GB2445421A - Delivery gun drive and retraction - Google Patents

Delivery gun drive and retraction Download PDF

Info

Publication number
GB2445421A
GB2445421A GB0700213A GB0700213A GB2445421A GB 2445421 A GB2445421 A GB 2445421A GB 0700213 A GB0700213 A GB 0700213A GB 0700213 A GB0700213 A GB 0700213A GB 2445421 A GB2445421 A GB 2445421A
Authority
GB
United Kingdom
Prior art keywords
drive shaft
drive
gun
delivery gun
trigger
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0700213A
Other versions
GB0700213D0 (en
Inventor
David Foster
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Summit Medical Ltd
Original Assignee
Summit Medical Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Summit Medical Ltd filed Critical Summit Medical Ltd
Priority to GB0700213A priority Critical patent/GB2445421A/en
Publication of GB0700213D0 publication Critical patent/GB0700213D0/en
Priority to PCT/EP2007/011382 priority patent/WO2008080590A1/en
Publication of GB2445421A publication Critical patent/GB2445421A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C17/00—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces
    • B05C17/005—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes
    • B05C17/01—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes with manually mechanically or electrically actuated piston or the like
    • B05C17/0116—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes with manually mechanically or electrically actuated piston or the like characterised by the piston driving means
    • B05C17/012—Stepwise advancing mechanism, e.g. pawl and ratchets
    • B05C17/0123—Lever actuated
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/88—Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices
    • A61B17/8802—Equipment for handling bone cement or other fluid fillers
    • A61B17/8805—Equipment for handling bone cement or other fluid fillers for introducing fluid filler into bone or extracting it
    • A61B17/8822—Equipment for handling bone cement or other fluid fillers for introducing fluid filler into bone or extracting it characterised by means facilitating expulsion of fluid from the introducer, e.g. a screw pump plunger, hydraulic force transmissions, application of vibrations or a vacuum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C17/00—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces
    • B05C17/005—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes
    • B05C17/01—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes with manually mechanically or electrically actuated piston or the like
    • B05C17/0116—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes with manually mechanically or electrically actuated piston or the like characterised by the piston driving means
    • B05C17/012—Stepwise advancing mechanism, e.g. pawl and ratchets
    • B05C17/0123—Lever actuated
    • B05C17/0126—Lever actuated comprising an element, e.g. an arc compensating element, articulated at one end on the lever and at the other end on the piston rod driving means, e.g. a pawl
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30518—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements with possibility of relative movement between the prosthetic parts
    • A61F2002/3052—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements with possibility of relative movement between the prosthetic parts unrestrained in only one direction, e.g. moving unidirectionally
    • A61F2002/30522—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements with possibility of relative movement between the prosthetic parts unrestrained in only one direction, e.g. moving unidirectionally releasable, e.g. using a releasable ratchet
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2220/00—Fixations or connections for prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2220/0025—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C17/00—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces
    • B05C17/005—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes
    • B05C17/01—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes with manually mechanically or electrically actuated piston or the like
    • B05C17/014—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes with manually mechanically or electrically actuated piston or the like comprising means for preventing oozing

Abstract

A delivery gun 100 for e.g. bone cement comprises a main body 110 having proximal 60 and distal 170 ends and a longitudinal axis extending therebetween. A drive shaft or rod 300 is moveable distally by a drive means e.g. pawl 500 moved by a trigger like lever 400 and is prevented from proximal movement by a non return means e.g. a back plate 570. In a first invention the drive and non return means are linked e.g. by a release rod 600, such that when the back plate is actuated to release the shaft, the pawl or a drive plate is moved out of contact with the shaft. Avoids having to rotate a tooted shaft out of register with a pawl and potentially scoring the rod on retraction. In another invention, the drive means comprises a drive pawl and the non return means comprises a plate. The pawl allows high drive forces and the plate provides locking increments of less than one ratchet tooth.

