US2390117A

US2390117A - Rolling door construction

Info

Publication number: US2390117A
Application number: US549230A
Authority: US
Inventors: Michelman Nathan
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-08-12
Filing date: 1944-08-12
Publication date: 1945-12-04
Anticipated expiration: 1962-12-04

Description

Dec. 4, 1945. v N. MICHELMAN ROLLING DOOR CONSTRUCTION Filed Aug. 12, 1944 5 Sheets-Sheet l INVENTOR. .A/a/fimz Micky/ma! Dec. 4, 1945. N, MA 2,390,117

ROLLING DOOR CONSTRUCTION md Aug. 12, 1944 '5 meets-511m 2 v I N VEN TOR. fVa Mair Mic/vellum? N. MICHELMAN ROLLING DOOR CONSTRUCTION Filed Aug 12, 1944' 5 Sheets-Sheet 3 IN VEN TOR. .Aaf/mu Niche/man D60 4, 1945. I N, M|CHELMAN 2,390,117

ROLLING DOOR CONSTRUCTION Filed Au 12, 1944 I 5 Sheets-Sheet 4.

IIIIIIII'JIIIIIIII'IIIIII Dec. 4, 1945. -N. MICHELMAN ROLLING noon CONSTRUCTION Filed Aug; 12, 1944 5 Sheets-Sheet 5 INVENTOR.

A a/19601 M 50/10/1220:?

Patented Dec. 4, 194

UNITED STATES PATENT OFFICE ROLLING DOOR CONSTRUCTION NathanMichclman, Brooklyn, 'N. Y.

Application August 12, 1944, :SerialNo. 549,230

"17 Claims.

This invention relates to rolling doors adapted to be wound upon a drum located at the head of the doorway and to be unwound therefrom, and is more specifically directed to the provision of improved=d-riving mechanisms for such doors.

Rolling doors of considerable length and weight, such as are employed in factoriesgarages or the like, are generally provided with ad-riving mechanism operated by an electric motor, to facilitate the raising and lowering of the door.

Since, however, such power drive may occasionally breakdown, a manually operable driving mechanism is also incorporated in the structure. Usually, the two driving mechanisms "are entirely independent and are operated through separate gearing means. The resulting structure is therefore complicated and expensive to manufacture. Furthermore, the usual constructions lack suitable meansfor automatically 'controlling the operation "of the electric motor and for braking the door at the end of its downward or upward movement.

It is therefore an object of the invention to provide a rolling door structure comprising power driving means and hand driving means adapted Another object of the invention is to provide means for automatically shutting off the electric motor at the end of the downward or of the upward movement of the door, said means being controlled by elements associated with the door shaft.

Still another object of the invention is to provide means for braking the door shaft that are automatically actuated to brakingposition simultaneously with the shutting off of the electric motor efiected as aforementioned.

These and other objects will become apparent in the following description of the invention illustrated in the drawings, wherein:

Fig. 1 is a front elevational View of the power and hand drive mechanisms for rolling doors according to the invention, and of the. braking mechanism associated therewith.

Fig. 2 is "a side =elevati'onal view of the structure of Fig. 1.

Fig. 3 is a fragmentary front elevational view 'of the device of Fig. 1 illustrating details of the braking mechanism.

Fig. 4 is a top plan view of the structure shown in Fig. 3.

Fig. 5 is a front-elevation similar to the view 'of Fig. 1, with parts of the structure removed to illustrate the gearing of the device.

Fig. 6 is a horizontal sectional view on the line 66 of Fig. 5.

Fig. '7 is a vertical sectional view on line 1 o'f Fig.1, in the direction of the arrows.

Fig. 8 is an enlarged top plan view of the means for controlling the electric motor for the "door driving mechanism.

Fig. 9 is a side 'elevational view of the structure of Fig. 8.

Fig. 10 is a front elevation of the samestructure illustrating the construction of the limit switches associated therewith.

Fig. 11 is a rear elevation of the same structure.

Fig. 12 is a front elevational view illustrating a diiierent embodiment of the power and hand drive mechanisms.

