U.S. patent application number 14/246154 was filed with the patent office on 2015-10-08 for crossbow with take-up cables higher than let-off cable.
This patent application is currently assigned to POE LANG ENTERPRISE CO., LTD.. The applicant listed for this patent is POE LANG ENTERPRISE CO., LTD.. Invention is credited to Eldwin Chang.
Application Number | 20150285582 14/246154 |
Document ID | / |
Family ID | 54209478 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150285582 |
Kind Code |
A1 |
Chang; Eldwin |
October 8, 2015 |
CROSSBOW WITH TAKE-UP CABLES HIGHER THAN LET-OFF CABLE
Abstract
A crossbow includes a stock, a riser disposed at a front of the
stock, a pair of limbs attached to opposite ends of the riser,
first and second pulleys respectively mounted on rear tips of the
limbs, and a bow string set. The stock. Each of the first and
second pulleys includes a primary wheel and a secondary wheel. The
bow string set includes a let-off cable, a first take-up cable and
a second take-up cable. The let-off cable extends across and over
the track of the stock and has opposite ends respectively trained
about the primary wheels of the first and second pulleys. In
particular, both of the first and second take-up cable extend
across the stock and are substantially positioned higher than the
let-off cable.
Inventors: |
Chang; Eldwin; (Taichung
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
POE LANG ENTERPRISE CO., LTD. |
Taichung City |
|
TW |
|
|
Assignee: |
POE LANG ENTERPRISE CO.,
LTD.
Taichung City
TW
|
Family ID: |
54209478 |
Appl. No.: |
14/246154 |
Filed: |
April 7, 2014 |
Current U.S.
Class: |
124/25 |
Current CPC
Class: |
F41B 5/105 20130101;
F41B 5/123 20130101 |
International
Class: |
F41B 5/12 20060101
F41B005/12; F41B 5/10 20060101 F41B005/10 |
Claims
1. A crossbow comprising: a stock having at its top a track for
receiving a projectile and at its bottom a trigger for launching
the projectile; a riser disposed at a front of the stock; a pair of
limbs attached to opposite ends of the riser; first and second
pulleys respectively mounted on rear tips of the limbs, each pulley
including a primary wheel and a secondary wheel adjacent to the
primary wheel; a bow string set including a let-off cable, a first
take-up cable and a second take-up cable; the let-off cable
extending across the track of the stock at a height above the track
of the stock and having opposite ends respectively trained about
the primary wheels of the first and second pulleys; the first
take-up cable extending across the track of the stock with one end
strung about the secondary wheel of the first pulley and the other
end anchored to the second pulley; and the second take-up cable
extending across the track of the stock with one end strung about
the secondary wheel of the second pulley and the other end anchored
to the first pulley; and at least one retaining rod positioned in
between the first take-up cable and the let-off cable to lift up
the first take-up cable to the height above the track of the stock,
the retaining rod has one end secured to the riser and the other
end extending in between the first take-up cable and the let-off
cable; wherein the first and second take-up cables are both
substantially positioned higher than the let-off cable.
2. A crossbow as recited in claim 1, wherein at least the first
pulley is eccentric.
3. (canceled)
4. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a crossbow, and more
particularly to a crossbow with a bow string set having take-up
cables higher than a let-off cable thereof.
[0003] 2. Description of the Related Art
[0004] One type of compound bow is illustrated in U.S. Pat. No
3,486,495 (1969). In this bow, rotatable, variable leverage pulley
members are equipped on the tips of the bow limbs. A bowstring is
wound over the pulley members to provide mechanical advantage, and
less force is required to hold the bowstring in a fully drawn
position than to hold the bowstring at an intermediate draw
position. Similar to the compound bow, a crossbow also employs the
pulley members to provide similar functions.
[0005] FIG. 4 illustrates a conventional crossbow 900, comprising a
stock 91, a riser 92 positioned at a front of the stock 91, two
limbs 93, 94 with front ends attached to the riser 92, two
eccentric pulleys 95, 96 respectively mounted to rear tips of the
limbs 93, 94 and a bow spring set 97. The stock 91 has at its top a
track 911 for receiving a projectile (not shown) and at its bottom
a trigger 912 for launching the projectile. Each of the eccentric
pulleys 95 (or 96) is consisted of a primary wheel 951 (or 961) and
a relatively smaller secondary wheel (not shown) underneath the
primary wheel 951 (or 961). The bow spring set 97 includes a
let-off cable 970 and two substantially Y-shaped take-up cables
971, 972.
[0006] Specifically, the let-off cable 970 has opposite end
portions respectively trained about the two primary wheels 951, 961
of the eccentric pulleys 95, 96. Each of the take-up cables 971 or
972 has one end trained about one of the secondary wheels, and the
other end anchored to the other secondary wheel. The two take-up.
cables 971, 972 are positioned at a height substantially lower than
the let-off cable 970 and intersect with each other at the stock
91. In order to avoid interrupting the launching of the projectile,
a slot 910 is defined in a front of the stock 91 so as to permit
the take-up cables 971, 972 to pass therethrough and keep away from
a launching path of the bow.
[0007] However, this configuration has disadvantages in that the
slot 910 would have to be specially formed, thus raising the cost
of the bow and lessening the strength of the front of the stock 91.
