US1845904A - Interlocking mechanism - Google Patents

Description

Feb. 16, 1932; T. BRADY 1,845,904

INTERLOCKING MECHANISM Filed April 1, 1930 2 Sheets-Sheet 1 Z3 a L; *7 v 1. [21b 2'2 2'2 BY ATTORNEY Feb. 16, 1932. T, BRADY 1,845,904

INTERLOGKING MECHANISM Filed April 1, 1930 2 Sheets-Sheet v 2 42M BM-4% INVENTOR FIQZ BY ATTORNEY Patented Feb. 16, 1932 UNITED STATES PATENT OFFICE THOMAS BRADY, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO OTIS ELEVATOR COM- PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY INTERLOOKING MECHANISM Application filed April 1, 1930. Serial No. 440,685.

The invention relates to interlocking mechanism and particularly to interlocking mechanism for the hatchway doors of elevator installations.

It is desirable to lock the doors, which afford access to elevator hatchways from the corridors, in closed position in order to lessen the possibility of in]ury to ersons who might otherwise open a door and all into the hatch- Way or be struck by the moving car. It is also desirable to associate circuit controlling mechanisms with the locking mechanism for each door in order to prevent movement of the car in the hatchway when any door is not locked in closed position.

In some elevator installations, particularly those in which an attendant is provided in the car, it is sometimes deemed desirable to arrange these circuit controlling mechanisms for operation to enable starting of the car when the door in closing reaches a predetermined point slightly in advance of its fully closed and locked position in order to avoid delays in operation of the car arising from awaiting movement of the door to fully closed and locked position.

In such arrangements there is a possibility of a prospective passenger grasping the door after it passes the predetermined point and reopening the door to enter the car, thus exposing himself to the danger of being injured by the moving car or at least delaying the car by causing operation of the circuit controlling mechanism associated with the door so as to stop the car.

A feature of the present invention resides in preventing reopening of a hatchway door after it has reached a predetermined point in closing until the door is first moved to fully closed position.

A second feature resides in preventing full reopening of a hatchway door ifthe door is left partially open, in the event that the door in closing has been moved to a predeter mined point slightly in advance of fully closed position.

A third feature resides in rmitting completion of the starting circuits for an elevator car when the hatchway door in closing reaches a predetermined position slightly in advance of fully closed and locked position and in preventing interruption of these circuits as a result of an attempt to reopen the door after it reaches this point but before the door is fully closed. p

A fourth feature is the provision of a toggle lever system for operating a hatchway door and looking it in closed position in conjunction with a pawl carried by one of the toggle levers for cooperating with a rack on the hatchway wall at the side of the door opening to prevent reopening of the door after the door in closing reaches a osition slightly in advance of fully closed an locked position.

A fifth feature is the provision of an interlocking switch which is connected to the locking mechanism for a hatchway door for operation thereby and which is arranged to ell'ectively perform its functions even in the event of failure of the operating connections between the switch and the lock.

Other features and advantages will become apparent from the specification, taken in connection with the accompanying drawings wherein one embodiment of the invention is illustrated.

In the embodiment of the invention to be described the hatchwa-y door is slidably mounted for movement relatively of the opening in the hatchway wall through which acoess is had to the elevator car. A toggle lever is pivotally mounted on the hatchway wall at the side of the door opening. A similar toggle lever is connected at one end to the first toggle lever and its other end is pivotally connected to the door. The toggle levers assume a straight line position when the door is fully closed to lock the door in closed position. A handle is formed on the toggle lever connected to the door for breaking the toggle levers to unlock the door and to open the door. A closing device connected to one of the toggle levers is operable, as the door is opened, for biasing the door to closed position. A pawl carried by the toggle lever mounted on the hatchway wall is arranged to cooperate with a tooth of a rack mounted on the hatchway wall atthe side of the door opening. In the event that the opening direction beyond the above mentioned predetermined point and to permit operation of the car after closing movement of the door to this point butprior to movement of theidoor to fully closed position in which it is locked by the toggle levers. A link connects the door locking toggle levers to a switch operating member pivotally mounted on the hatchway wall. The switch operating member is connected by a link to a switch rod and is also provided with a finger cooperating with a cam and stop on the switch rod to open and close the switch in the event of disconnection of the link between the switch member and switch rod. The switch operating member is weighted for automatically opening the switch to prevent operation of p the elevator car in the event of disconnection of the link between the toggle levers and the switch operating member.