Fig. 13 is a horizontal section on line 13-13 of Fig. 12, showing a modified clutch mechanism employed in the embodiment of Fig. 12.

Fig. 14 is an enlarged fragmentary view, partly in section, of a different embodiment of braking mechanism.

Fig. 15 is a perspective view of one of the split rings of Fig. 14 forming part of the braking mechanism.

Fig. 16 is a front elevational view illustrating still another embodiment of braking means.

Fig. 17 is a side elevational view, partly in section along line 11-11 of 16.

Fig. 18 is an enlarged fragmentary horizontal section and Fig. 19 is an enlarged fragmentary vertical section, on lines 18-18 and 1-9-1 9 of Fig. 16, respectively.

Referring now in detail to the drawings, numeral 10 indicates the shaft of a rolling door suitably supported at the head of the doorway and carrying, for,rotation therewith, a conventional coaxial drum 11, to which there is secured, :as at 12, the end of a flexible door or curtain 14 adapted to be wound upon the drum H and formed of a plurality of sections or slatsi-nterconnected in the usual manner. Suitable counterbalancing mechanism (not shown) is provided for the assembly.

The end of the shaft I carries, for rotation therewith, a, hollow shaft I5 keyed thereto, as at I6, which extends through a bearing I! of a supporting plate I8, fastened to the wall laterally of the door, and through a bearing 29 of further fixed plate 22. The hollow shaft I5 has an end portion 24, which is threaded for the purpose that will become hereafter apparent. A plate or covering 25 is fastened to the plate 22, as by means of screws or bolts 28, and has a bearing 21 through which the hollow shaft I 5 also extends. The covering 25 cooperates with the plate 22 to form a casing for a gear train through which the shaft I5 and the door shaft I0 are driven, in the manner that will now be described.

A shaft 28 is freely mounted in a pair of

bearings

29, 39, provided in the plate 22 and covering 25, respectively, below the shaft I5, and extends outwardly of the covering 25. Fastened to the shaft 28, at the rear of bearing 29, is a stop collar 3I, and between the bearings 29, 38, there is a pinion 32 likewise fastened to the shaft 28. This pinion meshes with a spur gear 34 fast on-a short shaft 35 which is rotatable in

further bearings

36, 31 formed on the plate 22 and the cover 25, respectively.

The shaft 35 also has, fast thereon, a pinion 38, which in turn meshes with another spur gear 39 secured, as by bolts 48, to a flange 4| which may be integral with the shaft I5. As will be apparent. rotation of the lower shaft 28 will result in' i longitudinal displacement of the pulley on the shaft 28 is prevented by the collar 46 suitably fastened to the shaft and received in a recess of the hub of the pulley. The assembly described "constitutes the power drive for the door shaft I8,

is freely mounted a sprocket Wheel 53, which carries a continuous chain 54 extending downwardly to a position within reach of the operator, when the assembly is mounted at the head of the doorway.

The hub of sprocket wheel 53 is provided with teeth 55, and is maintained in fixed longitudinal position relative to the shaft 48 by means of a stop collar 56, which is fastened to the shaft and is received within a suitable recess formed in the hub. The assembly just described constitutes the hand drive for the door shaft I8, and is manifestly inoperative as long as the sprocket wheel 53 is free to rotate relative to the shaft 48. To render selectively operative either the power drive or the hand drive, the following mechanism is provided.

A clutch 58 is mounted, for rotation therewith, on the outwardly extending portion of the shaft 28 of the power drive assembly, the shaft being suitably splined, as at 59, "to permit longitudinal movement thereon of the clutch 58 between the pulley 42 and a stop collar 60 fastened to the end of the shaft. The clutch 58 grooved as shown at 6I is provided with teeth 62 opposite the teeth of the hub of pulley 42 and adapted to engage these latter for the purpose that will hereafter become apparent.

