Animal cage and door latch

An animal cage having a hinged door with extending horizontal latching pins that engage a latch is disclosed. The latch is provided with sound deadening parts and spacers to provide quiet operation.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a cage for animals. More particularly, the 
present invention relates to a latching mechanism for securing the cage 
door. 
2. Description of the Related Art 
Animal cages are well known in the art and have many uses, such as 
transporting pets, transporting wild animals for relocation, housing 
research animals, and so forth. It is also known to provide an animal cage 
with a door that is hinged along one side wall, with the hinges typically 
being attached to the edge of the side wall. The door can be secured in a 
closed position by a latch fastened to the side wall opposite the hinges. 
Latches for this purpose are of many different types and designs. Many of 
them are noisy and difficult to operate. This shortcoming presents a 
significant problem in settings such as animal laboratories which may have 
hundreds of animal cages. Such cages must be opened and closed frequently, 
adding significantly to the general background noise. In addition, some 
animals may rattle the cage doors. 
Accordingly, there is a need for an animal cage and latching mechanism that 
reduces the noise generated by opening and closing the cage door. 
SUMMARY OF THE INVENTION 
Accordingly, it is a primary object of the present invention to provide an 
animal cage having a hinged door and a latching mechanism that is quieter 
in operation than those of the prior art. 
It is another object of the present invention to provide an animal cage and 
latching mechanism capable of securing any size animal. 
Other objects and advantages of this invention will become apparent from 
the following description taken in connection with the accompanying 
drawings, wherein is set forth by way of illustration and example, an 
embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As required, a detailed description of the preferred embodiment of the 
present invention is disclosed herein. It is, however, to be understood 
that the disclosed embodiment is merely exemplary of the invention, which 
may be embodied in many various forms. Therefore, specific structural and 
functional details disclosed herein are not to be interpreted as limiting, 
but merely as a basis for the claims and as a representative basis for 
teaching one skilled in the art to variously employ the present invention 
in virtually any appropriately detailed structure. 
Referring to FIG. 1, there is shown an animal cage 10 having a rear side 
wall 12, a first side wall 14, a second side wall 16, a bottom wall 18, 
and a top wall 20 joined together to form a three dimensional cage. The 
walls may be joined by any conventional fasteners such as bolts or rivets, 
which may be fastened to internal angle iron members, and so forth. 
Alternatively, naturally the cage 10 may be a molded structure, such as 
conventional two-piece pet carriers. 
The front of the cage is covered by the door 22 that is connected to the 
first side wall 14 by the pair of hinges 24 on the hinged edge at the door 
22. The door 22 may comprise a mesh of horizontal and vertical bars 26, 
which may be welded into a grid, woven, and the like. Naturally, the door 
may be of any desired construction, as may be the side walls. The door 22 
further includes two means for engaging a latch on the side of the door 
opposite from the hinges 24, or latching edge of the door 22. In this 
particular embodiment, the door 22 includes two latching pins 28 spaced 
apart from one another and comprising short metal bars welded to the door 
22 and extending horizontally therefrom for a short distance, such as two 
or three inches (five or seven cm), to engage the latch 30 for securing 
the cage door. 
Referring to FIG. 2, there is shown the latch 30 in greater detail in the 
closed position. The latch 30 further comprises the latch bar 32 and two 
door latch guides 34. The latch bar 32 includes a handle means 36, which 
may be an arcuate detent in the outwardly projecting edge of the latch bar 
32, which allows the user to open the cage door 22 easily by pushing the 
latch bar 32 with a forearm, shoulder, and so forth, allowing the user to 
open the door without his hands. The latch 30 is shown in the open 
position in FIG. 3. 
Referring to FIG. 4, the door latch guides 34 include a flat flange portion 
38 which includes two apertures 40 for mounting the latch 30 on the edge 
of the second side wall 16. Conventional fasteners such as screws or 
rivets 42 (FIG. 1) secure the latch 30 to the cage 10. 
Still referring to FIG. 4, in one embodiment the latch bar 32 is spaced 
from the bracket portion of the guides 34 by a pair of bushings 46, for 
providing quiet operation of the latch. The bushings 46 are made from 
nylon, or other sound absorbing or deadening material. In the preferred 
embodiment, the bushings 46 are made of acetal. Because the latch bar 32 
and the door latch guides 34 are made from stainless steel, in operation 
the latch 30, is quite noisy, because the latch provides unwanted sounds 
when the door 22 is opened or closed, or shaken. The sounds are produced 
when the latch bar 32, the door latch guides 34, the rivets 56, the 
latching pins 28 and the cage 10 impinge on one another. The use of a 
softer nonmetallic bushing material for bushings 46 greatly reduces the 
noise encountered in opening and closing the door 22 and the noise the 
animals may generate by rattling the cage doors. 
