The invention relates to a walker for the disabled, especially for disabled, injured and age-weakened persons.
Walking aids such as crutches or walking sticks are known in various designs and are made of different materials.
Walking aids usually have only one ground support point. Therefore, such walker is inherently unstable and may fall over when the user needs to release it for a short time. The fall of a walker can be very problematic for the user, as users of walking aids are often limited in their freedom of movement and a fallen walker can not pick up on their own from the ground.
From the DE202004009149U1
is a foot part for a walker known to prevent the unwanted falling over of walking aids by a large foot part is attached to the walker, whereby the ground support surface is increased. The disadvantage here is that the foot part must be made very large and therefore disturbs when walking with the walker. A user may, for example, get caught while walking with an object on the foot part, which can lead to a fall.
From the FR2820027
is a walker with extendable and adjustable additional feet known, which prevent the unwanted overturning of the walker by increasing the number of ground support points. A disadvantage of this walker is the complex mechanical construction for fixing the additional feet on the walker. In addition, the additional feet can be deflected while walking with the walker unwanted from its rest position which can trigger an attachment to an object and a fall of the user.
The present invention is therefore an object of the invention to provide an improved walker, which is not affected by the aforementioned shortcomings.
In particular, a walker is to be created, which can remain stably stable in an upright position without having to be held by a user.
Furthermore, the walker should allow a safe and stable placement while walking with the walker.
In addition, the walker should be used on difficult and / or uneven surfaces, as well as on stairs.
In addition, the walker should allow an elastic and joint-gentle walking.
Furthermore, the walker should support the user when getting up and sitting down.
The walker should also be simple and easy to manufacture and operate. The walker should not differ significantly from a conventional walker, especially in terms of weight and dimensions.
This object is achieved with a walker having the features specified in claim 1. Advantageous embodiments of the invention are specified in further claims.
The walker, which is suitable for assisting walking for the disabled, in particular for age-weakened, injured or ill people, comprises a shaft, at the first End a handle is arranged and at the second end of a foot part is arranged.
According to the invention, a manually operable, one- or multi-part adjusting means is provided which is connected on the one hand to the shaft and on the other hand coupled to the foot part or coupled, which in a first position of the adjusting means fixedly or dimensionally stable coupled to the shaft and in a second position of the actuating means is held flexible relative to the shaft or preferably rotatable about at least 5 °.
The shaft may be in one or more parts and is preferably telescopically adjustable.
The handle is preferably aligned transversely to the shaft. The user can move some of his body weight over the handle on the walker, so that his feet are relieved when walking. The walker preferably comprises above the handle an inclined shaft portion, which is preferably inclined in the region of the handle by a few degrees to the main axis of the shaft. At the not connected to the shaft end of the second shaft portion, an arm holder is preferably provided, which serves to receive the forearm of the user so that it is laterally fixed and guided. Due to the inclination between the shaft and said shaft portion, the forearm can be stored in an ergonomically comfortable position.
In the first position of the one- or multi-part actuating means, also referred to as a standing position, the foot part and the shaft are mechanically stable or dimensionally stable coupled to each other. Due to the mechanically stable coupling, the stability of the walker is improved, so that an unintentional falling over, especially during a Standstill, is prevented. This position of the actuating means is selected in particular when the user is standing. The walking position is also ideal for climbing stairs, wherein the foot part is preferably rotatable in one direction or the other by 180 °. In the standing position, the walker thus additionally serves as a holding column that holds the user in an upright position. In this configuration, the walker is also standalone, so that the user can sit on a bench and leave the walker standing. The walker can therefore not fall to the ground and must not be repealed. In addition, the user can pull up on the walker again.
The walker according to the invention therefore not only supports walking and standing, but also getting up and sitting down.
In a second position of the one- or multi-part actuating means, also referred to as the walking position, the mechanically stable or dimensionally stable coupling between foot part and shaft is canceled, so that the foot part with respect to the shaft about at least one axis, preferably an axis parallel to the ground, is rotatable or can be elastically deformed. Preferably, a rotation of the foot part to the shaft in the manner of an ankle joint of at least 5 ° is possible. The flexibility between the foot part and the stem makes it easier to walk with the walker, because the foot part can directly align with the floor when sitting on the floor, even if the walker is usually not perpendicular to the floor when it is set up. By aligning the foot part along the floor, the contact surface and thus also the static friction and sliding friction is increased, which reduces the risk of slipping of the walker on the floor and an associated fall of the user. Even when unintentionally attaching the foot part to an object becomes Risk of a fall is reduced, since the foot part by the flexibility to the shaft is easier to free from a hooked position with an object.
