Hanger assembly

An expansible load-bearing junction box hanger assembly adapted for installation from beneath the ceiling and through a junction box opening in the ceiling, includes a pair of walls having a plurality of spike protrusions to engage two spaced adjoining ceiling joists and an elongated linearly expanding brace device which is aligned with and connected between the walls. The brace device expands from a short to a longer length to force each of the walls to contact and engage their respective ceiling joists. Each wall is provided with a receiving groove adjacent to the spike protrusions. The hanger assembly further includes an alarm device, a battery cell, and a contact switch disposed in each receiving groove and actuated when the walls engage their respective ceiling joists. The contact switches electrically connect the alarm device to the battery cell to operate the alarm device when actuated, thereby indicating that the hanger assembly has fully engaged the ceiling joists.

BACKGROUND OF THE INVENTION 
1. Field Of The Invention 
The invention relates to a hanger assembly for suspending heavy objects 
such as ceiling fans, more particularly to such a hanger assembly which is 
adapted for installation through a junction box opening in a ceiling 
without the necessity for entry into the space above the ceiling. 
2. Description Of The Related Art 
A conventional hanger assembly for suspending heavy loads, as disclosed in 
U.S. Pat. No. 4,463,923, is shown in FIGS. 1A and 1B. The center portion 
of a previously installed light-weight hanger assembly has been removed, 
leaving stub portions 240 intact. The hanger assembly 100 is maneuvered 
through a junction box opening 210 in a ceiling 200 and is to be installed 
between parallel horizontal joists 220 and 230. The hanger assembly 100 
includes a plurality of points 110 to engage and bite into the respective 
joists 220 and 230 when extended. The points 110 are disposed on feet 120A 
and 120B which straddle the stub portions 240. The hanger assembly 100 is 
provided with an elongated tubular brace member 130 having a hexagonal 
outer peripheral surface and a central axial bore 140 that is internally 
threaded on one end 131. One end 151 of a threaded rod 150 mates with the 
end 131. The other end of the rod 150 is rigidly mounted on the foot 120B. 
The end 132 of the brace member 130 is rotatably mounted on the foot 120A. 
During installation, the hanger assembly 100 is initially at a minimum 
length and the brace member 130 and the rod 150 are supported by the feet 
120A and 120B in a direction parallel to the plane of the ceiling. The 
brace member 130 is then rotated, as by engagement with a wrench, to 
expand the hanger assembly 100 and urge the points 110 to bite and engage 
the respective horizontal joists 220 and 230. Rotation of the brace member 
130 is stopped when the points 110 have tightly engaged the respective 
joists 220 and 230. A pair of bracket members (not shown) have opposing 
surfaces complementary to the outer peripheral surface of the brace member 
130 and are tightly secured to the brace member 130 by means of screws. 
Finally, a junction box of the load to be suspended is mounted on the 
bracket members. 
A main disadvantage of the hanger assembly disclosed in U.S. Pat. No. 
4,463,923 is that since the hanger assembly is installed from beneath the 
ceiling and through a junction box opening in the same, one cannot be sure 
if the hanger assembly has been properly installed, i.e., the points fully 
engaged the respective ceiling joists. Furthermore, there is a possibility 
that the brace member 130 might disengage from the rod 150 if the distance 
between the joists 220 and 230 is wider than the total length of the brace 
member 130 and the rod 150. 
SUMMARY OF THE INVENTION 
Therefore, the objective of the present invention is to provide an 
expansible load-bearing junction box hanger assembly adapted for 
installation from beneath the ceiling and through a junction box opening 
in the same, said hanger assembly incorporating an alarm device which is 
actuated when the hanger assembly has fully engaged the ceiling joists. 
Another objective of the present invention is to provide an expansible 
load-bearing junction box hanger assembly having provisions to prevent the 
untimely disengagement of the rod from the brace member. 
Accordingly, an expansible load-bearing junction box hanger assembly of the 
present invention includes a first wall and a second wall spaced from the 
first wall. The first and second walls each have a plurality of spike 
protrusions to engage two spaced adjoining ceiling joists. An elongated 
linearly expanding brace means is aligned with and connected between the 
first and second walls. The brace means readily expands in length to force 
each of the first and second walls to contact and engage their respective 
ceiling joists. The brace means includes a tubular member rotatably 
mounted to the first wall and a threaded rod member threadedly and 
telescopically connected to the tubular member. One end of the threaded 
rod member is in fixed non-rotative engagement with the second wall. The 
first and second walls support the brace means in a direction 
substantially parallel to the plane of the ceiling. A junction box 
connecting means rigidly connects a junction box of a heavy load to the 
central section of the brace means. 
Each of the first and second walls has a receiving groove adjacent to the 
spike protrusions. The hanger assembly further comprises an alarm device, 
a cell means, and a switching means including a contact switch disposed in 
each of the receiving grooves and actuated when the first and second walls 
engage their respective ceiling joists. The switching means electrically 
connects the alarm device to the cell means to operate the alarm device 
when the switching means is actuated, thereby indicating that the hanger 
assembly has fully engaged the ceiling joists. 
The tubular member has a threaded bore and an inward annular flange at one 
end. The threaded rod member is in sliding contact with an inner annular 
edge of the annular flange. The threaded rod member has an enlarged 
threaded end extending into the tubular member and engaging the threaded 
bore. The threaded rod member thus contacts two portions of the tubular 
member: the first portion being at the threaded bore of the tubular member 
and the second portion being at the annular flange. The increase in the 
area of contact between the tubular member and the threaded rod member 
enhances the stability of the hanger assembly and correspondingly 
increases the load-bearing capacity of the same. The annular flange also 
serves to prevent the disengagement of the threaded rod member from the 
tubular member during the expansion of the brace means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 2 and 3, the preferred embodiment of a hanger assembly 
according to the present invention is shown to comprise an elongated 
tubular brace member 10, a threaded rod member 30, and a pair of engaging 
walls 40A and 40B. 
