An improved print-cartridge carriage for ink-jet printers. It contains: (a) a carriage frame having a first recess, a second recess, a pair of spaced L-shaped, and a bearing allowing the carriage frame to be horizontally movable; (b) a gripping spring disposed in the first recess; (c) a pair of spring loaded buttons disposed in the second recess, each of spring loaded buttons has a first bevel surface; and (d) a gripping member having two symmetrically lateral second bevel surfaces. Each of the second bevel surfaces is slidably and respectively engageable with one of the first bevel surface such that the gripping member can be moved relating to the spring loaded buttons and be lifted upwardly when the spring loaded buttons are pressed inwardly. The gripping member further includes a protruded stud formed on a top location of the gripping member of upward engagement with the gripping spring, and an outwardly projecting latch formed on a bottom location of the gripping member for holding a ledge of a print cartridge by a downwardly gripping force provided by the gripping spring.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an improved print-cartridge carriage for holding 
a print cartridge which has a ledge on a top edge and a plurality of 
contact pads on a lateral wall for use in ink-jet printers, and, more 
particularly, to an improved print-carriage in which the print cartridge 
can be easily removed using only one hand of the user. 
2. Description of the Prior Art 
In thermal ink-jet printers of the type that use heat to produce air 
bubbles in order to expel ink-droplets through the nozzles thereof, the 
print cartridge and the cartridge thereof are typically manufactured in 
separate integral structures, in that it is desirable that the print 
cartridge be designed as a disposable cartridge, due to its limited life 
span. 
FIGS. 1 and 3 illustrates a print-cartridge carriage (A) for mounting a 
print cartridge (B) which is disclosed in U.S. Pat. No. 4,907,018, to 
Pineapple's et al. FIG. 2 illustrates the structure of a print cartridge 
(B), which is already disclosed in U.S. Pat. No. 4,755,836, to Ta et al. 
The print-cartridge carriage of the Pinkerpell's disclosure includes a 
base support (C), which has a snap-spring (X) disposed at the upper 
portion thereof and a pair of L-shaped members (D) disposed at the lower 
portion thereof. The base support further has an interconnect strip (E) 
which has a plurality of electrically conducting lines (F) built therein 
for transferring electrical signal generated by a microprocessor, wherein 
each conducting line (F) terminates on a spring pad (G) provided at the 
carriage. The base support also includes a bearing (H) for being engaged 
with a carriage rod of the printer for permitting the carriage to be 
horizontally movable (not shown in the drawings). 
FIG. 2 is a perspective view of the print cartridge (B), which includes a 
ledge (1) and a reference pad (J). The bottom of the carriage is provided 
with a printhead (K) which has a plurality of nozzles formed therein, 
through which the ink droplet may inject out onto paper sheets by the 
heating of specific resisters. The back of the print cartridge (B) is 
provided with a contact strip (L), which has a plurality of contact pads 
(M) formed thereon to be engageable with the terminals of the electrically 
conducting lines of the interconnect strip (E), for transferring 
electrical signal generated by the microprocessor to the print cartridge, 
which will cause specific resistors associated with the nozzles to be 
heated so as to control the injection of the ink-droplets to produce a 
desired print pattern. 
As illustrated in FIG. 1, a user may take the reference pad (J) of the 
print cartridge (B) of the type to be pivotally rested on the L-shaped 
members (D) to allow the print cartridge (B) to turn about the L-shaped 
members (D), as showed by arrow-head P1, such that the print cartridge (B) 
can be locked onto the base support (C) of the carriage (A) by the 
engagement of the ledge (I) and the snap spring (X). Reversely, the print 
cartridge (B) may be removed from the base support (C), by applying a 
moment, the direction of which is reverse to P1. 
Although such a carriage allows the ink-jet printers to be used easily by 
the user, yet the process of removing the print cartridge would require a 
relatively large force and great care to remove it from the carriage (A) 
and to avoid the dropping of the print cartridge. As can be seen in some 
other embodiments, the carriages are further provided with chutes, 
respectively, to prevent the print cartridge (B) from dropping to the 
ground. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a print cartridge 
carriage to allow a print cartridge to be easily removed therefrom and can 
also avoids the dropping of the print cartridge during the removing 
process.

DETAILED DESCRIPTION 
Referring to FIGS. 4 and 5, the print-cartridge carriage (10) of the 
present invention includes a gripping spring (12); a pair of spring loaded 
buttons (14a), (14b), each of which respectively has a bevel surface 
(15a), (15b). The spring loaded buttons 14a and 14b has a compression 
spring (16) located therebetween. As shown in FIG. 5, the compression 
spring (16) forces each button to move outwardly when no external force is 
present (14a), (14b). 
The print cartridge (B) for this invention is generally constructed like 
the one shown in FIG. 2 with a ledge (I) at a top edge a reference pad (J) 
at the bottom, and a contact strip (L) on the back. The contact strip (L) 
has a plurality of contact pads (M) located on a lateral wall. 