Description

2445421
i
BONE CEMENT DELIVERY GUN
The present invention relates to a cement delivery gun, in particular, but not exclusively, for use in dispensing orthopaedic bone cement for surgical procedures.
Orthopaedic bone cement is used in many surgical procedures throughout the world to secure hip, knee and other metallic prostheses in an appropriate anatomical position. The bone cement is prepared immediately prior to each procedure by mixing a powder and a liquid, before applying the bone cement to the desired place within the body.
Conventionally, ihe bone ceincui may be inserted iuio ihe body by hand or is injected into the body using a bone cement delivery gun, types of which include a ratchet gun and a plate gun.
A ratchet gun, such as shown in figure 1, uses a toothed drive shaft and obtains forward movement via a drive pawl which engages the teeth and moves the shaft when the gun trigger is squeezed. Typically two teeth are moved per full stroke of the trigger. The drive shaft is stopped from returning in the opposite, backward direction upon release of the drive pawl via positive engagement of a second pawl, a return pawl, with the teeth.
The positive engagement of the drive pawl with the teeth provides great force for driving the cement out of the delivery gun, especially under high pressure. Unfortunately, a disadvantage of such guns is that the return pawl must also fully engage each tooth of the drive shaft in order for it to prevent backwards movement of the drive shaft upon release of the trigger.
Proper engagement of the return pawl with the teeth therefore requires that the trigger of the gun be positioned at a particular point, (e.g. mid or end of the trigger travel, when one full stroke moves the shaft two teeth), to allow the teeth to align and so
1
requires the operator to completely and fully compress the trigger to gain full movement. During pressurisation of higher loading this is very difficult to achieve, especially for operators with small or less strong hands.
Once the cartridge has been emptied and the operator wants to reset the gun to its start position, the operator rotates the drive shaft anticlockwise or clockwise about its axis, so that the teeth no longer engage the return pawl and the operator is then able to slide the drive shaft back, over the pawls, to its original position. A major problem associated with this, however, is that, when pulling the drive shaft back over the hard drive pawl, the drive pawl may damage the drive shaft, by producing scoring marks on the shaft. Such damage stops the drive shaft running smoothly through the guide bushes and therefore may also result in subsequent damage to these parts, thereby shortening the product life cycle.
Another type of conventional gun is a plate gun, as shown in figure 4. A piate gun uses a drive plate to push a drive shaft forward, by contacting and gripping the external surface of the drive shaft which runs through a hole in the drive plate. Since the plate surrounds the drive shaft, it can grip the surface without the need for teeth and so a smooth-surfaced drive shaft is used. By rocking backwards and forwards, the drive plate moves the shaft forward.
The plate gun also has a back plate which is tilted at an angle during advancement of the drive shaft, so that it grips the drive shaft and thereby stops backward movement of the shaft. When the operator wants to return the drive shaft back to its original start position, the back plate is pushed inwards to release the grip on the shaft. Due to the fact that the back plate can grip the drive shaft at any point offered, unlike the ratchet gun, the drive shaft can be moved forward in small, non-uniform steps (unlike the ratchet gun). Therefore, during pressurisation, the hand can be positioned at an optimum position to generate forces, i.e. partly open at the start of the trigger compression, and compress in small steps. A disadvantage of this type of gun, however, is that, because it does not have positive engagement of a drive pawl with teeth, as described above, a plate gun having a comparable size and geometry to a ratchet gun cannot generate the same forces as the similarly sized ratchet gun. To gain higher forces, the handle and trigger length of the plate gun must be extended,
2
thereby making the gun less compact.
Thus, although delivery guns are known, there remains a need for a new improved type of delivery gun which is able to overcome the disadvantages of the prior art guns, as discussed above. In particular, there remains a need for a gun which is both able to generate high forces, and which is also able to move a drive shaft forward in small, non-uniform steps, thereby allowing operators of lesser strength to be able to dispense a material, e.g. bone cement from the gun with greater case. There also remains a need to provide a gun that does not experience the same problems associated with prior art guns, wherein contact between the drive shaft and either the drive pawl or the drive plate results in damage to the drive shaft as it is returned to its original start position.
A first aspect of the present invention provides a delivery gun comprising a main body having a proximal end and a distal end, and a longitudinal axis extending between the proximal and distal ends, a drive shaft moveable along the longitudinal axis, drive means for moving the drive shaft in a proximal direction, return means for preventing movement of the drive shaft in a distal direction, and further comprising release means to release contact of the drive means and the return means with the drive shaft.
The release means may be movable between a first position and a second position, wherein, in the first position, both of the drive means and the return means are in contact with the drive shaft, and wherein, in the second position the drive means and the return means are not in contact with the drive shaft.
Preferably, the release means comprises a release rod which extends between the drive means and the return means.
The drive means also preferably comprises means for receiving the release means or release rod. The means for receiving the release rod may be a ledge, or step, formed in and/or along a side of the drive means, the step having a first end, which is adapted to receive the distal end of the release rod, and a second end which acts as a stop for
3
the distal end of the release rod. In one embodiment, the release rod is slidably received in the means for receiving the release rod.
The opposite, proximal end, of the release rod is preferably adapted to be connected to the return means. Therefore, movement of the return means in a first, distal direction results also in movement of the release rod in the first, distal direction, which consequently results in the release rod being received in the step of the drive means until the distal end of the release rod comes into contact with the distal end of the step in the drive means.
Preferably, the drive means is movable about a pivot point, so that when the distal end of the release rod contacts the distal end of the step, any further movement of the release rod in the distal direction results in pivotal movement of the drive means about the pivot point, thereby rotating the drive means away from the drive shaft and releasing the contact between the drive means and the drive shaft.
Also in a preferred embodiment, the drive shaft comprises a toothed surface which extends along the drive shaft in the longitudinal direction. In one embodiment, the toothed surface does not extend completely around the circumference of the drive shaft, however, drive shafts with toothed surfaces that extend completely around the circumference would still be within the scope of the present invention. The drive shaft may also comprise a smooth proximal portion, comprising no teeth, and a toothed distal portion.
In the preferred embodiment, the return means comprises a plate and the drive means comprises a pawl and the drive pawl engages with the teeth of the drive shaft.
The return plate may preferably be biased proximally by a biasing means, such as a spring, so that, when the biasing means is in its uncompressed state, the plate lies in a plane that is tilted at an angle to the axis perpendicular to the longitudinal axis, L. The plate may further comprises a hole therethrough, through which the drive shaft extends.
4
In the preferred embodiment, the return means, or plate, may be movable between a first position wherein the plate is positioned at a first angle so that the edges of the hole of the plate contact the outer surface of the drive shaft and a second position wherein the plate lies in a plane perpendicular to the longitudinal axis and does not contact the drive shaft.
