US2170689A - Scaffolding suspension - Google Patents

Description

E. L. LOOMIS SCAFFOLDING SUSPENS ION Aug. 22, 1939.

Filed Jan. 31, 1938 2 Sheets-Sheet 1 Aug. 22, 1939. E. Loomis SCAFFOLDING SUSPENSION 5 2 Sheets-Sheet 2 Filed Jan. 31, 1938 Patented Aug. 22, 1939 UNITED STATES ATENT OFFICE 17 Claims.

This invention relates to scaffolding suspension.

It is an object to provide means for suspending a scalfold, especially, for example, one such 5 as painters use, so that it can with relative ease be set into position to support men for working on a wall of a building, and so that, when once set, it can be moved over the entire length and height of that wall without a re-setting of its supports.

To this end the invention utilizes the track and trolley type of suspension; and it provides improvements whereby the track is applicable for ample support in a simple manner by any roof; that is, by a roof which is level or of any ordinary pitch, and which has any ordinary type f roof surface. The track will rest on the roof approximately over the Wall on which the work is to be done, without cantilever or out-rigger construction, and without the necessity that the roof be` provided with any permanent brackets or other means for attachment.

It is a feature that the individual parts which require to be handled for the installing are light, and can be handled easily both for the installing and for their removal; that the suspension can be made without injuring the roof; and that there is ample safeguard against injury to any person `through failure of the apparatus. The facility with which the stage can be moved to any part of the wall, by manipulation from the stage itself, saves hours of time. It eliminates the need of workmen coming down, and climbing again to the roof, and moving their tackle and its supports to a fresh location for getting into position to work on an adjoining section' of wall. Also, in the case of painting, it facilitates better eXecution of the work, by permitting the painting to continue horizontally at each level, freshly and uniformly without the diversity which results when a period of drying intervenes before the next adjoining section is painted.

Apparatus embodying the invention can be used either for a long staging, suspended on two supports; or for each individual painter to oper- Aateon a light separate support like a boatswains chair. In case of a, house with pitch roof the same track and trolley which is used on the side of the house can also be used along the steep of the roof at the gable ends. On it the painter can get up close to the peak, and can follow down the coping, all the way to the corner of the building, thus avoiding laps in the painting.

With the attaining of the essential, that the apparatus involved shall be safe for those who use it, the invention combines the attaining of the further useful objectives that the apparatus shall be simple in construction; inexpensive to manufacture; easy to set up and to operate; and yet, notwithstanding its light weight, be thoroughly strong and practical.

The specific combination of elements by which the above and other advantageous results are accomplished includes a light truncated triangular wooden sleeper or sill, made in sections to l0 be coupled together endwise, and to rest directly on the normal surface of the roof. On this sill lies a round-topped rail adapted for endwise continuity with similar rails on other sections, on which is to run a trolley having grooved wheels. For ordinary use the sill may be of light wood with cross section having a 221/2 angle; and the rail may be of ordinary iron gas pipe. Ridge ties or other suitable fastenings can keep this sill from slipping off the edge of the roof, tackle with end blocks can move the trolley as far as the rail extends; and a latch can anchor the trolley anywhere along the line.

rI'he suspension of scaffolding from the trolley is by a stiff U-bow, set on its side; so that its top limb, having its end secure on the trolley, projects outward to beyond the edge of roof and eaves trough; its bowl drops down to a level below the eaves; and its lower limb runs in to a location which preferably is directly under the trolley, and holds the tackle by which the scaffold is suspended. With the parts thus indicated there are combined other structural features, and other features providing for safety, which will appear from the description which follows, and from the accompanying drawings. The drawings illustrate one embodiment of the invention, to which, however, the patent is not limited.

It is intended that the patent shall cover, by suitable expression in the appended claims,what rever features of patentable novelty exist in the invention disclosed.

