Portable smoke alarm

A portable alarm is provided with a smoke detecting mechanism and circuit connected to an audible signal activated on the presence of smoke and all contained in a compact housing. To this conventional combination the invention interposes a connector means in the circuit between the detector and alarm which connector means includes a highly visible elongated external hanging electrical lead that is plugged into an opening in the housing to complete the circuit through the electrical lead thus, at all times, conspicuously indicating the armed/unarmed condition of the alarm.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a well-known type smoke alarm which is modified by 
making it portable and using a switch connector means in the circuit 
connecting the sensor and alarm which circuit is completed by engaging an 
external attached electrical lead that is highly visible. 
2. Description of the Prior Art 
Many smoke alarms are now available at low cost for use in residences of 
all kinds. They sense the abnormal conditions of smoke and/or fire by 
photo-electric, heat-sensing, and ionization means and all are well known. 
The alarms are mounted in a convenient place as a stairwell and usually 
comprise a combination of a smoke-detecting mechanism of any suitable type 
and a separate signal alarm means with a circuit connecting the detecting 
mechanism and alarm to provide a signal on the presence of the abnormal 
condition, such as smoke. As herein used and in the claims, the more 
common term "smoke" is intended to include fire, heat, or any other 
similar abnormal condition being sensed to trigger an alarm. These 
components are generally arranged in a compact, foraminous housing in a 
small package. The foraminations permit the entrance of the abnormal 
condition such as smoke so that it can be detected to activate the alarm. 
These alarms have become quite compact and low cost due to the use of 
small components and integrated circuitry and are battery operated or 
driven by the usual AC home voltage. Typical battery-operated smoke alarms 
may detect low battery voltage and signal a warning that a replacement 
battery is required, as in U.S. Pat. No. 4,030,086. Also, compactness is 
enhanced by the use of a piezoelectric horn of small size using few parts 
for easy assembly and compact size, as in U.S. Pat. Nos. 4,330,729 and 
4,302,695, all three patents of common assignment. The compactness of 
smoke alarms also permits portability and such small devices are available 
for use in temporary residences such as hotel and motel rooms for use by 
travelers. 
The portable alarms generally carry some means of attaching the alarm over 
a doortop or door handle or suitably setting it up in the room as a safety 
measure. Generally, all smoke alarms are required to indicate a low 
battery condition and usually are not designed to be inactivated 
conveniently for fear they would be turned off on false alarms and not 
reset. It is common to have to remove the battery or fan the air around 
the smoke detector in order to stop the alarm once sounded if it is not a 
true emergency condition. The need exists for a portable smoke alarm that, 
on brief inspection, is readily visible as armed or unarmed in order to 
lend utility to the device for traveling people. 
It is therefore an object of this invention to provide a convenient 
arrangement for a portable alarm that can be easily armed or unarmed and 
whose condition is readily apparent on visual inspection. 
Another object is to provide a portable alarm that is easily activated or 
armed but does not use a conventional ON/OFF switch that is easy to forget 
and leave in the OFF or inoperative position. 
SUMMARY OF THE INVENTION 
Briefly stated, in carrying out the invention a portable alarm is provided 
having a smoke detecting mechanism and a signal alarm means with a circuit 
connecting the mechanism and alarm to provide a signal on the presence of 
an abnormal condition such as smoke. These conventional components are 
housed in a compact, foraminous housing in a small package. The invention 
comprises modifying this conventional package by providing an electrical 
connecting circuit including an elongated electrical lead. The electrical 
lead is highly visible and extends outside of the housing to hang from the 
housing. Connecting means such as a phone plug is provided on one end of 
the electrical lead to connect to a matching phone jack for completing the 
electric circuit through the electrical lead. This combination provides an 
electrical lead forming a hanging appendage on the housing and visibly 
indicating the armed or unarmed condition of the alarm.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings and particularly to FIG. 1, there is shown a 
standard smoke detector that is enclosed in a compact housing and formed 
of a foraminous plastic such as louvred cover 12 that is hinged to a back 
or base housing 14 on which the various internal components are mounted as 
shown in FIG. 2. The louvres 16 permit the entrance of smoke to be 
detected by the internals of the smoke detector as is well known. The 
internal components are quite small for an overall suitably shaped package 
that, by the use of modern components in a square shape, may be on the 
order of four to five inches square maximum. Normally, the packaged 
housing 10 is permanently attached at an appropriate place in a home such 
as the top of a stairwell to perform its emergency signaling in the 
presence of smoke. As shown in FIG. 2, the internal components are 
straightforward and include a suitable detecting mechanism 18 whose 
details are well known and which is mounted on the housing 14 and has 
slots 20 into which smoke may enter from louvres 16. To emit an audible 
alarm, a small piezoelectric horn 22 is also mounted on the back housing 
14 as described in said U.S. Pat. No. 4,330,729 supra. A voltage or a 
power source is provided by a 9-volt battery 24 and all are interconnected 
by a circuit, that may be similar to said U.S. Pat. No. 4,030,086 supra. 
