US3278158A

US3278158A - Lifting mechanism, actuating means therefor and slab anchoring means therefor

Info

Publication number: US3278158A
Application number: US387838A
Authority: US
Inventors: Saldana Juan Angel
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-08-06
Filing date: 1964-08-06
Publication date: 1966-10-11
Anticipated expiration: 1983-10-11
Also published as: GB1070459A

Description

2. O lull* 2 oct- 11 1966 J. .sALDANA 3,278,l58

LIFTING MECHANISM, ACTUATING MEANS THEREFOR AND SLAB ANCHORING MEANS THEREFOR 6 Sheets-Sheet 1 Filed Aug. 6, 1964 Junn Angel Soldana Fig l INVEN-roR BYM ATTORN EYS och 11, 1966 J. LIFTING MECHANI AND SLAB ANGHORING MEANS THEREFOR Filed Aug. e, 1964 SM, ACTUATING MEANS THEREFOR 6 Sheets-Sheet 2 A. SALDANA Juan Angel Soldona INVENTOR ATTORN EYS Filed Aug. e, 1964 Oct. 11, 1966 J. A. sALDANA 3,278,158 LIFTING MECHANISM, AGTUATING MEANS THEREFOR AND SLAB ANCHORING MEANS THEREFOR 6 Sheets-Sheet 5 mmm INVENTOR 78 l BYM;,2.

ATTORNEYS oct. 11, 1966 J. A. sALDANA 3,278,158

LIFTING MECHANISM, ACTUATING MEANS THEREFOR AND SLAB ANCHORING MEANS THEREFOR 6 Sheets-Sheet 5 Filed Aug. 6, 1964 Juan Angel Soldono INVENTOR BY M429@ ATTORN EYS Oct. l1, 1966 J. A. sALDANA LIFTING MECHANISM, ACTUATING MEANS THEREFOR AND SLAB ANcHoRING MEANS THEREFOR 6 Sheets-Sheet 6 Filed Aug. 6, 1964 ril Juan Angel Soldanu INVENTOR ATTORNEYS United States Patent O LIFTING MECHANISM, ACTUATING MEANS THEREFOR AND SLAB ANCHORING MEANS THEREFOR Juan Angel Saldana, 619 Jackson Keller Road, San Antonio, Tex. Filed Aug. 6, 1964, Ser. No. 387,838 26 Claims. (Cl. 254-106) This inve-ntion relates to a lifting mechanism for use in construction or building erection and more particularly it relates to an improved actuating means for such a mechanism which enables it to easily and precisely raise and lower heavy structural members and to an anchoring means for such members. For convenience, the invention rmay be referred to as a tri-wedge linear actuator.

In the erection of multi-story buildings, the common method of construction entails fabrication of the steelwork or framework land subsequent pouring of the concrete floors. Naturally, the ground floor -of such a building is easily formed and installed, but the upper oors of such a building are much more diflicult to construct. The wet 'concrete must be hauled up by elevators, the forms must be laid, tand the floor is then subsequently poured. It involves considerable expenditures of both time :and money to produce floors in such a manner Iand as each licor is completed, the sam-e amo-unt of time and money must again be spent to form the next higher floor. It must therefore be appreciated that construction of a building by such a -method is more costly, more time-consuming, involves a greater labor output, 4an-d the risk 4of the erected formwork collapsing during the pouring of the wet concrete presents another structural problem that must always be considered seriously in the design of the structure.

However, the 4only alternative to the practice of forming each floor at its preselected height is to form and pour all of the floors tat ground level, one `on top of the other, after each slab has been sprayed with separator fluid, and subsequently to transport each to its respective height. This alternative solution has been suggested at various times in the past, but heretofore no practical and economical equipment has been developed for elevating the preformed concrete llo-ors or slabs. It has been suggested that large hydraulic jacks be utilized to produce the desired slab lifting effects, but such jacks are in themselves extremely costly and require great amounts of hydraulic iluid, in addition to electrical connections, for their operation, not to mention the specialized training required to develop operators capable of controlling heavy hydraulic jacks accurately and safely. Fur-thermore, hydraulic jacks lack the necessary precision and fine response characteristics needed to accurately position each slab at its desired elevation, unless they are controlled by highly experienced specialized operators. In addition, the same hydraulic jacks designed to lift heavy structures, -or slabs, can not be used in any other position, such as t-o produce linear motion to heavy objects requiring horizontal, or angular, uniform displacement-s. It would require another type of hydraulic jack specially designed for producing horizontal or inclined motion.

Ratchet-type and screw-type jacks are likewise not particularly suited for the type of work envisioned by the present invention. The conventional ratchet-type jack is prone to slippage `and is lacking in proper precisional movements between successive steps. It also requires an extremely powerful actuating device to operate such a jack since the load is moved from dead Arest strictly by a pivotal lifting movement and the force exerted is direct lifting force which, in the case of heavy concrete structures, must be in the order of thousands of pounds. In the case `of' screw-type jacks, the lifting platform 'advances others.

ice

or retracts along the helical screw thread path by means of winding around the screw stem. Obviously, if it were attempted to use several such spaced screw jacks to lift or elevate a heavy slab, there would be no way for the platforms to spin labout their respective screw stems and still support the slab. Furthermore, even if it would be possible to devise a system whereby conventional rotary screw jacks could be utilized, the-re would still be a problem of slight cooking ofthe load if one platform 'advanceda slight bit further 'along the screw thread than -did the Moreover, a heavy load would tend to cause the jack to lock upon the screw threads.

It can thus be seen that conventional construction methods have serious shortcomings and deficiencies which could be benecially eliminated. Also, t-he existing types of lifting mechanisms or jacks are not particularly suitable for use in alternative forms of construction methods. The present invention is directed essentially toward a lifting mechanism for use in the alternate method of building construction, but it is not limited solely to a means for lifting preformed oors or slabs. While the essential emphasis of the lifting device of the present invention is `directed toward a slab transfer mechanism, it is equally well suited for numerous other raising and lowering operations of steel, Wood and concrete structures, including the lifting of massive formwork required in the slipform method of construction. It can operate from anysuitable base and it performs with equal efficacy whether mounted lat ground level or on a columnar support many stories above the ground or whether it is hung by its central stern and thus movable relative to the ground.