The gun may further comprise a trigger, the upper end of the trigger being adapted to be connected to the drive means and the gun may further comprise a handle which projects down from the main body of the gun, wherein relative movement between the trigger and the handle results in movement of the drive means in the distal direction.
The trigger may be movable relative to the handle via rotation about a pivot point. There may also be attached, to the upper end of the trigger, a further biasing means, e.g. a spring, which biases the trigger about the pivot point, in a direction away from the handle.
A second aspect of the present invention provides a delivery gun comprising a main body having a proximal end and a distal end, and a longitudinal axis extending between the proximal and distal ends, a drive shaft moveable along the longitudinal axis, means for moving the drive shaft in a proximal direction, means for preventing movement of the drive shaft in a distal direction, wherein the means for moving the drive shaft in the proximal direction comprises a drive pawl and the means for preventing movement of the drive shaft in a distal direction comprises a plate.
Preferably, at least a portion of the surface of the drive shaft comprises teeth and the drive means of the gun is adapted to be aligned with and engage these teeth.
Preferred embodiments will now be described by way of example only, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a perspective view of a conventional ratchet type gun FIG. 2 shows a cross-sectional side view of a conventional ratchet type gun.
5
FIG. 3 shows a side view of the drive pawl in relation to the teeth of the drive shaft for a conventional ratchet type gun
FIG. 4 shows a side view of a conventional plate gun.
FIG. 5 shows a side cross-sectional view of a conventional plate gun.
FIG. 6 shows a side view of a gun according to the present invention, at the start of travel.
FIG. 7 shows a side view of a gun according to the present invention, with the trigger fully compressed and the drive pawl engaged.
FIG. 8 shows a side view of a gun according to the present invention, showing the drive pawl being released to allow backwards movement of the drive shaft. FIG. 9 shows a side view of the drive pawl of the present invention in relation to the teeth of the drive shaft.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 depicts a perspective view of a conventional ratchet type gun, 10, and Figure 2 depicts a side cross-sectional view of the same gun.
The conventional ratchet type gun has a main body, 11, extending from a proximal end, 16, to a distal end, 17, along a longitudinal axis, L. A handle, 12, projects downwardly from the gun main body, 11, in a direction that is usually, but not always, slightly offset at an angle, A, from the peipendicular axis, P. The handle is generally offset at varying angles in order to provide an easier and more comfortable fit for the operator when gripping the handle in use.
The handle has an outer surface, 13, and an inner surface, 14. In use, the operator would grip the outer surface, 13, of the handle with the palm of their hand and so this surface may be formed or made having different surface contours, 15, so that it conforms more closely to the shape of the operator's hand when gripping.
Before use, a cartridge, 20, having a proximal end, 21, and a distal end, 22 and containing mixed bone cement which is ready for injection, is connected at its proximal end, 21, to the distal end, 17, of the main body, 11, of the gun, 10, as shown in Figures 1 and 2.
6
Extending through the main body of the gun, 11, is a drive shaft, 30- The drive shaft,
30, extends along the longitudinal axis, L, of the main body, 11, entering the main body via an entry hole, 18, having a guide bush, 18A, at its proximal end, 16, and exiting the body via an exit hole, 19, also having a guide bush, 19A, at its distal end, 17.
The drive shaft, 30, is generally cylindrical in shape and comprises a toothed surface,
31, which extends along part of the length of the drive shaft in the longitudinal direction but which does not usually extend more than approximately 20-50% around the circumference of the drive shaft. Therefore, approximately 50-80% of the surface of the drive shaft in a circumferential direction is smooth, and the remaining surface toothed. The teeth are shaped as shown in figure 3, so that the angles of the edges mirror the upper surface of both the return, 50, and drive pawls, 51.
At its proximal end, 32, the drive shaft, 30, usually has a knob, 34, to prevent the proximal end of the drive shaft from entering the entry hole, 18, of the main body and also so that the operator can grip the drive shaft more easily.
At its distal end, 33, the drive shaft has a plate, 35, which is shaped so as to fit within the cartridge (usually circular) and which extends in a plane perpendicular to the longitudinal axis of the drive shaft, 30. When the cartridge, 20, is connected to the distal end, 17, of the gun, the drive shaft also extends through the cartridge, as shown in Figure 2, so that the plate, 35, acts as a plunger, and pushes the mixed bone cement out of the distal end, 22, of the cartridge when the drive shaft is moved from the proximal end of the gun to the distal end, as described below.
Attached to the main body of the gun, 11, is a trigger, 40, which, similarly to the handle, 12, described above, projects downwardly, in a direction substantially perpendicular to the longitudinal axis of the main body, 11, of the gun, 10. The trigger, 40, is attached at its upper end, 42, to the main body of the gun, 11, via attachment means, such as a bolt, 41, for example.
7
Attached to the upper end, 42, of the trigger, 40, is a spring, 44, which connects the upper end of the trigger to the inside wall, 14, of the handle, 12.
Also attached to the upper part, 42, of the trigger, 40, is a drive pawl, 50. The drive pawl sits in a ledge, 56, formed in the upper part of the trigger, 40 and is attached to the trigger by a bolt, 55, about which the drive pawl, 50, can pivot. The upper surface of the drive pawl is shaped as shown in figure 3, so that the shape minors the shape of the teeth, thereby resulting in positive engagement with the teeth. When the drive pawl is engaged with the teeth of the drive shaft, force applied to the drive pawl results in pivotal movement of the drive pawl about its pivot point, 41, and results in movement of the drive shaft in the distal direction, as described below.
Attached to the main body, 11, of the gun, 10, there is also a return pawl, 51. Again, the return pawl is attached via a bolt, 57, about which the return pawl pivots. The return pawl also has an upper surface which is shaped to reflect ilic shape of ihe Leeih, 31, of the drive shaft.
Operation of the conventional ratchet gun will now be described with reference to figures 2 to 3.
Prior to use, the operator of the conventional ratchet type gun, 10, attaches a cartridge, 20, to the distal end, 17, of the gun. At this stage, the drive shaft, 30, would be positioned so that the majority of the shaft extends out of the proximal end of the gun and the plate, 35, is close to the distal end of the gun. The operator would ensure that the drive shaft has its toothed edge facing downwards so that the upper ends of both the drive pawl, 50, and the return pawl, 51, would be facing the teeth, 31, of the drive shaft.
Once the cartridge is attached, the operator would then grip the handle, 12, of the gun in the palm of his hand and with his fingers, grip the trigger, 40. To eject bone cement from the cartridge of the gun, the operator would then squeeze the trigger, 40, of the gun, so that the trigger, 40, travels towards the stationary handle, 12, of the gun.
8
The force exerted by the operator to move the trigger towards the handle, 12, is transmitted to the drive pawl, SO, which, due to its positive engagement with the teeth, 31, of the drive shaft, 30, results in movement of the drive shaft, 30, along the longitudinal axis, in the distal direction, 17. Thus, the plate, 35, at the distal end of the drive shaft, acts as a plunger, which pushes the bone cement from the proximal end, 21 of the cartridge, 20, out of a hole at the distal end, 22, of the cartridge.
As the trigger is squeezed even closer to the handle, the trigger fits snugly into the cavity of the handle until it can move no further due to its contact with the inner wall, 14, of the handle. During the squeezing movement of the trigger, the spring, 44,
which is biased towards the inner surface 14 of the handle, is pulled from its relaxed, coiled position, to a stretched position, and the teeth of the drive shaft, 30, slide over the return pawl, 51, which provides no resistance to movement of the drive shaft in the distal direction.
