Bicycle shock absorption structure

A kind of improved bicycle shock absorption structure, specifically referring to a kind of improved bicycle shock absorption structure featuring a unitary configuration of the bicycle crankset with rider's saddle of the seat cluster that, furthermore, provides direct elastic characteristics upward and downward during operation. Utilizing the force of human physical weight and pedaling power, whenever the wheels are subjected to impact, the unified structure automatically responds by absorbing the shock by elastically rising and falling, the obvious shock absorption effects of which are not only immediately apparent to the rider while seated or standing, but the bicycle does not lose speed, the bicycle frame does not flex and forceful brake application does not adversely affect the effective performance of the shock absorption structure. Most significantly, the advantages offered by the invention includes the retaining of a unified design for the bicycle frame so that there is no front or rear wheel wobble, no adverse effect on power transmission system during shock absorption operation, and a luggage rack can be securely and easily installed over the rear wheel.

BACKGROUND OF THE INVENTION 
Although there are numerous kinds of bicycle shock absorber devices, most 
can be classed into the two main categories as transmission system-related 
and non-transmission system related. Of these, the so-called 
non-transmission system related variety mainly consists of systems 
installed on the front end of a bicycle frame, such as on the front fork, 
handle bar, stem and seat post, which are directly installed and have an 
integrated resilient component (such as a coil spring, leaf spring or 
elastomer, etc.). Since this type of installation is does not directly 
connected to the transmission system, they are simpler and less complex 
and of course the shock absorption characteristics are mainly focused on 
the hands of the rider and provide no benefits to the body of the rider. 
Furthermore, the so-called transmission system-related variety mainly 
consists of rear stays (such as the seat stays and chain stays in which 
the rear wheel is mounted) that are not fixed, but active installations 
equipped with a shock absorber that provides effective shock absorption 
characteristics for the body of the bicycle rider. In terms of shock 
absorption performance, the aforesaid variety is further divided into the 
three categories of low pivot point shock absorption systems, high pivot 
point shock absorption systems and linked axle-type shock absorption 
systems, with each category having several dozen variations of respective 
shock absorption devices. The aforesaid low pivot point shock absorption 
system refers to a pivot point at the rear wheel that is resilient in 
upward and downward movement and is positioned below the center line of 
the front and rear wheels. As indicated in FIG. 1, the shock absorber (30) 
is installed in between the seat stays (11) and the top tube (13), and the 
chain stays (12), in addition to having one end conjoined to the lower end 
of the seat stays (11), the other end is below the center line (C) of the 
front wheel (A) and the rear wheel (B), with the active installation near 
the bottom bracket (14), which enables, when the rear wheel (B) subjected 
to impact, the providing of a resilient upward and downward movement of 
the pivot point (M) to achieve effective shock absorption. This type of 
structure can be said to be structurally simpler, lighter in weight and 
results in reduced chain stretch during shock absorption operation, and 
although having the advantage of less effect on the transmission system, 
when the rear wheel is subjected to impact, the locus of wheel movement 
tends to be upward and forward, which produces a loss of wheel traction. 
Furthermore, the bicycle frame flexes when large physical objects are 
encountered. Since the aforesaid structure provides for rear wheel 
mounting at the seat stays and chain stays, and is not a solidly anchored 
active installation, whether riding or during brake application, wobbling 
readily occurs in the aforesaid rear wheel (wheel wobble increases in 
direct proportion to the assembly clearances of the seat stays and chain 
stays), and during braking operation, the braking force increases the 
shock absorber pressure, which decreases shock absorption efficiency and 
affects structural integrity. In the high pivot point shock absorption 
system, as indicated in FIG. 2, the middle of the high pivot point (M) is 
above the center horizontal line (C) of the rear wheel (B). With this type 
of structure, since the pivot point is positioned over the center 
horizontal line of the rear wheel, therefore, after shock absorption, the 
rear wheel moves rearward and is capable of automatically producing a 
horizontal shock absorption effect. As a result, when the rear wheel is 
impacted, reduction in bicycle speed is minimal and the bicycle rider 
feels less impact. However, the chain stretch tension increases 
considerably and pedal rebound force becomes greater, which produces 
adverse effects on the transmission system, and the aforesaid pedal 
rebound force is directly transferred to the bicycle rider, with the 
shortcoming of creating discomfort to the bicycle rider. Naturally, since 
the seat stays (11) and the chain stays (12) are both active 
installations, therefore, the aforementioned wobble produced by the rear 
wheel as well as the increased shock absorber (30) pressure from the 
application of bicycle braking force cannot be improved upon. Furthermore, 
the linked axle-type shock absorption system, as indicated in FIG. 3, is a 
high pivot point design with the pivot point (M) located above the center 
horizontal line (C) of the rear wheel (B). However, the aforesaid bottom 
bracket (14) is designed to move together with the rear wheel (B) and 
since the aforesaid bottom bracket moves with the rear wheel, therefore, 
during shock absorption, the advantages are that the effect on the 
transmission system is lessened and there is no pedal rebound. However, 
due to the simultaneous movement design of the bottom bracket and the rear 
wheel, the bicycle rider enjoys the shock absorption performance when 
riding in a seated position, but all shocks due to ground surface 
irregularities are transmitted to the rider when riding in the standing 
position, thereby resulting in periods when all shock absorption 
characteristics are predictably absent. Furthermore, during shock 
absorption operation while riding in the standing position, the feet are 
continuously subjected to shock from the ground surface, which adversely 
affects the comfort of the rider. Naturally, since the seat stays and the 
chain stays (12) are active installations, therefore, wobbling occurs in 
the aforesaid rear wheel and the force of brake application increases 
shock absorber (30) pressure, both of which cannot be overcome. In other 
words, although the three shock absorption systems consisting of the 
aforesaid low pivot point, high pivot point and linked axle-type each have 
the advantage of being usable, each type has several shortcomings. To the 
user, this obviously presents certain advantages and inconveniences in 
application. Furthermore, during the shock absorption operation of each 
type, the aforesaid rear wheel moves upward and downward and, therefore, 
conventional baggage racks that are mounted over the rear wheel cannot be 
installed or cushioned by the shock absorption structure. 
