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Publication numberUS2320604 A
Publication typeGrant
Publication dateJun 1, 1943
Filing dateApr 10, 1942
Priority dateApr 10, 1942
Publication numberUS 2320604 A, US 2320604A, US-A-2320604, US2320604 A, US2320604A
InventorsDickson James T, Jackson Lynn E
Original AssigneeFirguson Door Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 2320604 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)


4 sheets-shea 1 Filed April l0, 1942 TUN lll.




4 Sheets-Sheet 2 June l, 1943- E. JACKSON ET Al.-


Filed April 1o, 1942 June l, 1943.

Filed' April 1o, 1942 L. E. JACKSON ETAL DOOR ' 4 Sheets-Sheet 3 l [Wflzfons Igual M0530,

June 1,1943- E. JACKSON Erm. l 2,320,604

DOOR y Filed April 1o, 1942 4 sheets-sheet 4 Patented June 1, 1943 i DOOR Lynn E. Jackson, Los Angeles, and James T. Dickson, Playa Del Rey, Calif., assignors to Firguson Door Co., Los Angeles, Calif., a corporation of California Application April 10, 1942, Serial No. 438,436

10 Claims.

This invention relates to doors and in its more particular aspects relates to door lifting devices.

In the operation of large doors such as telescopic doors employed in aircraft hangars, factories and the like, serious difficulties have presented themselves in the way of jamming of the doors due to stretch or other pecularities which render it impossible to obtain uniform tension on the plurality of cables required for lifting such doors. Such doors are often used to span extremely wide openings so that a relatively large number of lifting cables are secured to the top edge of the door at spaced points therealong. The side edges of the doors usually operate in guideways. In some cases such doors are composed of overlapping telescopic panels and the upper ends of the lifting cables are windable about stepped pulleys to effect the lifting or telescoping of the panels. If those cables do not exert substantially equal pull on the door panels, jamming of the door or undue stress on cables results.

We have found that by employing, in combination with such a door, tension equalizing members interposed between the lifting element and door those diculties are simply and efficiently overcome.

It is therefore among the principal objects of this invention to provide, in combnation with a sliding door or the like utilizing a plurality of lifting members, means for equalizing the tension on all the lifting members.

Another object is the provision in such a combination of means for providing intercommunication between the several equalizing elements and particularly of those equalizing elements serving each of the respective side halves of the door.

Our invention also contemplates improvements in equalizing elements particularly suitable for use in such combinations.

How those as well as still further objects and accomplishments of the invention are attained will become obvious from the following detailed description of a presently preferred embodiment thereof, for which purpose reference will be made to the accompanying drawings, in which:

Fig. l is an elevation;

Fig. 2 is a longitudinal section showing the hydraulic equalizer;

Fig. 3 is a view taken on line 3-3 of Fig. 2;

Fig. 4 is a diagram showing intercommunication between the hydraulic equalizers;

Fig. 5 is a longitudinal section of a variational form of hydraulic member;

Fig. 6 is a section taken on line 6-6 of Fig. 5;

Fig. 7 is a fragmentary elevation showing a further modified form of device;

Fig. 8 is a medial sectional view, partly in elevation, showing a modified form of equalizer mounting;

Fig. 9 is an elevation, partly in section, taken online 9 9 of Fig. 3; and

Fig. l is a reduced fragmentary plan view taken on line Ill-I0 of Fig. 8.