Once the trigger is squeezed as far as it can go, (or as far as the operator would like it to go), the operator releases his grip on the trigger and the spring, 44, biases the trigger, 40, back to return to its original, open position. Due to the connection of the drive pawl with the trigger, and the feet that it rests in the ledge, 56, of the trigger, movement of the trigger, 40, back to its original position also results in movement of the drive pawl back to its original position and so the drive pawl, 50, is released from its engagement with the teeth, 31. The drive pawl is then positioned in alignment with teeth that are positioned more proximal, 16, on the drive shaft than the teeth with which it was previously engaged (for example, two teeth more proximal if each squeeze of the trigger moves the drive shaft the distance of two teeth).
When the trigger is back in its fully open position, the drive pawl, 50, is then positioned, ready for engagement with these more proximally positioned teeth, when the trigger is squeezed again and the whole process repeated.
Upon release of the trigger, (and the corresponding release of the drive pawl, 50, from the teeth of the drive shaft), the drive shaft, 30, is prevented from moving back in the proximal direction (e.g. due to back pressure from the cement, or even from attempted manual movement of the drive shaft) due to the positive engagement of the return
9
pawl, 51, with the teeth of the drive shaft, 30. As described above, when the drive shaft is moving in the distal direction, the return pawl, 51, does not engage with the teeth of the drive shaft, as, unlike the drive pawl, the return pawl is not resting on a ledge, 56, and so provides little resistance to the movement of the drive shaft. The shape of the teeth and the corresponding upper surface shape of the return pawl also provide little resistance when the drive shaft is being moved in the distal direction.
In contrast to this, however, any pressure which may force the drive shaft in the opposite, proximal direction, (such as back pressure from the bone cement or pulling of the drive shaft backwards by the user) would then be met with resistance from the return pawl, 51, and prevented, due to its positive engagement with the teeth.
Once the drive shaft, 30, has been moved through the gun and cartridge so that the cement is dispensed and no more drive shaft extends from the proximal end of the gun, the cartridge is removed and the gun is 'reset' by the operator gripping the knob, 34, of the drive shaft, 30, and rotating the drive shaft, 30, either clockwise or anticlockwise about the longitudinal axis, so that the teeth, 31, no longer face down and engage the pawls, 50,51.
Since the smooth surface of the drive shaft now faces downwards, the pawls can no longer engage with the shaft and the operator can then pull the drive shaft in the proximal direction, so that the majority of the drive shaft, 30, now protrudes from the proximal end of the gun again, ready for the whole process to be repeated with a new cartridge.
Figure 3 is an enlarged side view of a conventional ratchet type gun, showing the relative positions of the drive pawl, 50, in relation to the teeth, 31, of the drive shaft 30. When moving the drive shaft forward, the apices, 58, of the drive pawl, 50, would be in contact with the correspondingly shaped indent, 36, of the teeth, 31 and so force applied to the drive pawl would result in movement of the drive shaft.
Following removal of pressure on the trigger, and so removal of the drive pawl from the teeth, the drive pawl would then move back in the distal direction, 16, as shown in
10
figure 3, ready for engagement with the next set of teeth, more proximally positioned on the drive shaft, 30.
In order for the conventional ratchet gun to fully engage each tooth on the return pawl, 51, and thereby prevent baclcwards movement of the drive shaft, the trigger, 40, needs to be positioned to allow the next tooth/teeth along the shaft to align with the return pawl, 51. Typically, two teeth are moved per full stroke of the trigger, and so engagement would normally be at the middle and end of the trigger travel. This therefore requires the operator to fully compress the trigger to gain full movement.
Unfortunately, a problem arises when the trigger of the gun has not been squeezed far enough for the shaft to have been moved the distance of at least one tooth (as shown in figure 3). This may occur due to the operator not being strong enough, or wherein the bone cement is particularly viscous, or during pressurisation or higher loading, in such situations, it may be very difficult or even impossible to squeeze the trigger, 40, to its fully closed position, or even to squeeze it so that the drive shaft moves the distance of one tooth over the return pawl, 51. In such a case, release of the trigger, 40, would therefore result in the drive pawl, 50, not passing the pitch, 37, of the teeth and so the distance, d, as shown in figure 3 would be lost by return travel of the pawl along the drive shaft.
In cases where the operator is not strong enough to move the pawls even the distance of one tooth, the drive shaft would never move forward and the bone cement would not be dispensed from the gun at all.
A further problem associated with this type of conventional gun is that, due to the fact that the shaft must be turned clockwise or anticlockwise about its axis to move it bade to its original position, the hard drive pawl, 50, may damage the drive shaft, 30, by producing scoring marks on the shaft. Such damage stops the drive shaft, 30, running smoothly through the guide bushes, 18A and 19A, and therefore also results in subsequent damage to these parts, thereby shortening the product life cycle.
11
A further type of conventional gun is called a plate gun, an example of which is shown in figures 4 and 5. Like numerals are used to depict like features from figures 1 to 3 and so these will not be described again. Figure 4 shows a side view of a conventional plate gun, before the cartridge, 20, is attached, whereas figure 5 shows a side cross-sectional view of the plate gun with the cartridge, 20, attached to its distal end, 17.
The drive shaft, 30, used in the conventional plate gun is generally cylindrical in shape and has a smooth outer circumferential surface.
Connected to the upper end, 42, of the trigger, 40, is a drive plate, 56, which lies generally in a plane, P2, perpendicular to the longitudinal axis, L, of the gun. The plate, 56, has a hole in the centre of it, through which the drive shaft, 30, passes. The drive plate, 56, therefore surrounds the drive shaft, 30 and the inner edges of the hole in ihe plaie contact the eAlciTial surface of the drive shaft, 30 and grip it.
The upper end of the drive plate, 56, is attached to the main body, 11 of the gun via a hinge, 52. Movement of the drive plate, 56, about this hinge results in the lower end of the plate being movable proximally and distally, whilst the upper part of the plate remains fixed at the hinge. In other words, movement of the plate about this hinge results in the plate tilting to different degrees from an angle perpendicular to the longitudinal axis of the gun.
When the trigger of the gun is in the open position, (i.e. before the trigger is squeezed), the plate lies at an angle approximate to the perpendicular axis, P2, (90 degrees to the longitudinal axis, L) contacting and gripping the surface of the drive shaft, 30.
When the trigger, 40, is in the second, closed position (shown in dotted lines in figure 6), the drive plate is tilted about the hinge and due to grip of the inner surface of the hole around the drive shaft, the tilting of the drive plate moves the drive shaft in the distal direction.
12
A spring, 44, is positioned distal of the drive plate, 56, and surrounds the drive shaft, 30. The spring is in its uncompressed and unstressed state when the trigger is in the open position, and is in a strained, compressed state when the trigger is closed.
Attached to the main body, 11, of the gun there is also a back plate, 57, which is movable about a second hinge, 54 at its upper end. In between the back plate 57, and the main body, 11, of the gun there also lies a spring, 53, which biases the back plate proximally, so that the back plate lies in a plane that is at an angle to the perpendicular axis P3, with the bottom end of the back plate, 57, being biased more proximally than the upper, hinged, end. In other words, the back plate is tilted when the spring, 53, is not compressed and under strain. The back plate, 57, also has a hole in its centre, through which the drive shaft, 30, extends. Due to the fact that the spring, 53, biases the back plate, 57 distally, and due to the shape of the hole, in use, when the operator is driving the drive shaft forward, the inner surfaces of the hole grip the outer surface of ihe drive shaft, 30.
