Door latch mechanism

A door latch and lock mechanism especially for storm doors and screen doors, having a latch and a lock bolt. The latch can be retracted from the outside by a button which pushes a plunger in a lengthwise direction. When the plunger is rotated in one direction it will lock the latch in the latched position and also extend the locking bolt to its locked position. When the plunger is rotated in the opposite direction, the latch is released and the bolt is retracted. The plunger is rotated in one direction or the other from the outside of the door by a key operated mechanism spaced from the push button and operatively connected to the plunger by connecting links.

This invention relates generally to latch mechanisms and refers more 
particularly to a door latch mechanism for storm doors and screen doors 
and the like. 
BACKGROUND AND SUMMARY OF THE INVENTION 
Storm doors and screen doors in present use are locked and unlocked from 
the outside by means associated with and incorporated in the latch 
operating handle. This positioning of the means for locking and unlocking 
immediately marks the door as a storm or a screen door, rather than the 
primary door of the dwelling. Primary doors usually place the outside lock 
operating mechanism above the latch operating mechanism. 
One of the objects of this invention is to provide a construction in which 
the lock operating mechanism on the outside of the storm or screen door is 
displaced from the latch operating mechanism, so that the storm or screen 
door has the appearance of a primary door. 
These and other objects of the invention will become more apparent as the 
following description proceeds, especially when considered with the 
accompanying drawings.