In the drawings:

Figure 1 is an elevation of the hatchway side of a door embodying the interlocking mechanism of the present invention;

Figure 2 is a side view of the interlocking mechanism shown in Figure 1, the hatchway door being omitted;

Figure 3 is an enlarged view of the rack plate and pawl illustrating the position of the pawl when the door is fully closed and locked;

Figure 4 is a view similar to Figure 3 bu showing the position of the pawl when the door is fully opened;

Figure 5 is a view similar to Figure 3 but showing the pawl in locking engagement with the rack tooth as a result of an attempt to reopen the door after the door in closing has reached a predetermined point in advance of fully closed position;

Figure 6 is an enlarged view of the interlocking switch with one of the casing covers removed to illustrate the relation of the switch parts when the door is closed and locked; and

Figure 7 is a view similar to Figure 6 but showing the relation of the switch parts when the door is unlocked and opened.

Referring 'to Figure 1, the numeral 21 designates a hatchway door suspended from hangers 22 cooperating with a track 23 to guidethe door in its movement transversely of the door opening. One end of a toggle lever 24 'is'pivotally mounted between lugs guide pawl roller 36 25 extending from a bracket 26 mounted on a plate 29 secured to the hatchway wall 27 at one side of the door opening. The other end of lever 24 is pivotally connected to a similar toggle lever 28 which is pivotally mounted on the hatchway door., The toggle levers 24 and 28-Wl1en in the straight line position constitute a lock for preventing opening of the door from the corridor. A handle 31 is provided on lever 28 for break-' ing the toggle levers to unlock the door and foroperatingthe levers to open and close the door. 7

The toggle levers24 and 28 do not assume a straight line position to lock the door until the door is moved to fully closed position. It is therefore desirable to provide additional means effective to lockthe door and prevent reopening thereof particularly from the cor,- ridor, when the door is moved to a predetermined point in closing or in the event that the forward edge of the door remains positioned between this point and its fully closed position after the closing operation.

Referring also to Figures 2, 3, 4 and 5, a pawl 32 is providedat one end with an opening for receiving a stud 33. Stud 33 extends through openings formed in the bifurcations 34 of an extension 35 of toggle lever 24 and serves as a pivot pin for pawl'32. A roller 36 .is mounted at the end of pawl 32 for cooperation with a rackdesignated as a' whole by the numeral 37. -;Rack' 37 comprisesa plate 38 having a base portion 39 secured to plate 29 at the side of the door opening. Plate 38 is provided with a slot 40 into which pawl roller 36 projects for movement as the door is opened and closed. Slot 40 is formed to provide an extension ortooth 41 for cooperating with the roller; as will be described hereinafter A cam 42 formed on plate 38 extends into slot 40 and divides the slot into a channel 43 between one side edge of the slot and the cam and a channel 44 between the cam and tooth .41. Channels 43 and 44 will hereinafter be referred to as the opening and closing channels, respectively. Slot 40 also has a third channel 45. Cam 42 also acts to in its movement in slot 40.

The casing 46 of an interlock switch designated as a whole by 47, is also mounted on plate 29 at the side of the door opening. Referring also to Figures 6 and 7 ,the interlock switch comprises a pair of spaced contacts 48 carried by conductive springs 50 which are iso is limited by the engagement of a stop 56, formed on the rod, with boss 54.