A further clutch 64 is similarly mounted on the shaft 48 of the hand drive mechanism, for conjoint rotation therewith and longitudinal movement therealong, and is likewise provided with teeth 65, opposite teeth of the hub of sprocket wheel 53. Said clutch is also grooved as at 66 (see Fig. 2). A rod 88 is rotatably supported, in fixed vertical position, by

brackets

69, 10, II that are suitably secured to the plate 22, the rod extending downwardly as far as necessary to locate a knob 12, carried at the lower end thereof within reach of the operator. Fast on the rod 68 are a pair of spaced members I4, I5 extending in opposite directions laterally of the rod and formed with forked end portions I6. II. respectively, pro vided with depending studs I8, I9 that project 5 into the grooves BI and as of the clutches 5a and is inoperative as long as the pulley 42 is free to rotate on the shaft 28; to render the assembly operative, whenever desired, a suitable means or clutch device is provided to drivingly associate the shaft 28 with the pulley 42, as will be hereafter described.

The ratio of the complex of pulleys 43-42 and gear couplings 39-383432 is such that, when the assembly is rendered operative, the speed of rotation of shaft ID will be of an order suitablefor proper opera ion of the door. For instance, with a motor speed of 1800 revolutions P. M. the speed of the shaft III will be approximately 4 revolutions P. M. whereby a conveniently slow movement of the door will be obtained. Such a considerable reduction has the further advantage of permitting the use of an electric motor of a comparatively low power, with a corresponding reduction in the cost of the device.

The construction also comprises means for hand operation of the door shaft I0. Referring now particularly to Figs. 5 and 6, it will be observed that a shaft 48 is journalled in bearings of the plate 22 and covering 25, as at 49, 50, and has fastened thereto a stop collar 5I abutting against the bearing 49 rearwardly thereof; a pinion 52 is fast on the shaft 48 between the bearings 49, 58, and meshes directly with the gear 39 fastened to the hollow shaft I5. On a portion of the'shaft 48 extending outwardly from the covering 25 there and 64.

As will be apparent. by manipulating the knob 12 to rotate the rod 68 in opposite directions, the forks I6 and I1 may be swung to reciprocate the associated clutches 58 and 64 on their shafts 28 and 48, thereby bringing the teeth GI and thereof into engagement with the

teeth

45 and 55 of the pulley 42 and sprocket wheel 53, or disengaging the same therefrom. Obviously, when the teeth are interen aged. rotation of the pulley 42 or of the sprocket wheel 53 will cause rotation of the. respective shaft 28 or 48 through the associated clutch 58 or 64 which is mounted on its shaft for rotation therewith. and therefore the power drive or the hand drive mechanism will be rendered operative to drive the door shaft I0 and to raiseor lower the rolling door according to the direction of rotation of the shaft.

The forked members I4, 15, which extend in opposite directions, are angularly staggered, on the rod 68, by such an amount that, when the clutch SI of the power drive mechanism is moved into the position in which it en ages the teeth of pulley 42, the clutch 64 of the hand drive.

mechanism is simultaneously disen aged from the teeth of the sprocket wheel 53, and vice versa. Normally. the clutch BI wi l be in engagement with the teeth'of pulley 42, when the door is being raised or lowered, since the power drive is normally used and the hand drive mechanism is provided only for emergency cases. The members I4 and I5 may also hav a neutral position wherein neither of the clutches is operatively connected to the respective pulley and sprocket wheel, and both the power and the hand drive devices will then be inoperative.

As will be readily seen, both power and hand operation of the door is effectedthrough th gear 39 common to both mechanisms, with a considerable simplification of the structure as compared with the devices of the prior art, and the shifting from power to hand operation, and vice versa, is accomplished in a single operation through the manipulation of only one element of the structure.

As will be observed from Figs. 5 and 6-, the casing of the driving mechanism also embodies a pair of bearings 89, 8i, disposed at the left of gear 39 symmetrically with the bearings 49, 50. The shaft 48 of the hand drive may be mounted in said bearings 80, 8i, so that the hand drive assembly may be shifted to the left of the structure whenever it is preferable to have the assembly in such a position.

Figs. 12 and 13 illustrate a modification of the driving means hereinbefore described, in which the construction of the mechanism is still further simplified.