The inventive walker therefore supports, if necessary, four movements of the user namely:
- A) safe and yet elastic walking,
- B) the safe standing;
- C) safe climbing stairs; and
- D) the assured getting up and sitting down.
In the standing position of the adjusting means, the walking aid also remains vertical and can be easily grasped again.
The walker can also be individually adapted to the user and adjusted in height. Furthermore, the preferably detachable foot part can also be replaced by a larger or smaller foot part.
The one or more adjusting means are preferably designed rod or tubular. The adjusting means should increase the total weight of the walker only minimally, which is why rod and / or tubular elements, which have a high mechanical strength with reduced material requirements, are preferred. In addition, the adjusting means should not appreciably increase the risk of unwanted attachment with the walking aid during walking, so that a volume-minimized embodiment of the adjusting means is also preferred.
In a preferred embodiment, the adjusting means is designed as a shaft piece movably mounted on the shaft in the axial direction. Preferably, the pipe section is mounted outside the shaft and encloses this completely or partially. The adjusting means can be moved up and down along the shaft. Preferably, the actuating means in at least two positions, a walking position, in which there is no mechanical coupling between the foot part and the shaft, and a fixing position, in which a brought about by the adjusting part mechanically stable connection between the foot part and shaft, are kept stable. In this position, the adjusting means can be fixed in such a way that they do not automatically release themselves, in particular due to vibrations or impacts occurring when walking with the walking aid. The stable support in the two positions can be achieved by grooves, projections, grooves, snap elements, screws and threads or other means known in the art for guiding components.
The foot part preferably has a foot part shaft, which can be coupled to the adjusting means. The tubular adjusting means preferably has an inner diameter, which is adapted in the region of the Fussteilschafts this, so that the tubular adjusting means can be performed at least approximately form-fitting manner over the Fussteilschaft. In the region of the shaft, the tubular adjusting means preferably has an inner diameter which is adapted to the outer diameter of the shaft, so that the tubular adjusting means can abut the shaft at least approximately positively. In the second position of the tubular actuating means is formed by the positive contacts between the tubular actuating means and the Fussteilschaft on the one hand and the tubular actuating means and the shaft on the other hand, a mechanically stable connection between the foot part and the shaft.
The tubular actuating means is preferably provided on the inside with a coating, in particular a Teflon coating, which controls the movement of the actuating means along the shaft facilitates and reduces the friction between the actuating means and shaft.
In a further embodiment of the invention, the adjusting means is designed in several parts and preferably comprises one or more additional supports, which are arranged on the shaft of the walking aid. At least two additional supports are in the fixing position on the foot part, preferably supported on the support plate, so that the foot part can not be rotated about an axis parallel to the ground and thus fixed. In the walking position, the additional supports are withdrawn along the shaft or attached to the shaft so that the foot part regains the necessary mobility for the walking position.
Preferably, the adjusting means can be moved via an operating knob and / or an operating handle on the handle from the walking position to the fixing position and vice versa. Preferably, an actuator is provided, by means of which the actuating means can be actuated. The adjusting means may e.g. be formed by a piston which is extendable from the actuator. The tubular actuator is e.g. connected to the actuator piston.
When using an actuator, the change of the adjusting means between the fixing position and walking position and vice versa can be controlled by a signal which is emitted by a remote control or by a mobile phone, preferably via special software. The remote control may preferably be selectively attachable to one or more positions of the walker.
In a further preferred embodiment, the adjusting means are connected to a cable or cable or an inner tube arranged in the shaft, that by actuation of the cable or cable or by moving the inner tube of the change between fixing position and walking position is triggered.
The actuator preferably comprises a motor, which is preferably arranged inside the shaft and which is powered by a battery, which is preferably arranged in the shaft, or a solar module arranged on the outside of the shaft, preferably a flexible solar cell, more preferably an organic solar cell is supplied.