Referring now to the drawings, we show our invention applied to a telescopic door of the type generally illustrated and described in the copending application of Lynn E. Jackson, Serial Number 384,686, filed March 12, 1941, which doors are now in general use in aircraft hangars, factories and the like. In this door structure hollow columns dene the sides of the doorway of a building, said columns carrying oppositely disposed exterior vertical tracks or guideways G, along which overlapping door panels 1, 8 are vertically slidable into and out of position closing the doorway, the doors being adapted tobe telescoped in the superstructure above the doorway opening dened by the dotted line 9 in Fig. 1. In Fig. 1, the panels 1, 8 are shown in slightly telescoped condition, the floor of the building being defined by the line I5 and the ceiling being defined by the line I 6. A drive shaft extends from one column 5 to the other end and is journalled at 2| adjacent its ends for rotation. Spirally grooved, stepped cone pulleys 23 are secured at equidistantly spaced points along the shaft 20, the shaft being driven by motors M connected by belts B to worms W. While the number of pulleys 23 and drive units M, B, W' depends of course upon the width and weight of a particular door, we here show two drive units M, B, W and six pulleys 23 each having two steps corresponding with the number of panels 1, 8. Counterweight pulleys are secured on the respective ends of the shaft 20 within the respective columns 5 and each pulley 30 has windable therearound a cable 3| from the lower end of which a counterweight 32 is suspended.

Up to this point the door and lifting structure are substantially as described in said copending application and we do not claim that structure per se in the present application.

Windable at their upper ends in the spiral grooves of the respective steps of the respective pulleys 23, we provide lifting cables 35 which are connected at their lower ends to the top edges of the respective door panels l', 8 as will now be described.

As best shown in Fig. 1, we connect to the upper edge of each of the door panels 8 at spaced points therealong a plurality of hydraulic tension equalizing elements generally designated E, there being one of such elements for each cable. Each or" these elements is comprised of a pair of cylinders 40, 4| (see Fig. 2) clamped between end plates 42, 43 by bolts 44 in such manner that the cylinder ends engage the plates in fluid-tight engagement. Pistons 45, 46 are slidably mounted in the respective cylinders, each having a connecting rod 4l resting at its inner end in a recess in the piston and thence slidably passing through hole 50 in end plate 43 and secured at its lower end in a cross plate 52. A central upwardly disposed connecting rod 55 is secured at its lower end in medial opening 55 in cross plate 52 by nut 57 and extends upwardly through plates 43, 42 between the cylinders 44 and threadedly carries at its upper end a turnbuckle 60, in the eye of which the lower end of the cable 35 is secured. End plate43 is secured to thel top edge portionsl of' a door panel by bolts' 60, nuts 68a and .spacer sleeves 69. Any suitable fluid may be used in the iluid chambers 40a in the cylinders.

We provide intercommunication between each pair of fluid chambers 40a of each equalizer E and provide intercommunication also between all the devices E on eachside half of each door panel. That is, in the door of Fig. 1 there are six equalizers E for panel l and a like number for panel 8 and the three equalizers E for the right side half of panel 'I are in intercommunication through pipe 65 and branches 6| and the three equalizers for the left side half of panel 1 are interconnected into a unit by a like pipe and branches. Equalizers for the panel 8 are interconnected in like manner. In this manner it is insured that regardless of inequalities in the cables or pulleys, each panel of the door will be at all times operated evenly.

In operation, to telescope the door panels l, 8 from the Vposition of Fig. 1, motors M are operated to rotate worm W, drive shaft and pulleys 23 to wind cables 35 about the latter while counterweight cables 3| unwind from pulleys 30. In the event, because of cable stretch or inequalities in the diameters of the steps of the pulleys 23 or any other difficulty which normally would cause a greater pull on one or more of the cables than on others, the equalizers E interposed between the bottom ends of the cables and the panels function to equalize the tension on all cables at each of the respective side halves of each door panel so that the doors travel along the tracks evenly and without jamming. Of course to return the door panels to closed position, motor M is operated in the reverse direction and the weight of the door panels causes said panels to move downwardly as the cables 35 are unwound from their respective pulleys and counterweight cables 3| are simultaneously wound around the pulleys 30, the equalizers acting in the same manner as before described.

We employ as the equalizing elements E hydraulic members having a pair of parallel, relatively small-diameter cylinders ybecause the overlapping panels 8 necessarily must not be spaced too far apart and thus equalizing elements E of such design and construction do not project outwardly beyond the pla-ne of the side faces of the door far enough to present an obstruction.