Another consideration in connection with lifting mechanisms or jacks is the anchoring devices which are utilized to secure the slabs to be lifted to the spaced lifting mechanisms which elevate the slabs to their desired location. Such anchoring devices should be cooperatively intereng-ageable With the lifting mechanisms but should be prevented from rotating during operation of the mechanisms. Additionally, such anchorage devices should be capable of aligned and superposed positioning so that several slabs, stacked one upon the other, may be lifted initially as -a unit. Moreover, during lifting of such stacked slabs as a unit, it is generally desirable to be able to separate one slab in the stack from the other slabs therein so as to permit spaced mounting of the slabs. As an example, if four stacked slabs are lifted as a unit from ground level, such slabs -should be separable, at various stages of the lifting, to provide the rst through fou-rth floors of a structure being erected. In order to permit such separation during lifting, means m-ust be pr-ovided for disassociating each slab, and its anchoring devices, from the lifting mechanisms when the slab has reached its preselected elevation.

It is, therefore, an object of the present invention to overcome the problems and shortcomings associated with prior art construction operations and lifting mechanisms utilized therein and to provide i-n their stead an improved lifting mechanism which easily and precisely raises and lowers heavy structural members.

Another object of this invention is to provide a lifting mechanism having an improved actuating means therein which facilely moves the mechanism through its desired' incremental raising and/ or lowering operations.

Another object of this invention is to provide a lift mechanism actuating means having reduced friction and increased efciency.

Another object of this invention is to provide a rugged and durable lifting mechanism which is easy to install and operate and which can be inspected and serviced without undue effort.

Another object of this invention is to provide a lowcost, high-strength lifting mechanism wherein any danger of backslipping during lifting of a load is eliminated.

Another object of this invention is to provide, for a lifting mechanism, an improved actuating means which operates simply and effectively and which produces precision movements.

Another object of this invention is to provide, for use in combination with such lifting mechanisms, suitable anchorage devices which support the loads to be lifted and which can be utilized to guide such loads along and to facilitate their attachment to, spaced structural members.

Other objects, advantages and salient features `of the invention will become apparent from the following detailed description, which, taken in connection with the annexed drawings, discloses a preferred embodiment thereof.

The foregoing objects are attained by providing a lifting mechanism which surrounds and which operates in conjunction with a threaded stem or post. Relative movement between the mechanism and the stem produces the desired raising or lowering effect. The mechanism itself may be mounted in a fixed position in which case operation of the actuating means would cause the hanging threaded stern to either raise or lower. Alternatively, the threaded stem may be hung from a fixed position in which case operation of the actuating means would cause the `lifting mechanism to climb up or down the stem. In either inst-ance, the stern is subjected only to tensile stresses in every operation.

The interior of the lifting mechanism itself is divided into an upper and lower chamber, each having within it a fixed wedge and a pair of slidable wedges movable beneath the fixed wedge. None of these wedges contacts the threaded stern which never lrotates during oper-ation of the `activating means. On the upper surface of each fixed wedge, an internally threaded gear circumferentially surrounds the threaded stern. The actuating means within the chambers operate synchronously and oppositely. When the slidable wed-ges in the lower chamber move in lone direction, those in the upper chamber move in the opposite direction. In operation, movement of the lower slidable wedges and the concomitant rotation of the lower stem engaging locking gear causes the stem and the mechanism to move incrementally relative to one another. While the lower wedges and gear are moving in one direction, the upper ones are moving in an opposite direction. Subsequent movement of the upper slidable wedges and the concomitant rotation of the upper stem engaging locking gear causes the stem and the mechanism to again move incrementally relative to one another. The foregoing operation of the lower wedges is then repeated, and the operation continues sequentially, thus continuously moving the stem and mechanism relative to one another to produce either a raising or a lowering operation, which can be selectively controlled by operating the proper lever on the central -control panel.

In operation, the lifting mechanisms may, for example, be mounted upon spaced structural members such as steel columns. The slabs to be lifted are stacked, one upon the other, at ground level within anchorage devices surrounding each of the steel columns. The stem in the lifting mechanisms yare lowered into engagement with the anchorage devices and are subsequently raised to lift or elevate the stacked slabs. As the lowermost slab reaches its -desired elevation, the anchorage devices supporting that slab are disengaged from the stems lafter the slab supporting members are maintained at that elevation by welding or bracing them to the columns. The other stacked slabs are then raised further until the next slab reaches the desired elevation. The foregoing steps are then repeated until all of the slabs have been mounted at spaced intervals along the steel columns.

Referring to the drawings:

FIGURE 1 is a transverse sectional view of a lifting mechanism, and associ-ated control panel in accordancel with the principles of the present invention;

FIGURE 2 is a transverse sectional view taken substantially along line 2-2 of FIGURE 1;

FIGURE 3 is a transverse sectional view taken substantially along line 3-3 of FIGURE l;

FIGURE 4 is a transverse sectional view taken substantially along line 4-4 of FIGURE 1;

FIGURE 5 is an exploded view of the actuating means housed within the mechanism of the present invention;

FIGURE 6 is a sequential series of sectional views similar to FIGURE 1 and illustrating, from A to E, a complete progressive sequence of movements of the actuating means;

FIGURE 7 is an end view of an interconnected pair of lifting mechanisms functioning as a singe unit;

FIGURE 8 is a side view of the mechanisms of FIG- URE 7;

FIGURE 9 is an exploded perspective view of an anchorage means in accordance with the principles of the present invention;

FIGURE 10 is a fragmentary sectional view of the anchorage means within stacked slabs poured at ground level and not yet engaged to the lifting mechanism;

FIGURE 1l is a fragmentary sectional view of the anchorage means in engagement with a portion of the lifting mechanism;

FIGURE l2 is a fragmentary perspective view of a structural member and an A-shaped brace used therewith for supporting said anchorage means at a preselected level;

FIGURES 13, 14, and 15 Iare sequential side elevational views of lifting mechanisms mounted upon structural members and elevating slabs retained within the anchorage means to predetermined levels at which they are retained by braces; and

FIGURE 16 is a transverse sectional view taken substantially along line 16-16 of FIGURE 15.

