This invention relates to a rotation locking device for locking the rotation of a shaft in medical equipment and the like. More particularly this device is for locking the unwanted swinging movement or rotation of a shaft and for a system of preventing the rotation of an outer shaft about an inner shaft. In particular this device relates to a convenient operation of rotation locks which can be used in medical and other equipment.
Prior art
There are therapeutic uses for radiation of different kinds. For example, blue light is used in treatment of hyperbilirubinaemia and infra red radiation may be used to maintain the thermal balance of neonates. Patients requiring therapy by radiation are typically placed in a horizontal position and the source of radiation is positioned above them. During the course of treatment or observation, radiological and other procedures may require the positioning of other equipment in the same place above the patient. Thus the source of radiation needs to be moved away temporarily during such procedures.
This is commonly achieved by pivoting the equipment on a shaft. It may then be swung away, when desired, from the location used for therapy. After the radiological or other procedure, the radiation equipment may now be turned to the therapy position by turning it back about the shaft. To prevent undesirable swinging of the equipment away from the desired position during therapy, it is fitted with a locking mechanism that holds it in place.
Currently used locking mechanisms require the continuous use of both hands
of an operator or care provider. .These locking mechanisms have a spring that
operates a pin which presses on the shaft and thereby prevents rotation. To turn the
shaft, such as during radiological procedures, the pin must be manually drawn back
by the retracting the spring. One hand of the operator must be used for releasing the
lock. The other hand must be used to rotate the radiation unit simultaneously. Thus
currently used rotation locks are inconvenient to use.
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The prior art US6916176 discloses the rotation lock device for preventing the rotation of a shaft especially for hand pieces used in medical treatments. The endoscopic surgical apparatus with a rotation lock is disclosed in US5836960. The prior art US4832299 discloses an improved clamp fixture which supports a medical instrument or the like in a selected orientation relative to a variety of different support structures. Even though there are many patents and patent applications which clearly describe rotation locks, there Is a need to address the problem faced by operators in rotating equipment, especially while giving radiation therapy.
In the case of radiation therapy, sometimes there is a need to position another equipment along with the source of radiation equipment in the same place above the patient. In such circumstances, the source of radiation equipment has to be moved away temporarily. After the radiological or other procedure, the radiation equipment must be returned to the therapy position by turning it back about the shaft. To prevent undesirable swinging of the equipment away from the desired position during therapy, it is fitted with a locking mechanism.
Problems or the drawbacks faced with the prior art
Currently used locking mechanisms require the continuous use of both hands of an operator during radiological and other procedures. These locking mechanisms have a spring that operates a pin which presses on the shaft and thereby arrests the rotation. The pin must be manually drawn back by retracting the spring to turn the shaft. One hand of the operator must be used for releasing the lock. The other hand must be used to rotate the radiation unit simultaneously. Thus currently used rotation locks are inconvenient to use.
The present invention completely solves the problem of a rotation lock device with an enhanced constructional feature. The rotation lock device comprises two spring-actuated locking pins to lock the rotation of the shaft. The ease of operation of the rotation locks has been improved, thereby overcoming the problem faced by the operators.

Aims & Objects of this Invention
The principal object of the present invention is to provide a device for locking the rotation of a shaft.
It is another object of the present Invention to provide a system to arrest the rotation of the shaft to prevent undesirable swinging of the equipment away from the desired position during therapy.
It is yet another object of the present invention to improve the convenience of operation of rotation locks and to provide ease of operation to the operators during radiation therapy.
It is a further object of this present Invention to operate the lock with one hand.
It is yet another object of the present invention to use the rotation locks In any medical equipment and other equipment.
It is a further object of this present invention to use the rotation lock in equipment involving radiation..
Statement of the Invention
This invention, a rotation locking device for locking the unwanted swing or movement or any other rotation of a shaft In medical or other equipment, comprises an inner shaft and an outer shaft movably placed for turning or rotating against each other; the said outer shaft is housed on top or below the equipment to be moved or swung away when required; the said locking device has a first locking pin provided on the said outer shaft, preventing the outer shaft from moving about the inner shaft, consequent to the first locking pin being in alignment with a profile/depression/slot on the Inner shaft, and the said outer shaft Is movably provided about the inner shaft, after the said first pin is turned out of alignment, subsequent to the retraction of the first locking pin, the said second locking pin pressing against the first locking pin by engagement with the said first locking pin;