Switch 47 is arranged to be operated as the doors are opened and closed. Rod 53 is connected by a link 57 to a weighted member 58 pivotally mounted on plate 29 adjacent casing 46. Member 58 also has a finger 60 which projects into the space between stop 56 and a cam 61 on the rod for cooperating with cam 61 and. stop 56. A link 62 is connected at one end to member 58 and at its other end is connected to toggle lever 24. The

contacts 48 of switch 47 are connected in a control circuit for the elevator car, such as a 1 starting circuit for the car, and are arranged to be bridged by contact 55 to permit starting of the car only when the hatchway door is locked to prevent opening thereof.

A combined door closing and checking deas vice, designated as a whole by 63, is provided for moving the door toward closed position.

This device may be of the type described in applicants prior patent No. 1,685,081 issued on Sept. 25, 1928, and will not be described in detail herein as reference may be had to the patent for a detailed description. The piston rod 64 of this device is connected to toggle lever 24, being pivotally mounted on stud 33 between the bifurcations 34 of the ex- 36 tension 35 of the toggle lever. Piston rod 64 is raised as the door is opened for storing energy in a spring within the casing of the de-- vice 63 for moving the door toward closed position.

a: The operation is as follows: When it is desired to open the hatchway door the car attendant grasps and pulls down on the handle 31.. Toggle levers 24 and 28 are thus broken to unlock the door as they move from a straight line position. Toggle lever 24 pivots upwardly about bracket 26 raising pawl roller 36 from the position shown in Figure 3 into contact with cam 42, which guides the roller into opening channel 43. As handle 31 is op crated to open the door, pawl roller 36 is rai seed with toggle lever 24 and moved through opening channel 43. As pawl roller 36 passes over cam 42, the upper edge of slot 40 depresses the roller into engagement with the back of tooth 41 for guiding the roller into channel 45.

Lever 24 also acts, as the door is opened, to operate closing device 63 for storing energy to close the door and moves link 62 downwardly to rock member 58 clockwise. Such rocking of member 58 causes link 57,assisted by engagement of finger 60with cam 61 on switch rod 53, to withdraw the rod and move bridging contact 55 from between the contacts 48. The arrangement is such that contact 55 is moved frombridging relationship with contacts 48 when the door has been opened to a predetermined point, for example four inches from its fully closed position. As a result, switch 47 is opened to prevent operation of the car while the door is open. When the door has been moved to its fully opened position, pawl roller 36 is ositioned within channel 45, as shown in igure 4, and the spring of door closing device 63 is fully tensioned for moving the door to closed position. Bridging contact 55 is positioned out of engagement with contacts 48, as shown in Figure 7.

When it is desired to close the door, handle 31 is released and the spring of door closing device 63 acts to operate toggle levers 24 and 28 to close the door. As toggle lever 24 moves downwardly about bracket 26, pawl roller 36 is moved forwardly in channel 45 toward cam 42. Toggle lever 24 also acts through link 62 to rock member 58 counterclockwise. Such counterclockwise movement of member 58 causes link 57, assisted by the engagement of finger 60 with stop 56 on switch rod 53, to move the rod upwardly.

As the door approaches closed position, pawl roller 36 strikes cam 42 and is guided thereby into closing channel 44 so that as the forward edge of the door reaches a predetermined oint, for example four inches from fully closed position as previously stated, the roller 36 is in channel 44 immediately beyond the tooth 41 of rack 37. Coincidently, contact 55 bridges contacts 48, closing switch 47 to enable operation of the elevator car.

As the door is moved to fully closed position, pawl roller 36 continues to be moved forwardly in channel 44 and beneath cam 42 to the position illustrated in Figure 3, and toggle levers 24 and 28 assume a straight line position to lock the door.