In accordance with the principles of the present invention and as can be seen from the various figures thereof, there is provided a threaded central stem generally designated 20, and mounted upon the stem is a lifting mechanism generally designated 22. The lifting mechanism is provided with an actuating means generally designated 24 which moves the lifting mechanism relative to the central stem. A drive means or means for operating the actuating means 24 is also provided, and this drive means is generally designated 26. Anchorage means generally designated 27 is provided for use in combination with the lifting mechanism 22.

Referring now to FIGURE 1, it will be seen that the lifting mechanism 22 is provided with a housing preferably formed of a metal such as steel and generally designated 28, having three side walls 60, an upper end wall 3-2, a lower end wall 34, and a center wall 36 spaced medially between said end Walls. Removable interlocked side panels 38 are utilized to close the housing 28 by providing its fourth wall, thus forming a square or rectangular shape. The panels 318 are retained by suitable bolts 40 which are removable to permit ready servicing and inspection of the interior of the mechanism 22.

The center wall 36 divides the interior of the housing 28 into an upper chamber 42 formed between the center wall and the upper end wall 32 and a lower chamber 44 formed between the center wall and the lower end wall 34. An elongated boss 46 is formed integrally with the top end wall 32 and depends therefrom into the upper chamber 42. A similar elongated boss 48 is formed integrally with the center wall 36 and depends therefrom into the lower chamber 44. A series of axially aligned apertures 50, `5.2, and 54 extend respectively through the upper end wall 32, the center wall 36 and the lower end wall 34. These apertures have a common diameter which is slightly greater than the width of the central stern 20 and -together they form a central 'bore which extends through the lifting mechanism 22 and accomm-odates the central stem 20. The center stem 20 is an elongated highstrength steel rod of variable length and is provided on its exterior surface with screw threads 56, preferably of the c-oarse or acme type.

An actuating means 24 is mounted within each of the

chambers

42 and 44, and each actuating means includes .a fixed wedge 58, as shown in FIGURES l and 5. The ixed wedge 518 has a substantially fiat upper surface 60 which extends normally lto the axis of the central stem 20 and which extends completely across the chamber. It also has a tapered lower surface l62 whi-ch extends angularly to the axis of the central stem 20 and which merges into a vertical slotted wall 64. A central aperture 66 extends through each fixed wedge .and these apertures 66 correspond in diameter to the

apertures

50, 52 and 54 and thus form part of the mechanism central bore. A pair of spaced guides 68 extend upward from the upper surface 60 of the wedge and these guides interfit with another pair of spaced guides 70 which depend from the bosses 46 and 48. The exact interfitting of the

guides

68 and 70 is illustrated in FIGURE 4. A pair of spaced parallel ribs 72 depend from the lower surface 62 of the fixed wedge '8 on opposite sides of the aperture 66.

The purpose of the ribs 72 is to accurately position a pair of linearly movable means or slidable wedges which are mounted beneath each fixed wedge. Each slidable wedge 74 has a generally rliat lower surface which extends normally to the axis of the central stem and a tapered upper surface extending angularly to the post at the same angle as the fixed wedge lower surface '62. Roller bearing means in the form of high-strength steel cylindrical casters 76 having V-grooves, as in FIG. 5, are fitted into semi-cylindrical recesses in the upper and lower surfaces of the wedges 714 to reduce friction between the slidable wedge and its adjacent fixed surfaces. The upper slidable wedge pair 714 has its lower surfaces resting on the center wall 36 and its upper surfaces slidable along the lower surface 62 of the upper fixed wedge 58. The lower slidable wedge pair 74 has its lower surfaces resting on the bottom end wall 34 and its upper surfaces slidable along the lower surface 62 of the lower fixed wedge 58. The replaceable caste-rs 76 are retained lin position by the wide walls F and the ribs 72 as shown in FIGURE 3.

As can be seen, the slidable wedges 74 are somewhat smaller than `the width of the

chambers

42 and 44 so that they can be slid linearly back and forth within the chambers. To accomplish this, each slidable wedge 74 is provided with an internally threaded hole 78 which extends completely therethrough parallel to the wedge lower surface and thus normal to the central stem 20. Each threaded hole 78 accommodates an externally threaded rod 80 which extends completely across the housing 218 and which is connected to the drive means 26 to move the slidable wedges in a manner to be presently described. The fixed wedge vertical walls 64 are slotted, as shown on iFIG. 5, to permit the rods k80 to pass therethrough.

The actuating means 20 also includes, in each chamber, a rotatable post-engaging locking gear `82 having an internally threaded aperture l814 which meshes with the threads 56 on the central stem 20. -In the upper chamber, the locking gear 82 is mounted between the fixed Wedge S8 and the upper end plate -32 and has a path of travel limited by the fixed wedge upper surf-ace 60 and the lower end of the depending boss 46. In the lower chamber, the locking gear 82 is mounted between the fixed wedge 58 and the center Wall 36 and has a path of travel limited by the fixed wedge upper surface 60 and the lower end of the depending boss 48.

In order to rotate the locking gears 82, it is necessary to provide locking gear drive means. T-o this end an .auxiliary electric motor 86 is provided in each of the

chambers

42 and 44. The motor l86 drives a non-circular shaft 88 upon which a gear 90 is slidably mounted. The shaft 88 extends into a shallow circular recess 92 in the fixed wedge 518. Each locking gea-r is provided exteriorly with an annular groove 94 having teeth 96 therein which mate with the teeth on the gear 90 as shown in FIGURE 4. Thus, operation of the motor 86 causes the gear 90 to rotate the locking gear 182 and thereby cause it to travel either up or down the threaded central stem 20, the direction of travel being dependent upon the direction of rota- -tion of the motor 86. As `the locking gear travels either upward or downward, the gear 90 which fits within the locking gear recess 94 is likewise caused to travel either upward or downward by sliding movement along the noncircular shaft 88 which is always held in circular recess 92 as it rotates by operating motor `86. The means for operating the motor -86 and for determining its direction of rotation will be described presently.