When the back plate, 57, is pushed inwards, about the hinge, 54, by the operator, the back plate moves so that it lies in a plane, P3, substantially perpendicular to the longitudinal axis, and the inner surfaces of the hole in the back plate no longer grip the outer surface of the drive shaft, 30, thereby releasing its grip from the drive shaft.
Operation of the conventional plate gun will now be described with reference to figures 4 and 5.
As described above for the ratchet gun, once the cartridge is attached, the operator would then grip the handle, 12, of the gun in the palm of their hand and with their finger(s), grip the trigger, 40. To eject bone cement from the cartridge of the gun, the operator would then squeeze the trigger, 40, of the gun, so that the trigger, 40, travels towards the handle, 12, of the gun, as shown by the dashed lines in figure 5.
The force exerted by the operator to move the trigger towards the handle, 12, is transmitted to the drive plate, 56, which, moves from the first position, wherein the drive plate lies in a plane, P2, substantially perpendicular to the longitudinal axis, L, to a second position, wherein the plate is tilted and lies at an angle from the
13
perpendicular plane. The inner surface of the hole in the drive plate grips the outer circumference of the drive shaft, 30, so that, once tilted, the movement of the drive plate results in movement of the drive shaft in the distal direction. The plate, or plunger, 35, positioned at the end of the drive shaft, 30, will therefore push the contents of the cartridge, 20, towards the distal end, 22, of the cartridge so that the bone cement leaves the cartridge via the exit hole, 23, at the cartridge distal end.
When the trigger is squeezed and moves from the first open trigger position, to the second, closed trigger position (shown in dashed lines in figure 5), the spring, 44, is compressed under the pressure created by the drive plate moving in the distal direction. Once the operator has squeezed the trigger, 40, as far as it will go/he is able to squeeze it, the operator releases the trigger, 40, and the spring, 44, which is now in the compressed state, will push the drive plate, 56, back to its original position, which in turn will also push the trigger, 40, back to its open, starting position.
Since the back plate, 57, is biased proximally by the spring, 54, the drive shaft, 30, is prevented from moving back in the proximal direction upon release of the trigger and drive plate, 56. The drive shaft, 30, therefore remains in position while the trigger and drive plate, 56, reset to a position more proximal along the drive shaft, ready for the next squeeze of the trigger.
Once the drive shaft, 30, has been moved through the gun and cartridge so that the cement is dispensed and no more drive shaft protrudes from the proximal end of the gun, the cartridge is removed and the gun is 'reset' by the operator pressing on the back plate, 57. By moving the back plate from its tilted position, to a position, P3, perpendicular to the longitudinal axis, the hole in the centre of the drive plate no longer grips the drive shaft, allowing it to be moved freely within the hole. The operator therefore can pull the drive shaft out of the gun in the proximal direction to reset the gun for use with a further cartridge.
Although such guns are widely used, a problem associated with these plate guns is that the use of a plate to move the drive shaft forward is often not able to generate high enough forces, and in particular, not able to generate the high forces that ratchet guns can generate.
14
Figure 6 depicts a side view of a gun, 100, according to the present invention.
The gun, 100, has a main body, 110, extending from a proximal end, 160, to a distal end, 170, along a longitudinal axis, L. A handle, 120, projects downwardly from the gun main body, 110, and may be slightly offset at an angle, A, from the perpendicular axis, P4. The handle may be offset at varying angles in order to provide an easier and more comfortable fit for the operator, when gripping the handle in use.
The handle has an outer surface, 130, and an inner surface, 140. In use, the operator would grip the outer surface, 130, of the handle with the palm of their hand and so this surface may be contoured in such a way to compliment the shape of the operator's hand when gripping. The handle also may be hollow, having a cavity, which comprises the inner surface, 140. This cavity, and the contours of the inner surface, 140, are generally shaped and structured to mirror the corresponding surface of the trigger, 400, so that when the trigger is fully engaged, the trigger fits inside the cavity, as described below.
Before use, a cartridge, (not shown), containing the material to be dispensed, e.g. mixed bone cement, is connected at its proximal end to the distal end, 170, of the main body, 110, as described in relation to the ratchet and plate guns, above.
Extending through the main body of the gun, 110, is a drive shaft, 300. The drive shaft, 300, extends along the longitudinal axis, L, of the main body, 110, entering the main body via an entry hole, 180, having a guide bush, (not shown) at its proximal end, 160, and exiting the body via an exit hole, (not shown), also having a guide bush, (not shown) at its distal end, 170.
The drive shaft, 300, is generally cylindrical in shape, a portion of which comprises a toothed surface, 310, which extends along the surface of the drive shaft in the longitudinal direction but which, in the embodiment shown in figure 6, does not extend completely around the circumference of the drive shaft and not more than approximately 20-50% around the circumference of the drive shaft. Therefore, in this embodiment, for the toothed section of the drive shaft, approximately 50-80% of the
15
surface of the drive shaft in a circumferential direction is smooth, and the remaining surface toothed. The drive shaft, 300, may also comprise a smooth portion, comprising no teeth, at its proximal end, 320, as shown in figure 6.
Since, as explained in greater detail below, when resetting the drive shaft of the present invention, the teeth of the drive shaft can still face the drive pawl, without causing damage due to scoring (as in the conventional ratchet guns), the gun could also be modified to prevent rotation of the drive shaft about its longitudinal axis, thereby negating the need for the operator to locate the position of the teeth relative to the drive pawl prior to use.
In another alternative embodiment, the toothed surface may extend around the complete circumference of the drive shaft, thereby negating the need for the user to determine, prior to use, the location of the teeth of the drive shaft, relative to the drive pawi.
At its proximal end, 320, the drive shaft, 300, comprises a knob, 340, to prevent the proximal end of the drive shaft from entering the entry hole, 180, of the main body and also so that the operator can grip the drive shaft more easily.
At its distal end, 330, the drive shaft has a plate, 350, which may be shaped to fit the inner surface of the cartridge, 20, but in figure 6 is shown as being circular and lying flat in a plane perpendicular to the longitudinal axis of the drive shaft, 300.
When the cartridge, 20, is connected to the distal end, 170, of the gun, the drive shaft would also extend through the cartridge, as the drive shaft is moved in the distal direction, in order to push the mixed bone cement out of the distal end of the cartridge.
Attached to the main body of the gun, 110, is a trigger, 400, which, similarly to the handle, 120, described above, projects downwardly, in a direction substantially perpendicular to the longitudinal axis of the main body, 110, of the gun, 100. The trigger, 400, is attached at its upper end, 420, to the main body of the gun, 110, via attachment means, such as a bolt, 410, for example. Whereas the handle, 120, of the
16
gun remains stationary relative to the main body of the gun (due to the fact that it is made either unitary with the main body, or is simply fixed in position relative to the body), the bolt, 410, attaching the trigger to the main body, 110, acts as a pivot point for the trigger, 400, so that the trigger is movable relative to the handle, (and relative to the main body of the gun) via rotational movement about this pivot point.
Also attached to the upper end, 420, of the trigger, 40, is a spring, 440, which connects the trigger to the inside wall, 140, of the handle, 120.
