US 2634149 A
Description (OCR text may contain errors)
R. H. WISE DOOR LOCK April 7, 1953 Filed Oct. 10. 1950 2 SHEETSSHEET l RALPH H.- WISE INVE TOR.
ATTORNEYS Patented Apr. 7, 1953 DOOR LOCK Ralph H. Wise, Wayne, Mich, assignor to Ford Motor Company, Dearborn, Mich, a
tion of Delaware corpora- Application October 10, 1950, Serial No. 189,453
I 4 Claims. 1
This invention relates generally to a door latch mechanism and particularly to a door latch mechanism of the rotatable bolt and pawl type for use on motor vehicle doors. An object of the invention is to provide an improved door latch mechanism of the type latch from the associated keeper. The improve-.
ment of the present invention resides in the provision of a pawl formed of two pivotally connected sections. One of the sections is pivotally mounted upon a suitable support, and the other section has means thereon for engaging the rotatable ratchet of the latch mechanism to hold the latter in its latched position. In the usual pawl and ratchet construction in locks of this type, a considerable force is exerted by the ratchet against the pawl by reason of the compression of the resilient weather strip around the edges of the door when the door'is in its closed position. This pressure, and the resulting friction between the pawl and ratchet, must be overcome by the actuating mechanism to disengage the pawl from the ratchet to unlatch the vehicle door. The articulated two section pawl disclosed in this application facilitates the disengagement of the pawl from the ratchet and makes itpossible to readily swing the pawl away from the ratchet regardless of the pressure ex-. erted by the ratchet upon the pawl. In fact, after a slight initial movement of the pawl by the actuating mechanism, the force exerted by the ratchet upon the pawl actually assists in the disengagement.
Other objects and advantages of this invention will be made more apparent as this description proceeds, particularly when considered in connection with the accompanied drawing, wherein:
Figure 1 is a longitudinal vertical crosssectional view through the rearward portion of a motor vehicle body incorporating the present invention.
Figure 2 is a vertical transverse cross-sectional view taken on the line 2-2 of Figure 1 and showing the latch mechanism in locked position.
Figure 3 is a view similar to Figure 2 but showing the pawl and ratchet in a partially disengaged relationship.
Figure 4 is a view similar to Figures 2 and 3 but showing the pawl completely disengaged from the ratchet.
Figure 5 is a cross-sectional view taken on-the Figure 6 is a cross-sectional view taken on the line 6--5 of Figure 2. a
The drawings illustrate the latch mechanism of the present invention as applied to the luggage compartment door of an automobile body, but it will be understood that the device is also applicable to other doors and closure member of motor vehicles as well.
The present invention constitutes an improvement in the construction shown in the co-pending application of Thomas C. Dingman and John W. Jamieson, Serial Number 157,574, and since a considerable portion of the construction of the present invention is the same as that shown in the above co-pending applicatiomreference is made thereto for a more detailed description thereof.
Referring now to the drawings, the reference character ll indicates the luggage compartment door of an automobile body. The door comprises bosses 24 formed in an L-shaped reinforcing member 26. l
A bracket 21 is mounted within the case 2i and forms a partition wall between the front and rear walls of the case. The bracket 21 extends through aligned rectangular openings 28 and 29 The rotor and ratchet are adapted to be held in latched position by means of an articulated two section pawl or toggle. The lever 36 forms one section of the toggle, and is pivotally mounted upon the partition wall 21 of the case by means of a shoulder stud 31. The-wall 2'! is formed with boss 38 forming a bearing surface for the ratchet and the toggle linkage. U The ge cq q ,SQ t Qn 9 the tactic l n a e ,c mpris a pawl 39 carried by the lever 36 and pivotally connected thereto by means of a shoulder stud 4|. As best seen in Figure 6, the portion of the pawl 39 pivotally connected to the lever 36 is offset from the main body portion of the pawl so that the pawl and the lever generally lie in the same plane adjacent the boss 38 formed on the partition wall 21 of the case. Inasmuch as the opposite end of the shoulder stud 4| is riveted over the rearward side of the lever .36., an elongated slot 42 is formed in the wall 21 to provide clearance therefor.
