US1040504A

US1040504A - Door opening and closing device.

Info

Publication number: US1040504A
Application number: US69551312A
Authority: US
Inventors: Henry C Bundy
Original assignee: ERNST PINSONNEAULT; FRED MORRISON
Current assignee: ERNST PINSONNEAULT; FRED MORRISON
Priority date: 1912-05-06
Filing date: 1912-05-06
Publication date: 1912-10-08
Anticipated expiration: 1929-10-08

Description

H. O. BUNDY.

DOOR OPENING AND CLOSING DEVICE.

APPLICATION FILED MAYG, 1912. 1 40,504. Patented Oct. 8, 1912.

3 BHEETS-BHBET 1.

WIN. E] g I 4? A T TORZVE'YZ COLUMBIA PLANDCIRAPM C0..WA$H|NOTO D. c.

:2 INVENTOR.

h. 2 El m l a H N uli 2 II [NVLNTOR ATTORNEY.

V H.G.BUNDY. DOOR OPENING AND ULOSIN G DEVICE.

APPLICATION IILBD MAY 6,1912.

Patented Oct. 8, 1912.

3 snnms-sfinm 2.

WITNESSES Hen/y C Bung z) uoLUMnIA PLANDCIRAPH 60., WASHINGTON, n. c

H. G. BUNDY. DOOR OPENING AND CLOSING DEVICE.

APPLICATION FILED MAY 6, 1912.

Patented Oct. 8, 1912.

3 SHEETS-SHEET 3.

[N VEN TOR. Henry C Bum/y WITNESSES ATTORNEY.

COLUMBIA ILANDGRAPII c0., WASHINGTON, L c.

TTED STATES PATENT OFFICE.

HENRY C. BUNDY, OF WATERTOWN, NEW YORK, ASSIGNOR OF TWO-THIRDS T FRED MORRISON AND ERNST PINSONNEAULT, OF WATERTOWN, NEW YORK.

DOOR OPENING AND CLOSING DEVICE.

Specification of Letters Patent.

Patented Oct. 8, 1912.

To all whom it may concern Be it known that I, HENRY C. BUNDY, a citizen of the United States, residing at lVatertown, in the county of Jefferson and State of New York, have invented certain new and useful Improvements in Door Opening and Closing Devices, of which the following is a specification.

This invention relates to improvements in devices for operating doors or like parts, and is designed especially for opening and closing the doors of fire departments and other structures.

The invention relates particularly to improvements in the device shown and de-' scribed in the United States Patents Nos. 829,265, 975507 and 988265, bearing dates respectively August 21, 1906, November 15, 1910, and March 28, 1911.

The object of the invention is to provide a novel, simple and effective mechanism for opening a door or like part immediately upon the unlatching or otherwise releasing of the same, and for automatically closing the door or part after the lapse of a predetermined time, without assistance or attention from any other source.

A further object is to provide a device of the class which will allow a door to be operated by hand at will, and which may be employed for automatically opening the door either outwardly or inwardly.

A further object is to provide electrically operated means carried by the main device, and associating therewith mechanically 0perated means carried by the door frame for measuring the interval of time during which the door may remain open, and for effecting the automatic releasing and closing of the door at the end of said interval.

A further object is to improve and simplify the construction and arrangement, and to reduce the number of parts, for rendering the device less expensive and less liable to get out of order. And a further object is to provide a device of the class in which the 1 same power or means employed for opening 1 the door are utilized for closing the said 1 1 wrought iron.

part.

The advantages of the invention will be I understood from the detailed description; which follows, and by reference to the accompanying drawings, in which- Flgure 1 1s an inslde face view of a pair of doors; showing my complete device applied thereto, the same being adjusted and set for opening the door. Fig. 2 is an enlarged top plan view of the device illustrated in Fig. 1. Fig. 3 is an enlarged elevational View of the same. Fig. 4 is an enlarged plan view; showing the device after it has opened the door. Fig. 5 is a central longitudinal section through the device shown in Fig. 41. Fig. 6 is a horizontal section through the main-spring and easing; showing the winding of the spring when the device is in the position shown in Figs. 4 and 5. Fig. 7 is a similar sectional view; showing the winding of the main-spring when the device is in the position shown in Figs. 1, 2 and 3. Fig. 8 is a sectional view substantially on line 8-8 of Fig. 4; showing the spring motor employed for rotating the main-spring and related parts. Fig. 9 is a sectional view substantially on line 99 of Fig. 4. Fig. 10 is an enlarged detail sectional view of the electromagnetically controlled tripping device. Fig. 11 is an enlarged side elevation of the clock-work timing mechanism. Fig. 12 is a broken detailed view of the electric contacts controlled by the clock-work. Fig. 13 is a top plan view of the device; showing the adaptation of the same for opening the door outwardly; also showing a modification of the construction and disposition of the motor. Fig. 1 1 is a central longitudinal section of the same- Fig. 15 is an elevational view; showing the latter device reversed for closing the door.