Movement of the slidable wedges 74 is controlled by the actuating means 26. This actuating means is mounted adjacent one housing wall 30 having integral webs 98 and extending perpendicularly therefrom. Removable steel end plates 102 a-re secured to the housing 28 by suitable fasteners such as bolts 104 and between these end plates and the housing side wall 30, a gear train receiving cavity 106 is formed. A main electric drive motor 108 is mounted upon the web 98 and the motor shaft 110 extends through an aperture 112 in the web 98 and into the web 100. A removable housing cover 114 ts over the motor and is retained by bolts 116 which connect to the web 98 and the upper end plate 32. As indicated by the dashed lines in FIGURE l, the motor 108 may be considerably larger than is illustrated and in such a situation, the housing 114 would be enlarged accordingly, though retained in the same fashion as illustrated.

The main motor shaft is provided with a worm 118 which drives a Worm wheel to form a worm gear which operates a gear train within the cavity 106. The worm wheel 120 is formed integrally with a larger gear 122 and both are freely mounted to a perpendicularly fixed shaft 124. The shaft extends through the end plates 102 and is provided with an end cap 126. Two smaller gears 128 intermesh with the larger `gear 122 and these smaller gears are mounted on the ends of the upper chamber threaded rods 80 by means of cap nuts 130. A second larger gear 132, similar in size and tooth construction to the gear 122, is freely mounted to a perpendicularly fixed shaft 134 which extends through the end lplates 102 and is provided with an end cap 136. The gear 132 meshes with the gear 122 and is driven thereby in an opposite rotational direction. Two smaller gears 138, similar to the gears 128, intermesh with the larger gear 132 and these smaller gears are mounted on the ends of the lower chamber threaded rods 80 by means of cap nuts such as 130.

The gear train and its connection with the drive motor 108 is fully illustrated in FIGURE 2 from which it becomes apparent that if the motor rotates the shaft 110 in a clockwise direction, the worm wheel 120 and its interconnected larger gear 122 will also rotate in a clockwise direction. Thus, the smaller gears 128, which can also be referred to as the upper chamber slidable wedge driving gears, will rotate in a counter-clockwise direction, and their rotation will cause the upper chamber slidable wedges 74 to move linearly away from .their driving gears. The gear 132 is :also driven by the gear 122 and thus gear 132 will also rotate in a counter-clockwise direction. Thus, the smaller gears 138, which can also be referred to as the lower chamber slidable wedge driving gears, will rotate in a clockwise direction, and their rotation will cause the lower chamber slidable wedges 74 to move linearly toward `their driving gears. It can thus be appreciated that power from the electric motor 108 can be transmitted, through the gear train, directly to the upper and lower chamber slidable wedge pairs to cause these wedge pairs to linearily move in synchronization and in opposite directions. Naturally, when the electric motor 108 is reversed automatically, the movement of the slidable wedge pairs will `also be reversed.

Before describing the sequential steps in the operation of these motors.

of the lifting device 22, there will be described the means for controlling the operation of the drive means motor 110 and also for ycontrolling the locking gear drive means motors 86.

Naturally, each of these motors is suitably connected to an electric power supply by wires 162 and 164 leading to electrical control panels 166, FIG. 1, and ythe power can be turned on or off at this power distribution point. Before the power is turned on, it is necessary to check the levels of the

wedges

62 and 74 thru peep holes 152 and to set them with wrench 156 as on FIG, 6 at A or C; then to engage one of the levers on the control panel 166, FIG. l, either Up for lifting or Down for lowering. The directionality of prime motor 108 and shaft 110 is determined by electrical switch means such as two micro-switches 142 mounted in the slotted wall of fixed wedges 58, FIG. 5. When the slidable wedges 74 strike and close the two switches, they cause the motor to change direction. Thus, when the upper slidable wedges 74 engages against the slotted wall of upper xed Wedge 58, it closes the two switches 142 and causes the motor 108 to rotate the shaft 110 clockwise the instant upper slidable wedges retract and open upper switches 142. The motor will continue this clockwise lrotation until such time as .the lower slidable wedge 74 engages against the slotted wall of lower fixed wedge 58 and closes its two switches 142. This reverses the action of the motor 108 and causes it to rotate counterclockwise the instant lower slidable wedges retract and open lower switches 142 until the upper slidable wedges again engages the upper switches 142 shown in FIG. 5.

The foregoing operation is repeated again and again, thus causing the electric motor 108 to continually reverse the operational directions of the gear train. Thus, the slidable wedges 74 `are slid back and forth within their chambers.

Although the movement of the slidable wedges controls the main motor 108, the locking gears themselves are driven by separate auxiliary motors 86, and it is necessary to provide additional means for controlling the operations Such control means again takes the form of electrical switch means such as two micro-switches 142 which are mounted in the vertical outer walls 64 of the fixed wedges 58, as shown on FIG. 5. Each microswitch 142 is connected to each motor 86 and to prime motor 108. Thus, the instant the power is applied when the upper chamber micro-switches 142 are engaged `and closed by the slidable wedges 74, it causes the upper chamber motor S6 to rotate clockwise when lifting, or counterclockwise when micro-switches 142 are opened for Lowering, depending on which lever is engaged on control panel 166, FIG. l, through electrical wires 162 and 164 connected to Lifting mechanism at panel box 160.