The lever 36 and the pawl '39 are formed with abutting flanges E3 and 44 respectively limiting relative pivotal movement between the leyer and pawl in one direction. The lever and pawl are normally held in this limiting position by "means of a spiral spring 48 having its inner end seated in a 'slot "formed in the head of the shoulder rivet 4| non-rotatably carried by the pawl 39, and having its outer end engaging a flange 41 struck upwardly-from the pawl 39. It will thus be seen that while the lever 36 and pawl 39 forming the two sections of the toggle linkage are normally held in their extended "position "by the spring 43, the toggle'maybe-collapsed against the "force of the spring.
The pawl 39 is formed with a projection 48 engageable with the teeth f the ratchet '33 to hold the latter against clockwise rotation. 'Referring particularly to *Figure 2, it will be seen that in the "latched position of the mechanism, thepivotal axistl between the lever 33 and pawl 39 is located slightly below a line 53 extending from the axis 31 of the pivotal connection between the lever 36 and the supporting wall 2'! and the efiective point of contact between "the projection 4'8 of the pawl 39 and the adjacent tootho'f the ratchet 33. The -eiiective point of contact is of course the outermost pointof the ratchet tooth engaging the pawl. Theslightly over-center relationship of the two sections of the toggle linkage is eiiective to maintain the latter extended and *to hold the ratchet in its latched position until released by aseparate'actuating force. It will be noted that a spiralspring 5!, having its inner end seated in the slotted head of the shoulder 'rivet '31 non-rotatably mounted upon the supporting wall 27, and its outer end engaging a fiange=52 struck upwardly from thelever 33, continually urges the lever 33 and the pawl 39 engaged therebyin acounterclockwise direction toward its latched position.
In the illustrated embodiment of the invention the'rotor 31 'is adapted to be engaged by-a keeper 59. As shown in'Figure 1,-the keeper 59 is secured by bolts 5| toafixed bracket iii-welded to the stationary body structure. Referring now to Figure 2, theupper'portion of "the-keeper -53 is formed with *a toothed-projectionBS adapted to engage the rotor 3I between adjacent teeth thereof. The edge of the --keeper opposite-the toothed projection '63 slidably engages -a fixed cam 64 -rigidly=mounted-within the case =2l. It will be apparentthatthe closingmoveinent of the luggage compartment -door H causes the projection-'63 on=the'--'keeper to engage the rotor and rotate the latter in :a =counterclockwise directionas-seen in Figure 2-until-the lat-chedposition is reached, and conversely, the opening movement of the door is-accompaniedby a clockwise rotation of the-rotor to 'free' the-latter from the keeper.
Thexleverwfi -isrormed with an upwardl-yand rearwardly bent arm 53 projecting into the path of the lower arm 5:; of a bell crank lever pivotally mounted upon the upper portion of the supporting wall 22- by means of a rivet 56. The upper arm 5? of the bell crank lever is detachably connected to a link 58 connected to a suitable actuating mechanism (not shown) such as a door handle or other operating device. Upward movement of the link 58 by the actuating mechanism swings the bell crank lever in a counterclockwise direction and through its contact with the arm 55 of the lever 36 rotates the latter in a clockwise direction against the action of the spring 5i. When the luggage compartment door II is closed, the weather strip [6 between the periphery of the door and the adjacent body structure is compressed and exerts a force tending to open the door. This results in a force being exerted by the ratchet :teeth :upon the projection :48 of the pawl 39, and the resulting friction resists swinging :movementof the pawl away from the ratchet. The toggle formed'by the pivotally connected lever 36 and pawl 39, however, is resiliently held in extended position only by the spiral spring-tit, and initial actuation of the lever 35 bythe bell crank lever 5? .causes the toggle to break and to move to the position shown in Figure 3. It will be seen that in :this position the abutting flanges 3 and i l of the lever 36 and pawl 33 respecti elyhave separated and-the relative pivotal movement between the lever and pawl has resulted in movingthe :axis :41 of the pivotal connection therebetween to a position above the line 5 connecting the pivotal axis *3] with the efiective point :of contact between the ratchet tooth and the pawl.