In the drawings, 2 and 3 represent parts of a pair of doors, the door 2 being hinged at 41 to the side part 5 of the frame for opening into the building, and 6 represents the top part of the frame. The doors and frame may follow the usual constructions.

My improved door opening and closing device will now be described.

7 represents a bracket which is mounted in an L-shaped shoe or part 8, to which it may be secured by any suitable means. The bracket 7 and the part 8 are preferably secured to the frame 5 by bolts 9. The

parts

7 and 8 should be made of eithercast or 10 represents a U-shaped support, which is pivoted to the bracket 7 by a bolt or pin 11 which pierces both of said parts, the said bolt having a head to engage the vertical portion of the bracket 10, and the opposite end of the bolt being fitted with a nut 12 for holding the parts in place. The arms 10' of the support 10 are correspondingly perforated to receive a bolt 13 which is held in place by nuts 14.

15 represents a cylindrical casing, open at one end, which is rotatably disposed in the

support

10, and 16 represents an arbor which is journaled in the said casing. Both the casing 15 and the arbor 16 are disposed concentrically to the bolt 13 which pierces the arbor.

17 represents a circular cap which closes the open end of the casing 15, for holding the arbor truly concentric in the casing. One end of the arbor has a relatively large flange 16 which is provided with sockets 16 to receive a locking-pin 18 which pierces one arm 10 of the support 10 for preventing the arbor from rotating with the casing 15.

19 represents a number of radial sockets formed in the edge of flange 16, which are provided for receiving a suitable instrument for rotating the arbor for winding and unwinding a main-spring 20 which is employed for opening and closing the door. The main-spring 20 is preferably spirally wound and disposed concentrically in the casing 15. The inner end of the said spring engages a longitudinal slot of the arbor 16, while the outer end of said spring engages a slot in the casing 15. The turning of the arbor in the direction indicated by the arrow in Fig. 4 will wind up the spring 20, for giving it tension or power for rotating the casing. 15 on said arbor. In practice the spring 20 is preferably wound to a certain tension sufficient to move the door 2 through an arc of 90 or more, and this normal tension is maintained by means of a clamping ring 21, which surrounds the main-spring. When the arbor 16 is manipulated in the right direction, the spring 20 may be wound to a still greater extent for giving it power for opening the door, as will later be explained. When the spring 20 is first wound, and the ring 21 is placed around the spring, the spring is allowed suflicient recoil, to effect the movement of the door in, the proper direction by its normal tension, when the device is in the position. shown in Figs. 4, 5 and 6.

22 represents a hub or sleeve which is preferably cast with the casing 15, and which is bored out centrally to receive one end of a main operating lever 23, which is held rigid in said sleeve by a set-screw 23. Beyond the hub 22 the rod or lever 23 is preferably square in cross section. The lever 23 is operatively connected to the door 2 by means of a spring motor 24, which. is pivotally mounted on a bracket 25, the said bracket being secured to the door 2 by means of bolts 25. The motor 24 consists of a hollow cylindrical body. or casing 26, havmg an open end for the insertion of a spirally wound spring 27, which provides the power for rotating the lever 23 and the door opening casing and

