US2106955A - Lock - Google Patents

Description

Feb. l, 1938. D. D. MCA. Mor-'PITT LOCK Filed Aug. 25, 1.9556 2 Sheets-Sheet 2 I f5 p5 92 A12 mfq;

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Patented Feb. 1, 1938 UNITED STATES LOCK Duncan Douglas McArthur Moffitt, Arapito,

Westport, New Zealand, assigner to The Mofiitt Automatic Lock port, New Zealand, a land Company Limited, Westcorporation of New Zea- Application August 25, 1936, Serial No. 97,837 In New Zealand October 21, 1935 6- Claims.

This invention relates to latches for doors, and in particular motor Vehicle doors and the like.

The object of the present invention is to en- 5 able the latch bolt to be withdrawn and held clear of the face of the door, and to be released when the door is closed.

According to the present invention, a latch bolt is formed on the end of a latch rod slideable in the latch casing, and normally tends to be projected forwardly into engagement with a recess in the frame, while manual means are provided to retract the rod and bolt. A releasing rod r projects through the hinged end of the door and is under tension of a spring which normally tends to project the releasing rod in a rearward position, so that as the door is opened this rod moves rearwardly. A retaining pawl is pivoted in the casing and is adapted to engage and retain the latch rod in a retracted position, means being provided so that when the door is unlatched, the retaining pawl will be actuated through the medium of the releasing rod to engage the latch rod, but when the door is closed, such releasing rod will again actuate the retaining pawl in order to disengage it from the latch rod and permit such rod to be projected forward under the pressure of its spring.

In one form, a trip member is provided which is pivoted to the releasing rod, and adapted to fall into alignment with the said rod, and with a rod controlling the pawl, this trip member being raised when the handle is initially turned in order to permit the retaining pawl to engage the latch rod, but returns into position on the release of the handle, so that when the door is being closed, the releasing rod will, through the medium of the trip member, actuate the pawl and so release the latch rod.

In another form, the retaining pawl is simply pivoted to a rod which is in turn pivoted to the releasing rod, the opening of the door enabling the releasing rod to o-perate the pawl to engage the latch rod, but the closing of the door causes the releasing rod to disengage the pawl and permits the latch rod to be projected forward into position.

The invention will be described with the aid of the accompanying drawings, wherein:-

Figure l is a side elevation partly in section of the lock.

Figure 2 is a similar View but showing the position of the parts during the unlatching operation.

Figure 3 is also a similar View showing the position of the parts when the door is being opened.

Figure 4 is a cross section on line A-A Figure l.

Figure 5 is a cross section on line B-B Figure l.

Figure 6 is a plan showing a door partly open.

Figure 7 is an elevation partly in section of a slightly modied form of the lock.

Figure 8 is a similar view showing the position of the parts during the opening operation.

Referring to the drawings, and first to Figures l to 5, a latch rod I has a latch bolt 2 with a conical engaging endto enter a conical recess in a socket 3 within the frame 4, the bolt 2 and the rod I being adapted to be projected forward into the recess by means of a coil spring 5 in compression between a pin and washer 6 on the latch rod I and a part 1 of the lock casing, through which the end of the rod I is guided. The other end forming the latch bolt 2 is guided in a socket 8 tted into an end member 9 of the door. In some cases the socket may form part of the lock casing. A lever I is fixed on a cross member or bar I I, to which handles I2 (see Figures 4 and 6) are secured upon the exterior of the door. This bar II is pivoted in the sides I4 and I5 forming the lock casing, these sidesY being xed to the part 1 and to transverse parts I6 and I1. The lever I0 has pivoted on its upper end a pawl I8 adapted to engage a shoulder I9 on the ro-d I. A coil spring 2li, attached to the lever I0 and anchored at a convenient point on the member 9 of the door, tends to retain the lever in the position shown in Figures 1 and 3. A retaining pawl 2l is pivoted to the casing on a pin 22 which traverses the sides I4 and I5, the other end of the pawl being pivoted to the end of a rod 23 slideable in the part I1. of the casing, and herein referred to as a pawl rod. 'I'he end of the pawl 2| is adapted to engage a shoulder 24 on the rod I. A releasing rod 25 slideable in the part 1 and in the end member 26 of the door, is normally adapted to be projected rearwardly by a coil spring 21 in compression between the part 1 and a washer 28 and pin 29. A trip arm 30, pivoted to the releasing rod 25, is adapted to align with the pawl rod 23 and with the releasing rod 25, and is normally retained in alignment by a at spring 3| fixed to the rod 25 and bearing on the trip arm 30.

The rear end of the releasing rod 25 passes through the end member 26 and is adapted to strike the member 32 of the door frame, or an adjustable stop 33 set therein.

A coil spring 34 around the pawl rod 23 is in compression between the part I1 of the casing and a washer 35 held against a pin 36. The hole in the part I1, through which the pawl rod passes, is slightly larger than the rod, so that a little vertical movement of the pawl rod can take place to permit the arcuate movement of the pawl 2I. A bell crank lever 31 forms a trip lever and is pivoted on a pin 33 in the sides I4 and I5 of the casing. This trip lever is shown in Figure bifurcated, the ends of the forks 39 thereof having a pin 40 which will engage under the trip arm 30. The other end of the trip lever is connected by a link 4| to the lever I0.