In this embodiment, the gearing of the power drive described remains unchanged. but a longer shaft 82 is substituted for the shaft 28 (see Fig. 13). The sprocket wheel 53 of the hand drive mechanism carrying the chain 54 is freely mounted on the forward portion of the shaft 82 and is prevented from longitudinally moving along the shaft by the collar 83, secured at the end. of the shaft, and the collar 84 received within a recess of the hub of the sprocketwheel. The position of this latter is inverted with respect to the showing of Fig. 6 so that the teeth 55 thereof face the teeth 45 of the pulley 92.

A clutch 35 is mounted on a suitably splined portion of the shaft 82, as shown at 89, between the sprocket wheel 53 and the pulley 92, for rotation with the shaft and reciprocation thereon. Said clutch is provided with

teeth

87, 88 projecting therefrom in opposite directions, and adapted to engage either the teeth 45 of the pulley 92 or the teeth 55 of the sprocket wheel 93 in th* reciprocation of the clutch along the shaft 82. The clutch is centrally grooved, as shown at 93, to receive the studs of the fork 76 of the member M which is mounted on the rod 99 as in the embodiment previously described.

As will be readily understood, the rotation of the rod 98 brought about by the manipulation of the knob T2, as hereinbefore explained, will therefore longit dinally displace the clutch 85 along the shaft 82, and cause the teeth '87 of the.

clutch to engage the teeth 45 of the pulley 42 while simultaneously disengaging the teeth 89 from the teeth 55' of the sprocket wheel 53, or vice versa. In the first case, the pulley 42 wi l thus become operatively connected to the shaft 82, and the motor M will be enabled to drive the door shaft I9 through th gear train hereinbefore described, while the sprocket wheel 53 will idle on the shaft 92; in the second case, the sprocket wheel will be operatively connected to the shaft and, through the same train of gears, to the door shaft I9 for hand driving thereof, while the pulley 92 will idle on the shaft.

Reference will now be had particularly to Figs. 8 to 11,, which illustrate the means for autoof the rolling door.

An internally threaded collar is mounted on th threaded end portion 24 of the shaft I5 fastened to the door shaft III, and has an upwardly extending portion 9| forming a bushing slidably mounted on a stationary shaft 92. This latter is fastenedto aforementioned covering 25. The collar 99 is therefore prevented from rotating with the threaded portion 24 of the shaft I5 during rotation of this latter, and is caused to travel therealong in opposite directions according to the direction of rotation of th shaft. The aforementioned extension 9! of the collar is provided with a pair of projecting cams 93, 94 having identical profile, the purpose whereof will become later apparent.

A further stationary shaft is secured to the covering 25 above the shaft 92, and carries, pivotally mounted thereon intermediate their ends, a pair of

levers

96, 91, at the rear ends whereof there are formed cam surfaces 98 and 99. Said cam surfaces have an identical profile and'are adapted to be engaged by the cams 93, 94 of the collar 90 during the reciprocation of this latter.

The levers 96, 9'! are provided, at their forward end, with downwardly extending depending studs I00 and are associated with a pair of switches I92, I03 (hereinafter referred to as limit switches by reason of their function). Each limit switch comprises an element I04 Slldlblfi therein and urged by a spring I05 to an upward position in which a contact element I 06 closes the switch, as shown in Fig. 10 and the studs I99 of the

levers

96, 91 rest on said elements I94 of the limit switches. As will be apparent, whenever one of the cams 93, 94 engages the cam surface qf the respective lever, this latter will be rocked and the stud I00 thereof will depress the member I94 of the associated switch to a lowermost position, to displace the contact element I96 and the various parts being returned to their initial position upon disengagement of the cam from the cooperating cam surface of the lever.

The electric motor 44 is reversible, and either the limit switch I92 or the limit switch I03 is closed at any given time, due to the arrangement of the cams and levers illustrated (see particularly Fig. 11). In such condition of the switches, the motor can alway be started, and the direction of its rotation will depend upon which one of the switches is closed at the time. The opening of the switch initially closed, following the engagement of one of the cams with'the lever associated therewith, .will shut off the motor, but, since in the meantime the other switch will have closed, the motor can be started again in the reverse direction. The electric circuits required for such operation of the motor form no part of the invention and may be conventional, and therefore will not be described.