spring

15 and 20. The inner end of the spring 27 engages a slot in an arbor 28, which is disposed concentrically in the said casing, the outer end of the spring 27 passes through a slot 26 of the casing 26. Under this arrangement the rotation of the arbor in opposite directions winds and unwinds the spring 27. One end of the arbor 28 is provided with a large flange or head 29 which closes the open end of the casing 26, the opposite end of said arbor passes through a perforation in the closed end of the casing 26, and is threaded to receive a nut 30, which is employed for holding the arbor in place, and also for holding the said arbor from rotation at certain times. The lever 23 passes through and reciprocates in a square hole in the arbor 28, and the free end of the said lever is fitted with a handle 31, which is made rigid on the lever by means of a set-screw 31. The object of the handle 31 is to enable the operator to rotate the main-spring 20 and its casing 15 on the pivot bolt 11 for setting the device in the positions shown in Figs. 1, 2, 3 and 7, wherein the main-spring 20 appears to be wound or coiled around the arbor 16 clockwise for rotating the casing 15 in the direction for opening the door 2. When the operator swings the handle 31 from the positions shown by the full lines, to that shown in dotted lines in Fig. 8, and also to the positions shown in Figs. 1, 2, 3 and 7 the lever 23, owing to its connection with the arbor 28 of the motor, rotates the said arbor in the direction for rewinding or increasing the tension of the spring 27, for giving the said spring sufficient power to rotate the main-spring 20 and its casing from the positions shown in Figs. 1, 2, 3 and 7 back to the positions shown in Figs. 4, and 6, in which the main-spring appears to be wound in the direction for closing the door 2. In this way the single main-spring 20 is utilized for opening and closing the door, instead of employing two oppositely wound main-springs, as shown and described in the former patents referred to.

32 represents a projecting lug or part carried by the flange 29 of the arbor 23, which engages

lugs

33 and 33 carried by the casing 26 of the motor, for limiting the rotary movement of the arbor 28, as well as the main-spring 20 and its casing 15, to sub-- stantially onehalf a revolution. The full and dotted lines in Fig. 8 illustrate the feature and operation of the stop 3233.

34 represents a part carried by the support or yoke 15, which is rigidly secured to the said support, and which serves in part for stopping the recoiling movement of thesaid support and the main-spring 20 when they are rotated from the positions shown in Figs. 1, 2, 3 and 7 to the positions shown in Figs. 4, 5 and 6. For this purpose the part 34 is provided with a knocker-arm 35, which is arranged to engage or strike one wing of the Lshaped bracket 8 each time the device is released (see dotted lines in Fig. 3 and full lines in Figs. 4 and To hold the door opening and closing parts in the position indicated in Figs. 1, 2, 3 and 6, in readiness for opening the door 2, I provide a latch or bolt 36 which is disposed in a hollow chamber in the part 34, the said latch being normally held in the extended position anc is rendered yieldable by a spring 37. When the door opening and closing parts are rotated a half turn from the positions shown in Figs. 4, 5 and 6 to that shown in Figs. 1, 2, 3 and 7 for setting the device for opening the door, the latch bolt 36 engages a roller 38 which is carried by a yieldable stop 39, which is pivoted by a rod 40 within a casing 41 of an electrically controlled part which is disposed beneath the main-spring 20 and bracket 10, the casing 41 being secured to the bracket 7 by means of a screw or bolt 42. The roller 38 is pivoted in a recess in the stop 39 by a rod or pin 43, the opposite ends of which project beyond the lateral edges of the stop, and are received in semi-circular notches 44, which are formed in corresponding edges of a pair of pending triggers 45, which are eccentrically mounted on the opposite inner walls of the casing 41 by pins 46, as best seen in Fig. 10. When the tripping attachment, comprising the roller 38, the stop 39 and the triggers 45 is at rest and awaiting operation, the triggers 45 are disposed vertically, by their connections with the stop 39, which is normally held in its upward position shown in Figs. 1, 3, 5 and 10, by means of a spring 47 which is carried by the pivot rod 40.

48 represents an electromagnet which is disposed in the casing 41, and secured to the bottom thereof by a screw 48.

49 represents the armature of the magnet 48 which is pivoted to the casing 41' by a

49, and 50 represents a spring which is employed for holding the armature away from the magnet (see Fig. The arrangement of the armature is such that when it is in the released position last described, its free edge is disposed behind and engages the free ends of the triggers 45 for holding the said triggers and also the stop 39 rigidly in their normal positions, as shown in Figs. 1, 3, 5 and 14. The stop 39 and the roller 38 are held in the position last described at all times whether the door is open or closed, excepting for an instant just preceding the closing of the door by the device. When the main-spring is rotated as described for setting the said spring in position for opening the door (see Figs. 1, 2, 3 and 7) the latch 36 when brought into engagement with the roller 38, yields against its spring 37, which allows the latch to pass over the roller, when it will again be projected its full length by the spring 37, and at this time the point of the said latch drops behind the roller 36, and the said roller will then hold the latch and all the rotative parts in the said position until the armature 49 is actuated by the magnet 48 as shown in Fig. 10, at which time the power of the spring 27 of the motor becomes effective by the yielding of the stop 39 and roller 38 under the pressure of the latch 36, and the said latch will then pass over the roller, as indicated by the dotted lines in Fig. 10, whereupon the main-spring and its bracket and the lever 23 will recoil or rotate from the positions shown in Figs. 1, 2, 3 and 7, to that shown in Figs. 4, 5 and 6.