With the foregoing structural and constructional details of the invention rmly in mind, it is now possible to describe the operation of the lifting mechanism 22, and to fully understand such operation, reference is made to FIGURE 6 which illustrates the operation in sequential steps. In view A, it will be noted that the upper chamber slidable wedge 74 is in engagement with the xed wedge vertical slotted wall 64 as shown on FIG. 5. This means that the two upper chamber switches 142, as shown on FIG. 5, are closed, as in view A, thus causing the main motor 108 to rotate clockwise, and the upper chamber auxiliary motor 86 to rotate clockwise when lifting. The lower chamber auxiliary motor 86 does not rotate during this phase because it is the lower locking gears turn to carry the load up one increment. As a result of these rotations, the gear train causes the slidable wedges 74 to move synchronously in opposite directions and simultaneously the auxiliary drive means causes the upper locking gear 82 to thread down for two increments the control stem 20 and the lower locking gear 82 to take up the load carried by the central stem 20 for one increment. This is illustrated in view B. These opera- CTI tions continue until the gears and wedges reach the position of view C wherein the lower chamber slidable wedge 74 is in engagement with the vertical slotted wall 64, as shown in FIGURE 5. In this position, the two lower chamber switches 142 are closed, as shown in FIGURE 5 and FIG. 7(6), and the operation of the motor 108 is reversed. This causes the slidable wedges 74 to reverse their direction of linear movement and also causes the upper locking gears 82 to take up for one increment the load carried by the stem 20, and the lower locking gears to thread down along the stem 20 for two increments. This is shown in view D. These same operations continue until the gears and wedges reach the position of view E wherein they are returned to their original positions as shown in view A. This completes one cycle of operation and during this cycle the threaded central stem 20 has moved downward two increments. The size of an increment depends on the capacity of the unit. The switches are emergency switches for shutting off the power source and thus stopping the actuating means when either motor S6 burns out a fuse or otherwise develops trouble.

Referring again to views A and B of FIGURE 7, when the upper motor 86 fails to operate during lifting, the upper locking gear does not thread down the stem 20, even though the slidable upper wedges have raised the load one normal increment, View A. Since the upper gear has not threaded down the normal two increments, the upper gear closes the emergency switch 140 when the lower slidable Wedges, view B, carry the load up one more normal increment. When the emergency switches 140, either top or bottom, are closed by either locking gear, it is an indication that the lifting is to be stopped until the burned fuse or other power trouble is corrected.

It should be noted that the locking gears 82 are always in abutting engagement with the fixed wedges 58 and these tixed wedges are always in abutting engagement with the slidable wedges 74 but only one chamber at a time carries the load. Thus, the load acting upon either the mechanism 22 and the stems 20 is always fully distributed within either chamber of the unit, and the use of the dual chambers thereby provides a double factor of safety when lifting or lowering heavy loads with the mechanism 22. The form shown in FIGURE l wherein the upper locking gear 82 is out of engagement with the xed wedge 58 is only for purposes of simpler illustration to show how a locking gear not carrying the load is easily threaded along the stem 20 by the motor 86. The load is automatically and alternately transferred from one locking gear to the other.

The lifting mechanism 22 can be utilized in two separate ways, both of which take advantage of its movement relative to the central stem 20. One way is to attach the mechanism 22 to a beam or column to keep it lixed, in which case the stem 20 moves up or down and the load is carried by the stem. The other way is to hang the stem and to allow the mecchanism 22 to crawl up or down the post. If this latter mounting means is used, the mechanism must be bolted, strapped, or otherwise connected to the object to be lifted. Such strapping can be secured by utilizing a pair of lifting eyes, such as illustrated at 144 in FIGURE l, to facilitate attachment of the structural load to be lifted or lowered. The lifting eyes 144 are also used when raising the unit to the top of a column or removing it therefrom by means of a crane.

In certain instances where extremely heavy loads are to be lifted, it may be desirable to utilize two mechanisms 22 in tandem. Such an arrangement is shown in FIG- URES 7 and 8 wherein the two mechanisms 22 are spaced apart and connected by a steel connector, a variable boxed plate 146 which is suitably axed to the two mechanisms. The tandem unit is mounted on steel girders 148 which are supported by a beam or column 150.

9 Using such a tandem arrangement, it becomes possible to lift double the loads which can be lifted by a single unit.

Of course it will be recognized that other minor constructional features can be included without departing from the spirit and scope of the present invention while nonetheless enhancing its practical capabilities. For example, peep-holes 152 may be provided to permit visual determination of the position of the various wedges, all of which should be set as shown in views A or C of FIG- URE 6, by means of a wrench 158, FIGURE 8, before connecting the main power source wires 168 to the control panel 166. Pivotally mounted covers 154 can be provided to normally close such peepholes in the same manner illustrated in FIGURE 7. Also, the bolts 40 and 104 can be quickly and easily removed by a wrench 156 as shown in dotted lines in FIGURE C. This permits removal of the

panels

38 and 102 to facilitate ready servicing and inspection of the interior of the mechanism 22.

Referring now to FIGURE 9, the anchorage means 27 and the component parts thereof are illustrated. A slab supporting member generally designated 161 has a body portion 163 projecting toward an opening 167, and having a top plate 171 and

webs

165 and 168 extending from the base 169 thereof to receive and support the slabs to be lifted. The opening 167 is provided at the center of member 161 for accommodating, and permitting said supporting member to be mounted about, a suitably shaped structural member such as, for instance, a steel column. In the illustration of FIGURE 9, the opening 167 is shaped as a reversed squared C to receive a wide flange column or H-beam. It should be understood that, in actual practice, the size and shape of the member 161, the

Webs

165 and 168 thereon and the opening 167 therein, may be varied in order to compensate and balanceagainst stresses normally encountered in elevating concrete slabs and the like.

As can best be seen on FIGURE l1, a bore 170 extends through the projected body portion 163 and is juxtaposed to the web 174 of a wide flange column 172 which extends through the opening 167, after the slab supporting member 161 is inserted over the column; therefore, the bore 170 is adjacent to the web 174 of the column and is spaced between the anges 176 thereof to align and receive anchorage means 27. At the lower end of the body portion 163, the bore 170 merges into an enlarged circular counterbore 178 having a short flat recess 180 extending from an edge thereof toward the base 169 of slab supporting member 161. The bore is shaped to receive a removable anchor base lock ring generally designated 182 and having a circular body portion 184 which lits within the icounterbore 178 and a short foot portion 186 which tits within the at recess 180. At least one aperture 188 extends through the foot portion 186 and aligns a threaded aperture 190 in the base of the body portion 163. A screw 192 can pass through the aperture 188 and thread into the aperture 190 to thus removably attach the anchor base lock ring 182 to the supporting member 161.