After the door has been moved to or be yond the four inch position it cannot be fully reopened either from the ear or the corridor until'after it is moved to fully closed position. In the event that a person desiring to use the elevator car grasps door 21 to stop its closing movement and tries to reopen the door to enter the car, after the door has been moved to or beyond the four inch point but not to fully closed position, the resulting movement of toggle lever 24 causes movement of roller 36 of pawl 32 into engagement with tooth 41 of rack 37 as shown in Figure 5, thus preventing the door from being reopened more than four inches. The attempt to reopen the door also results in contact 55 being moved downwardly between contacts 48. However, contact 55 and contacts 48 are so arranged that contact 55 is not moved out of bridging engagement with contacts 48 unless the door is opened more than four inches. As a result, the door cannot be reopened from the corridor and switch47 remains closed to prevent stopping of the car, it in operation, as a consequence of the attempt to reopen the door. When the intending passenger, finding it impossible to open the door sufficiently to enter the car, releases the door the closing device 63 acts to move the door to fully closed position and the toggle levers straighten to lock the door. 7

It is to be noted that, in the event that'the door has not fully closed, the car attendant may reopen the door, as far as the four inch position, to free the apparel or effects of pas sengers, which may have been caught between the edge'of the door and the side of the door opening.

In the event that a closing'device such as 63 is not provided for automatically closing the door but instead the door is closed by the car attendant through manipulation of handle 31, it may happen that the car attendant might move the door toward closed position only to an extent sufficient to close switch 47 for enabling completion of the car starting circuits. The car might then leave the floor at which the door is located while the door remained partially open, that is with its forward edge positioned somewhere between four inches of closed position and the fully closed position. However, even in such cases the door cannot be reopened from the cor ridor sufiiciently to permit access to the hatchway nor to open switch 47, and as a consequence stop the car if it is in operation. An attempt to open the door beyond the four inch point would result in causing the roller 36 of pawl 32 to engage the tooth 41 of rack 37, thus preventing further movement of the door and opening of switch 47, as previously described.

The arrangement of the means for operating switch 47, when toggle levers 24 and 28 are operated to unlock and open the door, is such that the switch is operated even in the event of the failure of the one or more of the operating connections between the switch and the toggle levers. For example, if the fastening means connecting the member 58 to rod 53 through link 57 should become disconnected, the cooperation of finger 60 with cam 61 on rod 53 would effect opening of the switch as the door is unlocked and opened and the cooperation of finger 60 with stop '56 on rod 58 would effect closing of the switch as the door is locked and closed. In the event that the fastening means connecting link 62 to member 58 or to toggle lever 24 should become disconnected, member 58 would be moved clockwise by gravity and act through link 57, or finger 60 and cam 61, to immediately open switch 47, thus preventing operation of the car until the defective parts are repaired. 1 7

It is to be noted that after the door in closing has been moved to a predetermined point in advance of fully closed position the pawl and rack cooperate to prevent reopening of the door from the corridor until the door has been fully closed. Thus, the pawl and rack act to lessen the possibility of a prospective passenger being injured as a resiilt of attempting to open the door,when it is nearly closed. When the door is fully closed the toggle levers act to prevent opening of the door from the corridor.

Itis also to be noted that the interlocking switch is arranged to be operated before the door is fully closed and locked, thus lessening delays in operation of the car. As the interlocking switch is arranged to be locked in operated condition when the door in closing reaches a predetermined point in advance of fully closed position it cannot be reopened until the door has been fully closed. As a result, an attempt to open the partially closed door does not effect reopening of the interlocking switch and thereby delay the car 1101' interfere withthe functioningof the switch as a safety device.

Furthermore the 1 construction and arrangementof the operating means for the interlocking switch insures the desired oper ation of the switch under all conditions.

Although the interlocking switch has been described as operated upon movement of the door in either direction to a point located a predetermined distance from iully closed position, it is to be understood'that the interlocking switch may be arranged to be opened on unlocking of the door or on movement of the door from fully closed position, and closed only upon movement of the door to, or locking of the door'in, fully closed position.