Of course, in the meanwhile manufacturers have provided resilient component 
shock absorbers installed at the seat post of saddles such that during 
shock absorption, the aforesaid rear wheel cannot move upward and 
downward, thereby improving upon the shortcomings of the aforesaid 
transmission system effects as well as the inability to install baggage 
racks. However, the structure is still completely ineffective when riding 
in the standing position and, furthermore, although the saddle moves 
upward and downward while riding in the seated position, the pedals are 
incapable of a matching upward and downward movement, of which the 
resulting shortcoming is discomfort to the feet of the bicycle rider. 
In summation, the foregoing description conveys the knowledge that the 
aforementioned structure of the conventional bicycle shock absorption 
devices obviously still have a number of utilization shortcomings that can 
be improved. 
SUMMARY OF THE INVENTION 
Therefore, the primary objective of the invention herein is to provide a 
kind of improved bicycle shock absorption structure, wherein the crankset 
and the seat cluster are integrated into a single unit and, furthermore, 
is capable of elastic ascending and descending performance, and since the 
invention herein is not rigidly integrated to the bicycle frame, 
therefore, when the bicycle tires are subjected to impacts that produces 
shock in the bicycle frame, the body of the bicycle rider is not subjected 
to any direct impact whether riding in a standing or seated position due 
to the shock absorption effectiveness of the bicycle frame. 
Another objective of the invention herein to provide a kind of improved 
bicycle shock absorption structure, wherein the bicycle frame is of a 
unified structural design such that when the rear wheel is subjected to 
impact, no upward and downward movement occurs and during the shock 
absorption process, the bicycle does not lose speed, the bicycle frame 
does not flex, the rear wheel does not wobble and the functioning of the 
transmission system remains unaffected. At the same time, the aforesaid 
force of brake application does not directly affect the shock abortion 
component by increasing the load of the shock absorption structure, while 
the aforesaid baggage rack can be firmly and easily installed over the 
rear wheel without affecting shock absorption efficiency. 
Yet another objective of the invention herein to provide a kind of improved 
bicycle shock absorption structure, wherein connecting arm components are 
installed between the axle of the crankset and the axle of the rear wheel 
such that the crankset is not only maintained in the proper position, but 
during the shock absorption process when the crankset ascends and 
descends, the connecting arms operate within the movement radius of the 
crankset to prevent increases in chain stretch tension, the production of 
rebound at the pedals and adverse effects on the transmission system. 
To enable the examination committee to further understand the objectives, 
innovations and performance of the invention herein, the brief description 
of the drawings is followed by the detailed description of the invention 
herein.