The magnet 48 is connected with a timing mechanism which is preferably mounted on part 3 of the door frame, by a pair of

wires

51 and 52, the electric current for energizing the said magnet being supplied by means of a battery The timing mechanism consists of a clock-work which will now be described.

54 represents a base and 55 represents a front plate, the base being mounted on the frame 3 by means of a screw 56. 57 and 57 represent bolts for connecting the front and base together, the latter being spaced sufiiciently to receive the gears and other operating parts between them. 58 represents a spring for operating the clock-work, which is mounted upon and capable of being wound by a shaft 59, the outer end of the spring being anchored to one of the bolts 57. 60 represents a sector gear which is mounted upon the shaft 59, the said gear being directly connected to the said shaft by a radial arm 61, and the said gear is adapted for movement within a limited space in the said frame.

62 represents a pinion which is rigid on a shaft 63 and it is normally in engagement with and driven by the sector 60.

In Fig. 1 the clock-work is shown wound up by the closing of the door and held ready for operation, while in Fig. 11 the clockwork is shown run down, for closing the electric circuit which takes place at the end of its operation. The clock-work is wound up for measuring the interval of time the door 2 may remain open, as shown in Fig. 11, by a lever 64, which is made rigid upon the shaft 59, and a rod 65 which is pivoted to said lever by a pin 66. The rod 65 preferably extends along the top of the door and passes through a loop 67 of a part 68 which is secured near the top of the door, the rod 65 has free play in the loop 67 which is made large enough to permit the opening and closing of the door without cramping the rod.

69 represents an adjustable stop which is lever 64 andthe sector-gear from the posi tion shown by full lines in Fig. 11 and the position shown in Fig. 1. When the door is in the full open position, the loop 67 and the stop 69 are disconnected, as shown in Fig. 4. The sector-gear will then be operated from the position shown in Fig. 1 to that shown in Fig. 11 by the recoil of the spring 58. Each time the door closes the rod 65 is operated in the manner described, for winding the spring 58, and immediately following each opening of the door, the spring 58 exerts its power'for operating the sector. A train of gears and an escapement are employed for timing the running down of the sector-gear. The following describes the operation of these parts: 70 represents a spur-gear journaled on the shaft 63 and driven by a pawl 71 and a ratchet 72, which are respectively connected to the gear 70 and pinion 62. The. gear 71 meshes with and drives another pinion 73, carried by a shaft 74. The latter shaft carries an escapementgear 75, which is controlled by a double pallet 76, which is mounted upon a shaft 77, and a fan or a governor 78 also mounted upon the shaft 77, all cooperate for regulating or prolonging the operation of the clock-work to the desired extent. The sector or gear 60 is employed for opening and closing the electric circuit for operating the magnet 48 of the tripping device. The said electric circuit is normally open. 79 and 80 represent similar electric conductors which are mounted upon the opposite sides of an insulating part 81, which is secured to an arm 82 of the base 54. The free ends of the

conductors

79 and 80 are preferably flexible or spring-like, and are arranged to normally stand spaced apart, as shown in Figs. 1 and 12, while the clockwork is wound up. The tips or points of these parts form the contacts which are brought together for closing the circuits, by the power of the spring 58, exerted through the sector-gear 60 and a small arm or lever 84, which is pivoted to the extension 82 by a screw 85. The free end of the lever 84 is provided with a roller 86, which preferably consists of a non-conducting material, and engages the conductor 80 when under pressure of the sector-gear for closing the circuit through

wires

51 and 52, as shown in Fig. 11. As long as the door is held in closed position the spring 58 remains wound up to its highest tension, the sectorgear 60 at this time being thrown back to the position shown in Fig. 1, the contact points of the conductors 7 9 and 80 and also the lever 84 stands in the open position shown in Fig. 12, and the electric circuit is open.