In a further preferred embodiment, the foot part is preferably connected by at least one spring joint with the shaft, which comprises at least one spring element, such as a coil spring or a leaf spring. The spring element is used for damping during placement and allows the flexibility of the foot part with respect to the shaft in the walking position. Due to the restoring forces of the spring element, the foot part is also automatically returned to the rest position after a deflection. In preferred embodiments, the spring element is made of plastic or metal and designed as a spiral spring or leaf spring, or a combination of spring types. In walking position, the walker allows an elastic, safe and comfortable walking.
If the spring elements are designed as leaf springs, the shaft preferably has a square or rectangular cross-section, which facilitates the reception of the rectangular leaf springs. The rectangular shape of the stem and leaf springs facilitates precise alignment in the direction of the foot part. In the rectangular shaft no round inner tube are inserted, which the power transmission for actuating the actuating means and / or Rotation of the foot allows. The inner tube can protrude from the shaft, so that it can be easily operated.
In a preferred embodiment, the first end pieces of the spring elements are aligned parallel to the shaft and anchored in this. The second end pieces of the spring elements are inclined or aligned parallel to the support plate of the foot part and connected thereto. Preferably, not all second end pieces are oriented in the same direction. Preferably, each half of the second end pieces in different directions along the support plate.
In order to ensure sufficient stability in the fixing position against the unwanted falling over of the walker, the foot part, respectively the support plate must have a minimum size, so that the focus of the walker is in an upright position on the support plate. In order not to let the surface of the platen become too large, asymmetrical platen plates, in particular shoe-shaped platen plates or platen plates, are preferably used.
In particular, when climbing stairs, a foot part, respectively, a foot part with a support plate, which protrudes far from the shaft, be detrimental. In a preferred embodiment, therefore, an asymmetric foot part is provided, which is rotatably mounted about the axis of the shaft, so that when climbing stairs always the end of the support plate, which is closer to the shaft, can be oriented in the direction of walking. The rotatably mounted foot can be locked in at least two, preferably by 180 ° different positions.
In a preferred embodiment, the foot part, optionally the support plate made of an at least partially elastic material.
To increase the safety of use, the support plate can be provided on the side facing the floor with an anti-slip coating and / or a rough coating.
In further preferred embodiments, the walker comprises a light source, preferably a lamp, for illuminating the path ahead of the user of the walker and / or a mobile telephone or emergency telephone integrated in the walker.
The invention will be explained in more detail with reference to drawings. Showing:
- Fig. 1
- a walker 100 known from the prior art;
- Fig. 2
- an inventive walker 1 in a first preferred embodiment with a shaft 2, which is provided above with a handle 3 and below coupled via a spring joint 7 with a foot part 5 and provided with a movably mounted tubular actuating means 6;
- Fig. 3a
- the foot part 5 and a part of the shaft 2 of the walker of Fig. 1 with the tubular actuator 6 in the walking position;
- Fig. 3b
- the foot part 5 of Fig. 3a which has been deflected relative to the shaft 2 from the rest position;
- Fig. 3c
- the foot part 5 of Fig. 3a with the tubular adjusting means 6, shown partially cut, in the fixing position;
- Fig. 4a
- the foot part 5 in a second preferred embodiment with the tubular actuating means 6 of Fig. 3a and a preferably configured spring joint 7;
- Fig. 4b
- the foot part 5 in a third embodiment according to the invention with the adjusting means 6 'in the form of additional supports 6' in walking position;
- Fig. 4c
- the foot part 5 of Fig. 4b wherein shaft 2 and foot part 5 have been deflected from the rest position;
- Fig. 4d
- the foot part 5 of Fig. 4c with the adjusting means or additional supports 6 'in fixing position;
- Fig. 5a
- the foot part 5 of Fig. 4a in a fourth embodiment with spring elements 7 whose lower end pieces 72 are fixed on the foot part plate 51 and point in different directions;
- Fig. 5b
- the foot part 5 of Fig. 5a without the footing plate 51;
- Fig. 6a
- the foot part 5 of Fig. 3a with the adjusting means 6, which is pressed by a spring 8 down to the fixing position;
- Fig. 6b
- the foot part 5 of Fig. 3a with the adjusting means 6 against the spring 8 pulled up in the walking position;
- Fig. 7a
- the walker 1 of Fig. 2 arranged with a preferably designed actuating lever 92 and the arm holder 4 above the handle 3; and
- Fig. 7b
- the walker 1 of Fig. 7a with the arm holder 4 above and arranged laterally next to the handle 3.