The outer peripheral surface of the brace member 10 is non-round, the 
preferred configuration being octagonal. The brace member 10 has a central 
internally threaded bore 11 extending along the axis of the brace member 
10. A bracket member 50 complements the non-round outer peripheral surface 
of the brace member 10. The bracket member 50 is firmly and rigidly 
connected to a junction box 60. The bracket member 50 rigidly secures the 
brace member 10 to the junction box 60. The junction box 60 supports a 
load 70 which may be a ceiling fan (as shown in FIG. 4), a light fixture, 
a chandelier, or any similar article. A guide plate 12 having a central 
through hole 121 is mounted on one end of the brace member 10. The guide 
plate 12 thus forms an inward annular flange on the one end of the brace 
member 10. A mounting plate 21 is provided on the other end of the brace 
member 10. An elongated post 20 is similarly aligned with the axis of the 
bore 11 and has one end attached to the mounting plate 21. The elongated 
post 20 is thus stationary relative to the brace member 10. The engaging 
wall 40B has a recess 41B which receives a bearing member 22. The engaging 
wall 40B has a screw hole 44 which is transverse to the axis of and 
communicated with the recess 41B. The screw hole 44 receives a screw 45 
which prevents axial movement of the bearing member 22 out of the recess 
41B. The other end of the elongated post 20 extends into the recess 41B 
and is surrounded by ball bearings of the bearing member 22. The elongated 
post 20 is thus permitted to rotate with the brace member 10. 
The threaded rod member 30 has an enlarged threaded end 31 which mates with 
the bore 11 of the brace member 10. The other end of the rod member 30 is 
provided with an elongated rod portion 32 which is in sliding contact with 
an inner annular edge defining the central through hole 121 of the guide 
plate 12. The rod portion 32 is fixed to the engaging wall 40A at a recess 
41A of the same. The engaging walls 40A and 40B are provided with a 
plurality of spikes 42 to engage and bite into a pair of spaced horizontal 
ceiling joists (not shown) when actuated. A trapezoidal central notch 46 
is provided on a lower end of each of the engaging walls 40A and 40B to 
permit the engaging walls 40A and 40B to straddle stub portions which 
remain intact after a previously installed light-weight hanger assembly 
has been partially removed. The engaging walls 40A and 40B are further 
provided with a receiving groove 43 disposed adjacent to the spikes 42 and 
the trapezoidal notch 46. A contact switch 80 is provided in each 
receiving groove 43. When actuated, the contact switches 80 electrically 
connect an alarm device 92 to a battery cell means 91. The alarm device 92 
may be a light device, a buzzer or a combination of both. 
The preferred embodiment according to the present invention is installed as 
follows: The brace member 10 is first rotated to contract the hanger 
assembly to its minimum length. The hanger assembly is then maneuvered 
through a junction box opening in the ceiling until the engaging walls 40A 
and 40B rest on the ceiling. The engaging walls 40A and 40B support the 
brace member 10 and the rod member 30 in a direction parallel to the plane 
of the ceiling. The brace member 10 is then rotated so as to axially 
expand the hanger assembly and urge the spikes 42 to bite and engage the 
horizontal joists. Rotation of the brace member 10 causes axial movement 
of the rod member 30 to force the engaging walls 40A and 40B to contact 
the horizontal joists. (The rod member 30 is prevented from disengaging 
from the brace member 10 during the expansion of the hanger assembly by 
the guide plate 12.) When the spikes 42 have tightly engaged the 
horizontal joists, the horizontal joists fully depress the contact 
switches 80 to actuate the same. The contact switches 80 electrically 
connect the alarm device 92 to the battery cell means 91, thereby 
triggering the alarm device 92 into operation. The alarm device 92 sends 
out signals to indicate that the hanger assembly has been properly 
installed. A pair of electrical plugs 93 are also provided in the 
receiving grooves 43 and are pulled out to disable the alarm device 92. 
Rotation of the brace member 10 is then stopped and the bracket member 50 
is installed to firmly and rigidly secure the brace member 10 to the 
junction box 60. The secure connection between the bracket member 50 and 
the junction box 60 reduces the torque and vibrations of a ceiling fan 
load 70 to effectively minimize the shaking and the accompanying noise 
which is typically encountered during its operation. 
Referring to FIG. 4, the height of the engaging walls 40A and 40B is 
selected in conjunction with the length of the junction box 60 so that the 
lower edge of the junction box 60 will be substantially flushed with the 
lower surface of the ceiling. This arrangement effectively hides the 
electrical cables coming from the load 70 and extending into the junction 
box 60. 
The rod member 30 contacts two portions of the brace member 10: the first 
portion being at the bore 11 of the brace member 10 and the second portion 
being at the guide plate 12. The increase in the area of contact between 
the brace member 10 and the rod member 30 enhances the stability of the 
hanger assembly of the present invention and correspondingly increases the 
load-bearing capacity of the same. 
While the present invention has been described in connection with what is 
considered the most practical and preferred embodiment, it is understood 
that this invention is not limited to the disclosed embodiment, but is 
intended to cover various arrangements included within the spirit and 
scope of the broadest interpretation so as to encompass all such 
modifications and equivalent arrangements.