Let us now assume that the door shaft II), as seen in Fig. 10, has been rotated through the gearing described, in" a counterclockwise direction, to lower the door,'and the motor has been shut off by the opening of the limit switch I93. Cam 93 is now clear of cam surface 99 of lever 96 and switch I92 is closed, whereby the motor may be started to drive the door shaft I9 ina clockwise direction and raise. the door. In the ensuing clockwise rotation of the threaded portion 24 of shaft. I5, collar 99 is caused to travel towards the left, as indicated by the arrow in Fig.11, until cam 93 engages cam surface 98 of lever 96 and rocks this latter, whereupon the member I04 of the switch I02 is moved downwardly to open the switch, and the motor is shut off. The pitch of the thread of shaft portion 24 is such that collar 90 will travel the distance necessary for bringing cam 93 into engagement with cam surface 98 in the time required for shaft I to complete a number of revolutions suificient for fully raising the door, in the present embodiment four revolutions. Manifestly, during the operation described cam 94 has become disengaged from cam surface 99, and the spring I of limit switch I03 has closed this latter, simultaneously returning lever 91 to its initial position, whereby the motor may be started again in a reverse direction to rotate the door shaft counterclockwise and lower the door.

Reference will now be had particularly to Figs. 1 to 4 which illustrate one embodiment of braking means provided in the structure described. Pulley 42 mounted on the shaft 28 carries a brake drum I I0, which is surrounded by brake elements I I I, I I2 pivoted at one end thereof, as at I I3, and normally urged into frictional engagement with the surface of the drum by a spring I I4 connect-.-

ing the opposite ends of said brake elements. A lever H5 is pivotally mounted on a bracket IIG secured to the plate 22, and is formed with a transverse cam portion III engaging extensions H8, H9 of the brake elements III, II2.

A link I connects the end of lever I I5 to one end of a lever I2I, which is pivoted to the covering 25, as at I22, and pivotally carries at its other end a link I23 connected to a member I24 associated with an electro-magnet I25. the motor 44 is inoperative, the electro-magnet I25 is not energized and the assembly described is in the position illustrated in Fig. 1 wherein the spring H4 is shown to maintain the brake elements III, I I2 in engagement with the surface of the drum H0 and the door shaft is therefore braked.

The electro-magnet I25 is energized upon the starting of the motor 44, irrespective of the direction of rotation of this latter, suitable electrical connections being provided for this purpose. The member I24 is therefore caused to move upwardly, lever I22 is rocked, link I2I is moved downwardly and the pivoted lever H5 is rotated, to

cause the cam portion I I1 thereof to move brake elements III, II2 away from the drum H0, in opposition to the spring I I4. In this manner, the drum is released and the pulley 42 is permitted to drive the door shaft as hereinbefore described.

Concurrently with the shutting off of the motor;

the electro-magnet I25 is again tie-energized, whereupon the spring H4 is allowed to bring again the brake elements I I I, Il2 into frictional engagement with the drum II 0, to brake the pulley 42 and prevent any further movement of the d00r shaft I0.

An entirely different construction of the braking means is illustrated in Figs. 14 and 15. In this embodiment there are provided a pair of internally threaded rings I28, I28a that are directly mounted on the threaded end portion 24 of the shaft I5. The rings are cut in a plane perpendicular to the axis thereof, the cut extending through the threads of the rings in the manner illustrated in Fig. 15, to form substantially resilient ring portions I30, I3I and I30a, I3Ia. Bolts I32 force such portions of the rings toward one another and cause the thread portions incorporated therein to clamp therebetween the corresponding threads of the shaft portion 24, thereby locking the rings in fixed position.

The collar is mounted on. said threaded shaft portion 24 intermediate the rings I28, I200 and the distance between these latter is equal to the space travelled by the collar in its reciprocatory movement described. Therefore, at the end of each stroke the collar 90 will operate one of the limit switches I02, I03, through the action of its cams 93, 94 to shut oil! the motor, and simultaneously engage with one of its flat lateral faces the opposed flat face of one of the rings, thereby positively preventing any further rotation of the door shaft.

Figs. 16 to 19 illustrate a further embodiment of brake mechanism, which is particularly suitable for use in rolling doors of the character described of comparatively light construction.

