GERT F KOLBEL
Bullworker History - Gert F Kolbel - Gert Kölbel or Gert F Koelbel The original patent belonged to Arthur A. Pons. His was a simple device that consisted of two tubes with a handle at the
end with the resistance coming from a spring inside. Gert F Kolbel
modified the original patent originally calling it the Tensolator, by adding a
steel cable that wrapped around and through the handles of the device and
subsequently renaming it THE
BULLWORKER. This allowed the user to perform pulling exercises in a similar way
to chest expanders but having the additional benefits of compression exercises
which chest expanders and the like do not allow. Sales for this device and a
range of clones that it spawned took off dramatically with estimates that today
over 9 million such devices have been sold. Gert F Kolbel's last variant was the
Bullworker X5 which was a radical improvement on earlier versions. The
Bullworker was, and still is, the best selling home gym isometric device in the
world. Most of its sales world wide came from magazine and newspaper adverts. We
will look at how this product has recently been marketed in another section of
this site, our goals though are to remain true to the original ethos of Gert
F Kolbel whilst at the same time bringing the product and the training up to
date by utilising scientific knowledge which was not available to Kolbel but
which can make a big difference to the results attained.
Many famous people have used the Bullworker
to develop amazing physiques but Bruce Lee we are told also used it as a combat
weapon. When studying Kung Fu in Hong Kong Bruce Lee search for the ultimate
Kung Fu weapon. He tried staffs, swords and spears, but to no avail. Then one
day whilst working out, he got the idea to try out the Bullworker in a combat
environment. He used it in several underground weapons fighting tournaments and
was victorious every single time. When everyone asked Bruce what his secret was
he simply smiled and said "Everything I know I owe to Gert F. Kolbel." Bruce
continued to use the Bullworker as an integral part of his training during his
movie career but ceased using it as a weapon.
BULLWORKER PATENT - Patent application title:
Freely moveable strength training device for strengthening the body musculature,
which can be loaded by pulling
Inventors: Gert F. Koelbel
Agents: COLLARD & ROE, P.C.
Origin: ROSLYN, NY US
IPC8 Class: AA63B2102FI
USPC Class: 482122
A freely movable strength training device for strengthening the body musculature
can be loaded by pulling. The device has a housing and at least one spring
element arranged in the housing, which can be loaded via muscular strength. The
device has at least two pull elements which can be actuated by a user. All pull
elements are fastened on the spring element.
1: Freely moveable strength training device for strengthening the body
musculature, which can be loaded by pulling and which has a housing and at least
one spring element arranged in the housing, which can be loaded by means of
muscular strength,wherein it has at least two pull elements which can be
actuated by a user, wherein all pull elements are fastened on the spring element
2: Strength training device according to claim 1, wherein the housing (1) is
formed from plate elements (2) orientated parallel to one another.
3: Strength training device according to claim 2, wherein the spring element (5)
is a rod component which is inserted between two plate elements (2).
4: Strength training device according to claim 1, wherein the spring element (5)
has at least two sections (6) which run approximately parallel to one another
and on which the pull elements are fastened.
5: Strength training device according to claim 4, wherein the free ends (7) of
the sections (6) of the spring element (5) which run parallel to one another are
arranged in an inspection window (8) of the housing (1).
6: Strength training device according to claim 5, wherein travel markings for
the deflection of the free ends (7) of the sections (6) of the spring element
(5) which run parallel to one another are applied to the housing (1) in the
region of the inspection window (8).
7: Strength training device according to claim 5, wherein in each case, a force
indicator is arranged at the free ends (7) of the sections (6).
8: Strength training device according to claim 4, wherein the sections (6) which
run parallel to one another originate from deflection points for the spring
element (5), which are arranged in a line, and wherein a displacement part (12)
which changes the lever arm on the sections (6) for the pull elements (9) which
act thereon is pushed onto the sections (6).
9: Strength training device according to claim 1, wherein the spring element (5)
is configured as a guide for the displacement part (12) which encompasses
predetermined regions of the spring element (5).
10: Strength training device according to claim 1, wherein guide elements (11)
for the pull elements are arranged in the housing (1).
11: Strength training device according to claim 10, wherein each guide element
(11) is configured as a roller.
12: Strength training device according to claim 1, wherein each pull element is
configured as an at least double pull loop (9).
13: Strength training device according to claim 12, wherein each pull loop (9)
has a hand loop (9') for actuation with the hand and a foot loop (9'') for
actuation with the foot.