In Figs. 5 and 6, we show a variational form of equalizer comprising a single cylinder 10 whose ends are closed by end plates 12 clamped by bolts 13. Concentrically within cylinder |0 we mount a tubular element 16 centered by flanges 1l. Connecting rods 80 (here shown as three in number) have their inner ends a resting in recesses in the lower end of a piston 82, which latter is slidably mounted in the cylinder around tubular element 10. The lower ends of the connecting rods 80 slidably pass through end plate '|2 and are secured in a spider 85, which latter has a central opening in which a medial upwardly extending connecting rod 86 is secured. Rod 86 extends through tubular element 16 and is connected at its top end to a turnbuckle (not shown) in the manner before described. Plate 12 is connected by bolts 81, spacers 88 and nuts 89 to the top edge portion of a door panel in the manner before described.

In some cases one panel of a telescopic door may be considerably heavier than other panels, thus requiring equalizers of relatively larger capacity, which would necessitate that equalizers of various sizes be supplied. Also, due to the relatively greater load on the cables and winding pulleys operating the top panel of such a door, objectionable fatigue problems are presented by use of the relatively small pulleys on which said cables are wound. We have discovered that such problems may be easily and effectively overcome by the block and tackle type of lifting means shown in Fig. 7. Here we show only one side half of a door anddoorway like that of Fig. 1 and the parts are the same except that, instead of securing the equalizers E to the top edge of the upper panel 8, we secure them to the top member 90 of the doorway frame, the connecting rods 55 being downwardly disposed and connected by a turnbuckle to one end of the respective `cables 35a.. From this connection, the respective cables 35a extend downwardly and around respective sheaves 92 secured at spaced points along the top edge of upper panel 8a, and thence upwardly to be Windable about winding pulleys 23a. In this manner only half the weight of the panels is taken directly by the equalizers, and pulleys 23a may be of the same diameter as pulleys 23h around which the cables 35h leading to the lower panel 'la are wound.

We show in Figs. 8, 9 and 10 a modied mounting of the hydraulic tension equalizing elements which provides for swinging movement of the body of the equalizers with respect to the panel upon which they are mounted. Here the numeral |00 designates a door panel having side faces |00a, the panel being cut out to provide a recess |0| to receive the equalizer E'. Equalizer E is comprised of a cast body |03 presenting parallel cylinders |04 having liners |05 Within which pistons |01 slide. Connecting rods |08 connect the pistons to a U- shaped cross member |09 from which'central link ||0 leads upwardly through a hole in the body, a turnbuckle, not shown, being carried by the upper end of the link for fastening to a cable, not shown. The top of body |03 has a transverse rib I5 presenting a curved top face I6 which pivotally fits in a curved bearing |20 provided in the under-face of a bearing plate. |2| disposed against the inner face of channel member |22. While the opposed pressure normally maintains the equalizer in position on the panel, we provide bolts |23 to prevent the parts from separating in the event the pressure should be released. The holes |25, |26 provided in member |22 to pass bolts |23 and link H0, respectively, are elongated to permit of rocking movement of said bolts and link as rib H5 pivots in bearing |29, which happens when there is any relative lateral movement between the panel and cable. Tubes |30 provide intercommunication between the equalizer cylinders in the manner hereinbefore described.

The broad concept of our invention, as defined by the appended claims, of course may be carried out in structures varying from that herein specifically described, so that the details which we have hereinbefore employed to illustrate an adaptation of our invention are not to be taken as limitative.

We claim:

l. In combination with a slidable door, cables for applying lifting force to the door at spaced points between its side edges, and tension equalizing members, one interposed between each cable and the door, each of said tension equalizing members comprising a iiuid-c-ontaining cylinder and a piston slidably mounted therein, said piston being operably connected to a cable and said cylinder being operably connected to the door.

2. In combination with a telescopic door comprised of relatively slidable panels having ad jacent overlapping edges, cables for applying lifting force to the respective panels at spaced points between their side edges and tension equalizing members, one interposed between each cable and a panel, each of said equalizing members consisting of a pair of parallel fluid-containing cylinders secured to the overlapping portion of a panel, a pair of pistons, one slidably mounted in each cylinder and a connecting rod slidably disposed between the cylinders and being connected at its lower end to said pistons and connected at its upper end to a cable.