Forked members I35, I36 are connected, as shown at I31, I38, respectively, to the

levers

96, 91 that control the operation of the motor 44', and extend vertically downwardly therefrom, movement of the members relative to the levers being prevented by the interengagement of the upper forked end thereof with complemental enlarged portions I39 of the levers. The forked members are threaded at their lower end, as shown at I40, I in Fig. 19, t rigidly mount members I 42, I43 partially extending into a U- shaped member or channel I44, which is slightly wider than the members to permit a limited displacement of the channel relative to these latter for a purpose that will become hereafter apparent.

The channel I44 is provided with a downward extension I45 to which there is rigidly secured a brake element I46 which is pivotally connected to the plate 22, as at I41, and carries a brake shoe I48 adapted to frictionally engage the drum IIO of the pulley 42. A brace I49 is fastened to the channel extension I45 and to the brake element I45, to provide a rigid structure.

A coil spring I50 connected to a bracket I5I carried by the cover 25 and to the channel extension I45, normally causes the brake element I45 to swing about its pivot I4'I away from the drum III), to release the pulley 43, the swinging movement being limited to a minimum sufllcient to release the pulley by the engagement of the inner surface of the channel I44 with the members I42, I43 partially extending thereinto, as aforesaid.

Compression springs I53, respect vely mounted within recesses I54, I55 of the members I42, I43, rest upon the bottom wall of the channel I44. As will be apparent, when one of the levers 99, 91, for instance the lever 96, is rocked to move its forward end to a lowermost position and shut off the motor 44 in the manner hereinbefore described, the associated forked member I35 and the member I42 will move downwardly, and the respective spring I53 will be compressed, as illustrated in Figs. 16 and 19, to urge the pivoted brake element I46 toward the drum H0 and the brake shoe I48 into frictional engagement therewith in opposition to the spring I50, thereby braking the pulley 42. While this action is sufficient to overcome the inertia of the rotating elements and to arrest immediately the pulley when the motor is shut oif, the strength of the spring I53. is, however, not such as to prevent rotation of the pulley'under the driving action of the motor, so that the door shaft may be rotated in a reverse direction by starting again the motor while the brake mechanism is still in the operative position described. Manifestly, in the continued rotation of the door shaft, the forward end of the lever 96 will move upwardly lifting the forked member I35 and the member I42 associated therewith, whereby the brake elements may be returned by the spring I50 to their inoperative normal position described. Concurrently, the lever 91 is gradually rocked until it reaches the position in which it becomes effective to shut off the motor and to simultaneously operate again the brake through its forked member I36 and associated member I43 and spring I53.

It will be understood that changes and modifications may be made in the structures described and illustrated in the drawings without departing from the spirit of the invention or exceeding the scope of the claims.

I claim:

1. A driving mechanism for rolling doors comprising a rotatable door shaft, a gear train drivingly associated with said shaft, an electric motor, manually operable driving means, said motor and said manually operable driving means being operatively connectable to saiid gear train to drive said door shaft therethrough, and means effective to operatively connect the electric motor to the gear train, while simultaneously disconnecting the manually Operable driving means therefrom, and to operatively connect these latter means to the gear train while simultaneously disconnecting the electric motor therefrom.

2. A driving mechanism for rolling doors comprising a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, an electric motor, a pulley driven by said motor, a manually operable driving wheel, said pulley and said wheel being operatively connectable to said gear train to drive said door shaft at a reduced speed, and means effective to openatively connect the pulley to the gear train, while simultaneously disconnecting the manually operable wheel therefrom, and to operatively connect this latter to the gear train while simultaneously disconnecting the pulley therefrom.

3. A driving mechanism for rolling doors, comprising a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, an electric motor, a second rotatable shaft for driving said gear train, a third rotatable shaft drivingly associated with an element of the gear train, a manually operable driving wheel, and means effective to operatively connect the electric motor to the second shaft while simultaneously disconnecting the manually operable wheel from the third shaft, and to operatively connect said Wheel to this latter shaft while simultaneously disconnecting the motor from the second shaft.