In the accompanying drawings: 5

Figure 1 is a face elevation of an end section of track, with trolley and staging hanger thereon;

Figure 2 is a side elevation, the view being endwise of the trolley and track and being in section through the sleeper and rail thereon;

Figure 3 is a plan of the end section seen in Figure 1 showing sleeper, rail, trolley and hanger, and brackets for holding the sleeper on the roof;

Figure 4, on a larger scale, shows more clearly parts as they are seen in Figure 2 but as applied on a roof having steeper pitch;

Figure 5 is an isometric general View showing the apparatus applied to a roof of low pitch having asphalt flexible shingles; and

Figure 6 is an isometric View showing an end portion of apparatus applied at the peak of a gable end of a house.

Referring to the drawings, the embodiment which is here chosen for illustrating the invention shows a scaffold Ill suspended in ordinary manner by tackle I2 from the eye I4 of a staging hanger bow it whose upper limb I8 is secure in a trolley carriage 20 that runs on a track 22 lying on the wooden sleeper 24 which rests on the edge portion of a roof 26. The staging hanger it is a stiff bar of round iron or other metal in the general shape of a U lying on its side, so that the eye I4 where the weight of the scaffold is applied is directly under that part of the other end of this hanger bow which is secured at the middle of the two-wheel trolley, and incidentally, is directly under the line of the two wheels 2l thereof and rail 22 which constitutes the track on which the trolley runs. That rail may conveniently be made of 3A, iron gas pipe secured on the sleeper Z4 by screw bolts 23 which are set in the sleeper and are threaded through both sides, crossing the axis of the rail thus constituted.

As the tackle holding the scaffold is hooked through the eye I4 all stresses resulting from the load are imposed vertically on the rail. 22 and, through bolts 23 and sleeper 24, are imposed vertically on the edge portion of the roo-f, which is approximately directly over the wall, so that the Vertical component of the stress imposed by the scaffold is carried by the wall without any tendency to break out or buckle the wall or to impose undue stress on the rafters of the roof. The component which must be considered as being resolved parallel to the roof is resisted either by brackets 25 as illustrated in Figures 5 and 4 or by ridge ties (not shown) which may extend from the eye bolts 27 that are set in the sleeper, being ropes which may extend to hooks that are well known for engaging beyond the ridge or may extend to chimney or other fastening at higher location on the roof. In the particular embodiment chosen for illustration it is assumed that the roof has asphalt shingles, and these being iiexible can be turned up as at 28 so that brackets 25 can be held by nails driven through the holes 23, best seen in Figure 3, into roof boards and preferably into rafters. These holes have extension slots so that the brackets cannot hop out at the head of the nail; but when the brackets are removed the nails can be driven home and the shingles turned down into normal position. But on a roof whose surface is of tile, sla-te, wood or other inflexible material, or gravel, ties from the eye-bolts 2 would be used. By either arrangement the sleeper and rail-track are made secure against slipping off the edge of the roof; and this is accomplished without any permanent bracket or fixture on the roof.

The sleeper, bracket and trolley are adapted to be secured on a roof of any pitch by reason of the truncated triangular cross-section of the sleeper 2li for which an angle of 221/2o is suggested between the top side, shown horizontal in Figure 2, and the bottom side which rests on the bracket at the angle of pitch of the roof. In the case of a roof having 22%o pitch the plane of the trolley wheel 2I running or standing on its track 22 will be vertical through the track, and the deep grooves of the wheels, approximately semi-circular and resting on the rail 22, will hold the wheels from lateral displacement, particularly since the forces co-ming from the scaffold pass through the loose joint I4 vertically under the rail and wheels, and any lateral force applied to the scaffold I will not be transmitted higher than the loose `oint I4 and so cannot reach the trolley. If the roof be steeper as in Figure 4, at 26', the peculiar cylindrical shape of the gas pipe rail 22 permits the same relation of verticaiity of wheels over rails to exist, although the angle of the top side of the sleeper is now 2.21/2o from the horizontal, pitching outward. And the same would be true if the roof were horizontal, in which case the top surface of the sleeper would pitch inward, but without disturbing the secure position of the wheels on the rail.