While the pawl and rack locking device is particularly adapted for use with. a toggle lever system for locking and operating the door, it may also be employed in association with other types of door operating or locking devices. The interlocking switch and its operating means also are adaptable for use with other types of door locking devices.

As many changes could be 'made in the above construction and many apparently Widely different embodiments of this invention vcould be made without departing from the scope thereof, it is intended that all mat ter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limit ing sense.

7 hat is claimed is:

1. In combination with a closure; operating means for said closure; a stationary rack;

and a pawl carried by said operating means for engaging said rack to prevent reopening of said closure beyond a predetermined point in advance of fully closed position, after said closure has passed said point in closing, until said closure is first moved to fully closed position.

2. In combination with a closure; a toggle lever connected to said closure; a second toggle lever connected at one end to said first toggle lever and pivotally mounted at its other end adjacent the opening closed by said closure, said toggle levers assuming a straight line position for locking said closure when the closure is fully closed; means for breaking said toggle levers to unlock said closure and for operating said closure; a rack mounted adjacent the opening closed by said closure, said rack being provided with a and for operating said closure; a rack mounttooth; and a pawl carried by said second toggle lever for engaging said tooth to prevent movement of said closure in the opening direction beyond a predetermined point in advance of fully closed position, after the closure has passed said predetermined point 1n closing, until said closure is first moved to fully closed position.

3. In combination with a closure; a toggle lever connected to said closure; a second toggle lever connected at one end to said first toggle lever and pivotally mounted at its other end adjacent the opening closed by said closure, said toggle levers assuming a straight line position for locking said closure when the closure is fully closed; means for breaking said toggle levers to unlock said closure and for operating said closure; a rack mounted adjacent the opening closed by said closure, said rack being provided with a tooth; a pawl carried by said second toggle lever for engaging said rack tooth to prevent movement of said closure in the opening direction beyond a point at a predetermined distance from fully closed position, after the closure has been moved to said point in 010s ing, until said closure is first moved to fully closed position; and means for raising said pawl and maintaining it out of engaging relation with said rack tooth when the closure moved in the opening direction from fully closed position.

4. In combination with a door; a lever pivotally mounted adjacent the opening closed by said door, said lever being operable upon movement of said door; means for moving said door to its opened and closed positions; a pawl carried by said lever; and a stationarg rack plate provided with a tooth, said rac plate being also provided with a slot for guid- 1mg said pawl to cause its engagement with said tooth to lock said door against opening beyond a predetermined point in advance of fully closed position in the event that, subsequent to closing movement of said door to said point but prior to movement of saiddoor to fully closed position, said door is moved toward open position.

In combination with a door; a lever pivotally mounted adjacent the opening closed by said door, said lever being operable upon movement of said door to open or closed position; a rack plate mounted adjacent the opening closed by said door, said rack plate being provided with a slot; a pawl carried by said lever; a roller on said pawl, said roller extending into said slot and being movable determined point in advance of ully closed position in the event that, subsequent to closing movement of the door to said predetermined point but prior to movement of the door to fully closed position, said door is moved toward open position.

6. In combination with a door; a lever pivotally mounted ad'acent the opening closed by said door, said lever being operable upon movement of said door to open or closed position; a rack late mounted adjacent the opening closed y said door, said rack plate being provided with a slot; a pawl carried by said lover; a roller on said awl, said roller extending into said slot an being movable therein on operation of said lever when the door is opened or closed; a rack tooth on said late, said rack tooth extending into said slot 'or engagement by said pawl roller to lock said door against opening beyond a predetermined point in advance of fully closed position in t is event that, subsequentto closing movement of the door to said predetermined point but prior to movement of the door to fully closed position, said door is moved toward 0 en position; and means for preventing loc ing engagement of said pawl roller with said rack tooth when the door is moved from fully closed position.