14: Strength training device according to claim 12, wherein each hand and foot
loop (9', 9'') is formed from a one piece strap which is, in sections, laid in
layers which are on top of one another, and in which stitches are inserted to
form the hand and foot insertion points.
The invention relates to a freely moveable strength training device for
strengthening the body musculature, which can be loaded by pulling and which has
a housing and at least one spring element arranged in the housing, which can be
loaded by means of muscular strength.
Strength training devices are used for the body fitness of their users.
The spring element can be acted upon by using the strength of various muscle
groups, in order to load and, as a result, train the latter. In addition to
immobile strength training devices e.g. in fitness studios, freely moveable,
that is to say mobile strength training devices are known.
A mobile strength training device according to the generic type specified
above is described in DE 197 11 835 C2. This strength training device has pull
loops, of which one acts on a spring element and the other is attached to the
housing. Strength training is thereby enabled. However, the problem arises in
this case that a pull bar, which is guided against a displaceable spring clip
which produces the desired resistance, and which also bears the moveable pull
loops, assumes too steep an inclination in the event of larger effort from the
person training, so that the spring clip seeks the path of least resistance and
undesirably springs back to the initial position in the middle of training.
The object of the invention is to show a training device of the generic
type mentioned at the beginning, which allows handling which is uncomplicated
and safe for training.
This object is achieved according to the invention by a strength training
device with the features of claim 1. Advantageous developments and
configurations of the invention are given in claims 2 to 14.
In the case of a freely moveable strength training device for
strengthening the body musculature, which can be loaded by pulling and which has
a housing and at least one spring element arranged in the housing, which can be
loaded by means of muscular strength, it is provided according to the invention
that the strength training device has at least two pull elements which can be
actuated by a user, wherein all pull elements are fastened on the spring
In the case of the strength training device according to the invention, no
pull element is fastened directly on the housing of the strength training
device. All pull elements are guided as far as the spring element, so that the
forces from the pull elements are applied directly onto the spring element. In
this case, an arrangement of the pull elements is possible in such a manner that
a linear opposing application of forces into the spring element takes place so
that the latter is held securely between the pull elements and without the
occurrence of transverse forces. The direct fastening of at least two pull
elements to the spring spring element advantageously divides the spring travel.
Simple handling of the strength training device is additionally advantageously
According to a first development of the invention, it is provided that the
housing is formed from plate elements orientated parallel to one another. The
housing therefore has a simple configuration. Two plates can be provided, which
are arranged spaced apart from one another. An installation space is then formed
between the two plates, in which the spring element can be arranged. The pull
elements can be inserted laterally into this open housing and brought into a
holding connection with the spring element. In accordance with this development,
the strength training device shows an open configuration in a sandwich
construction, which also foregoes the use of plastic parts completely, in order,
in the clinical rehabilitation sector, to also enable disinfection of the inside
of the device in an autoclave. Stamina training with a device that is passed to
the next sick person which training serves faster recovery thereby becomes
possible in a hospital bed without having to fear a possible contamination of
the device by means of previous use by another person. Because such an internal
and external disinfection is also required in the manned space flight sector,
the suitability of the invention for body training to counteract astronauts'
isolation from gravity, which causes bone and muscle wastage, is shown for this
reason and also due to the low dead weight as well as due to the multifaceted
The spring element can in this case be a rod component which is inserted
e.g. in several windings between the two plate elements. The spring element is
then fixed between the plate elements in certain sections, other sections of the
spring element remain moveable for absorbing and outputting forces. The
preferred configuration of the spring element in which it is made from a round
material ensures a near wear-free accommodation of the pull elements.