The rail 22 constitutes a track on which they trolley can run lengthwise of the wall as far as the track extends. The apparatus is adapted for application to walls of any length by making the sleeper and track in sections, for which convenient lengths are ten feet, five feet and two and one-half feet, which can be coupled together endwise by any suitable means. The means illustrated is a stout U-loop 3@ whose two stub end portions can be dropped loosely into inclined holes provided for them in the front faces of adjoining sections. The coupling loop is safely held so by gravity, but, being loose, it can be easily lifted out. For further assuring smooth continuity of rail sections an axial pin 32 is fixed in one end of the hollow of each rail section, as a tenon to enter the end hollow of the adjoining rail sectionl Sleeper sections which are at the ends of the track have end-barrier stop-posts 36, with welded eyes 3S to which tackle may be attached for drawing the trolley along the track by ropes leading from the scaffold, as the rope 40 seen in Figure 5.

But by a pivoted latch 44, controlled from the scaffold by' a cord 46, the trolley can be locked in any position along the track where a hole or socket 42 is provided in the sleeper. For protecting the rope ill from wear an edge roller 48 may be installed on a very wide U-bond, which connects the end section to its end post in addition to such other fastening 49 as may be provided. The rail and other iron parts are preferably gal- Vanized.

Although no reason appears why any force originating below should pull the trolley from its track, de-railing might occur from an obstacle on the track;` for protective means the guard rail 34 is secured on the front face of the sleeper and projects above it far enough to catch and stop a trolley wheel 2| if it should be de-railed. This guard may be held secure on the sleeper by any means, but the drawing particularly illustrates light and strong enclosing straps of steel 54 which, by bundling the .guard rail and sleeper together and being secured to them tightly by screws, prevent any sepaarting of the two, and render harmless any splitting of the wood of either.

The trolley 25 has a frame which is parallel to the track, comprising two strong side bars, welded into a continuous unit, supporting between them the shafts G on which are the wheels 2l. The upper limb I8 of the bow hanger is mounted on the trolley at a mid-position between the two wheels. Preferably it can turn there, and is slidable in and out, securable at desired extent of projection from the trolley by any suitable means, as by acollar 52 on it between the bars, with screw for setting the collar tight at whatever degree of projecting of the limb I8 is desired. At its inner end, beyond the trolley, the limb l 8 of the hanger bow has two further safety devices, viz, a strong downward projecting claw or prong 5I, and the ring 53 from which a tie-back life line 55 may extend. Then if the trolley becomes de-railed the wheel will be stopped from sliding off the roof by the guard rail 34, assuming that the derailment is on the outer side; and the claw 5| will dig into the sleeper, or will engage behind the rail 22, or both; and, if for any cause these should not save the situation, the tie-back life rope 55 would do so after a short fall has occurred.

To permit travel of the trolley along its track such a life line should have some slack, whether this line runs directly to a roof Xture, or to a pulley for travel along a loop of rope extending along the roof between xtures (not shown). Therefore the line 55, leading from ring 53 to the fixture or pulley (not shown) to which it runs for security, may if desired, pass through block and tackle for changing its effective length, and be led thence down to the scaffold for convenient control.

For setting the apparatus to operate along the steep pitch of a roof, from the peak of a gable downward, there must be abundant security of attachment of the sleeper. This is instantly and conveniently provided by means of the ridge hook 64 and its coupling prong 52 for entering a hole 6G provided through the end section and end plates, as seen in plan in Figure 3. The hole is large enough to receive loosely this prong 52, upstanding from the shank in the plane of a hook which can engage beyond the ridge. as seen in Figure 6. To accommodate the shank of a hook without th-e sleeper being made unsteady by resting on it. a groove might be made in the bottom of the sleeper; but I avoid such a special construc-tion by providing on the hook a pillow for stabilizing the sleeper, comprising the cross bar 63 which extends from the hook shank in direction perpendicular to the plane of the hook and which underlies the full width of the sleeper'. When thus installed, and secured by brackets or b-y ties to prevent the sleeper being moved off the edge, the Aperson on the scaiold can move the trolley up and down the entire height and width yof the roof, as far as the track extends; and by using a similar apparatus on the opposite slope, and adjusting the elevation of the scaffold by its supporting tackle, can cover the whole end of the building. The ability of the upper limb of the hanger bow to turn in its bearing in the trolley allows that bow to hang vertically down even when the track and trolley are inclined up the steep slope of the gable, and this maintains the distribution of weight evenly on the two wheels.