Referring to FIGS. 9 and 10, there is shown the bushing 46 comprising a 
washer portion 48 of circular shape and a cylindrical portion 50 having a 
diameter smaller than that of the washer portion 48. The washer portion 48 
and the cylindrical portion 50 comprise superposed concentric circles in 
plan view (FIG. 9) having a central aperture 52 therethrough concentric 
with the washer 48 and cylindrical portion 50. As illustrated, the washer 
is a single unitary structure made from nylon. 
Again referring to FIG. 4, the bushings 46 are oriented with the smaller 
diameter cylindrical portion 50 facing inward toward the latch bar 32, 
which includes a pair of slots 54 (see FIG. 5) for receiving a rivet 56 
(see FIG. 3) or other suitable fastener that holds in place the sandwich 
consisting of two inwardly facing bushings 46, the outer walls of the 
bracket portion 44 of the door latch guides 34 through the apertures 45, 
(one on each side of the bracket 44), and, in the middle, the latch bar 
32. 
Referring to FIG. 11, there is shown an alternative and preferred 
double-stepped bushing 70 which is formed of a solid sound-deadening 
material such as nylon, or preferably acetal. The double-step bushing 70 
includes a large diameter circular washer portion 72, a step 74 that falls 
to a reduced diameter sleeve 76, which extends to the second step 78. The 
second step 78 falls to the still smaller diameter circular 
washer-engaging pin 80. Each of the three longitudinal portions of the 
double-step bushing 70, i.e., the outer surface 73 of the washer portions 
72, the sleeve 76, and the washer-engaging pin 80, comprises a cylinder. A 
central aperture 82 penetrates the whole length of the double-step bushing 
70 along its longitudinal central axis. When viewed from a plan view, the 
three cylindrical portions appear as concentric superposed circles. 
Referring to FIG. 12, there is shown the washer 86 having a cylindrical 
aperture 84 therethrough. The aperture 84 is slightly larger than the 
outside diameter of the washer-engaging pin 80 portion of the double-step 
bushing 70, so that the washer 82 can be pressed onto the pin 80. 
The apertures 82, 84 are both large enough to accommodate the shaft of the 
rivet 56. During assembly of the latch 30 of the animal cage 10, the 
double-step bushing 70 is inserted into the slot 54 of the latch bar 32 
and the washer, also preferably made of acetal, is pressed onto the 
washer-engaging pin 80 portion of the bushing 80. Frictional engagement 
holds the two pieces together. Then the door latch guide 34 is positioned 
over the latch bar 32 while the rivet 56 is inserted through the apertures 
45, 82, 84 and flattened or expanded as appropriate, to permanently couple 
the components together. 
Referring to FIG. 5, there is shown a side elevation of the latch bar 32, 
including the slots 54 and the aperture 56', which may be used for 
securing the cage door 22 in a closed position by inserting a pin or 
padlock through it. The pin or lock will prevent the latch bar 32 from 
being moved up as shown in FIG. 1 enough to unlatch the door 22 (see also 
FIG. 2). 
Also illustrated in FIG. 5 are the two hook portions 58, which engage and 
retain the latching pins 28. The hook portions 58 further include a 
straight-line inclined portion 60 for facilitating engagement of the 
latching pins 28 with the hook portion 58. The latching pins 28 ride along 
the inclined portions 60, translating a force against the latch bar 32 
that is directed into the second side wall 16 into a force having a 
vertical component, which causes the latch bar 32 to rise to the point 
that the latching pins 28 ride over the crest 62 of the hook portion 58, 
at which point the latch bar 32 falls downward by a small amount. Then the 
latching pins 28 are engaged in the right-hand portion of the hook 
portions 58, locking the door. 
Referring to FIG. 8, the door latch guides 34 further include a notch 63 
having a U-shaped channel portion 64 that terminates in a semicircular 
pattern, and a wider latching pin receiving Y-shaped portion 66, which 
allows the latching pins 28 to settle into the U-shaped channel portion 64 
more easily. The triangular shaped end flange 68 allows wider spacing of 
the fasteners 40, providing greater strength in the attachment of the door 
latch guides 34 on the cage. The bracket 44 of the door latch guide 34 
includes horizontal top slots 49, which permit assembly of the latch 30, 
see FIG. 4. 
It is to be understood that while certain forms of this invention have been 
illustrated and described, in the best mode currently known to the 
inventor has been disclosed, the invention is not limited thereto, except 
insofar as such limitations are included in the following claims.