Within the body portion 184, a polygonal recess 194, preferably octagonal, is formed. An anchor member generally designated 196 is formed with an enlarged octagonal base portion 198 designed to t contiguously within the recess 194 and a circular stem portion 200 designed to t contiguously within the recess 194 and a circular stem portion 200 designed to t contiguously within the bore 170. The anchor member 196 has an internal threaded bore 202 which threadab-ly receives and engages the stem 20 of the lifting mechanism 22. At its upper and lower ends, the anchor member is provided with recesses 204 surrounding the bore 202 and designed to receive hollow cylindrical spacing sleeves 206, the upper of which in turn receives a wood plug 207 to protect the threaded bores 202 when the stacked slabs are being poured.

The assembly of the anchorage means 27 can best be seen in FIGURE l1 wherein lifted concrete stacked slabs 208 are engaged thereby, and in FIG. 10 wherein stacked slabs on the ground slab are not engaged. The supporting members 161 surround the column 172 and support the slabs 208 upon their bases 169. Within each member 161, an anchor 196 is poistioned in the bore 170, and a sleeve 206 extends between recesses 204 in the top of one anchor and the bottom of the adjacent anchor to maintain such anchors in proper space alignment. The threaded stem 20 extends through the similarly threaded internal bores 202 in the anchors. As the stem 20 is raised or lowered by its associated lifting mechanism 22, the anchors 196 and hence the slabs 208 are accordingly raised or lowered. In order to prevent the anchors in stacked slabs from rotating about the stem when said stem is being threaded to engage stacked slabs for lifting, the anchor base lock ring 182 is employed to lock the octagonal base 198 of the anchor within the octagonal recess 194 in the ring. In addition, said lock ring 182 provides for the separation of stacked slabs parked as a unit anywhere on the column.

In FIGURE 11, the upper anchor 196 has a lock ring 182 surrounding Iit, but the lower anchor has no such ring since, for illustration, it was removed by unscrewing of the screw 192 after the slabs were secured to the columns. However, even though there is no lock ring surrounding the lower anchor, said anchor nevertheless remains in position within the bore since it is threadably engaged upon the stem 20. When it is desired to remove the lowermost anchor 196, a conventional Wrench may be utilized to engage its octagonal base 198 to unscrew the anchor off the stem 20. This operation is performed when the lowermost slab 208 has reached its desired elevation and has been secured to the columns. In order to support and connect the slab 208 and its supporting members 161 after the anchors 196 have been unscrewed, suitable brace means generally designated 210 are provided, as shown in FIGURE 12. Although the bra-ce means may take any suitable shape or form capable of either temporarily or permanently supporting a slab 208, one suitable form is that shown in FIGURE 12 wherein a pair of spaced legs 212 on the brace are attached and stifened by

crosspieces

214 and 215 and wherein spaced slots 216 are formed within the column web 174 to receive such legs with the crosspiece abutting against the web and against the crossplate 173 pre-welded to the column. In addition, a pair of steel pieces pre-welded to column anges counterbalances the slab load on the projected body portion 163 when the anchors 196 are removed and the slab is self supported by the brace 210.

Turning now to the operation and the cooperative interaction between the lifting mechanism 22 and the anchorage means 27, reference is made to FIGURE 13 wherein a pair of lifting mechanisms 22 are mounted upon the top of a pair of spaced beams or columns 172. Although such lifting mechanisms lcan be either of the single type or the tandem type as shown in FIGURES 7 and 8, the former is used in FIGURE l2 for purposes of simpler illustration. Ea-ch lifting mechanism thus has a threaded stem 20 which can be raised or lowered along the column 172. A pair of supporting members 161 surround each column with the lowermost of said members resting upon the foundation slab poured on ground, as shown in FIG. 10. Between each opposed pair of members 161, a floor slab 208 extends. Anchor members, lock rings and spacer sleeves are utilized in a stack of lifted slabs fin mid-air, as in FIGURE 10, and in FIG. 10 in a stack of slabs on the ground slab 209 just before they are engaged to threaded stem of the mechanism for lifting.

When it is desired to raise the two stacked slabs 208, the lifting mechanisms are operated to lower the stems 20 so that .they may be .threaded downward int-o the threaded bores 202 within the anchors 196. Then, the lifting mechanisms are re-engaged and set for lifting in order to raise the stems and hence to raise the supported slabs 208. When the slabs are raised to a level slightly above a preselected height, such as a first story level, the b-race means 210 is slipped through each column 172 to extend below the lowermost slab support members, vas shown in FIGURE 14, which is also a plane directly below the pre-welded steel pieces 175, as shown in FIG- URE l2. At this time, the screw 192 is removed and the lock ring 182 is likewise removed. Such removal can be easily accomplished between the spaced legs 212 of the brace means 210 as shown on FIGURE 16. Once the lock rings have been removed, wrenches can be used to unscrew the lowermost anchors 196 from the stems 20. When this has been accomplished, the l-owermost slab 20S is supported solely by having its supporting members 161 resting upon the brace means 210, which is counterbalanced by prewelded steel pieces 17S on FIGURE l2. If desired, the uppermost slab can rest in a parked position upon the lowermost one while the supporting members 161 carrying the lowermost slab are permanently afiixed t-o the columns 172 as by the brace means on EIGUR\E l2, or by field welding steel blocks to the column flanges directly below the slab supporting members 161. After completing said slab connections, the lifting mechanisms can continue to operate and raise the stems 20, thereby causing the uppermost slab 2018 to separate from the lowermost one and continue raising to a higher level, as shown in FIGURE 15. It should be noted that considerable time is saved and the operations of the lifting mechanisms are minimized when two or, at the most, four slabs are raised together and parked, stacked together, at each designated floor height, until the uppermost slab is finally raised alone to its permanent position. In addition, the use of the lock rings 182 is never required on a slab designated to be the roof, as shown in the two-story building example on FIGURE 10, because .theroof slab is always raised alone. Nor is the lock ring 182 ever required on the uppermost slab of a group of stacked slabs lifted together and parked at a preselected height so that the uppermost slab of the group can then be lifted alone to a temporary or permanent position and connected to the columns.