When the trolley is thus on a slope it is a feature of safety to set the latch 44 under the upper limb I8 of the hanger bow, as illustrated in Figures 1 and 5, for it is thus confined within a range of movement whence it can always catch in a socket 42 upon the rope 46 b-eing released. But this latch may, if desired be initially set pointing the other way from its pivot, especially when the track is level, and when so set it is still true that a gentle short pull on its cord 46 will lift it from its socket and leave it in position for latching again by gravity when released; but a sharp pull can throw it over its pivot so that it lies across the top of the upper limb I8, and is out of action, a condition sometimes convenient. A like sharp pull will restore it to active position.

One or more trolleys may be used on the same track; and they can be prevented from spreading apart too far by a tie between them as at 56; and can be kept apart by the tackle attached to their opposite ends; and can be adjusted in position together along the wall by pulling on either end which is appropriate. The rollers on the scaffold beams may be made to run horizontally along the wall, if desired.

In setting the apparatus for use the sleeper may ordinarily be set about two or three inches from the edge of a pitch roof, or be set flush with the edge of ya flat roof having no overhang. While v suitable tie backs may be used as precautions for abnormal events, lthe weight of the scaifold, suspended from the loose link joint at the eye I4, acts only downward on the lower end of the bow, and is imposed practically straight under the track; so that the resulting down pull on the wheels is straight to the center of the track. Even if the bow be canted outward, as when a roof has no overhang, the trolley wheels will be canted to an equal angle around the side of the rail. As far as the trolley is concerned the pull is always straight against the track. The track, in turn, rests in continuous intimate contact on the sleeper, and the sleeper likewise on the roof. The scaffold suspension structure therefore is organized so that the weight of scaffold with its rigging and load carried imposes no bending or sheering stresses on the rail or sleeper, but only crushing stresses; and, as these are considerably distributed over the roof, very light pieces, as ordinary wood and gas pipe, have sufficient strength. The making of the rail hollow, with tap bolt engaging both walls of the hollow to secure it, provides a rail of adequate strength which both is light, is` strongly fastened, and can be strongly coupled endwise. In the sleeper, the truncating of the triangular cross section disposes the weight of whatever material is present in the Wood so that a given weight of wood produces greater thickness and therefore yields greater `resistance to splitting, and so permits adequate strength to be attained with less weight. In practical experience a ten foot section of sleeper and rail may weigh only twenty-two pounds.

I claim as my invention:

1. A device for temporary application to a roof for scaiold suspension, comprising the combination of a portable sleeper adapted to lie removably over, on and along the edge portion of the roof without aid of attaching means permanently incorporated in the building at the edge of the roof; said sleeper having along its upper face a track rigid thereon; a trolley with all ci its supporting wheels in single line on that track; and, depending from the trolley, a stiff bow hanger from which the scaiold may be suspended. v

2. A device for temporary application to a roof for scaffold suspension, comprising the combination of a portable sleeper adapted to lie removably over, on and along the edge portion of the roof without aid of attaching means permanently incorporated in the building at the edge of the roof; said sleeper having along its upper face a track, rigid thereon, whose tread face is curved in cross section; a trolley, with all of its supporting wheels in single line on that track; the tread faces of those wheels being of shape t to run on that track in any of diverse angular positions about the axis of the track; the transverse pitch of the sleeper upper-face, which has the track, being at an angle to the transverse pitch of the sleeper under-face, which is toward the roof, said angle being of the class which ranges between 0 and 45, with optimum at 221/2", and, depending from the trolley, a stiff bow hanger from which the scaffold may be suspended.

3. A device for scaffold suspension, as in claim 1, in which the sleeper has a guard rail rising above its outer edge, normally free from contact with the trolley, for catching a dislodged trolley.