DETAILED DESCRIPTION OF THE INVENTION 
Referring first to FIG. 4, FIG. 5, FIG. 6 and FIG. 7, and as clearly 
indicated therein, the invention herein is an improved bicycle shock 
absorption structure that mainly consists of providing the rider with a 
seat cluster (40) and a movable crankset (50) integrated into a single 
unit and, furthermore, that slides up and down. The shock absorption 
structure (30) of the invention herein includes an outer tube (301) that 
is positioned around the lower extent of the seat cluster (40), and welded 
to the top tube (10) and the seat stays (11) and, furthermore, is firmly 
maintained in position by the seat tube (15) welded to the down tube (16), 
while the inner diameter of the top and the bottom ends have the 
respective threads (3011) and (3012) of a suitable depth; an adjustment 
sleeve (302) that is screwed into the threads (3011) inside the outer tube 
(301) and is secured by a lock nut (D) onto the positioning ring (3021) 
protruding into the inner diameter of the top end; a .perp. shaped shock 
absorber tube (303) that is inserted upwards into the outer tube (301) and 
replaces the conventional seat tube, with a horizontal sleeve (3031) 
affixed to the lower end that replaces the conventional bottom bracket and 
which has a small length of positive threads (3032) at the center section, 
while the top end provides for the insertion of the seat post (402) of the 
saddle (401) comprising the seat cluster (40) that is secured in position 
by an annular binder (403); a resilient shock absorber component (304) 
that can be a spring, elastomer or other elastic body and which is 
positioned inside the outer tube (301) inserted into the shock absorber 
tube (303), with the lower end situated against the positioning ring 
(3021) of the adjustment sleeve (302); a positioner nut (305) that is 
T-shaped and screwed onto the positive threads (3032) at the approximate 
center section of the shock absorber tube (303) and which keeps the top 
end of the resilient shock absorber component (304) at a set position, 
enabling the shock absorber tube (303) to move elastically up and down; an 
upper stop point resilient component (306) that can be a spring, elastomer 
or other elastic body and which is sleeved onto the shock absorber tube 
(303), with the lower end held against the surface at the upper end of the 
positioner nut (305); a lower stop point resilient component (307) that 
can be an elastomer, spring or other elastic body that is inserted into 
the shock absorber tube (303) and positioned over the upper stop point 
resilient component (306), with a recessed annular groove (3071) at the 
top end providing for a lock nut (3072) which is screwed into the threads 
(3011) inside the upper end of the outer tube (301); two connecting arms 
(308) and (308'), the forward ends of which are respectively conjoined to 
the two sides of the horizontal sleeve (3031) at the lower end of the 
shock absorber tube (303), while the other ends are respectively conjoined 
to the two sides of the axle (b) at the center of the rear wheel (B), of 
which there is a tubular sleeve (3081') protruding laterally from one end 
of the connecting arm (308') that is inserted into the horizontal sleeve 
(3031) at the lower end of the shock absorber tube (303) and, furthermore, 
provides for the placement of the guide hole (3085) at the end of the 
other connecting arm (308), and the inner diameter (3082') is the same as 
that of a conventional bottom bracket to accommodate the installation of 
the axle (501), the bearing retainers (502), the threaded mounting cups 
(503) and other crankset (50) components, with one side of the threaded 
mounting cups (503) providing for the screwing on of a lockring (504) and 
the fastening of the connecting arm (308'), and situated nearby is an 
anchor bolt (3083') that is fastened with a nut (E) after insertion into 
the through hole (3086) in the other connecting arm (308), thereby 
providing for the secure mounting of the two connecting arms (308) and 
(308'), with the other ends of the aforesaid two connecting arms (308) and 
(308') each having the respective guide holes (3087) and (3087') into 
which are installed the respective bushings (3088) and (3088') that 
comprise the means of active insertion and securing at the two sides of 
the rear wheel (B) axle (b). 
Utilizing the aforementioned structural components comprising the assembly 
of the invention herein, as indicated in FIG. 8, since the aforesaid outer 
tube (301) is welded to the bicycle frame (10) to form a rigid framework, 
therefore, after the shock absorber tube (303) is inserted into the outer 
tube (301), the resilient shock absorber component (304) between the 
adjustment sleeve (302) and the positioner nut (305) inside the outer tube 
(301) remains movable, directly providing for the installation of the 
saddle (401) of the seat cluster (40), while the horizontal sleeve (3031) 
at the lower end directly provides for the installation of the axle (501) 
of the crankset (50) such that whether the rider is seated on the saddle 
(401) or standing on the pedals (505), when the bicycle wheels (A) and (B) 
are subjected to impact (especially in situations wherein most of an 
adult's physical weight is biased over the rear wheel (B)), the aforesaid 
adult physical weight bearing directly onto the shock absorber tube (303') 
naturally results in an upward and downward elastic action that directly 
lowers and absorbs the force of impact, thereby allowing the seated or 
standing rider to fully experience the pressure cushioning effect of shock 
absorption; furthermore, due to the fastening of the positioner nut (305) 
at the upper extent of the shock absorber tube (303) and the load support 
provided by the upper stop point resilient component (306), therefore, 
when the shock absorber tube (303) is in the process of shock absorption 
and, furthermore, the resilient shock absorber component (304) is 
rebounding upward, since the aforesaid upper stop point resilient 
component (306) compresses, as a matter of course, the rebound force of 
the aforesaid shock absorber tube (303) is limited to a set upper point 
and thereby effectively damped, allowing the rider postured in the saddle 
(401) or standing on the pedals (505) to be isolated from rebound pressure 
up to the limits of the set position and consequently the occurrence of 
discomfort due to inappropriate decompression due to sudden obstruction; 
furthermore, since the top end of the outer tube (301) is equipped with a 
lower stop point resilient component (307), therefore, when the bicycle 
wheel is subjected to greater magnitudes of impact and the shock absorber 
tube (303) descends considerably, the annular binder (403) holding the 
seat post (402) of the saddle (401) can be set to a lower point of initial 
downward contact relative to the lower stop point resilient component 
(307) such that no contact is made with the upper end of the outer tube 
(301) and, as a matter of course, the aforesaid force of descent is 
immediately cancelled, not only allowing the rider to remain comfortable 
at all times, but also protecting the resilient shock absorber component 
(304), which prevents the occurrence of elastic fatigue and the shortening 
of effective service life; furthermore, since the resilient shock absorber 
component (304) is contained within the outer tube (301) and secured by 
the positioning ring (3021) of the adjustment sleeve (302), therefore, if 
necessary during utilization, the user can adjust the adjustment sleeve 
(302) at the lower end of the outer tube (301) upward or downward to 
adjust the tension exerted by resilient shock absorber component (304) 
against the shock absorber tube (303) to thereby vary the shock absorption 
elasticity of the shock absorber tube (303). 