the movement of the said second locking pin is controlled using the locking arrangement provided.
Thus according to another feature of this invention, the said two shafts are concentrically placed for their movement.
Thus according to yet another feature of this invention, the said two locking pins are either spring loaded or spring actuated to press against a shaft or pin.
Thus according to yet another feature of this invention, the said locking pins are provided at right angles to each other.
Thus according to yet another feature of this invention, the inner shaft has a slot providing the alignment for the said first locking pin, arresting the swing or movement of the outer shaft with respect to the inner shaft. .
Thus according to yet another feature of this invention, the inner shaft is provided with a slot or profile on its outer surface to provide for alignment with the said first locking pin.
Thus according to yet another feature of this invention, the said second locking pin pressing against the first locking pin is by way of engagement with the said first locking pin.
Thus according to yet another feature of this invention, the engagement between the first and second locking pins is provided with the help of a step or groove on the said first locking pin.
Thus acconding to yet another feature of this invention, the movement of the second locking pin is controlled by the key /roller/any alternative locking an'angement provided at the bottom end of the inner shaft.
Reference to Drawings
The invention will now be described in greater detail with reference to the schematic drawings accompanying this complete specification, wherein. Fig 1 shows a cross'sectional view of the locking device illustrating the rotation locking action at Position 1.

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Fig 2 illustrates a cross*sectlonal view of the locking of the first locking pin by the second locking pin at Position 1.
Fig 3 illustrates a cross-sectional view of the displacement of the second locking pin fronn first locking pin at Position 2 (any position away from Position 1)
Fig 4 illustrates three-dinnensional views of the roller and slot at the bottom of the inner shaft.
Detailed description of the invention
In medical treatment applications, the equipment involved may deliver radiation. Rotation may be required to move the equipment mounted on the outer shaft (or inner shaft), away temporarily when, for example, an X-ray image is to be obtained. The present invention describes a device for locking of such rotation of a shaft. The present invention also relates to a system for arresting the rotation of an outer shaft about an inner shaft.
Referring to the figs 1 to 4 of the accompanying drawings, the locking device comprises two spring-actuated locking pins, namely Pin A and Pin C, positioned at right angles to each other. The locking device has an outer shaft B on which any equipment can be mounted and also an inner shaft G (on which equipment may be mounted also). It is to be noted that the equipment can be mounted on the inner shaft also. These two shafts B and G are concentrically placed and are locked at the position 1. The first locking pin A prevents the outer shaft (B) on which radiation or other equipment is mounted, from turning or rotating about the inner shaft (G), by engaging in a profile or slot (F) on the inner shaft G (Position 1 of the equipment). The inner shaft G has a profiled depression or slot F provided on Its outer surface. The locking pin A is pressed against the inner shaft G by Spring 1. Fig.1 shows Pin A engaged in the slot as during use of the radiation equipment (position 1 of the equipment). Spring 1 keeps the Pin A pressed against the inner shaft G.