The sections which absorb forces are, according to a development at least
two sections of the spring element which run approximately parallel to one
another and on which the pull elements are fastened. One pull element is for
example arranged on each section, with which pull element a force can be exerted
on this section. If two pull elements are provided for two sections, then for
example both arms of the user or also both feet of the user can be provided for
For a successful handling of the strength training device according to the
invention, a development of the invention provides that the free ends of the
sections of the spring element which run parallel to one another are arranged in
an inspection window of the housing. The free ends of the spring element can be
seen in the inspection windows. Their deflection by means of a sustained pull on
the moveable sections of the free spring ends can be discerned for the user on
both sides of the device, thus also when checking the movement patterns in a
mirror, or for a trainer standing in front of the person exercising, and can be
exploited for the training. The travel markings on the housing for the free
spring ends, which can be read off in the region of the inspection window, give
information about whether the pull force is maintained decreasingly, evenly or
without it being a challenge. The person training can interpret this themselves
or by means of a trainer as the resistance having been set too high, correctly,
or too low, and, if necessary, correct it in accordance with the next
Furthermore, it is provided that, in each case, a force indicator is
arranged at the free ends of the moveable sections of the spring element. An
advantageously simple check on the pull force supplied in the region of the
inspection window which has the travel markings is always ensured with the aid
of the force indicator which is preferably of spherical design. The correct,
excessive or inadequate training efforts of a person using the training device
can therefore be determined by means of the position of the force indicator. The
spherical force indicators which are, for example, put onto the free ends are
prevented from coming off of their own accord, in particular, by means of the
arcs of the spring element which are guided over them.
For further constructive configuration of the strength training device
according to the invention, a development of the invention provides that the
sections which run parallel to one another originate from deflection points for
the spring element, which are arranged in a line, and that a displacement part
which changes the lever arm on the moveable sections for the pull elements which
act thereon is pushed onto the sections. The pull elements are fastened on the
sections which run parallel to one another. With the introduction of forces, the
parallel sections can then be pulled out of their parallelity and pulled away
from one another. If the force action is reduced, then the section springs back
to the parallel position once more.
The regions of the sections which move out of position can extend from the
free ends in the inspection window to the deflection points provided. In this
case, a deflection of the sections is enabled with a relatively small force. The
length of the regions of the sections which can be moved out of place is limited
by means of the displacement piece which is provided according to the invention.
The displacement piece namely fixes the distance between the sections in the
region of the arrangement of the displacement part. If this is therefore pushed
from the deflection points for the spring element in the direction of the free
ends of the spring elements, then the region of the sections which can still be
deflected by applying force becomes smaller. The lever effect is reduced and a
larger force is to be applied by means of the pull elements for the displacement
of the sections out of their parallel position. So, by means of the displacement
part, an increase in the forces to be applied for a certain design can be
achieved. Only two moveable built-in components are still present in the
interior of the housing with the spring element and the displacement part, as a
result, the robustness of the strength training device is increased. The open
construction of the housing makes a thorough cleaning possible, both for normal
household usage and usage when travelling or following usage on the beach with
soiling by sand, sun tan lotion, sea water, etc., by means of simply placing it
into a dishwasher and the latter's cleaning procedure. Owing to its compact
design, any form of movement and force development of both isokinetic and
isometric type is possible between two hands or two feet with the strength
training device loaded with a sustained pull. This is true both for short
movements in the region of up to 70 cm and/or for forms of movement of up to
2.30 metres, which can be carried out, for example, with hands raised high above
the head as far as the region of the feet with constant resistance accompaniment
of the device, and in this manner include many further muscles and muscle groups
in the training.
It lies furthermore within the framework of the invention that the spring
element is configured as a guide for the displacement part which encompasses
predetermined regions of the spring element when considered in the longitudinal
direction of the latter. Particularly the middle regions of the spring element
form guide rail sections for the displacement part which is preferably
configured in a clasp-shaped manner, wherein at the same time a self locking
friction-tight connection is advantageously given between the displacement part
and the spring element which serves as a guide In addition to the change of the
pull resistance on the moveable leg sections of the spring element in the weight
range of between 0.5 and 90 kg, an advantageous securing of the displacement
part on the spring element therefore takes place. The self-securing is increased
during a pull loading in that the sections of the spring element, which run
parallel to the outside edge of the training device in each case, by means of a
pull loading cause the spring element's inner sections, which are held moveably,
to bulge outwards and therefore effect a strengthened clamping of the
clasp-shaped displacement part. Furthermore, owing to the sections of the spring
element, which likewise consist of round material and are guided parallel to the
outside edge of the housing, the wear on the pull elements which are guided past
them is reduced to a minimum, even if the pull elements must be pulled at an
angle to the training device for certain forms of exercise.
The scale of the settable resistance to be given is available for pure
fitness exercises in the region of 0.5 to 40 kg. Athletic strength training with
sporting contour changes on the body are possible in the settable region between
40 and 90 kg. Even higher resistance values can also be achieved by replacing
the built-in spring. The production, the sandwich construction and the shaping
of the components are selected and designed so that they are not burdened with
the costs for expensive moulds and tools. For the most part, the components are
produced by laser cutting. It is in this manner that high-quality and sturdy
material can be offered on the market and a 20 year durability guarantee be
offered therefor, without considerable costs for moulds and tools and the
replacement thereof due to wear needing to be included in the calculation. The
laser cutting technology additionally allows immediate changes to be made to the
design at any time without any costs, maintenance and re-equipping times
The pull elements are guided laterally out of the housing. Preferably,
guide elements are provided for this purpose, which are e.g. in each case
configured as a roller.