Fig. 1 shows a known from the prior art walker 1. The walker comprises a shaft 2 to which a handle 3 is attached. The handle 3 is aligned approximately at right angles to the shaft 2. The handle 3 is mechanically stable connected to the shaft 2, and one-piece designs are possible. On the ground-facing side of the shaft 2, a foot part 5 is attached, which is often designed as a rubber element. The rubber element is mechanically flexible and dampens the walker 1 when placed on the ground. Walking aids 1 also often have an inclined shaft portion 21, which is angled in the region of the handle 3. Normally, an arm support 4 for the forearm of the user of the walker 1 is arranged on the inclined shaft portion 21 above the handle.
Fig. 2 showed a walking aid 1 according to the invention in a first preferred embodiment. The walking aid 1 comprises a shaft 2 and a handle 3 attached thereto. The walking aid 1 can also comprise an angled shaft portion 21 and an arm holder 4 attached thereto. The foot part 5 is connected via an elastic joint in the preferred embodiment of a spring element 7 with the shaft 2. In the embodiment shown, the foot part 5 comprises a support plate 51 and a foot shank 52. Platen 51 and foot shank 52 may be made in one piece or as two parts, for example, by a welded connection or a screw connection, connected parts. On the shaft 2, a preferably one-piece adjusting means 6 is mounted, which is designed in the embodiment shown as a piece of pipe. The position of the actuating means 6 can be moved, for example via an operating knob 91 on the handle 3 at least between a first and a second position.
In Fig. 2 is the tubular adjusting means 5 in the second position in which it was released from the foot part 5 and completely shifted over the shaft 2. Fig. 2 shows that the foot part 5 has a foot shank 52 and a support plate 51. The foot shank 52 preferably has the same cross-section as the shank 2. Preferably, the shank 2 and the foot shank 52 are cut in the manufacture of the walker 1 of a same tube. The tubular adjusting means 6 can therefore be displaced via the joint 7 and the foot shank 52 into a first position, in which the shank 2 and the foot shank 52 are preferably covered by the adjusting means 6 over the same length. The shank 2 and the foot shank 52, which are aligned coaxially in the rest position of the spring joint 7, can therefore be fixed by the adjusting means 6 in the first position in this coaxial alignment.
According to the invention, the shaft 2 of the walker 1 and the foot part 5 of the walker 1, which are hinged together, thus coupling elements 2, 52 which are rigidly coupled together by an adjusting means 6 in a first position and decoupled from each other in a second position. These two connected to the shaft or the foot part coupling elements 2, 52 and the adjusting means 6 may be configured arbitrarily. You only need to fulfill the coupling function and the decoupling function.
The adjusting means 6 can be easily raised by means of cable 9, which is connected to an actuating lever 92 and moved to the walking position. As far as e.g. within the shaft 2, a motor is connected to the actuating means 6, it can be operated with the control knob 91.
Fig. 3a shows a detail of the walker 1 of Fig. 2 with a part of the shaft 2, the foot part 5, the spring joint 7 and the adjusting means 6. The adjusting means 6 is shown in the walking position, in which no rigid connection between the foot part 5 and shaft 2 is produced by the adjusting means 6. The foot part 5, consisting of foot shaft 52 and support plate 51 can be moved relative to the shaft, as illustrated by the double arrow. The relative movement of shaft 2 and foot part 5 is made possible by a spring joint 7, which is connected both to the shaft 2 and to the foot part 5. The restoring force of the spring joint 7 is designed so that the foot part is moved back when not loaded in the rest position shown, in which the axes of the shaft and Fussteilschaft are at least approximately parallel.
Fig. 3b shows the walker 1 of Fig. 3a , wherein the shaft 2 and the adjusting means 6 located thereon are deflected relative to the foot part 5. The deflection shown occurs when walking with the walker 1, when the walker 1 is placed on the ground in front of the user's foot. The foot part 5, or the support plate 51 are aligned by placing along the floor, while the shaft 2 and the units attached thereto are deflected relative to the foot. The spring joint 7 is bent in this state. The spring joint 7 according to the invention is designed so that the deflection of the foot part shown relative to the shaft by the force exerted by the user of the walker 1 is possible.