When the equipment mounted on the outer shaft B has to be rotated, or to release the lock, Pin A Is retracted manually by hand. This makes the outer shaft B free to rotate about the inner shaft G. When the shafts B & G return to Position 1, they get locked again automatically. Now when Pin A is pulled out, spring loaded Pin C which is pressing against the Pin A engages with the step or groove provided on Pin A, as the Pin C is aligned with the step or groove provided on Pin A and gets seated in the groove which locks Pin A from any movement. Pin C is pushed against Pin A by Spring 2. This is illustrated in fig 2 of the accompanying drawings. The movement of Pin C causes the key or Roller D to sit In Profile E at the bottom end of the inner shaft G which is clearly seen in fig 4 of the accompanying drawings. The key or Roller D fixed on the locking Pin C moves it vertically when it moves into and out of the Profile E. The key may optionally be guided by a vertical slot on a plate attached to the outer shaft.
At this point (Point 1), the outer shaft B is free to rotate around the inner shaft G. Thus the locking pin A is held back once it has been retracted, and it is not necessary to hold it with one hand. The equipment mounted over the outer shaft B (or on the inner shaft G), may now be turned with the use of one hand alone. Thus the device can be handled with ease using only one hand.
When the outer shaft B is rotated from position 1 to any other position (Position 2), it causes the key or a RoHer D to slide out of Profile E, thus retracting Pin C as seen in fig 4. The downward displacement of key or Roller D causes the Pin C to disengage from the step or groove of the Pin A. This leads to Pin A being pushed against the inner shaft G by Spring 1. However, Pin A does not prevent further rotation because it Is not aligned with the profile or slot F on the inner shaft G and does not engage with it. Thus the outer shaft B and equipment mounted over it are stiK free to rotate-about the innfer shaft G. This is clearly illustrated in fig 3 which shows a cross-section of the displacement of the second locking pin C from the first locking pin A. But during the course of rotation, when the first Pin A gets realigned with the slot on the inner shaft G at Position 1, if is pushed by the spring into it, causing the lock to be activated again. When the outer shaft B is rotated back to
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Position 1, the first locking Pin A engages witli the profile or siot F on the inner shaft G which prevents the undesired rotation of the outer shaft B and equipment. Further, Roiler D rolis into Profile E. pressing Pin C against Pin A.
Thus the need to hold the locking mechanism open with one hand when turning the equipment is eliminated.
Applications and Advantages
1. Improves the convenience of operation of rotation locks used in the equipments in any field in general, but particularly this invention finds major application in the medical field.
2. Particularly finds an application in therapy involving administration of different kinds of radiation to the patient.
Although the invention has been described in detail with reference to the drawings, it is to be construed that it is only to define the features of the invention and describe the same with respect to a particular exemplary unit. It is always to be construed that minor modifications are possible in the invention, without departing from the spirit and scope of the invention.

I claim:
1. Rotation locking device for locking the unwanted swing or movement or any other rotation of a shaft in medical equipment, comprising an inner siiaft and an outer sinaft movably placed for turning or rotating against each other; said outer sliafl (or inner shaft) housing on top (below) the equipment to be moved or swung away when required; said locking device having a first locking pin provided on the said outer shaft, preventing the outer shaft from moving about the inner shaft, consequent to the first locking pin being in alignment with a groove/depression/slot on the inner shaft, and the said outer shaft being movably provided about the inner shaft, after the said first pin being in non-alignment with depression/groove/slot on the inner shaft, consequent to the retraction of the first locking pin, said second locking pin pressing against the first locking pin by engagement with the said first locking pin; the said second locking pin is being controlled for its movement with the locking arrangement provided on the inner shaft.
2. Rotation locking device as claimed in claim 1 wherein the said two shafts are concenthcally placed for their movement.
3. Rotation locking device as claimed in claim 1, wherein the said two locking pins are either spring loaded or spring actuated for tension against each other.
4. Rotation locking device as claimed in claims 1 & 3, wherein the said locking pins are provided at right angles to each other.
5. Rotation locking device as claimed in claim 1, wherein the inner shaft is having a slot providing the alignment for the said first locking pin, arresting the swing or movement of the outer shaft with respect to the inner shaft.

6. Rotation locking device as claimed in claim 5, wherein the Inner shaft is
provided with a slot or profile on its outer surface to provide fQr alignment with
the said first locking pin,
7. Rotation locking device as claimed in claim 1, v^rtierein the said second
locking pin pressing against the first locking pin is by way of engagement with
the said first locking pin.
8. Rotation locking device as claimed in claim 7, wherein the engagement
between the first and second locking pins is provided with the help of a step
or groove on the said first locking pin.
9. Rotation locking device as claimed In claims 1&8, wherein the movement of
the second locking pin is controlled by the key/roller/alternative locking
arrangement provided at the bottom end of the inner shaft.
10. Rotation locking device substantially as hereinbefore described and as
illustrated in the drawings accompanying the provisional specification.