Attached to the upper part, 420, of the trigger, 400, is means for moving the drive shaft in the distal direction. Such means may comprise a drive pawl, 500. The drive pawl, 500, is attached to the trigger by a bolt, 550, (figure 8) about which the drive pawl, 500, can pivot.
The drive pawl, 500, also has a ledge, or step, 560, formed in the side of it, as shown in figure 8, to receive thedistal end, 610, of a release rod, 600. The opposite, proximal end, 620, of the release rod, 600, is connected to a bade plate, 570, which is attached to the main body, 110, of the gun via a hinge, 540, about which it is movable proximally and distally.
Extending from the back plate 570, to the main body, 110, of the gun there also lies a biasing means, such as a spring, 530, which biases the back plate proximally, so that the back plate lies in a plane that is tilted an angle to the axis perpendicular to the longitudinal axis, L
In other words, the back plate is tilted when the spring, 530, is not compressed. The back plate, 570, has a hole therethrough, through which the drive shaft, 300, extends. Due to the fact that the spring, 530, biases the back plate, 570 proximally, when the operator is driving the drive shaft forward, the inner surfaces of the hole grip the outer surface of the drive shaft, 30 to prevent backward, proximal movement of the drive shaft.
When the back plate, 570, is pushed inwards, as shown by the arrow, B, in figure 8, the back plate moves about the hinge, 540, so that it lies in a plane, P4, substantially
perpendicular to the longitudinal axis, and the inner surfaces of the hole in the back plate no longer grip the outer surface of the drive shaft, 30, thereby releasing its grip from the drive shaft.
Operation of a new gun according to the present invention will now be described.
Prior to use, the operator of the conventional ratchet type gun, 100, attaches a cartridge, 20, to the distal end, 170, of the gun. At this stage, the drive shaft, 300, would be positioned so that the majority of the shaft is projecting out of the proximal end of the gun and the plate, 350, at the end of the drive shaft, 300, is close to the distal end, 170, of the gun.
Once the cartridge is attached, the operator would then grip the handle, 120, of the gun in the palm of their hand and with their fingers, grip the trigger, 400. To eject bone cement from the cartridge of the gun, the operator would then squeeze the trigger, 400, of the gun, so that the trigger, 400, travels towards the stationary handle, 120.
Figure 6 depicts the gun of the present invention at the start of travel of the drive shaft, 300 (with the cartridge not shown). At the start of travel, the drive pawl, 500 engages the teeth, 310 of the drive shaft, 300. The use of a drive pawl, having positive engagement with the teeth of a drive shaft, 300, is advantageous, in that it provides greater forces for driving the cement out, especially under high pressure.
As the trigger is squeezed by the operator, the trigger pivots about the bolt, pivot point, 410, resulting in movement of the drive pawl, also, in the distal direction. Because the drive pawl, 500, is positively engaging the teeth of the drive shaft, 300, as the operator squeezes the trigger further, the force exerted by the operator to move the trigger towards the handle, 12, is transmitted to the drive pawl, 500, which, in turn results in movement of the drive shaft, 300, along the longitudinal axis, in the distal direction, 170.
Thus, the plate, 350, at the distal end of the drive shaft, acts as a plunger, which pushes the bone cement from the proximal end of the cartridge.
18
As the trigger is squeezed even closer to the handle, the trigger fits snugly into the cavity of the handle until it can move no further due to its contact with the inner wall, 140, of the handle. As can be seen from figure 7, at this stage, the drive pawl, 500, is still positively engaged with the teeth of the drive shaft, 300 and the drive shaft would have moved the distance of two teeth, 310, in the distal direction, 170.
During the squeezing movement of the trigger, the spring, 440, which is biased towards the inner surface 140 of the handle, is pulled from its relaxed, coiled position, to a stretched position. Once the trigger is squeezed as far as it can go, (or as far as the operator would like it to go), the operator then releases his grip on the trigger and the spring, 440, biases the trigger, 400, back to return to its original, open position, as shown in figure 6.
Since the back plate, 570, is biased proximally by the spring, 540, the drive shaft, 300, is prevented from moving back in the proximal direction upon release of the trigger. The drive shaft, 300, therefore remains in position while the trigger and drive pawl, 500, reset to a position more proximal along the drive shaft, ready for the next squeeze of the trigger.
Once the drive shaft, 300, has been moved through the gun and cartridge so that the cement is dispensed and no more drive shaft protrudes from the proximal end of the gun, the cartridge is removed and the gun is 'reset' by the operator pressing on the back plate, 570.
By pressing on the back plate, (so that the distance 'X' shown in figure 6 is reduced to the distance 'Y', shown in figure 8), the grip of the back plate on the drive shaft is released, and the release rod, 600, is also moved distally, by sliding along the ledge, 560, in the drive pawl, 500. The rod pushes forward on the drive pawl to a dead stop, which is at the end of the ledge, 560. This in turn pushes the drive pawl, 500, downwards (as shown by the arrow C) to disengage from the drive shaft, as shown in figure 8.
19
Due to this release mechanism, the drive shaft can be pulled back through the body of the gun and out of the distal end, to 'reset' it back to its original position for use with the next cartridge, without the need for turning the shaft, as in the case of conventional ratchet guns, described above. Plus, due to the fact that the drive pawl does not contact the drive shaft when the drive shaft is being reset, the problem associated with ratchet guns wherein the drive pawl causes scoring on the smooth side of the drive shaft is overcome.
In addition to this, since the drive pawl of the present invention is not in contact with the drive shaft of the gun when the drive shaft is being reset, there is no need for the toothed surface of the shaft to be properly located relative to the pawl. Therefore, it could be foreseen that the entire circumference of the drive shaft may be toothed, thereby negating the need for the operator to rotate the drive shaft before use in order to correctly align the toothed surface with the pawls.
Alternatively, only one side of the drive shaft may comprise teeth and the gun may be modified so as to prevent rotation of the drive shaft about its axis, thereby also negating the need for the operator to correctly position the teeth relative to the pawls, whilst still preventing scoring on the drive shaft when it is being reset.
In addition to this, problems with scoring or scratching of the drive shaft that may occur in plate guns, due to the fact that the drive plate is in contact with the drive shaft when the drive shaft is pulled proximally through the gun, are also overcome, because in the present invention, neither the back plate, nor the drive pawl are in contact with the drive shaft when it is being moved in the proximal direction.
A further advantage of the gun of the present invention is that, unlike in the case of the conventional ratchet gun, due to the fact that the gun of the present invention comprises a back plate, instead of a back pawl, even if the trigger is not moved the distance of two teeth, or at least one tooth, once the trigger of the present invention is released, the back plate 560 will still hold the drive rod in position, because the back plate can grip the drive shaft at any point along its length. Therefore, on the next stroke, the travel of the shaft will start from the same position as the previous trigger movement without any loss in distance gained (figure 9). The result is that the
20
operator can apply any amount of force on the trigger and still move the drive rod forward, even if the drive shaft has not been moved the distance of two, or one, tooth. In situations where cement is required to be applied under pressure, (cement pressurisation) these smaller steps aid the operator, especially if they have smaller hands.
Advantages are provided by the combination of a drive pawl with a back plate, either with, or without the release rod, 600. Conversely, the release rod per se can provide advantages in combination with existing delivery guns.
21
• •
• •
•
• • • •• •
• • • • • • • ••
-22-