The actuation of the bell :crank lever 5:7 by the actuating mechanism to swing the lever '36 fromtheposition shown in Figure'3 to that-shown in Figure 4 is effective =to completely disengage the pawl 3.9 from the ratchet 33. During this phase of thedisengaging movement of 'the'latch mechanism the force-ofthe ratchet 33:upon the projection es of the -pawl:39 actually assistsin collapsing the toggle since the pivotal axis 4| between the two sections of the toggle linkage is above the center line-'50. Consequently only a very rncderate force need :be exerted by :the
actuating mechanism to unlatch the door lock. This is extremely advantageous with .door locks employing actuating mechanism of thepush button type or the key release-typein which-only a limited amount: of actuating forcecanrbe applied conveniently.
The pawl '39 isprovidedewith atongue 66 extending beyond the toothed projection 48. 'The extreme-end of the tongue fifi slides between the supporting wall 2? of the-case and'a flange-61 bent downwardly irom the upperportion of the caseto 'provide a guideway-therebetween. The pawl 39 is :thus held again-st inadvertent displacement. "The tongue 66 extends'over the adjacent ;tooth on the ratchet -33 =a-nd positively prevents movement of the pawl 39 beneath-the position shown in "Figure 2, thus -insuring the properreturnof-the pawl --to latching position with the-ratchet whenthe--actuating'mechanism is released and preventing thepawl 39 from being carried aroundwith-the ratchet when the toggle formed by the pawl and-'the lever -36 is collapsed.
It will be seen-that-the constructiondescribed above provides a simple yet effective latching device ada-pted to be unlatched'with-a minimum of efiort, and applicable to locked-mechanisms of various types for vehicle doors, luggage com- 7 partment lids and so forth.
It will be understood that the invention is not to be limited to the exact construction shown and described, but that various changes and mod-' ifications may be made without departing from the spirit and scope of the invention, as defined in the appended claims.
What is claimed is:
1. In a latch mechanism for a motor vehicle door, a support, a toothed latching device rotatably mounted upon said support, a lever member pivotallymounted upon said support adjacent said toothed latching device, a pawl member pivotally supported upon said lever member and having an integral portion directly engageable with the teeth of said toothed latching device to hold the latter in latching position, cooperating stop means on each of said members limiting pivotal movement between said members in one direction, spring means supported upon one of said members and engaging the other of said members to yieldably hold said members in said limited position, additional spring means urging said pawl member toward said toothed latching device, and actuating means engaging said lever linkage for selectively holding said ratchet against rotation in one direction, said toggle linkage including a link pivotally mounted on said support and a second link pivotally mounted upon and wholly supported by said first link, said second link having an integral projection thereon directly engageable with said toothed 6 1 ratchet, stop means determining the extended relationship of said toggle links, yieldable means operable upon said toggle linkage to urge said projection toward latching engagement with said ratchet, and actuating means for rotating one of said links about its axis to disengage said projection from said ratchet. 3'
3. The structure defined by claim 2 which is further characterized in that the pivotal axis between said links is slightly offset in the latched position of said mechanism from the line extending between the pivotal connection of said first link to said support and the effective point of contact between the projection on said second link and the adjacent tooth of said ratchet.
4. The structure defined by claim 2 which is further characterized inthat the pivotal axis between said links is slightly ofiset in the latched position of said mechanism from the line extending between the pivotal connection of said first link to said support and the effective point of contact between the projection on said second link and the adjacent tooth of said ratchet, said actuating means being engageable with said first link and effective upon operation to rotate the latter about its pivotal connection with said support and to swing the pivotal connection between said links to the opposite side of said line to enable said toggl linkage to collapse from its extended position to facilitate the unlatching of said mechanism.
. RALPH H. WISE.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 150,216 Almonte Apr. 28, 1874 339,245 Van Winkle Apr. 6, 1886 875,747 Streng Jan. 7, 1908 1,283,669 Chrisman et al Nov. 5, 1918 2,231,075 Lakin Feb. 11, 1941 2,259,670 Van Voorhees Oct. 21, 1941 2,560,477 Roethel July 10, 1951