7. In combination with a door; a lever pivotally mounted adjacent the opening closed by said door, said lever being operable upon movement of said door to open or closed position; a rack plate mounted adjacent the open ing closed by said door, said rack plate being provided with a slot; a pawl carried by said lever; a roller on said pawl, said roller ex tending into said slot and being movable therein on operation of said lever when the door is opened or closed; a rack tooth on said late, said rack tooth extending into said slot or engagement by said pawl roller to lock said door against opening beyond a predeterminedpoint in advance of fully closed po' sition in the event that, subsequent to closing movement of the door to said predetermined point but prior to movement of the door to fully closed position, said door is moved toward open position;and a cam on said plate, said cam extending into said slot for engagement by said pawl roller to guide said pawl roller away from looking engagemcnt with said rack tooth when said door is moved from fully closed position.

8. In an elevator installation; a hatchway, one wall of said hatchway being provided with a door opening; a sliding door for closing said opening; a toggle lever pivotally mounted on said door; a second toggle lever pivotally connected at one end to said firsttoggle lever and piv-otally mounted at its other end on the hatchway. wall at one side of the door opening, said toggle levers assuming a straight line position, when the plate mounted at said one side of said door opening, said rack plate having a slot; a pawl carried by said second toggle lever; a roller on said pawl, said roller extending into said slot and being movable therein as the door is unlocked, opened or closed; a rack tooth on said plate, said tooth project ing into said slot for engagement y said pawl roller to lock said door against reopening beyond a predetermined point in advance of fully closed position in the event that, subsequent to closing movement of said door to said predetermined point but prior to movement of said door to fully closed position, said door is moved toward open position; and a cam on said plate projecting into said slot for guiding said roller in its movement in said slot, said cam acting as the door is unlocked to guide said roller to prevent locking engagement thereof with said tooth as said door is moved from fully closed position and acting on closing move ment of said door to said predetermined point to guide said roller into position for engaging said tooth to prevent said reopening of the door. s

9. In an elevator installation; a hatchway door; means for locking the door in closed position; a switch; means connecting said switchto said locking means to cause said switch to be closed when the door is locked; and means for baising said switch to open position, said biasing means acting to open said switch in the event of disconnection of said switch from said locking means. 10. In an elevator installation; a hatchway door; means for locking the door in closed position; a switch; a switch operating member connected to said locking means; means connecting said switch operating member to said switch; and means cooperating with said operating member to efiect the operation of said switch in the event of failure of said connecting means.

11. In combination with a closure; a switch; means for causing said switch to be closed when the closure in closing reaches a point at a predetermined distance from fnlly closed position; and means for preventing the reopening of said switch and also the reopening of said closure beyond said point, after said closure has passed said point in closing, until said closure is first moved to fully closed position.

12. In combination with a door; a switch; means for causing said switch to be opened when said door in opening reaches a point a predetermined distance from fully closed position; means for causing said switch to be closedwhen the door in closing reaches said point; and means for preventing the reopening of said switch and also reopening of said door beyond said point, after said door has passed said point in closing, until said door is first moved to fully closed position.

13. In combination with a closure; a switch; means for causing said switch to be closed when the closure in closing reaches a point at a predetermined distance from fully closed position; means for operating said door; a stationary rack; a tooth on said rack; anda pawl carried by said operating means for engaging said tooth to prevent reopening of said switch, after the switch is closed when the door passes said point in closing, until said door is first moved to fully closed position.