Furthermore, since the aforementioned shock absorber structure (30) of the 
invention herein is not the same as the conventional system installed at 
the rear seat stays (11) and the rear chain stays (12), therefore, the 
invention herein provides rear seat stays (11) and the rear chain stays 
(12) for mounting the rear wheel (B) that are welded to the top tube (13) 
and the down tube (16) to form a unified bicycle frame (10), and unlike 
the case of the conventional pivot point (M) (as indicated in FIG. 1, FIG. 
2 and FIG. 3), as a matter of course, the aforesaid rear wheel (B) has no 
tendency to wobble and at the same time, during the shock absorption 
process, since the aforesaid rear wheel (B) does not move upward or 
downward, there are no negative effects on the power transmission system, 
reduction of bicycle speed and frame flexing as is the case with the 
conventional systems and, naturally, when the brakes are operated, the 
applied brake pressure will not adversely influence shock absorber 
component life or reduce shock absorber efficiency, which are the 
shortcomings of conventional shock absorber structures. 
Furthermore, since the two connecting arms (308) and (308') are attached 
exactly in between the lower end of the shock absorber tube (303) and the 
axle (b) of the rear wheel (B), therefore, in addition to the shock 
absorber tube (303) achieving non-sway stable mounting and benefiting the 
rider in pedaling the crankset (50), during the shock absorption process, 
the aforesaid connecting arms (308) and (308') at the axle (b) point of 
the rear wheel (B) directly provide the shock absorber tube (303) a radius 
of upward and downward movement, enabling the shock absorber tube (303), 
whether ascending or descending, to provide a fixed distance between the 
pedal cranks (506) and the chain wheel (507) of the crankset (50) and the 
rear wheel axle (b), which remains constant such that the chain (G) of the 
aforesaid drive system will not stretch under increased load, and the 
aforesaid pedals (505) will not be affected by drive system rebound; 
naturally, the operating distance of the aforementioned shock absorber 
tube (303) is not of extreme length and, furthermore, the interval between 
the lower stop point resilient component (307) at the upper end of the 
outer tube (301) consists of an appropriate assembly clearance (K) (as 
indicated in FIG. 7) and, therefore, when ascending and descending during 
operation, although a slight angle is produced by the connecting arms 
(308) and (308') due to conjoinment to the rear wheel axle (b), the normal 
rising and falling shock absorption characteristics remain unaffected. 
Furthermore, as mentioned in the foregoing section, since the installation 
of the shock absorber structure (30) of the invention herein is unlike the 
conventional structure in that no pivot point needs to be fabricated for 
the rear seat stays (11) and the rear chain stays (12), and no rising and 
falling movement occurs at the rear wheel (B), therefore, the 
aforementioned baggage rack (H) can be simply installed in a manner 
similar to that of the conventional variety at the top end of the rear 
seat stays (11), with the support member (h) at other end mounted to the 
rear wheel axle (b), enabling the bicycle frame to not only be equipped 
with a shock absorber structure (30), but at the same time allows the 
simple and convenient and, furthermore, rapid installation of a baggage 
rack (H) over the rear wheel without affecting the shock absorption 
characteristics. 
In the foregoing description, an aspect worthy of mention is that since the 
seat cluster (40) and the crankset (50) is directly mounted to the upper 
and lower ends of the shock absorber tube (303) in the shock absorber 
structure (30), therefore, during the shock absorption process, when the 
aforesaid saddle (401) and the pedals (505) are simultaneously ascending 
and descending, as a matter of course, assistance, smoothness, comfort are 
effectively provided to both legs of the bicycle rider with no impeding 
effects.