 143 is positioned, and motor 154 is fixed to walkway plank 151 such that wheel 153 will drive wheel 152.

As best seen in FIG. 5, an upper cross bar 172 carrying a pulley 173 is pinned in place at the top of the legs for each end of the scaffold. The free end of cable 120 is released from pins 174, 175 and 176, FIG. 12, which hold it to reel 142 to keep the cable from unwrapping and is passed under pulleys 139 and 138, around a pulley 58 on a cross brace 57 at one end of the: scaffold, up over the pulley 138 carried by the upper crossbar 172 at the same end of the scaffold and back down to where it is tied around the cross brace 57.

Another cable 177 has one end fixed to a reel 178 on shaft 143 and is normally wound therearound with its free end held against unwrapping pins on the reel that correspond to those on reel 142. In use, the free end of cable 177 is released from its holding pins and the cable is passed beneath a pulley 179 journaled on the same shaft 144 as is pulley 139, around a pulley 58 carried by rear cross brace 56, up and over the pulley 173 carried 4 by the upper brace 172 at that end of the scaffold and is then tied to the lower cross brace 56.

Operation of motor 154 will then drive shaft 143 and reels 142 and 178 to simultaneously take up cables 120 and 177. This will raise the cross braces 56 and 57, the walkway and the press assembly 22. By adding bracing, as required, and sections of end posts, the process can be repeated until the press assembly is properly positioned beneath the ceiling surface to which sheet material is to be affixed. The lift unit 21. can be attached to the press unit either before or after the cables 120 and 177 are used to raise the press assembly, walkways, etc. but will not be powered by motor 154 until cable 120 has been released from lower cross brace 57, pulleys 173 and 58 and been reconnected by passing it around pulley 140 on pivoted tension arm 141, pulleys 139 and 138 at the bottom of the press unit, pulley 119 on the derrick arm 74 and clamping it between member 135 and bolt head 136a, in the manner previously described.

Once the walkways are at desired height and cable 120 has been reconnected to operate the lift unit, motor 154 is started to pay out cable 120 and to allow the table assembly 111 to drop to its lowermost or receiving position. Sheet material, such as wall board 180, is placed thereon by a workman on the ground and, if necessary for lifting, the material is clamped to the table by clamps (not shown) preferably carried by the main frame 113 of thet table. A material handling apparatus such as is disclosed in our copending application Ser. No. 559,312,

filed June 21, 1966 can be used, for example, to position sheet material on table assembly 111.

After the sheet material is in place on the table assembly motor 154 is operated by control switch 1811, conveniently placed on the elevated handle 156c, to drive wheels 153 and 152 and therefore reel 142 to take up cable 120. This pivots derrick arm 74 to its upright position and positions the sheet material substantially parallel with the ceiling surface, above the head of an operator standing on plank 151. While the lift unit is raising the sheet material the workman on the ground can unlock wheels 24, move the scaffold beneath the ceiling surface on which the sheet material is to be placed and then relock the wheels. The operator on the scaffold then operates press motor 104 to drive reel 100 and take up hoist cable 98. This raises the inner tube 71 and presses the sheet material carried by the table tightly against the ceiling surface. The control switch for motor 104 is preferably carried on the handle 189 of a suction cup unit 190 so that the operator can control motor 104 while simultaneously using both hands, one of which holds the suction cup, to nail or otherwise fasten the sheet material in place.

Brake rod 156 is then manipulated in the manner previously described to positively hold wheel 152, shaft 143 and reel 142 against rotation.

After each sheet of material has been positioned, latch 129 is released, motor 104 is operated to lower the press assembly and motor 154 is operated to lower the lift unit to receive another sheet of material.

As is best seen in FIGS. 1 and 15, .main frame 113 of table assembly 111 preferably has roller bearings 182 protruding through side angles 114 and although the main frame can be used as a platform on which sheet material can be elevated, in many instances it is desirable to use a sliding frame 183. The sliding frame has angletype side members 184 that rest on the roller bearings and the slide frame will move beyond the main frame when the lift unit is in its lowered position so that the sheet material can be more easily placed thereon. This is especially useful if the walkways have been raised so that the apparatus can be used for a high ceiling. As the lift unit is raised the slide frame will move back into position centered over the main frame, or it can be manually moved back to that position.