After reading the foregoing descrip-tion, it should be apparent that the objects set forth at the outset of the specification have been successfully achieved. Accordingly, what is claimed is:

1. A lifting mechanism for selectively raising or lowering structural loads comprising:

a housing having a bore therethrough adapted to receive a threaded stem;

means for coupling said lifting mechanism with said threaded stern;

first and second actuating means within said housing f-or selectively moving said housing relative to said stem; each of said actuating means including linearly movable means which operate normally to said stem; and

drive means coupled with said linearly movable means and operative to move said first and sec-ond actuating means synchronously with said first actuating means moving in a direction opposite to the direction of movement of said second actuating means;

said drive means operation causing said linearly movable means -t-o move said housing relative to said stem to raise or lower a load axially along said stem. n

2. A lifting mechanism as defined in claim 1 wherein said actuating means includes at least one fixed wedge through which said bore extends and said linearly movable means includes at least one movable wedge engageable with said fixed wedge for selectively raising or lowering it.

3. A lifting mechanism as defined in claim 2 wherein said drive means includes an electric motor and a gear CII train responsive to -said electric motor and connected to said movable wedge for linear moving thereof.

4. A lifting mechanism for precisely and selectively raising and lowering structural members comprising:

a housing having an upper and a lower chamber therein and having a central bore adapted to receive a threaded cent-ral stem, said central bore extending between said upper and lower chambers;

means for coupling said lifting mechanism with said threaded central stem;

a fixed wedge mounted within each of said chambers and having an aperture therein coaxial with and diametrally similar to said central bore;

a pair of slidable wedges located adjacent each of said fixed wedges and adapted to slide therealong within each chamber;

electrically operable drive means connected to said slidable wedge pairs to move each pair linearly and to move said upper chamber slidable Wedge pair in a direction opposite to said lower chamber slidable wedge pair;

said linear movement of said wedge pairs causing said lifting mechanism to move relatively to said threaded central stem to effect a raising or a lowering operation.

5. A lifting mechanism as defined in claim 4 wherein said slidable wedges in a pair are spaced apart by a distance at least equal to the diameter of said central bore.

t6. A lifting mechanism as defined in claim 4 wherein, in each chamber, said slidable wedges are located beneath said fixed wedge and are spaced therefrom by roller bearing means.

7. A lifting mechanism as defined in claim 4 wherein said coupling means includes a rotatable locking gear located in each chamber above said fixed wedge and being internally threaded to engage and travel upon said threaded central stem.

8. A lifting mechanism as defined in claim 7 but further characterized by locking gear drive means connected to each of said locking gears and responsive to the movement of said slidable wedges to cause said locking gears to rotate.

9. A lifting mechanism as defined in claim 8 wherein electrically operable drive means includes a main electric motor responsive to movement of said locking gears and a gear train connecting said main electric motor to each of said slidable wedge pairs to effect their linear movement.

10. In a lifting mechanism having a dual-chambered housing coupled with and circumferentially surrounding a threaded central stem, actuating means for moving said housing and said stem relative to one another, said actuating means comprising:

a fixed wedge mounted within each chamber and having a substantially fiat upper surface and a tapered lower surface;

said fixed wedges having aligned apertures therethrough for non-engaging reception of said threaded central post;

a pair of slidable wedges mounted within each chamber and spaced from one another by a distance sufficient to accommodate said threaded central stern;

said slidable Wedges having a substantially fiat lower surface and a tapered upper surface tapering at substantially the same angle as said fixed wedge lower surface;

said slidable Wedge pair being located beneath said fixed wedge in each chamber and being spaced therefrom by roller bearing means;

said slidable wedges being shorter than the width of said chambers whereby said wedge pairs can be linearly moved across said chambers normally to said threaded central stem; and

slidable wedge moving means operable to linearly move 13 said upper chamber wedge pair and said lower chamber wedge pair in opposed directions.

11. An actuating means as defined in claim wherein said slidable wedge moving means includes a threaded rod extending through each slidable wedge and connected to a gear train which rotates said threaded rods and causes said slidable wedges to move linearly within said chambers.

12. An actuating means as defined in claim 10 but further characterized by a rotatable locking gear located in each chamber above said fixed wedge upper surface and threadably engaged with said central stem, and locking gear drive means operable responsive to movement of said slidable wedges 'to cause said locking gear to travel along said central stem.

13. An actuating means as defined in claim 12 wherein said locking geardrive-means includes an auxiliary electric motor connected to each of said locking gears and adapted to rotate the same, and an electric switch means actuated by said slidaB-ble'wedges to control said auxiliary electric motor.

14. In combination for raising and lowering structural loads:

an elongated externally threaded stem; and

a lifting mechanism mounted upon said stem;

said lifting mechanism including a housing having upper and lower end walls and a center wall which divides said housing into an upper chamber and a lower chamber;

said housing having axially aligned apertures in said end walls and center wall which define a central bore through which said threaded stem extends;

said central 'bore being diametrally larger than said threaded post whereby the walls of said bore are free from engagement with said stem;

a fixed wedge mounted within each chamber and having an upper surface substantially normal to said threaded stem and a lower surface extending angularly to said stern;

a pair of slidable wedges mounted within each chamber and spaced apart by a distance at least equivalent to the diameter of said central bore;

said slidable wedges having a lower surface substantially normal to said thread-ed stem and an upper surface extending angularly to said stern at the same angle as said fixed wedge lower surfaces;

said slidable wedges being mounted with their upper faces juxtaposed to said fixed wedge lower surfaces;

an upper locking gear threadably mounted upon said stem and movable between said upper end wall and said upper chamber fixed wedge upper surface;

a lower locking gear threadably mounted upon said stem and movable between said center wall and said lower chamber fixed wedge upper surface;

drive means operable to move said slidable wedges linearly within their respective chambers with said upper and lower slidable wedge pairs moving synchronously and in opposite directions;

locking gear drive means connected to each of said locking gears to alternatively and separately rotate said locking gears and cause each of them to travel alternatively along said threaded stem;

said locking gear drive means being operative in response to movement of said slidable wedges; and

said drive means being operative in response to movement of said locking gears.