Claims (28)

1. A delivery gun comprising a main body having a proximal end and a distal end, and a longitudinal axis extending between the proximal and distal ends, a drive 5 shaft moveable along the longitudinal axis, drive means for moving the drive shaft in a proximal direction, return means for preventing movement of the drive shaft in a distal direction, and further comprising release means to release contact of the drive means and the return means with the drive shaft.
10
2. A delivery gun comprising a main body having a proximal end and a dista! end, and a longitudinal axis extending between the proximal and distal ends, a drive shaft moveable along the longitudinal axis, means for moving the drive shaft in a proximal direction, means for preventing movement of the drive shaft in a distal direction, wherein the means for moving the drive shaft in the proximal direction 15 comprises a drive pawl and the means for preventing movement of the drive shaft in a distal direction comprises a plate.
3. The delivery gun of claim 2, further comprising release means to release contact of the drive means and the return means with the drive shaft.
20
4. The delivery gun of claims 1 or 3, wherein the release means is moveable between a first position and a second position, wherein, in the first position, both of the drive means and the return means are in contact with the drive shaft, and wherein, in the second position, the drive means and the return means are not in
25 contact with the drive shaft.
5. The delivery gun of claim 1 or 3, wherein the release means comprises a release rod which extends between the drive means and the return means.
• 30
6. The delivery gun of claim 5 wherein the drive means comprises means for receiving the release rod.
• • • •
• • • > • • • ••
• •
• •
•
• ••• • • • •••
• • • • • • • ••
23-
7. The delivery gun of claim 6 wherein the means for receiving the release rod may be a ledge, or step, formed in and/or along a side of the drive means, the step having a first end, which is adapted to receive the distal end of the release rod, and a second end which acts as a stop for the distal end of the release rod.
5
8. The delivery gun of claim 6 or 7 wherein the release rod is slidably received in the means for receiving the release rod.
9. The delivery gun of claim 1 or any of claims 3 to 8 wherein the proximal end 10 of the release means is adapted to be connected to the return means.
10. The delivery gun of claim 1 or any of claims 3 to 9, wherein movement of the return means in a first, distal direction results in movement of the release means in the first, distal direction, which consequently results in the release means being
1S received in a step of the drive means until the distal end of the release rod comes into contact with the distal end of the step in the drive means.
11. The delivery gun of any preceding claim, wherein the drive means is moveable about a first pivot point.
20
12. The delivery gun of claim 11, wherein when the distal end of the release means contacts the distal end of a step of the drive means such that any further movement of the release means in the distal direction results in pivotal movement of the drive means about the first pivot point, thereby rotating the drive means away
25 from the drive shaft and releasing the contact between the drive means and the drive shaft.
13. The delivery of any preceding claim wherein the drive shaft comprises a toothed surface which extends along the drive shaft in the longitudinal direction.
• •• 30
• • • • • • • ••
14. The delivery gun of claim 13, wherein the toothed surface does not extend completely around the circumference of the drive shaft.
-24-
15. The delivery gun of claim 13, wherein the toothed surface extends completely around the circumference of the drive shaft.
16. The delivery gun of claim 13 wherein the drive shaft comprises a smooth proximal portion, comprising no teeth, and a toothed distal portion.
17. The delivery gun of claim 13 wherein at least a portion of the surface of the drive shaft comprises teeth and the drive means is adapted to be aligned with and engage the teeth.
18. The delivery gun of any of claims 13 to 17 wherein the return means comprises a plate and the drive means comprises a pawl and the drive pawl engages with the teeth of the drive shaft.
19. The delivery gun of claim 2 or 18 wherein the return plate is biased proximally by a biasing means.
20. The delivery gun of claim 19 wherein the first biasing means is a spring.
21. The delivery gun of claims 19 or 20, wherein, when the biasing means is in its uncompressed state, the plate lies in a plane that is tilted at an angle to the axis perpendicular to the longitudinal axis L.
22. The delivery gun of claim 2 or any of claims 18 to 21 wherein the plate may further comprise a hole therethrough, through which the drive shaft extends.
23. The delivery gun of any of claims 18 to 22, wherein the plate is moveable between a first position wherein the plate is positioned at a first angle so that the edges of the hole of the plate contact the outer surface of the drive shaft and a second position wherein the plate lies in a plane perpendicular to the longitudinal axis and does not contact the drive shaft.
-25-
24. The delivery gun of any preceding claim, further comprising a trigger, the upper end of the trigger being adapted to be connected to the drive means.
25. The delivery gun of any preceding claim, further comprising a handle which projects down from the main body of the gun, wherein relative movement between the trigger and the handle results in movement of the drive means in the distal direction.
26. The delivery gun of claim 25, wherein the trigger is moveable relative to the handle via rotation about a second pivot point.
27. The delivery gun of claims 24 to 26 wherein a second biasing means is attached to the upper end of the trigger.
28. The delivery gun of claim 27, wherein the second biasing means is a spring, which biases the trigger about the second pivot point, in a direction away from the handle.
GB0700213A 2007-01-05 2007-01-05 Delivery gun drive and retraction Withdrawn GB2445421A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB0700213A GB2445421A (en) 2007-01-05 2007-01-05 Delivery gun drive and retraction
PCT/EP2007/011382 WO2008080590A1 (en) 2007-01-05 2007-12-21 Bone cement delivery gun