In operation, assuming that the door has been closed and the locking bolt is in position, as 'inl Figure l, in order to retract the latch bolt 2 to open the door, a handle I2 is operated, and the lever I is moved back and carries the rod I back to the position shown in Figure 2, thereby withdrawing the conically pointed. end 2 from its recess in the frame. At the same time, the coil spring 5 is further compressed. This movement also has caused the link 4| to operate the trip lever 37 and will cause the trip arm 30 to be moved out of alignment with the rodsf23 and 25, thereby permitting the rod 23 to travel rearwar-ds under the action of the coil spring 34', and will cause the retaining pawl 2| to engage behind the tooth or shoulder 24 on the latch rod I, and retain this'rod in its retractedposition.

' Upon the operator freeing the handle I2, the Vlever I0 andpawl V| 8 will return, under the action of the spring'20, back to the normal position, the link 4| returning the trip lever as'shown in Fig- Yures landA 3, but the trip arm 30 would .re-

main as in Figure 2. As the door is opened on its hinges, it will move away from the frame member 32l (see Figure 6) and the coil spring 2'! will `cause the releasing rod 25-to slide through thefr'ame 2liy and-carry back with it the trip arm 3|), which will then fall into alignment with the pawl rod 23, as shown in Figure 3. The rearward movement of the rod 25 vwould be limited by a` collar or washer 42. Y Y

When the door is being closed, upon the'rear end of: the releasing Yrod 25 striking the frame or stopV 33,'the trip arm 30 will be forced forward and in turn will force forward Vthe pawl vrod 23 and thus rotate the retaining pawl 2| backto the `position shown in Figure l', such movement disen- Y gagingY it from the shoulder 24; the rod moving back a little forv this purpose. Once the rod' is released, it will, under the pressure of its coil spring 5, be shot forward and the conical end 2 will enter the conical recess in the socket 3, and the mechanism will then assume the position shown in Figure' 1. v

'I'he conical end of the bolt 'ensures that any play will be taken up and will thus prevent any tendency to rattle or looseness.

In Figures 7 and 8, a modification is shown, in that the trip arm 3|) with the trip lever is eliminated, the pawl rodv 23 being pivoted to the releasing rod` 25'. l

In this case, the operation is that when the handle I2 is` rotated, theY lever I0 operates the pawl I8 which will engage the tooth I9 and car-V ries back the rod I as before. In this case, the

handlev would be retained inthe drawn-back po-V sition until the conical end of the bolt 2Qis clear of the socket, by which time the releasing rod 25 will have moved back far enough (as indicated in Figure 8) toraise the point of the pawl 2| toY engage the shoulder 24. When the door is being closed, however, the releasing rod 25 will push forward the pawl rod 2'3-and will cause the retaining pawlr 2| to disengage from the shoulder 24 Y What I claimV isr- Y 1. In a latch for doors, acasing, a latch rod slidable Yin said casing, an engaging end to said rod, a spring normally tending to project said `latch rod forwardly into engaging position,

means to retract said latch rod, a releasing rod projectable through the hinged edge of the door, k a spring to retain said releasing rod in projected position, a retaining pawl pivoted in said casing toA engage and retain said latch rod retracted, a pawl rod pivoted to saidl retaining pawl and guided in alignment with said releasing rod, means to retract saidl pawl rodl rearwardly and operate said retaining pawl to engaging position with said latch rod, and meansvto disengage said retaining pawl from said latch rod when said releasing rod is moved forwardly upon the closing of the door. 2'. In the latch as claimed in claim l, a pawl rod pivoted. to said retaining pawl, and guided in alignment with said'releasing rod, said pawl rod pivoted to the forward end of said releasing rod, so that when the door opens the saidwpawl spring to retain said releasing rod in a projected position, a retaining pawl pivoted in said casing to engage and retain said .latch rod retracted, a pawl rod pivoted to said retaining 'pawl and Vguided so as to be moved forwardly by the said releasing rod to disengage the pawl from said latch rod wheny the door is being closed, andY means whereby said pawl rod will permit the pawl to engage said latch rod upon the retracting move-A ment of said latch rod independent of movement of the releasing rod. Y Y

5. A .latch as claimed in claim` I, a spring to retractrvsaid pawl rod rearwardly and operate said retaining pawl to engaging position with said latch rod, a trip arm pivoted to said ,releasing rod and adapted to fall into alignment with said pawl rod to disengagesaid retaining pawl from the said latch rod when saidy releasing rod is moved forwardly upon the closing of the door, and means to raise said trip arm out ofralignment with Said pawl rod to permit said pawl rod to move rearwardly and acuate said retaining pawl to en gage'said latch rod, said trip arm adapted to return into alignment with the pawl rod when the door is opened.

6. A latch as claimed .in claim 1, a spring to retract said pawl rod rearwardly and operate said retaining pawl to engaging position with said latch rod, a trip arm pivoted to said releasing rod and adapted to fall into alignment with said pawl rod to disengage said retaining Vpawl from the said latch rod when said releasing rod is moved forwardly upon the closing of the door.

a trip lever pivoted in said casing, and forming a support for the trip arm, and adapted to raise said trip varm out of alignment with said'pawl rod, a link connecting one end of said trip lever to the means for retracting said latch rod, so that as the latch rod is retracted and said trip arm raised out of Yalignment said pawl rod is permitted to move rearwardly and actuate saidY retaining pawl.

DUNCAN DQUGLAS MCARTHUR MOFFI'I'I.

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