.14. In an elevator installation; a hatchway door; means for locking the door in closed position; a switch associated with said looking means; a switch rod operable to open and close said switch; an operating member for said switch rod; means for connecting said operating member to said locking means; a link connecting said operating member to said switch rod; means for operating said locking means to lock or unlock said door, said operating means, on operation to lock and unlock said door, acting through said locking means, said connecting means, said switch operating member, and said link to opcrate said switch rod for respectively closing and opening said switch; a cam on said switch rod; a stop on said switch rod; and a finger on said operating member for cooperating with said cam for opening said switch on unlocking of said door and for cooperating with said stop to close said switch on locking of said door, in the event of disconnection of 1iaid link from said switch rod or said mem- 15. In an elevator installation; a hatchway door; means for locking the door in closed position; a switch associated with said looking means; a switch rod operable to open and close said switch; an operating member for said switch rod; means for connecting said operating member to said locking means; a link connecting said operating member tosaid switch rod; means for operating said looking means to lock or unlocksaid door, said operating means, on operation, to lock and unlock said door, acting through said looking means, said connecting means, said switch operating member and said link to operate said switch rod for respectively closing and opening said switch; a cam on said switch rod; a stop on said switch rod; a finger on said operating member for cooperating with said cam for opening said switch on unlocking of said door and for cooperating with .3

said stop to close said switch on locking of said door, in the event of disconnection of said link from said switch rod or said member; means for operating said door; a stationary rack; a tooth on said rack; and a pawl carried by said locking means for en gaging said tooth to prevent reopening of said switch, after the switch is closed when the door passes said point in closing, until said door is lirst moved to fully closed position.

16. In an elevator installation; a hatchway door; means for locking said door in closed position; a switch associated with said locking means, said switch comprising a casing, a pair of spaced contacts in said casing, and a bridging contact for engagin said contacts to connect them electrica ll a switch rod guided for movement in sai casting, said rod being operable to move said contact out of and into bridging engagement with said contacts to respectively open and close said switch a boss on said casing; a stop on said rod for engaging said casing to limit the movement of said rod on operation thereof to close said switch; a cam on said rod; a weighted operating member for said switch rod pivotally mounted on said hatchway wail: a link connecting said switch rod to said member: a link connecting said member to said door locking means; means for 0 erating said locking means to lock or an ock said door, said locking means, on operation, acting through said switch operating member and said links to move said switch rod to close or open said switch; and a finger on said switch operating member, said finger cooperating with the cam on said switch rod to move the rod for opening said switch on unlocking of said door and cooperating with said stop on said rod to move the rod for closing said switch on locking of the door, in the event of disconnection of said first mentioned link from said switch rod or said switch operating member.

17. In an elevator installation; a hatchway; one wall of said hatchway having a door opening; a door for said opening; a toggle lever pivctall i' connected to said door; a second toggle lever pivotally connected at one end to said first toggle lever and pivotally mounted at its other end on said hatchway "all at one side of the door opening; said toggle levers acting to lock said door when closed; a switch associated with said toggle levers, said switch comprising a casing; a pair of spaced contacts mounted in said casing, and a bridging contact adapted to be interposed between and in engagement with said contacts for connecting them electrical- 1y; :1 switch rod guided for movement in said casing, said switch rod being operable to move said. contact out of and into engagement with said contacts to respectively open and close said switch; a boss on said casing; a stop on said rod for engaging said boss to limit the movement of said rod on operation thereof to close said switch; a cam on said rod; a switch operating member pivotally mounted on the hatchway wall at said one side of the door opening; means for connecting said switch operating member to said toggle levers; a link connecting said switch rod to said member for movement thereby; means for operating said toggle levers to unlock and open said door, said toggle levers, upon operation to unlock and o en said door, acting through said connecting means, said member and said link to cause movement of said switch rod to open said switch upon movement of said door to a predetermined point from closed position; means for operating said toggle levers to close said door, said toggle levers, upon operation to close said door, acting to move said switch rod to close said switch when said door in closing reaches said predetermined point; a rack mounted on the hatchway wall at said one side of the door opening; a pawl carried by said second toggle lever for engaging said rack to prevent opening of said switch after said door in closing reaches said predetermined point, in the event said door is subsequently moved toward open position prior to movement thereof to fully closed position; and a cam for raising said pawl to prevent locking enga ement thereof with said rack when said oor is unlocked and moved from fully closed position, thereby permitting opening of said switch after said door is unlocked and moved from fully closed position.

In testimony whereof, I have signed my name to this specification.

THOMAS BRADY.

Images