DETAILED DESCRIPTION 
Referring now more particularly to the drawings, the door latch mechanism 
there shown comprises a housing 10 on the inner side of the door having a 
latch 12, a latch operator or handle 14, a dead bolt 16 and bolt actuator 
17. There is complementary mechanism 15 on the outer side of the door for 
operating the latch. 
The housing 10 has a mounting portion 18 formed with a marginal flange 22 
adapted to bear against the inner surface of the door 23 when mounted 
thereon adjacent to the swinging edge thereof by fasteners 24, as shown. 
The latch 12 is pivotally mounted in the housing by a vertical pin 26. The 
latch has a latching arm 28 formed with an arcuate peripheral edge portion 
30 adapted to engage the keeper slot 32 in a fixed door jamb 34. The 
latching arm 28 is relieved along one side where indicated at 36 to 
receive the operating arm of the latch operator 14, as more fully 
described hereinafter. The latch 12 has a second arm 38 at a substantial 
angle to the camming edge 40 of the latching arm which is engaged by a 
compression coil spring 42 mounted in the housing. Spring 42 presses the 
latch to its extended or operative position shown in FIG. 1. The latch may 
be retracted to its inoperative position against the pressure of spring 42 
to release the door. 
The latch operator 14 is pivotally mounted in the housing on a vertical pin 
44 parallel to pin 26. The latch operator has an operating arm 46, the tip 
48 of which engages a surface 50 of the arm 38 of the latch to retract the 
latch when the latch operator is turned counter-clockwise from the FIG. 1 
position by hand pressure against the handle portion 52 formed on the 
second arm 54 of the latch operator. 
The bolt 16 is an elongated member of generally square cross-section but 
relieved with slots on opposite sides to receive guide ribs 56 in the 
housing. The bolt is mounted in the housing for horizontal sliding 
movement on its longitudinal axis from an extended locking position shown 
in dotted lines in FIG. 3 in which it projects towards the door jamb for 
locking engagement in a complimentary recess, not shown, to a retracted 
position inside the housing. 
The bolt actuator 17 has a hub 60 in the form of a circular disc mounted to 
turn on its own central horizontal axis which is perpendicular to the 
pivot pins 26 and 44. The hub 60 is mounted for axial rotation within the 
sleeve 62. The sleeve has mounting ring portions 64 engaged over studs 
formed within the mounting portion of the housing and retained thereon 
when the housing is bolted to the door by being clamped against the 
surface of the door. 
The bolt actuator 17 has a ring 70 formed on the hub 60 in concentric 
relation therewith. Ring 70 projects radially beyond the hub and has a pin 
72 near its periphery on one side which extends and engages in a vertical 
slot 74 formed in the adjacent side of the bolt. The latch operator may be 
rotated manually by means of a lever 76 projecting radially from the ring 
70 through an opening 78 in the housing. When the bolt actuator is in the 
position of FIG. 8, pin 72 retains the bolt in the retracted or 
inoperative position. Rotation of the bolt to the FIG. 9 position causes 
pin 72 to move the bolt to its extended position in which it may project 
into a suitable recess in the door jamb to lock the door. 
The ring 70 has an arcuate notch 71 in its outer edge portion of about 
90.degree. in extent. The ring is in a plane coinciding with the arcuate 
peripheral edge 30 of latch 12 (See FIGS. 8 and 9). When the bolt actuator 
is rotated to extend the bolt, the unnotched portion of the ring 70 
extends behind this peripheral edge portion 30 as seen in FIG. 9, 
positively preventing the latch from being retracted. Hence the door is 
prevented from being opened not only by the bolt 16 but also by the locked 
condition of the latch. The effect is that of a double dead bolt. However, 
when the bolt actuator is turned to the FIG. 8 position, the notch 71 is 
brought into register with the latch to provide clearance so that the 
latch can be retracted in the normal way. 
The complementary mechanism 15 on the outer side of the door for operating 
the latch comprises a housing 80 secured thereto by the fasteners 24. The 
housing has a recess 84 on the side facing the door. A plate 86 covers the 
recess and bears against the adjacent side of the door. 
The housing 80 has a lower horizontal passage 88 which extends into the 
recess 84. An opening 89 in the outer wall 90 of the housing opens into 
the chamber. 
A pusher assembly 92 extends through the passage 88. The pusher assembly 
comprises a push button 94 and a plunger 96. The push button 84 projects 
through the opening 89 and has a flange 98 inside the passage 88 which 
bears against the housing wall surrounding the opening 89 to prevent the 
button from separating from the housing. The button is capable of 
reciprocating horizontally within the passage 88, that is by finger 
pressure it can be pressed to the right in FIG. 2 in a direction in which 
it enters the housing passage. 
The plunger 96 is an elongated member of non-circular, specifically oblong 
rectangular, cross-section. The outer end of the plunger is received in an 
cylindrical extension 100 of the push button and has a reduced section or 
notch in each of its edges into which an annular rib 102 in the extension 
extends to prevent separation of the push button and plunger, while 
permitting the plunger to rotate relative to the button. The plunger 
extends horizontally in the same direction as the button and is capable of 
reciprocating, through an opening 104 in plate 86 and through an opening 
in the door, with its inner end disposed adjacent to a pad 106 on the 
operating arm 46 of the latch operator 14. When the push button is 
depressed, that is, moved to the right in FIG. 2, the plunger 96 also 
moves longitudinally to the right and its inner end engages the pad 106 on 
the operating arm 46 to move the arm in a direction which retracts the 
latch 12. 
The plunger extends through a rotatable member 110 which has a circular 
extension 112 on one end seated in the circular opening 104 in the cover 
plate 86. The hole in the rotatable member 110 through which the plunger 
96 extends has the same non-circular cross-section as the plunger. The 
plunger 96 is capable of sliding in a lengthwise direction through the 
rotatable member 110, but rotation of the plunger causes the rotatable 
member 110 to rotate in opening 104. The rotatable member 110 has a flange 
portion 115 in the housing recess 84. 
A compression coil spring 111 surrounds the plunger 96, bearing at one end 
against the rotatable member 110 and at the other end against the push 
button 94. As a result, the push button normally remains seated in the 
FIG. 2 position in which its flange 98 engages the outer wall of the 
housing and the rotatable member 110 remains seated with its extension 112 
disposed within the opening 104 in the cover plate. 
The housing 80 has a second passage 116 which is spaced vertically above 
the passage 88 and which likewise extends horizontally. The passage 116 
opens through the outer wall 90 of the housing and has an enlarged 
cylindrical portion 117 which opens into the recess 84. 
A rotatable member 120 has a cylindrical body portion 119 rotatably 
received in the enlarged portion 117 of passage 116 and has a flange 
portion 121 located in the housing recess 84. 
The rotatable member 120 has a pair of arms 122, 124 projecting laterally 
outwardly from the opposite sides of the flange portion 121. The rotatable 
member 110 has a pair of arms 126, 128 projecting laterally outwardly from 
the opposite sides of the flange portion 115. A link 130 is pivotally 
connected at the ends of arms 122 and 126 of the respective members 110 
and 120. A link 132 is pivotally connected at the ends of arms 124 and 128 
of the respective members 110 and 120. 
A key-operated locking unit has a plug 140 secured in the passage 116. The 
plug supports a rotatable shaft 142 which projects through an opening 144 
in rotatable member 120. The shaft 142 has diametrically opposite, 
longitudinally extending ribs 146. The opening 144 has diametrically 
opposite, radially inwardly extending lugs 148. Thus, when the shaft 142 
is rotated, the ribs 146 on the shaft engage the lugs to turn the 
rotatable member 120 between the positions of FIGS. 5 and 6. The shaft 142 
is turned by means of a key 150 inserted in the plug 140 in the usual 
manner. In the FIG. 5 position of the linkage, the rotatable member 110 
and plunger 96 are turned to the position extending bolt 16 and locking 
the latch 12 (FIG. 9). In the FIG. 6 position of the linkage, the 
rotatable member 110 and plunger are turned to the position retracting 
bolt 16 and releasing latch 12 (FIG. 8). 
When not operated by a key, the shaft 142 is freely rotatable in its 
cylinder 140 to permit the latch 12 to be locked and released and the bolt 
16 to be extended and retracted from the inside of the door by means of 
the handle 76.