US 1687248 A
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Description (OCR text may contain errors)
Oct. 9, 1928. 1,687,248
N. B. HURD HOSPITAL LATCH Filed Sept. 28. 1927 lmm mlmil lllmmll INVENTOR. M 16: W, mm W TORN S.
Patented Oct. 9, 1928.
. UNITED STATES PATENT OFFICE.
NORMAN B. HURD, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE AMERICAN HARDWARE CORPORATION, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OF CONNECTICUT.
Application filed September 28, 1927. Serial No. 222,587.
This invent-ion relates to certainimprovements in latches, particularly designed for hospital service where silent OPQIZIUOIIlS greatly to be desired.
The object of the invention is to provide a construction which will admit of the silent operation of the lockin g unit.
In the accompanying drawings- Fig. 1 is a side elevation of a latch constructed to embody my invention, with a part of the cap removed;
Fig. 2 is a similar view of the same with parts in a diiierent position;
Fig. 3 is a section on the line -3-3 of Fig. 2; I
Fig. 4 is a section on the plane oi the line 44 in Fig. 1;
Fig. 5 is a perspective view, relatively enlarged, of a roll back.
1 is the body portion of the latch case; 2 is the cap; 3 is the face plate; 4 is the dead bolt; 5 is the tail of the dead bolt; 6 is the hub of a roll back, having an offset or arm 7. 8 is a link pivotally connecting the end of the roll back arm 7 with the tail 5 of the bolt 4. Ihe hub of the roll back has its ends suitably seated in the case 1 and the cap 2, whereby it may be oscillated, as by the ordinary knob spindle (not shown). 1011 are eccentric portions on the roll back hub, each eccentric being provided with an abrupt shoulder at corresponding ends. 12 is a block, having a recess therein forming two eccentric portions in which the portions 10-11 oi' the roll back stand. At the end of each of the eccentric recesses in the block 12 are stop shoulders. There is sufiicient clearance in the recessed portions of the block 12, so that the roll back may be turned from the position indicated in Fig. 2 (where the bolt is projected) to the position indicated in Fig. 1 (where the bolt is retracted). The block 12 is made of a suitable sound deadening material. preferably, hard fiber, so that when the shouldered portions of the roll back hub come into contact with the stop shoulders of the block 12 (as indicated in Fig. 2) no noise will occur. In this position, which is the locking position of the bolt 4, it will be noted that the link 8 is sufficiently close to a dead center line to make it impossible to force the bolt 4 back by an instrument inserted between the door and the casing.
When the roll back is turned from the position shown in Fig. 2 to that shown in Fig. 1, the bolt 4 will be retracted, and when the eccentric portions thereon come into contact with the eccentric portions on the block 12, as indicated in Fig. 1, no noise will occur.
14 is a drag spring, which may be employed if desired to hold the locking bolt 4 in any desired position within the range of its reciprocation.
lVhat I claim is:
1. In a latch of the character described, a case, a bolt, a roll back, means of connection between the roll back and the bolt for reciprocating the latter as the rollback is turned, a shoulder on the roll back and a 70 stop within the lock case to check the stop on the roll back, one of said parts being formed of sound deadening material.
2. In a latch of the character described,
a case, a reciprocating bolt, a roll back for 75 operating the same, a shoulder on the roll back, and stop means of sound deadening material Within the case to limit the rotary movement of the hub.
3. In a latchot the character described, 8o
a case, a reciprocating bolt, a roll back for operating the same, a shoulder on the roll back, and stop means of sound deadening material Within the case to limit the rotary movement of the hub in bot-h directions.
NORMAN B. HURD.