Using the slide frame the sheet material can be readily positioned to abut other sheets previously placed on the ceiling, and it is not so necessary that the scaffolding be accurately positioned.

A handle 185, depending from the sliding frame hits a brace 115 of the main table to prevent the sliding frame moving beyond the main frame 113 to a point where it will become overbalanced and fall off. The handle 185 also allows an operator on the scaffold to easily position the sliding frame and material carried thereby.

The top face of the sliding frame is preferably covered with a padding material 186 to prevent damage to the sheet material being handled and if necessary conventional clamps (not shown) can be used to hold sheet material on the sliding frame. Naturally, if only the main frame were to be used as a material support, it would also be covered with padding material.

If desired, a brake can also be provided to slow rotation of wheel 152 when the derrick arm 74 of the lift unit is being .moved to its lowered position in the manner previously described. This brake can, for example, comprise a crank 186, FIG. 12, including an upwardly extending handle 186a and a weighted wheel engaging portion 186b, interconnected by a shaft 1860 that is journaled through a tube 187 fixed on plank 151. In many instances the gearing of motor 154 will be sufficient to prevent arm 174 dropping too fast, but, if not, pivoting of handle 156a will move portion 186b into engagement with the periphery of wheel 152 to slow its rotation, and will, therefore, slow the downward movement of arm 74.

Power to the power drill 104 and motor 154 and the switches controlling them is supplied from an extension cord 188, which also has a branch 188a to which a power nailing device, stapler or other powered tool can be connected.

With the apparatus of the invention two or three men can panel a ceiling surface as rapidly as six men could heretofore, and can do so without the physical exertion previously expended in manually lifting the sheets of material. The entire apparatus is readily set-up and easily disassembled so that little time is required to get ready for placing ceiling panels or to take the apparatus down upon completion of the job.

Whereas this invention is here described and illustrated with respect to a certain form thereof, it is to be understood that many variations are possible, without departing from the subject matter particularly pointed out in the following claims, which subject matter we regard as our invention.

We claim:

1. A material lift and press comprising a scaffold having supporting legs;

a press assembly carried by the scaffold, said press assembly being movable with respect to said legs and having walkways secured thereto for movement therewith with respect to the supporting legs, a first telescoping section, secured to and movable with the walkways and a second telescoping section movable with respect to the said first telescoping section;

a lift unit including an arm;

means pivotally connecting said arm of the lift unit to the second telescoping section;

a table assembly providing a broad material receiving and holding surface;

means pivotally connecting the table assembly to the arm of the lift unit at a point spaced from the connection of the arm to the second telescoping section, whereby the lift is pivotable to move the table assembly between a lowered material receiving position and a raised material placing position above the press assembly;

means for driving said lift unit to pivotally raise said arm and table assembly; and

means for driving said press assembly to extend the said second section from the first section; and

motor means for raising said press assembly and the walkways with respect to the legs.

2. A material lift and press according to claim 1, wherein the means for raising the press assembly and walkway includes a motor; a pair of reels driven by the motor; cables fixed to the reels; pulleys carried by the upper ends of the legs; and means attached to said press assembly below the pulleys, to which the cables are adapted to be connected.

3. A material lift and press according to claim 2, wherein the pivoted arm of the lift unit has a pulley on the end opposite the end to which the table assembly is connected; and one of the cables is adapted to be passed around the pulley and to be connected to the press assembly, whereby operation of the motor to drive the reel to which the cable is fixed will rotate the pivoted arm about its connection with the press assembly.

4. A material lift and press according to claim 3, wherein the table assembly has a frame suspended therefrom; a second arm is pivotally connected at one of its ends to the movable section of the press assembly and at its other end to the frame; said -.second arm extending substantially parallel with the pivoted arm and forming a parallel linkage therewith.

5. A material lift and press according to claim 4, further including means for releasably locking the table assembly to the pivoted arm when the said pivoted arm is substantially vertical and the table assembly extends substantially normal thereto.