A double pull loop on each side of the device preferably comprises a hand
loop and a foot loop, so that for the hands and the feet, but also for operating
the device using wrists and ankles, the same loops are not to be used. The hand
loops are smaller in size so that for exercises with crossed wrists, the hands
are allowed as close as possible to the device and so no part of the path of
movement is given up for this type of exercise.
Each hand and foot loop can, in this case be formed from a one piece strap
which is, in sections, laid in layers which are on top of one another, and in
which stitches are inserted to form the hand and foot insertion points. This
enables an efficient production of the loops.
An exemplary embodiment, from which further inventive features result, is
illustrated in the drawing. In the figures:
FIG. 1 shows a plan view of a strength training device for strengthening
the body musculature according to the invention,
FIG. 2 shows a side view of the spring element of the strength training
device according to FIG. 1,
FIG. 3 shows a side view of a pull element for the strength training
device according to FIG. 1, and
FIG. 4 and
FIG. 5: show side and plan views respectively of a component of the
strength training device according to FIG. 1.
The strength training device in FIG. 1 has a housing 1. The housing 1
formed from two plate elements 2 which are orientated parallel to one another.
Roller bodies 3 are inserted between the two plate elements 2, the pins 4 which
bear the roller bodies 3 additionally connect the two plate elements 2.
A spring element 5 is inserted between the plate elements 2. This spring
element 5 is also shown in FIG. 2, it is made out of spring steel and bent in
the manner of a clip. The diameter of the spring steel is e.g. 4 mm, the spring
preferably has the spring class C and consists of hardened high-grade steel.
In the housing 1, the spring element 5 is fixed with the roller bodies 3.
Inner sections 6 of the spring element 5 run parallel to one another starting
from roller bodies 3 which are arranged in a line. The free ends 7 of these
sections 6 are arranged in an inspection window 8 of the housing 1. Spherical
caps are placed on the free ends 7 for better discernibility.
The pull elements are configured as pull loops 9. FIG. 3 shows that a pull
loop of this type has two loop sections, namely a hand loop 9' and a foot loop
9''. The pull loop 9 is attached to the section 6 of the spring element 5 with
the section 10 of the pull loop. Guide elements 11 also serve the guiding of the
pull loops 9 in the housing 1.
A displacement part 12 is also assigned to the sections 6 of the spring
element 5 inside the housing 1. This displacement part 12 can be displaced on
the sections 6 parallel to the longitudinal axis of the housing 1. The length of
the sections 6 which can be deflected with the pull loops 9 is thus reduced, as
these sections 6 are fixed in a manner in which they cannot change length with
respect to one another in the region between the roller bodies 3 which are
arranged on a line and the displacement part 12.
The displacement part 12 is shown in FIGS. 4 and 5. It accommodates the
various sections 6 of the spring element 5 within itself, and consists in the
process of a one-piece wall spring made of spring steel. The material thickness
is e.g. 0.8 mm, the width 15 mm.
The plate elements 2 of the housing 1 can be cut out e.g. with a laser, as
a result, they can be produced very precisely. High-grade steel can again be
selected as material, so that an impression of high quality is created.
The Bullworker is one of the
few meaningful brands in the field of muscle building. At this point we do need
to make clear that we fully acknowledge any or all trademarks and the terms used
are purely to assist with identification. Virtually all of the top physiques of
a certain area have tried or used the bullworker at some stage although many
moved away from the product due, not in small part, to the instructions that
came with both the original and current variants of the product as they have all
failed to appreciate what muscle really need to grow. For training programs
recommended by the manufacturers check out our
bullworker training chart. Part of the reason for the
development of this site is in Bullworker terms to "go where no man has gone
before" and address the outer limits of the product exploring extreme training
programs aimed at getting extreme results. We will also look at the products in
terms of rehabilitation and weight loss but in the main the focus of this site
is on pure natural muscle building but at a level way beyond the originally
envisaged scope of the product.
- only for adults 21+ who want to add large amounts of muscle and burn excess