15. A combination as defined in claim 14 wherein said drive means includes a main electric motor, a gear train driven `by said motor, and threaded rods extending through each slidable wedge parallel to its lower surface, said gear train being connected to said threaded rods to cause them to rotate and thus linearly move said slidable wedges.

16. A combination as defined in claim 15 but further characterized `by electrical switch means adapted to be 14 actuated by locking gears to control said main electrical motor.

17. A combination as defined in claim 14 wherein said locking gear drive means includes, in each chamber, an auxiliary motor having a shaft depending therefrom and extending into a recess in the upper surface of said fixed gear and a gear slidably mounted on said shaft and engaging said locking gear for rotation thereof.

18. A combination as dened in claim 17 wherein said auxiliary motor shaft is non-circular.

19. A combination as defined in claim 14 but further characterized by roller bearing means interposed between said fixed and said slidable wedges and between said slidable wedges and said center and lower end walls which support them.

20. A combination as dened in claim 14 but further characterized by anchorage means for securing a load to said threaded stem for raising and lowering therewith, said anchorage means including:

a support member having a bottom base plate for direct support of the load and a top plate for the reversal reaction created during the lifting of the load and a body portion having an opening therein to accommodate a shaped structural member;

said support member body portion projecting toward the center of said opening and having a lbore extending therethrough;

an anchor member having a stem portion disposed within said vbore and a polygonal enlarged base portion appended to said stern portion;

said anchor member having a threaded internal bore extending therethrough for threadably receiving the threaded stem of the lifting mechanism to anchor the load thereto; and

a removable base lock ring removably secured to said support member and having a recess for accommodating said polygonal base portion to prevent rotation of said anchor member about said threaded stem and to provide for the separation of said anchor mem-ber from said support member when a plurality a slabs are simultaneously lifted.

21. In combination for raising stacked slab members and for spacing them at intervals along spaced upstanding structural columns:

a lifting mechanism mounted each of said columns;

a threaded stem extending through each lifting mechanism to be raised and lowered thereby; and

anchorage means for securing said stacked slab mem- -bers to said stems;

said anchorage means including a plurality of support members surrounding said columns and normally resting at the base thereof;

said support members having top and Ibottom base plates extending toward one another to underlie said slab members and support the same in stacked relation;

said anchorage means further including an anchor member within each of said support members;

said anchor members being aligned and internally threaded to receive said threaded stems and secure the stacked slabs thereto;

said anchorage means further including a plurality of locking means, one engaged with each of said anchor members and with each of said support members to prevent rotation of said anchor members and to provide for mid-air separation of stacked slabs lifted together so that each slab may easily be lifted and connected to the columns at preselected levels;

said lifting mechanisms being operable to raise said stems whereby stacked slabs are similarly raised;

said anchor members being removable from said support members, upon disengagement of said locking means, to permit the lowermost of said slabs to be disengaged from said stems at a predetermined level,

upon the upper end of 15 the next lowest slab to be disengaged from said stems at a higher level, and so on until all said slabs have been separated and spaced at various levels along said columns.

22. A combination as defined in claim 21 wherein said columns are wide flange and have web openings at spaced intervals therealong and wherein brace means can 'be inserted through said openings to support said slab mem- `bers by controlling the gravitational forces through balanced lever-action created by said brace means.

23. A combination as defined -in c-lairn 21 wherein spacer sleeves are disposed between the anchor members stacked upon one another, Ithe upper sleeve being adapted to be provided with a plug to protect the aligned threaded bores during the pouring of the concrete for said stacked slabs.

24. A combination as defined in claim Z1 wherein said locking means includes a non-circular aperture means and wherein said anchor members include a non-circular portion which fits within said 4aperture means thereby 16 preventing said anchor members fromy rotating relative to said locking means.

Z5. A combination as defined in claim 24, wherein said ynon-circular aperture means and anchor member portions are polygonal in configuration.

2'6. A combination as defined in claim 21, wherein said anchorage means further includes a releasable coupling mea-ns normally securing said locking means to sa-id support members, said coupling means, when released, disengaging said locking means from said anchor members.

References Cited by the Examiner UNITED STATES PATENTS 2,758,467 8/1956 Brown et al. 52-126 3,065,573 11/1962 Goldberg 52--126 3,154,292 10/1964 Rankin et al 254-105 3,179,374 4/1965 Walli 254--109 WILLIAM FELDMAN, Primary Examiner.

OTHELL M. SIMPSON, Examiner.

Claims

1. A LIFTING MECHANISM FOR SELECTIVELY RAISING OR LOWERING STRUCTURAL LOADS COMPRISING: A HOUSING HAVING A BORE THERETHROUGH ADAPTED TO RECEIVE A THREADED STEM; MEANS FOR COUPLING SAID LIFTING MECHANISM WITH SAID THREADED STEM; FIRST AND SECOND ACTUATING MEANS WITHIN SAID HOUSING FOR SELECTIVELY MOVING SAID HOUSING RELATIVE TO SAID STEM; EACH OF SAID ACTUATING MEANS INCLUDING LINEARLY MOVABLE MEANS WHICH OPERATE NORMALLY TO SAID STEM; AND DRIVE MEANS COUPLED WITH SAID LINEARLY MOVABLE MEANS AND OPERATIVE TO MOVE SAID FIRST AND SECOND ACTUATING MEANS SYNCHRONOUSLY WITH SAID FIRST ACTUATING MEANS MOVING IN A DIRECTION OPPOSITE TO THE DIRECTION OF MOVEMENT OF SAID SECOND ACTUATING MEANS;