4. A driving mechanism for rolling doors, comprising a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, a second rotatable shaft carrying means for driving said gear train, to effect rotation of the door shaft at a reduced rate relative to second shaft, an electric motor, a manually operable driving Wheel, and means effective to operatively connect the electric motor to said second shaft, while simultaneously disconnecting the manually operable wheel therefrom, and to operatively connect this latter to the second shaft while simultaneously disconnecting the motor therefrom.

5. A driving mechanism for rolling doors, comprising a rotatable door shaft, a gear train drivingly associated with said door shaft, a second rotatable shaft, means on said second shaft for driving said gear train in the rotation of the shaft, a power driven pulley and a manually operable driving wheel loose on said second shaft, and a clutch rotatable with the second shaft and selectively actuatable into engagement with either one of the pulley and wheel to connect the same with the second shaft for rotation therewith, thereby selectively permitting power and hand operation of the door shaft through the single gear train aforementioned.

6. A driving mechanism for rolling doors, comprising a rotatable door shaft, a gear train drivingly associated with said said door shaft, a second rotatable shaft, means on said secondshaft for driving said gear train in the rotation of the shaft, a power driven pulley and a manually operable driving Wheel loose on said second shaft, a clutch rotatable with the second shaft and means for selectively displacing said clutch into engagement with either one of the pulley and Wheel to connect the same with the second shaft for rotation therewith, thereby selectively facilitating power and hand operation of the door shaft through the single gear train aforementioned.

7. A driving mechanism for rolling doors, com-.

prising a rotatable door shaft, a gear train drivingly associated With said door shaft, a second rotatable shaft for driving said gear train, a pulley loose on said second shaft, an electric motor for driving said pulley, a third ro.atable shaft drivingly associated with an element of said gear train, a manually operable driving wheel loose on this latter shaft, a clutch on the second shaft, a further clutch on the third shaft, said clutches being rotatable with the shafts on which they are mounted and being actuatable into engagement respectively with the pulley and the manually operable driving wheel to cause the same to'rotate conjointly with their respective shafts, and means eflective to actuate the clutch mounted on the second shaft into engagement with the pulley, to facilitate power operation of the door shaft, while simultaneously disengaging the clutch mounted on the third shaft from the manually operable driving wheel, and to atual-e the last mentioned clutch into engagement with the wheel, to facilitate hand operation of the door shaft, while simultaneously disengaging the clutch mounted on the second shaft from the pulley.

8. A driving mechanism for rolling doors, comprising a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, a second rotatable shaft, gear means carried by said second shaft for driving said gear train, in the rotation of the shaft, a manually operable driving wheel and a pulley loose on the second shaft, an electric motor for driving said pulley, a clutch mounted on the second shaft for rotation therewith, intermediate said wheel and said pulley, said clutch being reciprocable on its shaft to selectively engage either one of said pulley and Wheel to connect the same to the second shaft for rotation therewith, thereby selectively facilitating power and hand operation of the door shaft through the single gear train aforementioned, and means for reciprocating said clutch.

9. In a rolling door construction, a rotatable door shaft, a reversible electric motor, gear means operatively connectable to said electric motor for driving said door shaft in opposite directions, means for shutting off the motor, and means effective in the rotation of the door shaft in either direction to actuate said means for shutting off the motor upon completion of a predetermined number of revolutions of the door shaft and means automatically operative to brake the door shaft simultaneously with the actuation of the means for shutting off the motor.

10. In a rolling door construction, a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, a pulley operatively connectable to said gear train, a reversible electric motor for driving said pulley, to rotate said door shaft through said gear train in opposite directions at a reduced rate relative to the motor, a brake associated with said pulley, means for shutting off the electric motor, means effective in the rotation of the door shaft in either direction to actuate said means for shutting off the motor upon completion of a predetermined number of revolutions of the door shaft, and means for automatically actuating said brake associated with the pulley simultaneously with the actuation of the means for shutting off the motor.