6. A material lift and press according to claim 3, further including a small friction wheel driven by the motor; a shaft for the reels; a large friction wheel fixed on the shaft and adapted to be driven by the small friction wheel.

7. A material lift and press according to claim 6, further including means for immobilizing the pivoted arm.

8. A material lift and press according to claim 7, wherein the means for immobilizingthe pivoted arm comprises a shaft carried by and slidable with respect to the walkway and spaced holes in the periphery of the large friction wheel into which the said shaft is adapted to be inserted.

9. A material lift and press according to claim 6, further including means for frictionally engaging the periphery of the friction wheel to retard rotation thereof.

10. A material lift and press according to claim 1, wherein the table assembly includes a main frame; a sliding frame carried by said main frame; and means for moving said sliding frame with respect to said main frame.

11. A material lift and press according to claim 10, wherein the means for moving said sliding frame with respect to said main frame includes roller bearing means between said frames; and handle means on the sliding frame for use in manually moving said sliding frame with respect to said main frame.

12. A material lift and press comprising a scaffold;

a press assembly carried by thefscaffold, said press assembly including telescopingsections, one of said sections being adapted to be rigidly, but removably connected to the scaffold and another section being movable and providing a pivot connection;

a lift unit including an arm connected to the pivot connection;

a table assembly providing a broad material receiving and holding surface connected to the arm and movable by said lift unit between a lowered material receiving position and a raised material placing position;

a frame suspended from the table assembly;

a second arm pivotally connected at one of its ends to the movable section of the press assembly and at its other end to the frame, said second arm extending substantially parallel with the pivoted arm and forming a parallel linkage therewith; and

means for driving said press assembly to raise said lift unit and material carried thereby.

13. A material lift and press according to claim 12, further including means for releasably locking the table assembly to the pivoted arm when the said pivoted arm is substantially vertical and the table assembly extends substantially normal thereto.

14. A material lift and press according to claim 13, wherein the means for driving the press assembly includes a press motor adapted to be fixed to the section connected to the scaffold; a reel driven by the press motor; a hoist,

cable having one end fixed to the reel, and its other end anchored to one of the sections of the press assembly, said cable, intermediate its length being passed around at least one guide pulley fixed to the upper end of the section connected to the scaffold, and around at least one pulley fixed to the lower end of the movable section.

15. A material lift and press according to claim 14, further including means to prevent undesired rotation of the reel driven by the press motor.

16. A material lift and press comprising a scaffold;

a press assembly carried by the scaffold, said press assembly including telescoping sections, one of said sections being adapted to be rigidly, but removably, connected to the scaffold and another section being movable and providing a pivot connection;

a lift unit including an arm connected to the pivot connection;

a table assembly providing a broad material receiving and holding surface, connected to the arm and movable by said lift unit between a lowered material receiving position and a raised material placing position; and

means for driving said press assembly to raise said lift unit and material carried thereby, said means including a press motor adapted to be fixed to the section connected to the scaffold, a reel driven by the press motor, a hoist cable having one end fixed to the reel and its other end anchored to one of the sections of the press assembly, said cable, intermediate its length, being passed around at least one guide pulley fixed to the upper end of the section connected to the scaffold and around at least one pulley fixed to the lower end of the movable section.

17. A material lift and press according to claim 16, further including means to prevent undesired rotation of the reel driven by the press motor.

18. A material lift and press according to claim 16, further including a suction cup; a handle for said suction cup; a control switch on the said handle for operating the press motor; and a cord interconnecting said control switch and said press motor.

References Cited UNITED STATES PATENTS 1,442,267 1/1923 Gross et al.

2,828,870 4/ 1958 Corley.

3,058,602 10/1962 Kilman.

3,089,599 5/ 1963 Casella.

3,181,711 5/ 1965 Stockton.

3,318,465 5/1967 Fisher.

FOREIGN PATENTS 1,378,978 10/1964 France.

GERALD M. FORLENZA, Primary Examiner F. E. WERNER, Assistant Examiner US. Cl. X.R.

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