The arrangement is such that the circuit connects the smoke-detecting 
mechanism 18 with the signal alarm or horn 22 and is powered by a battery 
24. 
Generally, a signal button 26 may be pushed occasionally to close the 
circuit and test the smoke alarm. As described, this device is well known 
and presently available on the market. 
In order to provide a more useful and flexible portable smoke alarm, the 
present arrangement has a hanger mechanism 28 that, conveniently, may be a 
plastic block 30 mounted on the housing and slotted to accommodate an 
L-shaped thin extendable hanger strap 32 having a long and a short leg as 
shown. The hanger strap 32 may be conveniently stacked for travel with the 
short leg in slotted block 30 as shown in FIG. 1 and then may be reversed 
by withdrawing and inserting the longer leg providing an elongated thin 
extendable adjustable hanger to fit over the top of a door 31 as shown in 
phantom in FIG. 2 when open or closed so the smoke alarm hangs inside the 
hotel room as will be apparent. 
In order to provide the necessary flexibility for a portable smoke alarm, 
the invention interrupts the normal connecting circuit within the smoke 
alarm by providing an opening 33 through the housing for first connector 
means 34 in the connecting circuit. For high visibility, an elongated 
electrical lead 36 is connected on the housing in the circuit to one side 
of the circuit and is of a length to extend outside the housing to hang 
therefrom with high visibility as shown in FIGS. 1 and 2. Thus, the 
circuit is electrically interrupted or completed through the electrical 
lead. The other end of the electrical lead includes a second connector 
means, which may be a simple phone plug 38, that connects to complete the 
circuit by any suitable means such as sliding between spring biased plates 
40 (see FIG. 3) inside a matching jack 42 forming the connector means in 
the connecting circuit. This permits repeated use necessary in a portable 
device. A preferred circuit connection of phone plug 38 and first 
connector means 34 containing spring biased plates 40 is shown in FIG. 4. 
Thus, insertion of the plug 38 completes the circuit through the 
electrical lead and the activation or arming of the smoke alarm as shown 
in FIG. 2. The traveling or unarmed condition of the alarm is shown in 
FIG. 1 with the electrical lead extending in a highly visible condition 
outside the housing by hanging therefrom. Usually, the phone plug 38 and 
test button 26 are bright red for visibility. 
Therefore, the smoke alarm of the present invention provides a compact 
portable smoke alarm that may be conveniently suspended by hanger 28 over 
any thickness of door when traveling and the entire device is normally 
completely unarmed--FIG. 1--by the hanging electrical lead entirely 
external of the smoke alarm. It is easily armed--FIG. 2--by inserting the 
electrical lead in the opening 33 in the housing to provide a device that 
is highly visible as to its armed/unarmed condition at all times. 
While I have hereinbefore shown a preferred form of the invention, obvious 
equivalent variations are possible in light of the above teachings. It is 
therefore to be understood that, within the scope of the appended claims 
with the term "smoke" as defined above, the invention may be practiced 
otherwise than as specifically described and the claims are intended to 
cover such equivalent variations.