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0700213A GB2445421A (en) 2007-01-05 2007-01-05 Delivery gun drive and retraction

Publications (2)

Publication Number Publication Date
GB0700213D0 GB0700213D0 (en) 2007-02-14
GB2445421A true GB2445421A (en) 2008-07-09

Family

ID=37801794

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0700213A Withdrawn GB2445421A (en) 2007-01-05 2007-01-05 Delivery gun drive and retraction

Country Status (2)

Country Link
GB (1) GB2445421A (en)
WO (1) WO2008080590A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8439930B2 (en) 2008-06-23 2013-05-14 Apatech Ltd. Dispensing instrument
WO2015063208A1 (en) 2013-10-31 2015-05-07 Electricite De France Method for optimizing the consumption and production of an electrical facility
US20220184655A1 (en) * 2019-03-20 2022-06-16 Altachem Nv Caulking gun

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11364062B2 (en) 2016-08-18 2022-06-21 Spinal Elements, Inc. Material delivery surgical device
CA3101054A1 (en) 2018-04-11 2019-10-17 Stryker Corporation Curable material dispensing system and methods of operating and packaging the same
CN115137960B (en) * 2022-07-26 2023-06-20 邹敏 Application applicator for superficial trauma treatment of skin and method of operating same

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2233587A (en) * 1940-04-05 1941-03-04 Crewe Samuel Calk gun
US2367347A (en) * 1942-02-03 1945-01-16 Pecora Paint Company Calking gun and operating mechanism therefor
US2768768A (en) * 1953-02-27 1956-10-30 Gibson Homans Company Calking gun
GB1183097A (en) * 1967-07-20 1970-03-04 Arthur Shaw Company Ltd Caulking Gun
FR2526070A1 (en) * 1982-04-28 1983-11-04 Begouen Jean Paul Extrusion gun for mastic - has coupling which prevents continuation of mastic flow when handle is released
GB2153009A (en) * 1984-01-19 1985-08-14 Tricom Ind Company Limited Food extruding device
US4813574A (en) * 1987-08-24 1989-03-21 Hwan Chi Chuan Wall-crevice stuffing material dispenser
US6672489B1 (en) * 2002-08-28 2004-01-06 Wu-Hsiung Huang Discharging device for a caulking gun

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1013454A (en) * 1910-07-22 1912-01-02 William E Sherbondy Grease-gun
LU76320A1 (en) * 1976-12-03 1978-07-10
DE3151662A1 (en) * 1981-12-28 1983-07-07 Hilti AG, 9494 Schaan Device for delivery of pasty products
DE8204360U1 (en) * 1982-02-17 1982-06-24 Fa. Poth KG, 6736 Edesheim Hand press
CA2085996A1 (en) * 1991-04-26 1992-10-27 Naoshi Umetsu Dispenser for viscous material
DE59609009D1 (en) * 1996-02-21 2002-05-08 Wilhelm A Keller Manual discharge device for a double discharge cartridge
US6450370B2 (en) * 1996-02-21 2002-09-17 Wilhelm A. Keller Manually operated dispensing device for a double dispensing cartridge
US6439439B1 (en) * 2001-01-12 2002-08-27 Telios Orthopedic Systems, Inc. Bone cement delivery apparatus and hand-held fluent material dispensing apparatus

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2233587A (en) * 1940-04-05 1941-03-04 Crewe Samuel Calk gun
US2367347A (en) * 1942-02-03 1945-01-16 Pecora Paint Company Calking gun and operating mechanism therefor
US2768768A (en) * 1953-02-27 1956-10-30 Gibson Homans Company Calking gun
GB1183097A (en) * 1967-07-20 1970-03-04 Arthur Shaw Company Ltd Caulking Gun
FR2526070A1 (en) * 1982-04-28 1983-11-04 Begouen Jean Paul Extrusion gun for mastic - has coupling which prevents continuation of mastic flow when handle is released
GB2153009A (en) * 1984-01-19 1985-08-14 Tricom Ind Company Limited Food extruding device
US4813574A (en) * 1987-08-24 1989-03-21 Hwan Chi Chuan Wall-crevice stuffing material dispenser
US6672489B1 (en) * 2002-08-28 2004-01-06 Wu-Hsiung Huang Discharging device for a caulking gun

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8439930B2 (en) 2008-06-23 2013-05-14 Apatech Ltd. Dispensing instrument
US9179958B2 (en) 2008-06-23 2015-11-10 Apatech Ltd. Dispensing instrument
WO2015063208A1 (en) 2013-10-31 2015-05-07 Electricite De France Method for optimizing the consumption and production of an electrical facility
US20220184655A1 (en) * 2019-03-20 2022-06-16 Altachem Nv Caulking gun
US11691174B2 (en) * 2019-03-20 2023-07-04 Altachem Nv Caulking gun

Also Published As

Publication number Publication date
WO2008080590A1 (en) 2008-07-10
GB0700213D0 (en) 2007-02-14

Similar Documents

Publication Publication Date Title
AU2010233924B2 (en) Medicament delivery device
US5638997A (en) Bone cement injector gun
US5893488A (en) Bone cement injector gun
GB2445421A (en) Delivery gun drive and retraction
US9179958B2 (en) Dispensing instrument
CN111295144A (en) Surgical instrument
US20020120235A1 (en) Automatic injection device with reset feature
EP0218877B1 (en) Implement for filling dental cavities
JPH0555134B2 (en)
GB2076473A (en) Extruder for food mixtures
US20090293685A1 (en) Pin lock pliers
US8672193B2 (en) Metering dispenser
US10953527B2 (en) Crimping tool for band clamp
EP0601244B1 (en) Apparatus for dispensing material from collapsible tubes
US20140323984A1 (en) Hand-Actuated Fluid Delivery Device Having Triggered Lock for Selectively Limiting Automatic Aspiration Stroke
EP1761194B1 (en) Dispensing cartridge comprising a locking assembly
US4331265A (en) Tube squeezer-dispenser with drip prevention
WO2009055087A1 (en) Hinge assembly for an injector
US20040187706A1 (en) Power dough and food materials press
CA2203855C (en) Applicator for dental filling materials
US20180125557A1 (en) Mixing and dispensing gun
CH618872A5 (en) Surgical instrument for the preparation and injection of a bone cement
TWI428160B (en) Medicament delivery device
US6945436B2 (en) Dispenser for limiting material extruded after actuation
CN112971891A (en) Hand-held electromechanical surgical instrument

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)