This would further cause a lower collimation degree of the track
910 of the stock 91 by which the launching of the projectile would
be adversely affected. In addition, the front of the stock 91 would
have to be thick enough for the forming of the slot 910, thus
raising the weight of the bow.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is an object of the present invention to
provide a crossbow to solve the aforementioned problems. The
crossbow includes a stock, a riser disposed at a front of the
stock, a pair of limbs attached to opposite ends of the riser,
first and second pulleys respectively mounted on rear tips of the
limbs, and a bow string set. The stock has at its top a track for
receiving a projectile and at its bottom a trigger for launching
the projectile. Each of the first and second pulleys includes a
primary wheel and a secondary wheel adjacent to the primary wheel.
The bow string set includes a let-off cable, a first take-up cable
and a second take-up cable. The let-off cable extends across the
track of the stock and is located at a height above the track of
the stock. Moreover, the let-off cable has opposite ends
respectively trained about the primary wheels of the first and
second pulleys. The first take-up cable extends across the track of
the stock with one end strung about the secondary wheel of the
first pulley and the other end anchored to the second pulley.
Similarly, the second take-up cable extends across the track of the
stock with one end strung about the secondary wheel of the second
pulley and the other end anchored to the first pulley. In
particular, the first and second take-up cables are both
substantially positioned higher than the let-off cable.
[0009] Preferred embodiment of the invention may have the following
additional characteristics, either alone or in combination:
[0010] The crossbow further comprises a retaining rod positioned in
between the first take-up cable and the let-off cable to lift up
the first take-up cable to the height above the track of the stock.
In one embodiment, the retaining rod has one end secured to the
riser and the other end extending in between the first take-up
cable and the let-off cable.
[0011] Further benefits and advantages of the present invention
will become apparent after a careful reading of the detailed
description with appropriate reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a top side perspective view of a crossbow in
accordance with the preferred embodiment of the present
invention;
[0013] FIG. 2 is a partial enlarged view of the crossbow shown in
FIG. 1;
[0014] FIG. 3 is a rear side view of the crossbow shown in FIG. 1;
and
[0015] FIG. 4 is a prior art.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0016] In the accompanying drawings, a crossbow 100 is illustrated
which includes a stock 1, a riser 2 disposed in a front of the
stock 1, a pair of limbs 3, 4 connected at their front ends in
fixed relation to the riser 2, first and second pulleys 5, 6
respectively mounted on rear tips of the limbs 3, 4, a bow string
set 7 connecting the two pulleys 5, 6, and a stirrup 8.
[0017] As shown in FIG. 1, the stock 1 has in its top a track 10
for receiving a projectile 11 (see FIG. 3) and at its bottom a
trigger 12 for discharging the projectile 11. Once the trigger 12
is squeezed, the projectile 11 would go off along the track 10.
[0018] Referring to FIG. 2, it will be best seen that the first
pulley 5 includes a primary wheel 51 and a relatively smaller
secondary wheel 52 adjacent to the primary wheel 51. Similarly, as
shown in FIG. 1, the second pulley 5 includes a primary wheel 61
and a relatively smaller secondary wheel 62 adjacent to the primary
wheel 61. The bow string set 7 includes a let-off cable 70, a first
take-up cable 71 and a second take-up cable 72. The let-off cable
70 extends across the track 10 of the stock 1 at a height above the
track 10 of the stock 1 and has opposite ends respectively trained
about the primary wheels 51, 61 of the first and second pulleys 5,
6. The first take-up cable 71 extends across the track 10 of the
stock 1 with one end strung about the secondary wheel 52 of the
first pulley 5 and the other Y-shaped end anchored to an axis of
the second pulley 6. In contrast, the second take-up cable 72
extends across the track 10 of the stock 1 with one end strung
about the secondary wheel 62 of the second pulley 6 and the other
Y-shaped end anchored to an axis of the first pulley 5. In
particular, the first and second take-up cables 71, 72 are both
substantially positioned higher than the let-off cable 70, as best
seen in FIG. 3.
[0019] Preferably, a pair of parallel retaining rods 21, 22 may be
employed to lift up the first and second take-up cables 71, 72 to
the height above the track 10 of the stock 1, as best seen in FIG.
3. In this embodiment, each of the retaining rods 21 or 22 has one
end secured to the riser 2 and the other end extending in between
the let-off cable 70 and a combination of the first and second
take-up cables 71, 72, as shown in FIG. 1 or 3. This ensures the
projectile 11 can be discharged without any interrupt of the first
take-up cable 71 or the second take-up cable 72. In this manner, no
slots will be needed to be defined in the front of the stock 1 as
taught in the prior art. Thus, the crossbow 100 can be produced at
relatively lower cost and light weight with higher rigidity and
collimation degree of the track 10 of the stock 1 for launching the
projectile 11.
[0020] It is noted that although the retaining rods 21, 22 are
shown in the preferred embodiment to be secured to the riser 2, the
retaining rods 21, 22 may be in other embodiments secured to the
stock 1 or other portions. It is also noted that, although the
first and second pulleys 5, 6 shown in the preferred embodiment are
both eccentric pulleys, any type of pulleys may be used as dictated
by the convention. For example, one may be idle while the other be
an eccentric pulley.
[0021] It is to be understood that the disclosed embodiments are
illustrative in nature and the invention is not to be limited to
any one or more embodiments except as set forth in the following
claims.
* * * * *