A gripping member (18) is provided which has two lateral bevel surfaces 
(20a), (20b) for matching respectively with the bevel surfaces (15a), 
(15b). The gripping member (18) further has a protruded stud (22) on the 
top thereof to engage with the gripping spring (12), and an outwardly 
projecting latch (24) at the bottom thereof for engaging with the ledge 
(I) of the print cartridge (please refer to FIG. 2). A carriage frame (30) 
is provided which has: a first recess (32) for receiving the gripping 
spring (12), a second recess (34) for receiving the spring loaded buttons 
(14a), (14b); a pair of spaced support brackets (40a), (40b); a pair of 
spaced L-shaped member (50a) (50b) disposed at the bottom portion of the 
carriage frame (30); and a bearing (36) provided at the back of the 
carriage frame (30) for slidable engagement with a carriage rod of the 
printer (not shown in the drawings) to allow the carriage to be 
horizontally movable along the carriage rod. 
The first recess (32) is formed perpendicular with the second recess (34). 
As shown in FIG. 6 and FIG. 7, the gripping spring (12) can exert a 
downward force to the protruded stud (22) of the gripping member (18), 
which in turn will cause the outwardly projecting latch (24) of the 
gripping member to hold the ledge (I) of the print cartridge (B). The 
bevel surfaces (15a), (15b) of the spring loaded button (14a), (14b) are 
slidably engageable with the bevel surface (20a), (20b) of the gripping 
member (18), respectively. As the user presses the spring loaded buttons 
(14a), (14b) inwardly, the gripping member (18) will be lifted upwardly to 
unlock the print cartridge (B). Upon releasing the pressing force, the 
compression spring (18) will push the spring loaded button (14a), (14b) 
outwardly, and thus back to its original position, therefore the gripping 
spring (12) will force the gripping member (18) to move downwardly in 
order to lock the print cartridge. 
As shown in FIG. 5 and 6, the carriage of the present invention can be 
further provided with a pair of support brackets (40a), (40b) to laterally 
support the print cartridge to further secure the mounting of the print 
cartridge (B). A cover (60), which can be mounted on the carriage frame 
(30) by using a fastening means, such as screws, can combine the 
mechanical elements, namely, the gripping spring (12), the gripping member 
(18), and the spring loaded buttons (14a), (14b) to form an integral 
mechanical combination to allow the mechanical elements therein to 
cooperate with each other in order to achieve the purpose of this 
invention, as described above. 
On the front lower portion of the carriage frame (30) is provided with an 
interconnect strip (E) which is generally constructed like the one shown 
in FIG. 3 and which has a plurality of electrically conducting lines (F) 
therein for transferring electrical signal from a microprocessor (not 
shown), wherein the terminals (80) of the electrically conducting lines 
(F) are configured to be engageable with the contact pads (M) of the 
contact strip (L) provided on the print cartridge (B), such that the 
electrical signal generated by the microprocessor may be transferred to 
the print cartridge (B) to control the injection of the ink-droplet. 
In the installing process of the print cartridge (B) (as shown in FIG. 8), 
the user may take the print cartridge (B), simply by the thumb and the 
forefinger of a hand, to place the reference pad (J) thereof onto the 
L-shaped members (50a) (50b), then turn the print cartridge (B) about the 
L-shaped member (50a) (50b), which is functioned as a pivot, as shown by 
the arrowhead Z, to have the ledge (1) of the print cartridge (B) snapped 
to the outwardly protruded latch (24) of the gripping member (18), and to 
have the contact pads (M) of the print cartridge in electrical contact 
with the terminal (80) of the carriage frame (30), thereby forming a 
electrical connection between the microprocessor and the print cartridge, 
as described above. 
Concerning the process of removing the print cartridge, a user may use his 
thumb and forefinger to press the spring loaded buttons (14a), (14b) 
inwardly and simultaneously, which allow the spring loaded buttons (14a), 
(14b) to move toward each other, thereby making the gripping member (18) 
lifted upwardly by the relative sliding movement between the bevel surface 
(15a) (15b) of the button and the bevel surface (20a) (20b) of the 
gripping member (18), to overcome the downward force of the gripping 
spring (12), so that the print cartridge (B) will be released from the 
carriage (10) and thus may naturally fall down into the palm of the user, 
therefore preventing the print cartridge from falling down to the ground 
caused by the carelessness of the user. 
In summary, the present invention has the following advantages: 
1. It can be operated easily with small force. It is ergonomically 
structured and user friendly. 
2. It can prevent the print cartridge from dropping during the removing and 
replacing operation. 
Although the present invention has been described and illustrated relative 
to a preferred embodiment thereof and a preferred use therefore, it is not 
to be so limited since changes and modifications can be made therein which 
are within the fill intended scope of the invention.