The spring joint 7 thus forms a hinge, which acts with a certain torque on the support, if the foot part 5 is fixed to the ground. Preferably, the spring joint 7 is formed such that this torque acts at the height of the arm holder 4 with a noticeable force. For only a few disabled persons, this force can be very low. For insecure and weak people can a higher force is provided. If this stabilization function is desired, a spring joint 7 is provided, which causes a force in the range of 5 to 50 Newtons in the region of the arm holder 4. Preferably, a spring joint is provided with a variable torque. For example, a plurality of spring elements are provided, which are preferably selectively slidable. In this way it is possible to stiffen the foot part not only completely, in the first position of the actuating means, but gradually.
Fig. 3c shows a detail of the walker 1 of Fig. 3a , wherein the adjusting means 6 is in the standing position, in which there is a mechanically stable coupling between foot part 5 and shaft 2 by the adjusting means 6.
Fig. 3d shows a detail of the walker 1 of Fig. 3c , wherein the tubular adjusting means 6 is shown in sectional view. The actuating means 6 is opposite Fig. 3a shifted to a position in which a mechanically stable coupling between foot part 5 and shaft 2 is provided by the adjusting means 6. A suspension along the axis of the shaft 2 is possible in the position shown of the actuating means 6, but can also, for example by blocking elements such as projections or nubs on the adjusting means 6, impossible. The remaining degrees of freedom of the foot part 5 are blocked. The inner diameter of the actuating means 6 is designed so that the actuating means 6 can be positively listed on the Fussteilschaft 52. Likewise, the inner diameter of the adjusting means 6 in the region of the shaft 2 is selected so that a positive connection between the shaft 2 and 6 actuating means.
Fig. 4a shows a detail of the walker 1 of Fig. 3a in a further inventive embodiment, with the Foot part 5, consisting of footer shaft 52 and support plate 51, and the shaft 2 and the adjusting means 6. The spring joint 7, which comprises one or more leaf springs or a spring assembly, both with the foot part 5, preferably with the footer shaft 51, as well connected to the shaft 2. The foot part 5 can be deflected relative to the shaft 2 from the rest position, as visualized by the double arrow.
Fig. 4b shows a detail of the walker 1 of Fig. 3a in a further inventive embodiment, with the foot part 5, consisting of the foot part shaft 52 and the support plate 51, and the shaft 2 and the spring joint 7. As adjusting means 6 'additional supports 6' on the shaft 2 are provided. The additional supports 6 'are shown in the walking position, in which no mechanical coupling between the foot part 5 and the shaft 2 by the adjusting means or the additional supports 6' is produced. The foot part 5 can be deflected relative to the shaft 2 from the rest position, as visualized by the double arrow.
Fig. 4c shows a detail of the walker 1 of Fig. 4b , wherein the shaft 2 and the additional supports 6 'arranged thereon are deflected relative to the foot part 5. The additional supports 6 'are arranged on the shaft 2, that even at the maximum deflection during use of the walker 1 does not come to a contact between the additional supports 6' and the foot part 5 and the support plate 51.
Fig. 4d shows a detail of the walker 1 of Fig. 4b , wherein the additional supports 6 'are shown in the fixing position, in which a mechanically stable coupling between the foot part 5 and the shaft 2 by the additional supports 6'.
Fig. 5a shows a detail of the walker 1 of Fig. 4a in a further embodiment according to the invention. The foot part 5, consisting of the footing shaft 52 and the support plate 51, is connected to the shaft 2 via the spring joint 7, which comprises a package of leaf springs 71. On the shaft 2, a control part 6 is arranged. The first end portions of the leaf springs or spring elements 71 are arranged inwardly of the shaft 2 in the shaft direction. The second end portions of the leaf springs or spring elements 72 are supported and angled on the support plate 51, wherein the second end of the spring elements 72 are bent apart so that a part of these second end pieces are inclined or even approximately parallel to the support plate 51 and connected thereto. Individual elements of the end pieces of the spring elements 72 point on the support plate 51 in at least two different directions, preferably opposite directions parallel to the running direction of the user of the walking aid 1. For fixing the foot part 5, the adjusting means 6 can be pushed over the foot part shaft 52 again.
The foot part 5 can be of any desired design and, e.g. have the shape of a shoe.
