1. A bowstring drawing device for a crossbow, the bowstring drawing device comprising:
a mounting base adapted to mount on a butt of the crossbow and having a rail;
a reeling device detachably attached to the mounting base and having
a casing with a bottom face having a rail recess defined in the bottom face to slidably engage the rail on the mounting base;
a wheel assembly accommodated inside the casing to reel a string;
a crank arm connected to and driving the wheel assembly; and
a clutch connected to and locking the wheel assembly; and
a hook retractably connected to the reeling device by the string.
2. The bowstring drawing device as claimed in claim 1, wherein the mounting base (10) is a U-shaped frame and has
a top face;
two sidewalls extending from the top face; and
the rail (11) formed on the top face and being dovetail-shaped,
wherein the rail recess (222) on the casing (22) is dovetail-shaped to correspondingly engage the rail (11) on the mounting base (10).
3. The bowstring drawing device as claimed in claim 2, wherein the casing (22) is composed of a rectangular base and a curved cover and has a front face, a rear face, two side faces and a bottom face;
two through holes (224) are respectively defined in the front face near the two side faces to allow the string to extend through the two through holes (224); and
the wheel assembly (24) has:
a polygonal shaft rotatably secured inside the casing (22);
two string wheels (242) mounted on the polygonal shaft (241) respectively beside the two side faces of the casing (22);
a driven wheel (244) mounted on the polygonal shaft (241) beside one of the string wheels (242);
a unidirectional wheel (245) also mounted on the polygonal shaft (241) beside the other string wheel (242); and
a driving wheel (243) rotatably driven by the crank arm (26) and engaging the driven wheel (244),
wherein, the clutch (28) detachably engages the unidirectional wheel (245);and
the string (35) has two ends respectively reeling on the two string wheels (242).
4. The bowstring drawing device as claimed in claim 3, wherein the clutch (28) has
an engaging end (282) engaging the unidirectional wheel (245);
a levering end (284) extending out of the rear face of the casing (22); and
a spring (286) clamped between the levering end (284) and the casing (22) to keep the engaging end (282) attaching the unidirectional wheel (245).
5. The bowstring drawing device as claimed in claim 4, wherein the hook (30) is U-shaped frame composed of two arms and a front edge and has
two distal ends;
a bottom face;
a string channel (32) defined through the whole U-shaped frame to allow the string (35) to extend through the hook (30) through the string channel (32) so as to connect the hook (30) and the reeling device (20);
two rollers (34) respectively attaching at the two distal ends of the U-shaped frame;
a barrel recess (36) defined at the bottom face at the front edge; and
two cutouts (38) respectively defined in the bottom face under the two arms.
6. The bowstring drawing device as claimed in claim 5, wherein the mounting base (10\u2032) is composed of two symmetrical shells.
7. The bowstring drawing device as claimed in claim 6, wherein the bowstring drawing device further has a backboard (40) detachably mounted on the casing (22) and adapted to mount on a butt of the crossbow.
8. The bowstring drawing device as claimed in claim 1, wherein the casing (22) is composed of a rectangular base and a curved cover and has a front face, a rear face, two side faces and a bottom face;
two through holes (224) are respectively defined in the front face near the two side faces to allow the string to extend through the two through holes (224); and
the wheel assembly (24) has:
a polygonal shaft (241) rotatably secured inside the casing (22);
two string wheels (242) mounted on the polygonal shaft (241) respectively beside the two side faces of the casing (22);
a driven wheel (244) mounted on the polygonal shaft (241) beside one of the string wheels (242);
a unidirectional wheel (245) also mounted on the polygonal shaft (241) beside the other string wheel (242); and
a driving wheel (243) rotatably driven by the crank arm (26) and engaging the driven wheel (244),
wherein, the clutch (28) detachably engages the unidirectional wheel (245); and
the string (35) has two ends respectively reeling on the two string wheels (242).
9. The bowstring drawing device as claimed in claim 1, wherein the hook (30) is U-shaped frame composed of two arms and a front edge and has
two distal ends;
a bottom face;
a string channel (32) defined through the whole U-shaped frame to allow the string (35) to extend through the hook (30) through the string channel (32) so as to connect the hook (30) and the reeling device (20);
two rollers (34) respectively attaching at the two distal ends of the U-shaped frame;
a barrel recess (36) defined at the bottom face at the front edge; and
two cutouts (38) respectively defined in the bottom face under the two arms.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for manufacturing a resistor of a semiconductor device, comprising the steps of:
forming a fine grain structure by depositing a polysilicon on the top of a semiconductor substrate at a temperature of 700 to 1000\xb0 C.;
doping the polysilicon with a dopant and thermally treating the same; and
forming a resistor pattern by patterning the polysilicon.
2. The method of claim 1, wherein the doping step is carried out in the range of concentration of E13cm2 to E14cm2 and with an energy size of 20 keV to 60 keV.
3. A method for manufacturing a resistor of a semiconductor device, comprising the steps of:
forming a polysilicon film with heteronuclei produced therein by depositing a polysilicon on the top of a semiconductor substrate to a first height and purging the same and then depositing a polysilicon to a second height and purging the same;
doping the polysilcon with a dopant and thermally treating the same; and
forming a resistor pattern by patterning the same.
4. The method of claim 3, wherein the doping step is carried out in the range of concentration of E13cm2 to E14cm2 and with an energy size of 20 keV to 60 keV.
5. The method of claim 3, wherein the first and second heights of the polysilicon are 100 to 500\xb0 C. respectively.
6. The method of claim 3, wherein the grain size is formed smaller by a deposition at a low temperature of 200 to 600\xb0 C.
7. The method of claim 3, wherein the deposition is carried out by either a CVD, a low temperature ALD or a plasma deposition.