4. A device for scaffold suspension, as in claim 1, in which the sleeper has a guard rail rising above its outer edge for catching a. dislodged trolley; the sleeper and guard rail being of wood, bound by metal strap ties which surround them.

5. A device for scaffold suspension, as in claim l, in which the sleeper is divided into sections laid end to end, and there are couplings comprising stiff, metal, open-ended loops set loosely into downward sockets at adjoining ends of sections.

6. A device for scaffold suspension as in claim 1, in which the track is a stiff metallic bar which rests on the sleeper in a contact therewith which is approximately continuous along the edge of 7. A device for scaffold suspension as in claim 1, in which the track is a sti metallic bar which has a round top exceeding of curvature, for the trolley Wheels to stand vertical on the rail thus constituted although the sleeper be lying on roofs having various degrees of inclination from the horizontal.

8. A device for scaffold suspension as in claim 1, in which the track is a bar constituting a trolley rail which is cylindrical exteriorly and is hollow and is in sections coupled endwise together and having at the couplings interior pins iixed in one section and removably fitting into the hollow of the adjoining section.

9. A device for scaffold suspension as in claim 1, in which the track is a bar constituting a trolley rail which is cylindrical exteriorly and is hollow, and there are anchorage bolts through the sleeper tapped into both walls which surround the hollow of the rail.

10. A device for scaffold suspension as in claim 1, wherein the track is a round topped bar constituting a trolley rail, and the trolley wheel is deeply grooved with around concave tread, and the other parts of the trolley and the hanger therefrom are at a distance from the upper part of the rail sufficient to provide clearance permitting the trolley and hanger to stand in various inclinations from the rail, to accommodate suspension on roofs of diverse pitch.

l1. A device for scaifold suspension as in claim l, in which the trolley has two wheels, arranged tandem on the track, and has a frame carried by those wheels, comprising two horizontal bars, between which the wheels are closely enclosed, the said stii bow hanger having its upper limb engaged slidably across said bars, with fastening means to hold it without cross slip.

12. A device for scaffold suspension as in claim 1, in which the trolley has two wheels arranged tandem on the track, and has a frame carried by those wheels, comprising two horizontal bars, between which the wheels are closely enclosed, the said stii bow hanger having its upper limb mounted on said bars with provision for its rotary turning adjustment thereon about the axis of said limb.

13. A device for scaffold suspension as in claim 1, in which the trolley has a latch, and the sleeper has notches in which the latch may engage; and means, adapted to manipulate the latch, extends from the latch to the scaiold.

le. A device for scaffold suspension as in claim 1, in which the trolley has a latch, and the sleeper has notches in which the latch may engage; and means, adapted to manipulate the latch, extends from the latch to the scaffold; said latch being a lever whose one end is adapted to engage a said notch, and whose other end has the said manipulating means; this lever being fulcrumed on the side of the trolley, with its` latch arm extending across the position of the upper limb of the hanger bow, and with its other end offset to the iront of the sleeper to swing past the fulcrum and thus to reverse the direction in which the latch arm extends and so to rest inactive on the said limb.

15. A device for scaffold suspension as in claim 1, in which the hanger bow has a claw at the end of its upper limb, directed downward, positioned for catching on the sleeper when the trolley is de-railed.

16. A device for scaffold suspension as in claim 1, further characterized for use on a gable end, by being combined with a hook, whose hook arm is adapted to engage down beyond the ridge oi a pitch roof and whose shank has a prong, up-

turned in the plane of the hook, adapted to hook through an end portion of the said sleeper, thereby tohold the sleeper on an inclined edge of gable.

1'7. A device for scaffold suspension as in claim 1, further characterized for use on a gabie end, by being combined with a hook whose hook arm is adapted to engage down, beyond the ridge of a pitch roo-f and whose shank has a prong, upturned, in the plane of the hook, adapted to hook through an end portion of the said sleeper, thereby to hold the sleeper on an inclined edge of gable; and whose said shank has also `a cross beam, perpendicular to the planeof the hook, and in a plane with the shank, to pillow the end portion cf the said sleeper.

ERNEST L. LOOMIS.

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