Fig. 5b shows the foot part 5 of Fig. 5a without the footing plate 51. In this embodiment, the second end pieces 72 of the leaf springs 7 can come into direct contact with the ground. This results in an intensive yet elastic contact with the ground. The walker 1 is therefore non-slip and resiliently supported on the ground.
The operation of the actuating means 6 can be done by at least one cable 9, a motor and / or a lever mechanism. In addition, at least one locking device may be provided, which holds the adjusting means 6 in the first or second position.
Fig. 6a shows the foot part 5 of Fig. 3a with the adjusting means 6, which is pressed by a spring 8 down in the standing position in which the foot part 5 is fixed. The adjusting means 6 is connected by a retaining screw 95 with the released cable 9.
Fig. 6b shows the foot part 5 of Fig. 6b with the actuating means 6, that of the cable 9, for example by means of the actuating lever 92 of Fig. 2 was pulled against the spring 8 up in the walking position. The actuating lever 92 and the cable 9 may be formed, for example, in the manner of a braking device. Instead of the wheel brake, the actuating means 6 of the walking aid 1 is actuated.
Particularly advantageous is the use of the return spring 8, which automatically shifts the released actuating means 6 in one or the other direction. For example, is a spiral spring 8 is provided above the tubular adjusting means 6, which presses against the tubular adjusting means 6 down. Once the lock is released, the tubular adjusting means 6 automatically shifts to the standing position, in which the shaft 2 and the foot part 5 are rigidly coupled together.
For actuation, therefore, only a cable 9 is required, which pulls the adjusting means 6 upwards. The cable 9 can be fixed in the second position of the actuating means 6 by a simple locking device. For example, a loop of the cable is guided into an area into which a bolt can be moved. This bolt keeps the cable in the raised position. Once the bolt, eg by pressing the operating knob 91 (see Fig. 2 ) is withdrawn, the cable is released again and the adjusting means 6 is automatically moved to the first position.
Fig. 7a shows the walker 1 of Fig. 2 arranged with a preferably designed actuating lever 92 and the arm holder 4 above the handle 3. The cup-shaped actuating lever 92, which is rotatably held, for example, the shaft 2 by means of a shaft, can be manually pulled up comfortably and takes in the sequence on the handle 3 in the shell. The operating lever 92 occupies little space in this position is preferably held and stored so that the user can intervene with the hand comfortably between the handle 3 and the operating lever 92, but this can grab and put on with extended hand. In this position, the actuating lever 92 is aligned coaxially with the handle 3 and can be conveniently held or fixed, for example by a ring which is pushed over the handle 3 and the actuating lever 92. After releasing the actuating lever 92, this is pulled by the spring 8 together with the actuating means 6 down.
The adjusting spring 8 is in this embodiment, a cylindrical coil spring which is integrated into the shaft 2 of the crutch 1 and connected by a connecting shaft 93 with the tension member 9 and held by a support shaft 94 at the lower end of the shaft 2. The connecting shaft 93 projects outwardly through a guide slot 20 and held in openings of the tubular actuating means 6. The tension element 9 and the adjusting means 6 are pulled down by the adjusting spring 8 and can be pulled upwards by operation of the actuating lever 92 in order to decouple the foot part 5 from the shaft 2.
The handle 3 and the arm holder 4 are arranged one above the other, which is why the user's hand inside (Arrow direction) and the wrist must run against the body, resulting in stress on the wrist.
Fig. 7b shows the walker 1 of Fig. 7a arranged with the arm holder 4 above and laterally next to the handle 3 or offset against the body of the user. In the embodiment shown, the shaft portion 21 is inclined or bent against the user. In this embodiment, the wrist is held above the handle and thereby relieved.
The inventive walker 1 thus not only supports the movement of the user, but also allows the ergonomic correct holding the walker. 1
Fig. 7b further shows a shaft 2 which is provided with a handle relief, such as a grid, grooves or nubs. In the sitting position, the user can thus safely grasp and hold the shaft 2 and stalk it.
LIST OF REFERENCE NUMBERS
- guide slot
- inclined shaft section
- arm bracket
- foot part
- Footrest shaft
- 6, 6 '
- actuating means
- Spring joint, such as spring package, spiral spring, leaf springs
- first end pieces of the spring elements
- second end pieces of the spring elements
- tension element
- actuating button
- actuating lever
- Sliding connection shaft
- holding shaft
- retention screw
- Retainer, gripping surface