11. In a rolling door construction, a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, a pulley operatively connectable to said gear train, a reversible electric motor for driving said pulley to rotate said door shaft through said gear train in opposite directions at a reduced rate relative to the motor, a brake associated with said pulley, means for shutting off the electric motor, means effective in the rotation of the door shaft in either direction to actuate said means for shutting off the motor upon completion of a predetermined number of revolutions of the door shaft, and means including an electromagnet for automatically actuating said brake associated with the pulley simultaneously with the actuation of the means for shutting off the motor.

12. In a. rolling door construction, a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, a pulley operatively connectable to said gear train, a reversible electric motor for driving said pulley to rotate said door shaft through said gear train in opposite directions at a reduced rate relative to the motor, a brake associated with said pulley, a pair of switches, each of said switches being adapted, upon opening, to shut off the motor, means effective in the rotation of the door shaft in either direction to open one of said switches, to shut off the motor, upon completion of a predetermined number of revolutions of the door shaft, and means for automatically actuating said brake associated with the pulley simultaneously with the actuation of the means for shutting off the motor.

13. In a rolling door construction, a rotatable door shaft provided with a coaxial extension rotatable therewith, a reversible electric motor, gear means operatively connectable to said electric motor for rotating said door shaft in opposite directions, a pair of switches, each of said switches being adapted, upon opening, to shut off the motor, a member mounted on said extension of the door shaft and adapted to reciprocate thereon during the rotation of the door shaft in opposite directions, and means operated by said member in the reciprocation thereof to open one of said switches upon completion of a predetermined number of revolutions of the door shaft in either direction.

14. In a rolling door construction, a rotatable door shaft provided with a coaxial extension rotil,

tatable therewith, a reversible electric motor, gear means operatively connectable to said electric motor for rotating said door shaft in opposite directions, a pair of switches, each of said 3 switches being adapted, upon openingfto shut off the motor, a member mounted on said extension of the door shaft for reciprocation thereon during the rotation of the door shaft in opposite directions, a pair of rockable levers associated with said switches and operable to open the same, and cam means carried by said member, said cam means being adapted, in the reciprocation of the member, to engage one of said levers and rock the same to open one of the switches upon completion of a predetermined number of revolutions of the door shaft in either direction.

15. In a rolling door construction, a rotatable door shaft, a threaded shaft secured to said door shaft for rotation therewith, a reversible electric motor, gear means operati'vely connectable to said electric motor for rotating said door shaft in opposite directions, a pair of switches, each of said switches being adapted, upon opening, to shut off the motor, a member mounted on said threaded shaft, means for causing said member to reciprocate on said threaded shaft during the rotation of the door shaft in opposite directions, means operated by said member in the reciprocation thereof to open one of said switches, to shut off the motor, upon completion of a predetermined number of revolutions of the door shaft in either direction, and means fixed on the threaded shaft adapted to engage said member simultaneously with the opening of the switch to prevent further rotation of the threaded shaft, thereby braking the door shaft.

16. In a rolling door construction, a rotatable door shaft, a threaded shaft secured to said door shaft for rotation therewith, a reversible electric motor, gear means operatively connectible to said electric motor for rotating said door shaft in opposite directions, a member mounted on said threaded shaft and adapted to reciprocate thereon during the rotation of the door shaft in opposite directions, means operated by said member in the reciprocation thereof to shut off the motor upon completion of a predetermined number of revolutions of the door shaft in either direction, a pair of threaded rings cut to provide split thread portions therein, said rings being fixed to the threaded shaft by causing said split thread portions thereof to frictionally engage the thread of the shaft, the reciprocable member engaging one of the rings concurrently with the operation of the means for shutting off the motor to prevent further rotation of the threaded shaft, whereby to brake the door shaft.

1'7. In a rolling door construction, a rotatable door shaft, a speed reducing gear train drivingly associated with said door shaft, a reversible electric motor, a second rotatable shaft operatively connected to said gear train, a pulley loose on said second shaft and driven by the electric motor, a clutch device operable to cause said pulley to drive said second shaft, to rotate the door shaft in opposite directions at a reduced rate relative to the motor, means for shutting off the motor, and means automatically operated in the rotation of the door shaft in either direction for actuating said means for shutting off the motor upon completion of a predetermined number of revolutions of the door shaft.

NATHAN MICHELMAN.