87 represents an adjustable stop for limiting the winding movement of the sector-gear. The inner end of this stop is intended to engage the arm 61 of said gear when the latter is thrown backward as shown in Fig. 1. The stop 69 is adjustable to different positions, for varying the travel of the sector-gear, for lengthening and shortening the interval of time between the opening and closing of the door.

When the opening and closing device is applied to the door, as shown'in the drawings, the device and its related parts will first be in its position shown in Figs. 4 and 5, the handle 31 being in the upper position, the winding of the main-spring appearing as in Fig. 6, and the latch-bolt 36 disposed on the upper side of the bracket 10. At this time the door must be in the open position as shown for bringing the lever 23 substantially in line with the pivot bolt 11. At this time the main-spring 20 is arranged to exert its power for rotating the casing 15, for swinging the lever 23 in the direction for closing the door. Before allowing the door to close, the operator should take hold of hand-lever 31 and pull it downwardly to the position shown in Figs. 1, 2, 3 and 7 and the dotted lines in Fig. 8. When the lever is swung to the depending position, the latch bolt 36 engages and is held by the roller 38 of the electric device, and the parts will remain temporarily in the rotated position. The half rotation of the device changes the direction of the winding of the main-spring 20 to that shown in Fig. 7, in which the said spring exerts its power for opening or holding the door open. The operator should then close the door and latch it. This closing of the door eifects the additional winding of the main-spring 20 which increases its power sufliciently to open the door when it is re leased. The door will then remain in the closed position with the main-spring ready to open the same, until someone manipulates a latch or other fastening, whereupon the door will be instantly swung open by the power of the spring 20. The door will then be held in open position until the sectorgear 60 of the clock-work moves from the position shown in Fig. 1 to that shown in Fig. 11. The running down of the sectorgear closes the circuit through the

wires

51 and 52, which energizes the magnet 48, which pulls the armature 49 away from the triggers 45. The stop 39 which has been holding the main-spring in the inverted position will instantly yield under the power of the motor 24 exerted through latch-bolt 36, the main-spring 20 and all of the other door-actuating parts will rotate to the released positions shown in Figs. 4, 5 and 6, which shifts the main-spring from the position shown in Fig. 7 to that shown in Fig.

6, whereupon the said spring will again exert its normal power for closing the door. The door will then remain closed until someone opens it and resets the device for a subsequent automatic operation, as described.

Figs. 13, 14: and 15 illustrate a slightly modified form of the opening and closing device which is employ-ed for swinging a door outwardly. Under this construction and arrangement the device is mounted upon one of the door jambs, as 88, being supported thereon by a bracket 7 and an angleplate 8, which are secured to the j amb by a bolt 9. In this modified device most of the door operating, and the controlling parts are exactly the same as in the main device, the principal changes consisting of the following: The bracket 7 is provided with a hollow part 26 in which is disposed a spiral spring 27, which provides power for rotating the main-spring 20 for adapting the said spring for alternately opening and closing the door. 11 represents a gudgeon or arbor formed integ'ally with the main-spring support 10. This gudgeon passes through the box 26 and the bracket 7 in which it is journaled, and is held in place by a nut 89. The inner end of the spring 27' engages a slot in the arbor 11 while the outer end of said spring passes through a slot 90 in the casing 26". Under this arrangement the spring 27' is wound up when the device is shifted from the position shown in Fig. 15 to that shown in Fig. 14, and is therefore capable of rotating the said device in the opposite direction when the main device is released. The rod or shaft 13' is preferably extended beyond one side of the support 10*, where it is formed into a handle 31", which is arranged concentric to the main-casing 15, instead of being mounted upon the free end of the door-operating-lever, as shown in the other views. 28 represents the lever for operating the door, which is pivotally connected at 91, to the main-spring casing 15. The pivot 91 is provided for allowing the lever 23 to yield to a slight extent independent of the main-spring casing, when the door is swung open by the device, as shown by the dotted lines in Fig. 18. The main-spring is held in the ready-to-operate position shown in Figs. 13 and 14 by the same latch-bolt and electromagnet controlling parts, as is illustrated in the preceding figures of the drawings, and the said parts are intended to be controlled by the same clock-work, as there shown. The lever 23 is yieldingly connected to the door by means of a bracket 92, having parallel lugs or arms 93, between which are disposed like rollers 941, the latter being pivotally held by bolts or pins 95 which pass through the lugs and said rollers. The lever 23" is positioned between and frictionally engages the rollers 94, and by this arrangement the said lever is allowed free play reciprocally while the door is opening and closing. The bracket 92 is secured to the door by bolts 95'. WVhen the main-spring and the operating lever 23" are rotated on the gudgeon 11, and set for opening the door, as shown in Figs. 13 and 14, the door will be held in the open position by means of a bolt 96 which is carried by one arm of the bracket 92, and for this purpose the lever 23 is provided with a notch 97. The bolt 96 is normally held in the downwardly extending position, ready to engage the said notch, by a spring 98, which is suitably housed in a casing 99. The bolt 96 only engages the notch 97 while the device is set for the opening of the door, and after the door is opened the said bolt will remain in the said notch for assisting in holding the door in said position, until the timing mechanism allows the motor spring 27 to rotate the main-spring and said lever from the position shown in Fig. 14., to that shown in Fig. 15. The rotation of the lever 23", as last described, shifts the notch 97 out of engagement with the bolt 96, as best seen in Fig. 15. As soon as the engagement of the bolt 96 and the notch 97 is broken, the door starts to close by the normal power or tension of the main-spring. 100 represents a latch or a locking-device for holding the door in closed position when the device is set for automatic action.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A door opening and closing device, comprising a main-spring normally wound and set for closing a door, means for manually setting and rewinding said spring for opening the door, and means for automatically reversing said spring for allowing it to close the door.