3. A closure for a doorway or the like comprising parallel overlapping panels disposed in the doorway for slidable movement with respect to each other and with respect to the doorway, cables for sliding said panels, and tension equalizing members, said tension equalizing members being connected to the respective panels at points spaced horizontally along the top edge thereof, each of said equalizing members comprising a pair of intercommunicating fluid-containing cylinders, a piston in each of the cylinders and means connecting said pistons to the respective cables.

4. The device of claim 3 in which the cylinders of each equalizing member are intercommunicating and in which the cylinders of all equalizing members on each .of the side halves of each of the panels are intercommunicating.

5. In combination with a structure having a doorway, a door slidably mounted in the doorway, sheaves rotatably secured at spaced points along the top edge of the door and lifting cables, one disposed around each sheave, intercommunieating iiuid containing cylinders secured to the structure, a piston in each of the cylinders, one end of each cable being secured to a piston, and

rotatable cable winding means carried by the structure, the other end of each cable being windable about said cable winding means.

6. In a device of the class described, a structure having a doorway, a door slidably mounted in the doorway, and door operating members spaced apart along the top edge of the door, each including a cable, means for winding the cable, a cylinder adapted to contain hydraulic uid, a piston slidably mounted in the cylinder and operatively connected to the cable, a downwardly facing bearing plate carried by the top edge of the door, and a rib carried by the top end of the cylinder, said rib having an upwardly facing curved portion pivotally bearing against the bearing plate, whereby to permit the door and cylinder to be relatively swingable.

'7. In combination, a sliding door, door lifting cables, 4means for simultaneously operating the cables and hydraulic tension equalizing means interposed between the door and the cables, said equalizing means comprising a plurality of fluid containing cylinders, ducts providing communication between the cylinders, a piston reciprocally mounted in each cylinder and an operative' connection between each piston and a cable.

8. A closure for a doorway or the like comprising a door slidably mounted in the doorway for movement into and out of position closing the doorway, cable members for so moving the doorg a plurality of sets of fluid containing cylinders secured in spaced relation to each other along the door, means establishing iluid communication between the cylinders of each set, the cylinders of each set having no communication with any cylinder of another set, a piston reciprocally mounted in each cylinder, an operative connection between each piston and a cable and means for simultaneously winding the cables.

9. In combination with a structure having a doorway, `a door slidably mounted in the doorway, sheaves rotatably secured at spaced points along the top edge of the door and lifting cables, one disposed around each sheave, iluid containing cylinders secured to the structure, a piston in each of the cylinders, one end of each cable being secured to a piston, and rotatable cable winding means carried by the structure, lthe other end of each cable being windable about said cable windingr means.

10. In combination with a structure having a doorway or the like, a door slidably mounted in the doorway, a plurality .of lifting cables for exerting lifting force at spaced points along the door, pulley means for simultaneously operating the cables and hydraulic tension equalizing means associated with each cable, each of the lastnamed means comprising a fluid containing cylinder and a piston operatively connected to one end of a cable, each of the cylinders being secured against movement with its carried piston.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4026343 *Aug 21, 1975May 31, 1977James Don ECounterweighted bifold closures
US5522192 *Aug 16, 1994Jun 4, 1996Frantl; ErichHangar
US5636579 *Jan 27, 1995Jun 10, 1997Protec CompanySecurity window adapted to prevent forced entry
US5860371 *May 30, 1997Jan 19, 1999Protec CompanySecurity window adapted to prevent forced entry
US6684931 *Feb 5, 2001Feb 3, 2004Hanover Door Systems (1966) Inc.Counter weight door
EP0641912A1 *Jul 26, 1994Mar 8, 1995"Conproject" Handelsvertretung und techn. Büro für Maschinenbau Frantl & Co. OHG.Hangar
U.S. Classification49/102, 160/190, 49/360, 49/123
International ClassificationE06B3/00, E06B3/01
Cooperative ClassificationE06B3/01
European ClassificationE06B3/01