2. A door opening and closing device, comprising a main-spring normally wound and set for closing a door, means for manually setting and increasing the tension of said spring for opening the door, and a motor carried b the door adapted for reversing said spring for allowing it to automatically close the door.

3. A door opening and closing device, comprising a main-spring normally wound and set for closing a door, means for manually setting and increasing the tension of said main-spring for opening the door, means for automatically reversing said main-spring for allowing it to close the door, and a timing mechanism for measuring the interval between the opening and the closing of the door.

1. A door opening and closing device, comprising a single main-spring normally wound and set for closing a door, means for inverting said main-spring and for giving it an extra tension for opening the door, a motor carried by the door adapted for restoring said main-spring to its normal position for allowing it to close the door, and a timing'mechanism adapted to permit or prevent the operation of said main-spring by said motor.

5. A door opening and closing device, comprising a single main-spring mounted near a door, a casing for said spring, a rotatable support for said casing, a lever carried by said casing, means for yieldingly connecting said lever to the door, means for rotating said main-spring a part of a turn for setting it for opening the door, and means for rotating said spring back to the first positionfor closing the door.

6. A door opening and closing device, comprising a main-spring having a normal tension sufficient to close a door, means for reversing and rewinding said spring for opening the door, a tripping mechanism for holdingsaid main-spring in said reversed position, a timing mechanism adapted for operating parts of said tripping mechanism for effecting the releasing of said spring, and a spring for ro-tating'said main-spring back to the first position for allowing it to instantly close the door.

7. In a door opening and closing device, the combination with a hollow casing, and a lever carried by said casing adapted to operatively connect with a door, a rotatable support for said casing, said support mounted near the door, a main-sprlngrin said casing, said spring normally wound in the direction for closing the door, manually controlled means for rotating said casing for setting said spring for opening the door, and means for rotating said casing to first position for allowing said spring to close the door.

8. In a door opening and closing device, the combination with a bracket mounted at one side of a door, and a rotatable support pivoted to said bracket, of a hollow casing, an arbor for pivoting said casing.

to said support, a main-spring in said casing, said spring connecting with said arbor and also with said casing, and having a normal tension suflicient to close the door,

a lever carried by said casing, a bracket car- 1 for opening the door, and a spring mg-lever carried by said casing, a bracket carried by the door adapted to operatively support said lever, a spring carried by the bracket on the door, a handle carried by said lever adapted for rotating both of said springs, for reversing the direct-ion of the winding of the main-spring so that it will open the door and for increasing the tension of the second spring so that it will restore the main-spring to first position after the door is open, and a timing device for i measuring the interval during which the door may remain open.

In testimony whereof I afliX my signature in presence of two witnesses.

HENRY C. BUNDY. Witnesses:

IRVING PARMETER, JOHN C. LAMON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.